[Ffmpeg-cvslog] r8640 - trunk/libavcodec/avcodec.h
diego
subversion
Sat Apr 7 16:07:34 CEST 2007
Author: diego
Date: Sat Apr 7 16:07:33 2007
New Revision: 8640
Modified:
trunk/libavcodec/avcodec.h
Log:
spelling/wording/grammar
Modified: trunk/libavcodec/avcodec.h
==============================================================================
--- trunk/libavcodec/avcodec.h (original)
+++ trunk/libavcodec/avcodec.h Sat Apr 7 16:07:33 2007
@@ -23,7 +23,7 @@
/**
* @file avcodec.h
- * external api header.
+ * external API header
*/
@@ -49,14 +49,14 @@ extern "C" {
/**
*
- * if you add a codec id to this list add it so that
- * 1. no value of a existing codec id changes (that would break ABI)
- * 2. closest to similar codecs
+ * If you add a codec ID to this list, add it so that
+ * 1. no value of a existing codec ID changes (that would break ABI),
+ * 2. it is as close as possible to similar codecs.
*/
enum CodecID {
CODEC_ID_NONE,
CODEC_ID_MPEG1VIDEO,
- CODEC_ID_MPEG2VIDEO, /* prefered ID for MPEG Video 1 or 2 decoding */
+ CODEC_ID_MPEG2VIDEO, /* preferred ID for MPEG-1/2 video decoding */
CODEC_ID_MPEG2VIDEO_XVMC,
CODEC_ID_H261,
CODEC_ID_H263,
@@ -161,7 +161,7 @@ enum CodecID {
CODEC_ID_THP,
CODEC_ID_SGI,
- /* various pcm "codecs" */
+ /* various PCM "codecs" */
CODEC_ID_PCM_S16LE= 0x10000,
CODEC_ID_PCM_S16BE,
CODEC_ID_PCM_U16LE,
@@ -180,7 +180,7 @@ enum CodecID {
CODEC_ID_PCM_U24BE,
CODEC_ID_PCM_S24DAUD,
- /* various adpcm codecs */
+ /* various ADPCM codecs */
CODEC_ID_ADPCM_IMA_QT= 0x11000,
CODEC_ID_ADPCM_IMA_WAV,
CODEC_ID_ADPCM_IMA_DK3,
@@ -215,7 +215,7 @@ enum CodecID {
CODEC_ID_SOL_DPCM,
CODEC_ID_MP2= 0x15000,
- CODEC_ID_MP3, /* prefered ID for MPEG Audio layer 1, 2 or3 decoding */
+ CODEC_ID_MP3, /* preferred ID for decoding MPEG audio layer 1, 2 or 3 */
CODEC_ID_AAC,
#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
CODEC_ID_MPEG4AAC,
@@ -237,7 +237,7 @@ enum CodecID {
CODEC_ID_SHORTEN,
CODEC_ID_ALAC,
CODEC_ID_WESTWOOD_SND1,
- CODEC_ID_GSM, /* As in Berlin toast format */
+ CODEC_ID_GSM, /* as in Berlin toast format */
CODEC_ID_QDM2,
CODEC_ID_COOK,
CODEC_ID_TRUESPEECH,
@@ -249,18 +249,18 @@ enum CodecID {
CODEC_ID_IMC,
CODEC_ID_MUSEPACK7,
CODEC_ID_MLP,
- CODEC_ID_GSM_MS, /* As found in WAV */
+ CODEC_ID_GSM_MS, /* as found in WAV */
/* subtitle codecs */
CODEC_ID_DVD_SUBTITLE= 0x17000,
CODEC_ID_DVB_SUBTITLE,
- CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG2 transport
- stream (only used by libavformat) */
+ CODEC_ID_MPEG2TS= 0x20000, /* _FAKE_ codec to indicate a raw MPEG-2 TS
+ * stream (only used by libavformat) */
};
#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
-/* CODEC_ID_MP3LAME is absolete */
+/* CODEC_ID_MP3LAME is obsolete */
#define CODEC_ID_MP3LAME CODEC_ID_MP3
#define CODEC_ID_MPEG4AAC CODEC_ID_AAC
#endif
@@ -274,8 +274,8 @@ enum CodecType {
CODEC_TYPE_NB
};
-/* currently unused, may be used if 24/32 bits samples ever supported */
-/* all in native endian */
+/* Currently unused, may be used if 24/32 bits samples are ever supported. */
+/* all in native-endian format */
enum SampleFormat {
SAMPLE_FMT_NONE = -1,
SAMPLE_FMT_U8, ///< unsigned 8 bits
@@ -290,16 +290,16 @@ enum SampleFormat {
/**
* Required number of additionally allocated bytes at the end of the input bitstream for decoding.
- * this is mainly needed because some optimized bitstream readers read
- * 32 or 64 bit at once and could read over the end<br>
- * Note, if the first 23 bits of the additional bytes are not 0 then damaged
- * MPEG bitstreams could cause overread and segfault
+ * This is mainly needed because some optimized bitstream readers read
+ * 32 or 64 bit at once and could read over the end.<br>
+ * Note: If the first 23 bits of the additional bytes are not 0, then damaged
+ * MPEG bitstreams could cause overread and segfault.
*/
#define FF_INPUT_BUFFER_PADDING_SIZE 8
/**
- * minimum encoding buffer size.
- * used to avoid some checks during header writing
+ * minimum encoding buffer size
+ * Used to avoid some checks during header writing.
*/
#define FF_MIN_BUFFER_SIZE 16384
@@ -317,7 +317,8 @@ enum Motion_Est_ID {
};
enum AVDiscard{
-//we leave some space between them for extensions (drop some keyframes for intra only or drop just some bidir frames)
+ /* We leave some space between them for extensions (drop some
+ * keyframes for intra-only or drop just some bidir frames). */
AVDISCARD_NONE =-16, ///< discard nothing
AVDISCARD_DEFAULT= 0, ///< discard useless packets like 0 size packets in avi
AVDISCARD_NONREF = 8, ///< discard all non reference
@@ -329,73 +330,74 @@ enum AVDiscard{
typedef struct RcOverride{
int start_frame;
int end_frame;
- int qscale; // if this is 0 then quality_factor will be used instead
+ int qscale; // If this is 0 then quality_factor will be used instead.
float quality_factor;
} RcOverride;
#define FF_MAX_B_FRAMES 16
/* encoding support
- these flags can be passed in AVCodecContext.flags before initing
- Note: not everything is supported yet.
+ These flags can be passed in AVCodecContext.flags before initialization.
+ Note: Not everything is supported yet.
*/
-#define CODEC_FLAG_QSCALE 0x0002 ///< use fixed qscale
-#define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / Advanced prediction for H263
-#define CODEC_FLAG_QPEL 0x0010 ///< use qpel MC
-#define CODEC_FLAG_GMC 0x0020 ///< use GMC
-#define CODEC_FLAG_MV0 0x0040 ///< always try a MB with MV=<0,0>
-#define CODEC_FLAG_PART 0x0080 ///< use data partitioning
-/* parent program guarantees that the input for b-frame containing streams is not written to
- for at least s->max_b_frames+1 frames, if this is not set than the input will be copied */
+#define CODEC_FLAG_QSCALE 0x0002 ///< Use fixed qscale.
+#define CODEC_FLAG_4MV 0x0004 ///< 4 MV per MB allowed / advanced prediction for H.263.
+#define CODEC_FLAG_QPEL 0x0010 ///< Use qpel MC.
+#define CODEC_FLAG_GMC 0x0020 ///< Use GMC.
+#define CODEC_FLAG_MV0 0x0040 ///< Always try a MB with MV=<0,0>.
+#define CODEC_FLAG_PART 0x0080 ///< Use data partitioning.
+/* The parent program guarantees that the input for B-frames containing
+ * streams is not written to for at least s->max_b_frames+1 frames, if
+ * this is not set the input will be copied. */
#define CODEC_FLAG_INPUT_PRESERVED 0x0100
-#define CODEC_FLAG_PASS1 0x0200 ///< use internal 2pass ratecontrol in first pass mode
-#define CODEC_FLAG_PASS2 0x0400 ///< use internal 2pass ratecontrol in second pass mode
-#define CODEC_FLAG_EXTERN_HUFF 0x1000 ///< use external huffman table (for mjpeg)
-#define CODEC_FLAG_GRAY 0x2000 ///< only decode/encode grayscale
-#define CODEC_FLAG_EMU_EDGE 0x4000///< don't draw edges
-#define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding
-#define CODEC_FLAG_TRUNCATED 0x00010000 /** input bitstream might be truncated at a random location instead
- of only at frame boundaries */
-#define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< normalize adaptive quantization
-#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< use interlaced dct
-#define CODEC_FLAG_LOW_DELAY 0x00080000 ///< force low delay
-#define CODEC_FLAG_ALT_SCAN 0x00100000 ///< use alternate scan
-#define CODEC_FLAG_TRELLIS_QUANT 0x00200000 ///< use trellis quantization
-#define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< place global headers in extradata instead of every keyframe
-#define CODEC_FLAG_BITEXACT 0x00800000 ///< use only bitexact stuff (except (i)dct)
+#define CODEC_FLAG_PASS1 0x0200 ///< Use internal 2pass ratecontrol in first pass mode.
+#define CODEC_FLAG_PASS2 0x0400 ///< Use internal 2pass ratecontrol in second pass mode.
+#define CODEC_FLAG_EXTERN_HUFF 0x1000 ///< Use external Huffman table (for MJPEG).
+#define CODEC_FLAG_GRAY 0x2000 ///< Only decode/encode grayscale.
+#define CODEC_FLAG_EMU_EDGE 0x4000///< Don't draw edges.
+#define CODEC_FLAG_PSNR 0x8000 ///< error[?] variables will be set during encoding.
+#define CODEC_FLAG_TRUNCATED 0x00010000 /** Input bitstream might be truncated at a random location instead
+ of only at frame boundaries. */
+#define CODEC_FLAG_NORMALIZE_AQP 0x00020000 ///< Normalize adaptive quantization.
+#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
+#define CODEC_FLAG_LOW_DELAY 0x00080000 ///< Force low delay.
+#define CODEC_FLAG_ALT_SCAN 0x00100000 ///< Use alternate scan.
+#define CODEC_FLAG_TRELLIS_QUANT 0x00200000 ///< Use trellis quantization.
+#define CODEC_FLAG_GLOBAL_HEADER 0x00400000 ///< Place global headers in extradata instead of every keyframe.
+#define CODEC_FLAG_BITEXACT 0x00800000 ///< Use only bitexact stuff (except (I)DCT).
/* Fx : Flag for h263+ extra options */
#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
-#define CODEC_FLAG_H263P_AIC 0x01000000 ///< H263 Advanced intra coding / MPEG4 AC prediction (remove this)
+#define CODEC_FLAG_H263P_AIC 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction (remove this)
#endif
-#define CODEC_FLAG_AC_PRED 0x01000000 ///< H263 Advanced intra coding / MPEG4 AC prediction
-#define CODEC_FLAG_H263P_UMV 0x02000000 ///< Unlimited motion vector
-#define CODEC_FLAG_CBP_RD 0x04000000 ///< use rate distortion optimization for cbp
-#define CODEC_FLAG_QP_RD 0x08000000 ///< use rate distortion optimization for qp selectioon
-#define CODEC_FLAG_H263P_AIV 0x00000008 ///< H263 Alternative inter vlc
+#define CODEC_FLAG_AC_PRED 0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
+#define CODEC_FLAG_H263P_UMV 0x02000000 ///< unlimited motion vector
+#define CODEC_FLAG_CBP_RD 0x04000000 ///< Use rate distortion optimization for cbp.
+#define CODEC_FLAG_QP_RD 0x08000000 ///< Use rate distortion optimization for qp selectioon.
+#define CODEC_FLAG_H263P_AIV 0x00000008 ///< H.263 alternative inter VLC
#define CODEC_FLAG_OBMC 0x00000001 ///< OBMC
#define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
#define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000
#define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
-#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< will reserve space for SVCD scan offset user data
+#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data.
#define CODEC_FLAG_CLOSED_GOP ((int)0x80000000)
-#define CODEC_FLAG2_FAST 0x00000001 ///< allow non spec compliant speedup tricks
-#define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< strictly enforce GOP size
-#define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< skip bitstream encoding
-#define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< place global headers at every keyframe instead of in extradata
-#define CODEC_FLAG2_BPYRAMID 0x00000010 ///< H.264 allow b-frames to be used as references
-#define CODEC_FLAG2_WPRED 0x00000020 ///< H.264 weighted biprediction for b-frames
+#define CODEC_FLAG2_FAST 0x00000001 ///< Allow non spec compliant speedup tricks.
+#define CODEC_FLAG2_STRICT_GOP 0x00000002 ///< Strictly enforce GOP size.
+#define CODEC_FLAG2_NO_OUTPUT 0x00000004 ///< Skip bitstream encoding.
+#define CODEC_FLAG2_LOCAL_HEADER 0x00000008 ///< Place global headers at every keyframe instead of in extradata.
+#define CODEC_FLAG2_BPYRAMID 0x00000010 ///< H.264 allow B-frames to be used as references.
+#define CODEC_FLAG2_WPRED 0x00000020 ///< H.264 weighted biprediction for B-frames
#define CODEC_FLAG2_MIXED_REFS 0x00000040 ///< H.264 one reference per partition, as opposed to one reference per macroblock
#define CODEC_FLAG2_8X8DCT 0x00000080 ///< H.264 high profile 8x8 transform
#define CODEC_FLAG2_FASTPSKIP 0x00000100 ///< H.264 fast pskip
#define CODEC_FLAG2_AUD 0x00000200 ///< H.264 access unit delimiters
-#define CODEC_FLAG2_BRDO 0x00000400 ///< b-frame rate-distortion optimization
-#define CODEC_FLAG2_INTRA_VLC 0x00000800 ///< use MPEG-2 intra VLC table
-#define CODEC_FLAG2_MEMC_ONLY 0x00001000 ///< only do ME/MC (I frames -> ref, P frame -> ME+MC)
-#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format
-#define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skiping
-#define CODEC_FLAG2_CHUNKS 0x00008000 ///< input bitstream might be truncated at a packet boundaries instead of only at frame boundaries
-#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< use MPEG-2 non linear quantizer
+#define CODEC_FLAG2_BRDO 0x00000400 ///< B-frame rate-distortion optimization
+#define CODEC_FLAG2_INTRA_VLC 0x00000800 ///< Use MPEG-2 intra VLC table.
+#define CODEC_FLAG2_MEMC_ONLY 0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC).
+#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format.
+#define CODEC_FLAG2_SKIP_RD 0x00004000 ///< RD optimal MB level residual skipping
+#define CODEC_FLAG2_CHUNKS 0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
+#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer.
/* Unsupported options :
* Syntax Arithmetic coding (SAC)
@@ -404,21 +406,20 @@ typedef struct RcOverride{
/* /Fx */
/* codec capabilities */
-#define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< decoder can use draw_horiz_band callback
+#define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
/**
* Codec uses get_buffer() for allocating buffers.
* direct rendering method 1
*/
#define CODEC_CAP_DR1 0x0002
-/* if 'parse_only' field is true, then avcodec_parse_frame() can be
- used */
+/* If 'parse_only' field is true, then avcodec_parse_frame() can be used. */
#define CODEC_CAP_PARSE_ONLY 0x0004
#define CODEC_CAP_TRUNCATED 0x0008
-/* codec can export data for HW decoding (XvMC) */
+/* Codec can export data for HW decoding (XvMC). */
#define CODEC_CAP_HWACCEL 0x0010
/**
- * codec has a non zero delay and needs to be feeded with NULL at the end to get the delayed data.
- * if this is not set, the codec is guaranteed to never be feeded with NULL data
+ * Codec has a nonzero delay and needs to be fed with NULL at the end to get the delayed data.
+ * If this is not set, the codec is guaranteed to never be fed with NULL data.
*/
#define CODEC_CAP_DELAY 0x0020
/**
@@ -427,10 +428,10 @@ typedef struct RcOverride{
*/
#define CODEC_CAP_SMALL_LAST_FRAME 0x0040
-//the following defines may change, don't expect compatibility if you use them
+//The following defines may change, don't expect compatibility if you use them.
#define MB_TYPE_INTRA4x4 0x0001
-#define MB_TYPE_INTRA16x16 0x0002 //FIXME h264 specific
-#define MB_TYPE_INTRA_PCM 0x0004 //FIXME h264 specific
+#define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
+#define MB_TYPE_INTRA_PCM 0x0004 //FIXME H.264-specific
#define MB_TYPE_16x16 0x0008
#define MB_TYPE_16x8 0x0010
#define MB_TYPE_8x16 0x0020
@@ -453,28 +454,29 @@ typedef struct RcOverride{
/**
* Pan Scan area.
- * this specifies the area which should be displayed. Note there may be multiple such areas for one frame
+ * This specifies the area which should be displayed.
+ * Note there may be multiple such areas for one frame.
*/
typedef struct AVPanScan{
/**
- * id.
- * - encoding: set by user.
- * - decoding: set by lavc
+ * id
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
int id;
/**
* width and height in 1/16 pel
- * - encoding: set by user.
- * - decoding: set by lavc
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
int width;
int height;
/**
- * position of the top left corner in 1/16 pel for up to 3 fields/frames.
- * - encoding: set by user.
- * - decoding: set by lavc
+ * position of the top left corner in 1/16 pel for up to 3 fields/frames
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
int16_t position[3][2];
}AVPanScan;
@@ -482,99 +484,99 @@ typedef struct AVPanScan{
#define FF_COMMON_FRAME \
/**\
* pointer to the picture planes.\
- * this might be different from the first allocated byte\
+ * This might be different from the first allocated byte\
* - encoding: \
* - decoding: \
*/\
uint8_t *data[4];\
int linesize[4];\
/**\
- * pointer to the first allocated byte of the picture. can be used in get_buffer/release_buffer\
- * this isn't used by lavc unless the default get/release_buffer() is used\
+ * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.\
+ * This isn't used by libavcodec unless the default get/release_buffer() is used.\
* - encoding: \
* - decoding: \
*/\
uint8_t *base[4];\
/**\
* 1 -> keyframe, 0-> not\
- * - encoding: set by lavc\
- * - decoding: set by lavc\
+ * - encoding: Set by libavcodec.\
+ * - decoding: Set by libavcodec.\
*/\
int key_frame;\
\
/**\
- * picture type of the frame, see ?_TYPE below.\
- * - encoding: set by lavc for coded_picture (and set by user for input)\
- * - decoding: set by lavc\
+ * Picture type of the frame, see ?_TYPE below.\
+ * - encoding: Set by libavcodec. for coded_picture (and set by user for input).\
+ * - decoding: Set by libavcodec.\
*/\
int pict_type;\
\
/**\
* presentation timestamp in time_base units (time when frame should be shown to user)\
- * if AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed\
- * - encoding: MUST be set by user\
- * - decoding: set by lavc\
+ * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.\
+ * - encoding: MUST be set by user.\
+ * - decoding: Set by libavcodec.\
*/\
int64_t pts;\
\
/**\
- * picture number in bitstream order.\
+ * picture number in bitstream order\
* - encoding: set by\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
int coded_picture_number;\
/**\
- * picture number in display order.\
+ * picture number in display order\
* - encoding: set by\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
int display_picture_number;\
\
/**\
* quality (between 1 (good) and FF_LAMBDA_MAX (bad)) \
- * - encoding: set by lavc for coded_picture (and set by user for input)\
- * - decoding: set by lavc\
+ * - encoding: Set by libavcodec. for coded_picture (and set by user for input).\
+ * - decoding: Set by libavcodec.\
*/\
int quality; \
\
/**\
* buffer age (1->was last buffer and dint change, 2->..., ...).\
- * set to INT_MAX if the buffer has not been used yet \
+ * Set to INT_MAX if the buffer has not been used yet.\
* - encoding: unused\
- * - decoding: MUST be set by get_buffer()\
+ * - decoding: MUST be set by get_buffer().\
*/\
int age;\
\
/**\
* is this picture used as reference\
* - encoding: unused\
- * - decoding: set by lavc (before get_buffer() call))\
+ * - decoding: Set by libavcodec. (before get_buffer() call)).\
*/\
int reference;\
\
/**\
* QP table\
* - encoding: unused\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
int8_t *qscale_table;\
/**\
* QP store stride\
* - encoding: unused\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
int qstride;\
\
/**\
- * mbskip_table[mb]>=1 if MB didnt change\
+ * mbskip_table[mb]>=1 if MB didn't change\
* stride= mb_width = (width+15)>>4\
* - encoding: unused\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
uint8_t *mbskip_table;\
\
/**\
- * Motion vector table.\
+ * motion vector table\
* @code\
* example:\
* int mv_sample_log2= 4 - motion_subsample_log2;\
@@ -582,16 +584,16 @@ typedef struct AVPanScan{
* int mv_stride= (mb_width << mv_sample_log2) + 1;\
* motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];\
* @endcode\
- * - encoding: set by user\
- * - decoding: set by lavc\
+ * - encoding: Set by user.\
+ * - decoding: Set by libavcodec.\
*/\
int16_t (*motion_val[2])[2];\
\
/**\
- * Macroblock type table\
+ * macroblock type table\
* mb_type_base + mb_width + 2\
- * - encoding: set by user\
- * - decoding: set by lavc\
+ * - encoding: Set by user.\
+ * - decoding: Set by libavcodec.\
*/\
uint32_t *mb_type;\
\
@@ -599,37 +601,37 @@ typedef struct AVPanScan{
* log2 of the size of the block which a single vector in motion_val represents: \
* (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)\
* - encoding: unused\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
uint8_t motion_subsample_log2;\
\
/**\
* for some private data of the user\
* - encoding: unused\
- * - decoding: set by user\
+ * - decoding: Set by user.\
*/\
void *opaque;\
\
/**\
* error\
- * - encoding: set by lavc if flags&CODEC_FLAG_PSNR\
+ * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.\
* - decoding: unused\
*/\
uint64_t error[4];\
\
/**\
- * type of the buffer (to keep track of who has to dealloc data[*])\
- * - encoding: set by the one who allocs it\
- * - decoding: set by the one who allocs it\
- * Note: user allocated (direct rendering) & internal buffers can not coexist currently\
+ * type of the buffer (to keep track of who has to deallocate data[*])\
+ * - encoding: Set by the one who allocates it.\
+ * - decoding: Set by the one who allocates it.\
+ * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.\
*/\
int type;\
\
/**\
- * when decoding, this signal how much the picture must be delayed.\
+ * When decoding, this signals how much the picture must be delayed.\
* extra_delay = repeat_pict / (2*fps)\
* - encoding: unused\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
int repeat_pict;\
\
@@ -640,50 +642,50 @@ typedef struct AVPanScan{
\
/**\
* The content of the picture is interlaced.\
- * - encoding: set by user\
- * - decoding: set by lavc (default 0)\
+ * - encoding: Set by user.\
+ * - decoding: Set by libavcodec. (default 0)\
*/\
int interlaced_frame;\
\
/**\
- * if the content is interlaced, is top field displayed first.\
- * - encoding: set by user\
- * - decoding: set by lavc\
+ * If the content is interlaced, is top field displayed first.\
+ * - encoding: Set by user.\
+ * - decoding: Set by libavcodec.\
*/\
int top_field_first;\
\
/**\
* Pan scan.\
- * - encoding: set by user\
- * - decoding: set by lavc\
+ * - encoding: Set by user.\
+ * - decoding: Set by libavcodec.\
*/\
AVPanScan *pan_scan;\
\
/**\
- * tell user application that palette has changed from previous frame.\
+ * Tell user application that palette has changed from previous frame.\
* - encoding: ??? (no palette-enabled encoder yet)\
- * - decoding: set by lavc (default 0)\
+ * - decoding: Set by libavcodec. (default 0).\
*/\
int palette_has_changed;\
\
/**\
- * Codec suggestion on buffer type if != 0\
+ * codec suggestion on buffer type if != 0\
* - encoding: unused\
- * - decoding: set by lavc (before get_buffer() call))\
+ * - decoding: Set by libavcodec. (before get_buffer() call)).\
*/\
int buffer_hints;\
\
/**\
- * DCT coeffitients\
+ * DCT coefficients\
* - encoding: unused\
- * - decoding: set by lavc\
+ * - decoding: Set by libavcodec.\
*/\
short *dct_coeff;\
\
/**\
- * Motion referece frame index\
- * - encoding: set by user\
- * - decoding: set by lavc\
+ * motion referece frame index\
+ * - encoding: Set by user.\
+ * - decoding: Set by libavcodec.\
*/\
int8_t *ref_index[2];
@@ -692,9 +694,9 @@ typedef struct AVPanScan{
#define FF_QSCALE_TYPE_H264 2
#define FF_BUFFER_TYPE_INTERNAL 1
-#define FF_BUFFER_TYPE_USER 2 ///< Direct rendering buffers (image is (de)allocated by user)
-#define FF_BUFFER_TYPE_SHARED 4 ///< buffer from somewhere else, don't dealloc image (data/base), all other tables are not shared
-#define FF_BUFFER_TYPE_COPY 8 ///< just a (modified) copy of some other buffer, don't dealloc anything
+#define FF_BUFFER_TYPE_USER 2 ///< direct rendering buffers (image is (de)allocated by user)
+#define FF_BUFFER_TYPE_SHARED 4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
+#define FF_BUFFER_TYPE_COPY 8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.
#define FF_I_TYPE 1 // Intra
@@ -704,10 +706,10 @@ typedef struct AVPanScan{
#define FF_SI_TYPE 5
#define FF_SP_TYPE 6
-#define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore)
-#define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer
-#define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content
-#define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update)
+#define FF_BUFFER_HINTS_VALID 0x01 // Buffer hints value is meaningful (if 0 ignore).
+#define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
+#define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
+#define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).
/**
* Audio Video Frame.
@@ -719,48 +721,48 @@ typedef struct AVFrame {
#define DEFAULT_FRAME_RATE_BASE 1001000
/**
- * main external api structure.
+ * main external API structure
*/
typedef struct AVCodecContext {
/**
- * Info on struct for av_log
+ * information on struct for av_log
* - set by avcodec_alloc_context
*/
AVClass *av_class;
/**
- * the average bitrate.
- * - encoding: set by user. unused for constant quantizer encoding
- * - decoding: set by lavc. 0 or some bitrate if this info is available in the stream
+ * the average bitrate
+ * - encoding: Set by user; unused for constant quantizer encoding.
+ * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
*/
int bit_rate;
/**
* number of bits the bitstream is allowed to diverge from the reference.
* the reference can be CBR (for CBR pass1) or VBR (for pass2)
- * - encoding: set by user. unused for constant quantizer encoding
+ * - encoding: Set by user; unused for constant quantizer encoding.
* - decoding: unused
*/
int bit_rate_tolerance;
/**
* CODEC_FLAG_*.
- * - encoding: set by user.
- * - decoding: set by user.
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
int flags;
/**
- * some codecs needs additionnal format info. It is stored here
- * if any muxer uses this then ALL demuxers/parsers AND encoders for the specific codec MUST set it correctly
- * too otherwise stream copy breaks
- * in general use of this field by muxers is not recommanded
- * - encoding: set by lavc.
- * - decoding: set by lavc. (FIXME is this ok?)
+ * Some codecs need additional format info. It is stored here.
+ * If any muxer uses this then ALL demuxers/parsers AND encoders for the
+ * specific codec MUST set it correctly otherwise stream copy breaks.
+ * In general use of this field by muxers is not recommanded.
+ * - encoding: Set by libavcodec.
+ * - decoding: Set by libavcodec. (FIXME: Is this OK?)
*/
int sub_id;
/**
- * motion estimation algorithm used for video coding.
+ * Motion estimation algorithm used for video coding.
* 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
* 8 (umh), 9 (iter) [7, 8 are x264 specific, 9 is snow specific]
* - encoding: MUST be set by user.
@@ -769,26 +771,26 @@ typedef struct AVCodecContext {
int me_method;
/**
- * some codecs need / can use extra-data like huffman tables.
- * mjpeg: huffman tables
+ * some codecs need / can use extradata like Huffman tables.
+ * mjpeg: Huffman tables
* rv10: additional flags
* mpeg4: global headers (they can be in the bitstream or here)
- * the allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
- * then extradata_size to avoid prolems if its read with the bitstream reader
- * the bytewise contents of extradata must not depend on the architecture or cpu endianness
- * - encoding: set/allocated/freed by lavc.
- * - decoding: set/allocated/freed by user.
+ * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
+ * than extradata_size to avoid prolems if it is read with the bitstream reader.
+ * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
+ * - encoding: Set/allocated/freed by libavcodec.
+ * - decoding: Set/allocated/freed by user.
*/
uint8_t *extradata;
int extradata_size;
/**
- * this is the fundamental unit of time (in seconds) in terms
- * of which frame timestamps are represented. for fixed-fps content,
+ * This is the fundamental unit of time (in seconds) in terms
+ * of which frame timestamps are represented. For fixed-fps content,
* timebase should be 1/framerate and timestamp increments should be
* identically 1.
- * - encoding: MUST be set by user
- * - decoding: set by lavc.
+ * - encoding: MUST be set by user.
+ * - decoding: Set by libavcodec.
*/
AVRational time_base;
@@ -796,43 +798,43 @@ typedef struct AVCodecContext {
/**
* picture width / height.
* - encoding: MUST be set by user.
- * - decoding: set by lavc.
- * Note, for compatibility its possible to set this instead of
- * coded_width/height before decoding
+ * - decoding: Set by libavcodec.
+ * Note: For compatibility it is possible to set this instead of
+ * coded_width/height before decoding.
*/
int width, height;
#define FF_ASPECT_EXTENDED 15
/**
- * the number of pictures in a group of pitures, or 0 for intra_only.
- * - encoding: set by user.
+ * the number of pictures in a group of pictures, or 0 for intra_only
+ * - encoding: Set by user.
* - decoding: unused
*/
int gop_size;
/**
- * pixel format, see PIX_FMT_xxx.
- * - encoding: set by user.
- * - decoding: set by lavc.
+ * Pixel format, see PIX_FMT_xxx.
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
enum PixelFormat pix_fmt;
/**
- * Frame rate emulation. If not zero lower layer (i.e. format handler)
+ * Frame rate emulation. If not zero, the lower layer (i.e. format handler)
* has to read frames at native frame rate.
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int rate_emu;
/**
- * if non NULL, 'draw_horiz_band' is called by the libavcodec
- * decoder to draw an horizontal band. It improve cache usage. Not
+ * If non NULL, 'draw_horiz_band' is called by the libavcodec
+ * decoder to draw a horizontal band. It improves cache usage. Not
* all codecs can do that. You must check the codec capabilities
- * before
+ * beforehand.
* - encoding: unused
- * - decoding: set by user.
+ * - decoding: Set by user.
* @param height the height of the slice
* @param y the y position of the slice
* @param type 1->top field, 2->bottom field, 3->frame
@@ -843,28 +845,28 @@ typedef struct AVCodecContext {
int y, int type, int height);
/* audio only */
- int sample_rate; ///< samples per sec
+ int sample_rate; ///< samples per second
int channels;
/**
- * audio sample format.
- * - encoding: set by user.
- * - decoding: set by lavc.
+ * audio sample format
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
- enum SampleFormat sample_fmt; ///< sample format, currenly unused
+ enum SampleFormat sample_fmt; ///< sample format, currently unused
- /* the following data should not be initialized */
+ /* The following data should not be initialized. */
/**
- * samples per packet. initialized when calling 'init'
+ * Samples per packet, initialized when calling 'init'.
*/
int frame_size;
int frame_number; ///< audio or video frame number
- int real_pict_num; ///< returns the real picture number of previous encoded frame
+ int real_pict_num; ///< Returns the real picture number of previous encoded frame.
/**
- * number of frames the decoded output will be delayed relative to
+ * Number of frames the decoded output will be delayed relative to
* the encoded input.
- * - encoding: set by lavc.
+ * - encoding: Set by libavcodec.
* - decoding: unused
*/
int delay;
@@ -874,37 +876,37 @@ typedef struct AVCodecContext {
float qblur; ///< amount of qscale smoothing over time (0.0-1.0)
/**
- * minimum quantizer.
- * - encoding: set by user.
+ * minimum quantizer
+ * - encoding: Set by user.
* - decoding: unused
*/
int qmin;
/**
- * maximum quantizer.
- * - encoding: set by user.
+ * maximum quantizer
+ * - encoding: Set by user.
* - decoding: unused
*/
int qmax;
/**
- * maximum quantizer difference between frames.
- * - encoding: set by user.
+ * maximum quantizer difference between frames
+ * - encoding: Set by user.
* - decoding: unused
*/
int max_qdiff;
/**
- * maximum number of b frames between non b frames.
- * note: the output will be delayed by max_b_frames+1 relative to the input
- * - encoding: set by user.
+ * maximum number of B-frames between non-B-frames
+ * Note: The output will be delayed by max_b_frames+1 relative to the input.
+ * - encoding: Set by user.
* - decoding: unused
*/
int max_b_frames;
/**
- * qscale factor between ip and b frames.
- * - encoding: set by user.
+ * qscale factor between IP and B-frames
+ * - encoding: Set by user.
* - decoding: unused
*/
float b_quant_factor;
@@ -916,9 +918,9 @@ typedef struct AVCodecContext {
int b_frame_strategy;
/**
- * hurry up amount.
+ * hurry up amount
* - encoding: unused
- * - decoding: set by user. 1-> skip b frames, 2-> skip idct/dequant too, 5-> skip everything except header
+ * - decoding: Set by user. 1-> Skip B-frames, 2-> Skip IDCT/dequant too, 5-> Skip everything except header
* @deprecated Deprecated in favor of skip_idct and skip_frame.
*/
int hurry_up;
@@ -933,19 +935,19 @@ typedef struct AVCodecContext {
#endif
int rtp_payload_size; /* The size of the RTP payload: the coder will */
- /* do it's best to deliver a chunk with size */
+ /* do its best to deliver a chunk with size */
/* below rtp_payload_size, the chunk will start */
- /* with a start code on some codecs like H.263 */
+ /* with a start code on some codecs like H.263. */
/* This doesn't take account of any particular */
- /* headers inside the transmited RTP payload */
+ /* headers inside the transmitted RTP payload. */
- /* The RTP callback: This function is called */
- /* every time the encoder has a packet to send */
- /* Depends on the encoder if the data starts */
- /* with a Start Code (it should) H.263 does. */
- /* mb_nb contains the number of macroblocks */
- /* encoded in the RTP payload */
+ /* The RTP callback: This function is called */
+ /* every time the encoder has a packet to send. */
+ /* It depends on the encoder if the data starts */
+ /* with a Start Code (it should). H.263 does. */
+ /* mb_nb contains the number of macroblocks */
+ /* encoded in the RTP payload. */
void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
/* statistics, used for 2-pass encoding */
@@ -959,16 +961,16 @@ typedef struct AVCodecContext {
int misc_bits;
/**
- * number of bits used for the previously encoded frame.
- * - encoding: set by lavc
+ * number of bits used for the previously encoded frame
+ * - encoding: Set by libavcodec.
* - decoding: unused
*/
int frame_bits;
/**
- * private data of the user, can be used to carry app specific stuff.
- * - encoding: set by user
- * - decoding: set by user
+ * Private data of the user, can be used to carry app specific stuff.
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
void *opaque;
@@ -978,23 +980,23 @@ typedef struct AVCodecContext {
/**
* fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
- * this is used to workaround some encoder bugs
- * a demuxer should set this to what is stored in the field used to identify the codec
- * if there are mutiple such fields in a container then the demuxer should choose the one
- * which maximizes the information about the used codec
- * if the codec tag field in a container is larger then 32bit then the demxuer should
- * remap the longer id to 32bit with a table or other structure alternatively a new
+ * This is used to work around some encoder bugs.
+ * A demuxer should set this to what is stored in the field used to identify the codec.
+ * If there are multiple such fields in a container then the demuxer should choose the one
+ * which maximizes the information about the used codec.
+ * If the codec tag field in a container is larger then 32 bits then the demuxer should
+ * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
* extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
- * first
- * - encoding: set by user, if not then the default based on codec_id will be used
- * - decoding: set by user, will be converted to upper case by lavc during init
+ * first.
+ * - encoding: Set by user, if not then the default based on codec_id will be used.
+ * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
*/
unsigned int codec_tag;
/**
- * workaround bugs in encoders which sometimes cannot be detected automatically.
- * - encoding: set by user
- * - decoding: set by user
+ * Work around bugs in encoders which sometimes cannot be detected automatically.
+ * - encoding: Set by user
+ * - decoding: Set by user
*/
int workaround_bugs;
#define FF_BUG_AUTODETECT 1 ///< autodetection
@@ -1003,7 +1005,7 @@ typedef struct AVCodecContext {
#define FF_BUG_UMP4 8
#define FF_BUG_NO_PADDING 16
#define FF_BUG_AMV 32
-#define FF_BUG_AC_VLC 0 ///< will be removed, libavcodec can now handle these non compliant files by default
+#define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default.
#define FF_BUG_QPEL_CHROMA 64
#define FF_BUG_STD_QPEL 128
#define FF_BUG_QPEL_CHROMA2 256
@@ -1011,49 +1013,49 @@ typedef struct AVCodecContext {
#define FF_BUG_EDGE 1024
#define FF_BUG_HPEL_CHROMA 2048
#define FF_BUG_DC_CLIP 4096
-#define FF_BUG_MS 8192 ///< workaround various bugs in microsofts broken decoders
-//#define FF_BUG_FAKE_SCALABILITY 16 //autodetection should work 100%
+#define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders.
+//#define FF_BUG_FAKE_SCALABILITY 16 //Autodetection should work 100%.
/**
- * luma single coeff elimination threshold.
- * - encoding: set by user
+ * luma single coefficient elimination threshold
+ * - encoding: Set by user.
* - decoding: unused
*/
int luma_elim_threshold;
/**
- * chroma single coeff elimination threshold.
- * - encoding: set by user
+ * chroma single coeff elimination threshold
+ * - encoding: Set by user.
* - decoding: unused
*/
int chroma_elim_threshold;
/**
- * strictly follow the std (MPEG4, ...).
- * - encoding: set by user
+ * strictly follow the standard (MPEG4, ...).
+ * - encoding: Set by user.
* - decoding: unused
*/
int strict_std_compliance;
-#define FF_COMPLIANCE_VERY_STRICT 2 ///< strictly conform to a older more strict version of the spec or reference software
-#define FF_COMPLIANCE_STRICT 1 ///< strictly conform to all the things in the spec no matter what consequences
+#define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to a older more strict version of the spec or reference software.
+#define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences.
#define FF_COMPLIANCE_NORMAL 0
-#define FF_COMPLIANCE_INOFFICIAL -1 ///< allow inofficial extensions
-#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< allow non standarized experimental things
+#define FF_COMPLIANCE_INOFFICIAL -1 ///< Allow inofficial extensions.
+#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
/**
- * qscale offset between ip and b frames.
- * if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset)
- * if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset)
- * - encoding: set by user.
+ * qscale offset between IP and B-frames
+ * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
+ * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
+ * - encoding: Set by user.
* - decoding: unused
*/
float b_quant_offset;
/**
- * error resilience higher values will detect more errors but may missdetect
- * some more or less valid parts as errors.
+ * Error resilience; higher values will detect more errors but may
+ * misdetect some more or less valid parts as errors.
* - encoding: unused
- * - decoding: set by user
+ * - decoding: Set by user.
*/
int error_resilience;
#define FF_ER_CAREFUL 1
@@ -1062,67 +1064,67 @@ typedef struct AVCodecContext {
#define FF_ER_VERY_AGGRESSIVE 4
/**
- * called at the beginning of each frame to get a buffer for it.
- * if pic.reference is set then the frame will be read later by lavc
+ * Called at the beginning of each frame to get a buffer for it.
+ * If pic.reference is set then the frame will be read later by libavcodec.
* avcodec_align_dimensions() should be used to find the required width and
- * height, as they normally need to be rounded up to the next multiple of 16
+ * height, as they normally need to be rounded up to the next multiple of 16.
* - encoding: unused
- * - decoding: set by lavc, user can override
+ * - decoding: Set by libavcodec., user can override.
*/
int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
/**
- * called to release buffers which where allocated with get_buffer.
- * a released buffer can be reused in get_buffer()
- * pic.data[*] must be set to NULL
+ * Called to release buffers which where allocated with get_buffer.
+ * A released buffer can be reused in get_buffer().
+ * pic.data[*] must be set to NULL.
* - encoding: unused
- * - decoding: set by lavc, user can override
+ * - decoding: Set by libavcodec., user can override.
*/
void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);
/**
- * if 1 the stream has a 1 frame delay during decoding.
- * - encoding: set by lavc
- * - decoding: set by lavc
+ * If 1 the stream has a 1 frame delay during decoding.
+ * - encoding: Set by libavcodec.
+ * - decoding: Set by libavcodec.
*/
int has_b_frames;
/**
* number of bytes per packet if constant and known or 0
- * used by some WAV based audio codecs
+ * Used by some WAV based audio codecs.
*/
int block_align;
- int parse_only; /* - decoding only: if true, only parsing is done
+ int parse_only; /* - decoding only: If true, only parsing is done
(function avcodec_parse_frame()). The frame
data is returned. Only MPEG codecs support this now. */
/**
- * 0-> h263 quant 1-> mpeg quant.
- * - encoding: set by user.
+ * 0-> h263 quant 1-> mpeg quant
+ * - encoding: Set by user.
* - decoding: unused
*/
int mpeg_quant;
/**
- * pass1 encoding statistics output buffer.
- * - encoding: set by lavc
+ * pass1 encoding statistics output buffer
+ * - encoding: Set by libavcodec.
* - decoding: unused
*/
char *stats_out;
/**
- * pass2 encoding statistics input buffer.
- * concatenated stuff from stats_out of pass1 should be placed here
- * - encoding: allocated/set/freed by user
+ * pass2 encoding statistics input buffer
+ * Concatenated stuff from stats_out of pass1 should be placed here.
+ * - encoding: Allocated/set/freed by user.
* - decoding: unused
*/
char *stats_in;
/**
- * ratecontrol qmin qmax limiting method.
- * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax
- * - encoding: set by user.
+ * ratecontrol qmin qmax limiting method
+ * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax.
+ * - encoding: Set by user.
* - decoding: unused
*/
float rc_qsquish;
@@ -1131,68 +1133,68 @@ typedef struct AVCodecContext {
int rc_qmod_freq;
/**
- * ratecontrol override, see RcOverride.
- * - encoding: allocated/set/freed by user.
+ * ratecontrol override, see RcOverride
+ * - encoding: Allocated/set/freed by user.
* - decoding: unused
*/
RcOverride *rc_override;
int rc_override_count;
/**
- * rate control equation.
- * - encoding: set by user
+ * rate control equation
+ * - encoding: Set by user
* - decoding: unused
*/
char *rc_eq;
/**
- * maximum bitrate.
- * - encoding: set by user.
+ * maximum bitrate
+ * - encoding: Set by user.
* - decoding: unused
*/
int rc_max_rate;
/**
- * minimum bitrate.
- * - encoding: set by user.
+ * minimum bitrate
+ * - encoding: Set by user.
* - decoding: unused
*/
int rc_min_rate;
/**
- * decoder bitstream buffer size.
- * - encoding: set by user.
+ * decoder bitstream buffer size
+ * - encoding: Set by user.
* - decoding: unused
*/
int rc_buffer_size;
float rc_buffer_aggressivity;
/**
- * qscale factor between p and i frames.
- * if > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset)
- * if < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset)
- * - encoding: set by user.
+ * qscale factor between P and I-frames
+ * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
+ * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
+ * - encoding: Set by user.
* - decoding: unused
*/
float i_quant_factor;
/**
- * qscale offset between p and i frames.
- * - encoding: set by user.
+ * qscale offset between P and I-frames
+ * - encoding: Set by user.
* - decoding: unused
*/
float i_quant_offset;
/**
- * initial complexity for pass1 ratecontrol.
- * - encoding: set by user.
+ * initial complexity for pass1 ratecontrol
+ * - encoding: Set by user.
* - decoding: unused
*/
float rc_initial_cplx;
/**
- * dct algorithm, see FF_DCT_* below.
- * - encoding: set by user
+ * DCT algorithm, see FF_DCT_* below
+ * - encoding: Set by user.
* - decoding: unused
*/
int dct_algo;
@@ -1205,36 +1207,36 @@ typedef struct AVCodecContext {
#define FF_DCT_FAAN 6
/**
- * luminance masking (0-> disabled).
- * - encoding: set by user
+ * luminance masking (0-> disabled)
+ * - encoding: Set by user.
* - decoding: unused
*/
float lumi_masking;
/**
- * temporary complexity masking (0-> disabled).
- * - encoding: set by user
+ * temporary complexity masking (0-> disabled)
+ * - encoding: Set by user.
* - decoding: unused
*/
float temporal_cplx_masking;
/**
- * spatial complexity masking (0-> disabled).
- * - encoding: set by user
+ * spatial complexity masking (0-> disabled)
+ * - encoding: Set by user.
* - decoding: unused
*/
float spatial_cplx_masking;
/**
- * p block masking (0-> disabled).
- * - encoding: set by user
+ * p block masking (0-> disabled)
+ * - encoding: Set by user.
* - decoding: unused
*/
float p_masking;
/**
- * darkness masking (0-> disabled).
- * - encoding: set by user
+ * darkness masking (0-> disabled)
+ * - encoding: Set by user.
* - decoding: unused
*/
float dark_masking;
@@ -1244,9 +1246,9 @@ typedef struct AVCodecContext {
int unused;
/**
- * idct algorithm, see FF_IDCT_* below.
- * - encoding: set by user
- * - decoding: set by user
+ * IDCT algorithm, see FF_IDCT_* below.
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
int idct_algo;
#define FF_IDCT_AUTO 0
@@ -1269,22 +1271,22 @@ typedef struct AVCodecContext {
#define FF_IDCT_SIMPLEARMV6 17
/**
- * slice count.
- * - encoding: set by lavc
- * - decoding: set by user (or 0)
+ * slice count
+ * - encoding: Set by libavcodec.
+ * - decoding: Set by user (or 0).
*/
int slice_count;
/**
- * slice offsets in the frame in bytes.
- * - encoding: set/allocated by lavc
- * - decoding: set/allocated by user (or NULL)
+ * slice offsets in the frame in bytes
+ * - encoding: Set/allocated by libavcodec.
+ * - decoding: Set/allocated by user (or NULL).
*/
int *slice_offset;
/**
- * error concealment flags.
+ * error concealment flags
* - encoding: unused
- * - decoding: set by user
+ * - decoding: Set by user.
*/
int error_concealment;
#define FF_EC_GUESS_MVS 1
@@ -1294,12 +1296,12 @@ typedef struct AVCodecContext {
* dsp_mask could be add used to disable unwanted CPU features
* CPU features (i.e. MMX, SSE. ...)
*
- * with FORCE flag you may instead enable given CPU features
- * (Dangerous: usable in case of misdetection, improper usage however will
- * result into program crash)
+ * With the FORCE flag you may instead enable given CPU features.
+ * (Dangerous: Usable in case of misdetection, improper usage however will
+ * result into program crash.)
*/
unsigned dsp_mask;
-#define FF_MM_FORCE 0x80000000 /* force usage of selected flags (OR) */
+#define FF_MM_FORCE 0x80000000 /* Force usage of selected flags (OR) */
/* lower 16 bits - CPU features */
#ifdef HAVE_MMX
#define FF_MM_MMX 0x0001 /* standard MMX */
@@ -1315,14 +1317,14 @@ typedef struct AVCodecContext {
/**
* bits per sample/pixel from the demuxer (needed for huffyuv).
- * - encoding: set by lavc
- * - decoding: set by user
+ * - encoding: Set by libavcodec.
+ * - decoding: Set by user.
*/
int bits_per_sample;
/**
- * prediction method (needed for huffyuv).
- * - encoding: set by user
+ * prediction method (needed for huffyuv)
+ * - encoding: Set by user.
* - decoding: unused
*/
int prediction_method;
@@ -1331,24 +1333,24 @@ typedef struct AVCodecContext {
#define FF_PRED_MEDIAN 2
/**
- * sample aspect ratio (0 if unknown).
- * numerator and denominator must be relative prime and smaller then 256 for some video standards
- * - encoding: set by user.
- * - decoding: set by lavc.
+ * sample aspect ratio (0 if unknown)
+ * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
AVRational sample_aspect_ratio;
/**
- * the picture in the bitstream.
- * - encoding: set by lavc
- * - decoding: set by lavc
+ * the picture in the bitstream
+ * - encoding: Set by libavcodec.
+ * - decoding: Set by libavcodec.
*/
AVFrame *coded_frame;
/**
- * debug.
- * - encoding: set by user.
- * - decoding: set by user.
+ * debug
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
int debug;
#define FF_DEBUG_PICT_INFO 1
@@ -1368,9 +1370,9 @@ typedef struct AVCodecContext {
#define FF_DEBUG_VIS_MB_TYPE 0x00004000
/**
- * debug.
- * - encoding: set by user.
- * - decoding: set by user.
+ * debug
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
int debug_mv;
#define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames
@@ -1378,47 +1380,47 @@ typedef struct AVCodecContext {
#define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
/**
- * error.
- * - encoding: set by lavc if flags&CODEC_FLAG_PSNR
+ * error
+ * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
* - decoding: unused
*/
uint64_t error[4];
/**
- * minimum MB quantizer.
+ * minimum MB quantizer
* - encoding: unused
* - decoding: unused
*/
int mb_qmin;
/**
- * maximum MB quantizer.
+ * maximum MB quantizer
* - encoding: unused
* - decoding: unused
*/
int mb_qmax;
/**
- * motion estimation compare function.
- * - encoding: set by user.
+ * motion estimation comparison function
+ * - encoding: Set by user.
* - decoding: unused
*/
int me_cmp;
/**
- * subpixel motion estimation compare function.
- * - encoding: set by user.
+ * subpixel motion estimation comparison function
+ * - encoding: Set by user.
* - decoding: unused
*/
int me_sub_cmp;
/**
- * macroblock compare function (not supported yet).
- * - encoding: set by user.
+ * macroblock comparison function (not supported yet)
+ * - encoding: Set by user.
* - decoding: unused
*/
int mb_cmp;
/**
- * interlaced dct compare function
- * - encoding: set by user.
+ * interlaced DCT comparison function
+ * - encoding: Set by user.
* - decoding: unused
*/
int ildct_cmp;
@@ -1440,65 +1442,65 @@ typedef struct AVCodecContext {
#define FF_CMP_CHROMA 256
/**
- * ME diamond size & shape.
- * - encoding: set by user.
+ * ME diamond size & shape
+ * - encoding: Set by user.
* - decoding: unused
*/
int dia_size;
/**
- * amount of previous MV predictors (2a+1 x 2a+1 square).
- * - encoding: set by user.
+ * amount of previous MV predictors (2a+1 x 2a+1 square)
+ * - encoding: Set by user.
* - decoding: unused
*/
int last_predictor_count;
/**
- * pre pass for motion estimation.
- * - encoding: set by user.
+ * prepass for motion estimation
+ * - encoding: Set by user.
* - decoding: unused
*/
int pre_me;
/**
- * motion estimation pre pass compare function.
- * - encoding: set by user.
+ * motion estimation prepass comparison function
+ * - encoding: Set by user.
* - decoding: unused
*/
int me_pre_cmp;
/**
- * ME pre pass diamond size & shape.
- * - encoding: set by user.
+ * ME prepass diamond size & shape
+ * - encoding: Set by user.
* - decoding: unused
*/
int pre_dia_size;
/**
- * subpel ME quality.
- * - encoding: set by user.
+ * subpel ME quality
+ * - encoding: Set by user.
* - decoding: unused
*/
int me_subpel_quality;
/**
- * callback to negotiate the pixelFormat.
+ * callback to negotiate the pixelFormat
* @param fmt is the list of formats which are supported by the codec,
- * its terminated by -1 as 0 is a valid format, the formats are ordered by quality
- * the first is allways the native one
- * @return the choosen format
+ * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
+ * The first is always the native one.
+ * @return the chosen format
* - encoding: unused
- * - decoding: set by user, if not set then the native format will always be choosen
+ * - decoding: Set by user, if not set the native format will be chosen.
*/
enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt);
/**
- * DTG active format information (additionnal aspect ratio
- * information only used in DVB MPEG2 transport streams). 0 if
- * not set.
+ * DTG active format information (additional aspect ratio
+ * information only used in DVB MPEG-2 transport streams)
+ * 0 if not set.
*
- * - encoding: unused.
- * - decoding: set by decoder
+ * - encoding: unused
+ * - decoding: Set by decoder.
*/
int dtg_active_format;
#define FF_DTG_AFD_SAME 8
@@ -1510,46 +1512,46 @@ typedef struct AVCodecContext {
#define FF_DTG_AFD_SP_4_3 15
/**
- * Maximum motion estimation search range in subpel units.
- * if 0 then no limit
+ * maximum motion estimation search range in subpel units
+ * If 0 then no limit.
*
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int me_range;
/**
- * intra quantizer bias.
- * - encoding: set by user.
+ * intra quantizer bias
+ * - encoding: Set by user.
* - decoding: unused
*/
int intra_quant_bias;
#define FF_DEFAULT_QUANT_BIAS 999999
/**
- * inter quantizer bias.
- * - encoding: set by user.
+ * inter quantizer bias
+ * - encoding: Set by user.
* - decoding: unused
*/
int inter_quant_bias;
/**
- * color table ID.
- * - encoding: unused.
- * - decoding: which clrtable should be used for 8bit RGB images
- * table have to be stored somewhere FIXME
+ * color table ID
+ * - encoding: unused
+ * - decoding: Which clrtable should be used for 8bit RGB images.
+ * Tables have to be stored somewhere. FIXME
*/
int color_table_id;
/**
- * internal_buffer count.
- * Don't touch, used by lavc default_get_buffer()
+ * internal_buffer count
+ * Don't touch, used by libavcodec default_get_buffer().
*/
int internal_buffer_count;
/**
- * internal_buffers.
- * Don't touch, used by lavc default_get_buffer()
+ * internal_buffers
+ * Don't touch, used by libavcodec default_get_buffer().
*/
void *internal_buffer;
@@ -1560,9 +1562,9 @@ typedef struct AVCodecContext {
#define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
/**
- * global quality for codecs which cannot change it per frame.
- * this should be proportional to MPEG1/2/4 qscale.
- * - encoding: set by user.
+ * Global quality for codecs which cannot change it per frame.
+ * This should be proportional to MPEG-1/2/4 qscale.
+ * - encoding: Set by user.
* - decoding: unused
*/
int global_quality;
@@ -1574,14 +1576,14 @@ typedef struct AVCodecContext {
#define FF_CODER_TYPE_DEFLATE 4
/**
* coder type
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int coder_type;
/**
* context model
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int context_model;
@@ -1589,7 +1591,7 @@ typedef struct AVCodecContext {
/**
*
* - encoding: unused
- * - decoding: set by user.
+ * - decoding: Set by user.
*/
uint8_t * (*realloc)(struct AVCodecContext *s, uint8_t *buf, int buf_size);
#endif
@@ -1597,7 +1599,7 @@ typedef struct AVCodecContext {
/**
* slice flags
* - encoding: unused
- * - decoding: set by user.
+ * - decoding: Set by user.
*/
int slice_flags;
#define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display
@@ -1613,7 +1615,7 @@ typedef struct AVCodecContext {
/**
* macroblock decision mode
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int mb_decision;
@@ -1623,105 +1625,105 @@ typedef struct AVCodecContext {
/**
* custom intra quantization matrix
- * - encoding: set by user, can be NULL
- * - decoding: set by lavc
+ * - encoding: Set by user, can be NULL.
+ * - decoding: Set by libavcodec.
*/
uint16_t *intra_matrix;
/**
* custom inter quantization matrix
- * - encoding: set by user, can be NULL
- * - decoding: set by lavc
+ * - encoding: Set by user, can be NULL.
+ * - decoding: Set by libavcodec.
*/
uint16_t *inter_matrix;
/**
* fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
- * this is used to workaround some encoder bugs
+ * This is used to work around some encoder bugs.
* - encoding: unused
- * - decoding: set by user, will be converted to upper case by lavc during init
+ * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
*/
unsigned int stream_codec_tag;
/**
- * scene change detection threshold.
- * 0 is default, larger means fewer detected scene changes
- * - encoding: set by user.
+ * scene change detection threshold
+ * 0 is default, larger means fewer detected scene changes.
+ * - encoding: Set by user.
* - decoding: unused
*/
int scenechange_threshold;
/**
- * minimum lagrange multipler
- * - encoding: set by user.
+ * minimum Lagrange multipler
+ * - encoding: Set by user.
* - decoding: unused
*/
int lmin;
/**
- * maximum lagrange multipler
- * - encoding: set by user.
+ * maximum Lagrange multipler
+ * - encoding: Set by user.
* - decoding: unused
*/
int lmax;
/**
- * Palette control structure
+ * palette control structure
* - encoding: ??? (no palette-enabled encoder yet)
- * - decoding: set by user.
+ * - decoding: Set by user.
*/
struct AVPaletteControl *palctrl;
/**
* noise reduction strength
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int noise_reduction;
/**
- * called at the beginning of a frame to get cr buffer for it.
- * buffer type (size, hints) must be the same. lavc won't check it.
- * lavc will pass previous buffer in pic, function should return
+ * Called at the beginning of a frame to get cr buffer for it.
+ * Buffer type (size, hints) must be the same. libavcodec won't check it.
+ * libavcodec will pass previous buffer in pic, function should return
* same buffer or new buffer with old frame "painted" into it.
- * if pic.data[0] == NULL must behave like get_buffer().
+ * If pic.data[0] == NULL must behave like get_buffer().
* - encoding: unused
- * - decoding: set by lavc, user can override
+ * - decoding: Set by libavcodec., user can override
*/
int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);
/**
- * number of bits which should be loaded into the rc buffer before decoding starts
- * - encoding: set by user.
+ * Number of bits which should be loaded into the rc buffer before decoding starts.
+ * - encoding: Set by user.
* - decoding: unused
*/
int rc_initial_buffer_occupancy;
/**
*
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int inter_threshold;
/**
- * CODEC_FLAG2_*.
- * - encoding: set by user.
- * - decoding: set by user.
+ * CODEC_FLAG2_*
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
int flags2;
/**
- * simulates errors in the bitstream to test error concealment.
- * - encoding: set by user.
- * - decoding: unused.
+ * Simulates errors in the bitstream to test error concealment.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int error_rate;
/**
* MP3 antialias algorithm, see FF_AA_* below.
* - encoding: unused
- * - decoding: set by user
+ * - decoding: Set by user.
*/
int antialias_algo;
#define FF_AA_AUTO 0
@@ -1729,166 +1731,167 @@ typedef struct AVCodecContext {
#define FF_AA_INT 2
#define FF_AA_FLOAT 3
/**
- * Quantizer noise shaping.
- * - encoding: set by user
+ * quantizer noise shaping
+ * - encoding: Set by user.
* - decoding: unused
*/
int quantizer_noise_shaping;
/**
- * Thread count.
+ * thread count
* is used to decide how many independent tasks should be passed to execute()
- * - encoding: set by user
- * - decoding: set by user
+ * - encoding: Set by user.
+ * - decoding: Set by user.
*/
int thread_count;
/**
- * the codec may call this to execute several independent things. it will return only after
- * finishing all tasks, the user may replace this with some multithreaded implementation, the
- * default implementation will execute the parts serially
+ * The codec may call this to execute several independent things.
+ * It will return only after finishing all tasks.
+ * The user may replace this with some multithreaded implementation,
+ * the default implementation will execute the parts serially.
* @param count the number of things to execute
- * - encoding: set by lavc, user can override
- * - decoding: set by lavc, user can override
+ * - encoding: Set by libavcodec, user can override.
+ * - decoding: Set by libavcodec, user can override.
*/
int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void **arg2, int *ret, int count);
/**
- * Thread opaque.
- * can be used by execute() to store some per AVCodecContext stuff.
+ * thread opaque
+ * Can be used by execute() to store some per AVCodecContext stuff.
* - encoding: set by execute()
* - decoding: set by execute()
*/
void *thread_opaque;
/**
- * Motion estimation threshold. under which no motion estimation is
- * performed, but instead the user specified motion vectors are used
+ * Motion estimation threshold below which no motion estimation is
+ * performed, but instead the user specified motion vectors are used.
*
- * - encoding: set by user
+ * - encoding: Set by user.
* - decoding: unused
*/
int me_threshold;
/**
- * Macroblock threshold. under which the user specified macroblock types will be used
- * - encoding: set by user
+ * Macroblock threshold below which the user specified macroblock types will be used.
+ * - encoding: Set by user.
* - decoding: unused
*/
int mb_threshold;
/**
- * precision of the intra dc coefficient - 8.
- * - encoding: set by user
+ * precision of the intra DC coefficient - 8
+ * - encoding: Set by user.
* - decoding: unused
*/
int intra_dc_precision;
/**
- * noise vs. sse weight for the nsse comparsion function.
- * - encoding: set by user
+ * noise vs. sse weight for the nsse comparsion function
+ * - encoding: Set by user.
* - decoding: unused
*/
int nsse_weight;
/**
- * number of macroblock rows at the top which are skipped.
+ * Number of macroblock rows at the top which are skipped.
* - encoding: unused
- * - decoding: set by user
+ * - decoding: Set by user.
*/
int skip_top;
/**
- * number of macroblock rows at the bottom which are skipped.
+ * Number of macroblock rows at the bottom which are skipped.
* - encoding: unused
- * - decoding: set by user
+ * - decoding: Set by user.
*/
int skip_bottom;
/**
* profile
- * - encoding: set by user
- * - decoding: set by lavc
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
int profile;
#define FF_PROFILE_UNKNOWN -99
/**
* level
- * - encoding: set by user
- * - decoding: set by lavc
+ * - encoding: Set by user.
+ * - decoding: Set by libavcodec.
*/
int level;
#define FF_LEVEL_UNKNOWN -99
/**
- * low resolution decoding. 1-> 1/2 size, 2->1/4 size
+ * low resolution decoding, 1-> 1/2 size, 2->1/4 size
* - encoding: unused
- * - decoding: set by user
+ * - decoding: Set by user.
*/
int lowres;
/**
- * bitsream width / height. may be different from width/height if lowres
- * or other things are used
+ * Bitstream width / height, may be different from width/height if lowres
+ * or other things are used.
* - encoding: unused
- * - decoding: set by user before init if known, codec should override / dynamically change if needed
+ * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
*/
int coded_width, coded_height;
/**
* frame skip threshold
- * - encoding: set by user
+ * - encoding: Set by user.
* - decoding: unused
*/
int frame_skip_threshold;
/**
* frame skip factor
- * - encoding: set by user
+ * - encoding: Set by user.
* - decoding: unused
*/
int frame_skip_factor;
/**
* frame skip exponent
- * - encoding: set by user
+ * - encoding: Set by user.
* - decoding: unused
*/
int frame_skip_exp;
/**
- * frame skip comparission function
- * - encoding: set by user.
+ * frame skip comparison function
+ * - encoding: Set by user.
* - decoding: unused
*/
int frame_skip_cmp;
/**
- * border processing masking. raises the quantizer for mbs on the borders
+ * Border processing masking, raises the quantizer for mbs on the borders
* of the picture.
- * - encoding: set by user
+ * - encoding: Set by user.
* - decoding: unused
*/
float border_masking;
/**
- * minimum MB lagrange multipler.
- * - encoding: set by user.
+ * minimum MB lagrange multipler
+ * - encoding: Set by user.
* - decoding: unused
*/
int mb_lmin;
/**
- * maximum MB lagrange multipler.
- * - encoding: set by user.
+ * maximum MB lagrange multipler
+ * - encoding: Set by user.
* - decoding: unused
*/
int mb_lmax;
/**
*
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int me_penalty_compensation;
@@ -1896,90 +1899,90 @@ typedef struct AVCodecContext {
/**
*
* - encoding: unused
- * - decoding: set by user.
+ * - decoding: Set by user.
*/
enum AVDiscard skip_loop_filter;
/**
*
* - encoding: unused
- * - decoding: set by user.
+ * - decoding: Set by user.
*/
enum AVDiscard skip_idct;
/**
*
* - encoding: unused
- * - decoding: set by user.
+ * - decoding: Set by user.
*/
enum AVDiscard skip_frame;
/**
*
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int bidir_refine;
/**
*
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int brd_scale;
/**
* constant rate factor - quality-based VBR - values ~correspond to qps
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
float crf;
/**
* constant quantization parameter rate control method
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int cqp;
/**
- * minimum gop size
- * - encoding: set by user.
+ * minimum GOP size
+ * - encoding: Set by user.
* - decoding: unused
*/
int keyint_min;
/**
* number of reference frames
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int refs;
/**
* chroma qp offset from luma
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int chromaoffset;
/**
- * influences how often b-frames are used
- * - encoding: set by user.
+ * Influences how often B-frames are used.
+ * - encoding: Set by user.
* - decoding: unused
*/
int bframebias;
/**
* trellis RD quantization
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int trellis;
/**
- * reduce fluctuations in qp (before curve compression)
- * - encoding: set by user.
+ * Reduce fluctuations in qp (before curve compression).
+ * - encoding: Set by user.
* - decoding: unused
*/
float complexityblur;
@@ -1987,7 +1990,7 @@ typedef struct AVCodecContext {
/**
* in-loop deblocking filter alphac0 parameter
* alpha is in the range -6...6
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int deblockalpha;
@@ -1995,14 +1998,14 @@ typedef struct AVCodecContext {
/**
* in-loop deblocking filter beta parameter
* beta is in the range -6...6
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int deblockbeta;
/**
* macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int partitions;
@@ -2013,97 +2016,97 @@ typedef struct AVCodecContext {
#define X264_PART_B8X8 0x100 /* Analyse b16x8, b8x16 and b8x8 */
/**
- * direct mv prediction mode - 0 (none), 1 (spatial), 2 (temporal)
- * - encoding: set by user.
+ * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal)
+ * - encoding: Set by user.
* - decoding: unused
*/
int directpred;
/**
- * audio cutoff bandwidth (0 means "automatic") . Currently used only by FAAC
- * - encoding: set by user.
+ * Audio cutoff bandwidth (0 means "automatic"), currently used only by FAAC.
+ * - encoding: Set by user.
* - decoding: unused
*/
int cutoff;
/**
- * multiplied by qscale for each frame and added to scene_change_score
- * - encoding: set by user.
+ * Multiplied by qscale for each frame and added to scene_change_score.
+ * - encoding: Set by user.
* - decoding: unused
*/
int scenechange_factor;
/**
*
- * note: value depends upon the compare functin used for fullpel ME
- * - encoding: set by user.
+ * Note: Value depends upon the compare function used for fullpel ME.
+ * - encoding: Set by user.
* - decoding: unused
*/
int mv0_threshold;
/**
- * adjusts sensitivity of b_frame_strategy 1
- * - encoding: set by user.
+ * Adjusts sensitivity of b_frame_strategy 1.
+ * - encoding: Set by user.
* - decoding: unused
*/
int b_sensitivity;
/**
- * - encoding: set by user.
+ * - encoding: Set by user.
* - decoding: unused
*/
int compression_level;
#define FF_COMPRESSION_DEFAULT -1
/**
- * sets whether to use LPC mode - used by FLAC encoder
- * - encoding: set by user.
- * - decoding: unused.
+ * Sets whether to use LPC mode - used by FLAC encoder.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int use_lpc;
/**
* LPC coefficient precision - used by FLAC encoder
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int lpc_coeff_precision;
/**
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int min_prediction_order;
/**
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int max_prediction_order;
/**
* search method for selecting prediction order
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int prediction_order_method;
/**
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int min_partition_order;
/**
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int max_partition_order;
/**
* GOP timecode frame start number, in non drop frame format
- * - encoding: set by user.
- * - decoding: unused.
+ * - encoding: Set by user.
+ * - decoding: unused
*/
int64_t timecode_frame_start;
} AVCodecContext;
@@ -2141,20 +2144,20 @@ typedef struct AVPicture {
* AVPaletteControl
* This structure defines a method for communicating palette changes
* between and demuxer and a decoder.
- * this is totally broken, palette changes should be sent as AVPackets
+ * This is totally broken, palette changes should be sent as AVPackets.
*/
#define AVPALETTE_SIZE 1024
#define AVPALETTE_COUNT 256
typedef struct AVPaletteControl {
- /* demuxer sets this to 1 to indicate the palette has changed;
- * decoder resets to 0 */
+ /* Demuxer sets this to 1 to indicate the palette has changed;
+ * decoder resets to 0. */
int palette_changed;
/* 4-byte ARGB palette entries, stored in native byte order; note that
* the individual palette components should be on a 8-bit scale; if
- * the palette data comes from a IBM VGA native format, the component
- * data is probably 6 bits in size and needs to be scaled */
+ * the palette data comes from an IBM VGA native format, the component
+ * data is probably 6 bits in size and needs to be scaled. */
unsigned int palette[AVPALETTE_COUNT];
} AVPaletteControl attribute_deprecated;
@@ -2371,7 +2374,7 @@ extern AVCodec xl_decoder;
extern AVCodec zlib_decoder;
extern AVCodec zmbv_decoder;
-/* pcm codecs */
+/* PCM codecs */
#define PCM_CODEC(id, name) \
extern AVCodec name ## _decoder; \
extern AVCodec name ## _encoder
@@ -2394,7 +2397,7 @@ PCM_CODEC(CODEC_ID_PCM_U24LE, pcm_u24l
PCM_CODEC(CODEC_ID_PCM_U32BE, pcm_u32be);
PCM_CODEC(CODEC_ID_PCM_U32LE, pcm_u32le);
-/* adpcm codecs */
+/* ADPCM codecs */
PCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);
PCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx);
@@ -2476,23 +2479,23 @@ attribute_deprecated void img_resample_c
/**
* Allocate memory for a picture. Call avpicture_free to free it.
*
- * @param picture the picture to be filled in.
- * @param pix_fmt the format of the picture.
- * @param width the width of the picture.
- * @param height the height of the picture.
- * @return Zero if successful, a negative value if not.
+ * @param picture the picture to be filled in
+ * @param pix_fmt the format of the picture
+ * @param width the width of the picture
+ * @param height the height of the picture
+ * @return zero if successful, a negative value if not
*/
int avpicture_alloc(AVPicture *picture, int pix_fmt, int width, int height);
/**
* Free a picture previously allocated by avpicture_alloc().
*
- * @param picture The AVPicture to be freed.
+ * @param picture the AVPicture to be freed
*/
void avpicture_free(AVPicture *picture);
/**
- * Fill in AVPicture's fields.
+ * Fill in the AVPicture fields.
* The fields of the given AVPicture are filled in by using the 'ptr' address
* which points to the image data buffer. Depending on the specified picture
* format, one or multiple image data pointers and line sizes will be set.
@@ -2500,12 +2503,12 @@ void avpicture_free(AVPicture *picture);
* the different picture planes and the line sizes of the different planes
* will be stored in the lines_sizes array.
*
- * @param picture AVPicture who's fields are to be filled in
+ * @param picture AVPicture whose fields are to be filled in
* @param ptr Buffer which will contain or contains the actual image data
- * @param pix_fmt The format in which the picture data is stored
- * @param width The width of the image in pixels
- * @param height The height of the image in pixels
- * @return Size of the image data in bytes.
+ * @param pix_fmt The format in which the picture data is stored.
+ * @param width the width of the image in pixels
+ * @param height the height of the image in pixels
+ * @return size of the image data in bytes
*/
int avpicture_fill(AVPicture *picture, uint8_t *ptr,
int pix_fmt, int width, int height);
@@ -2516,9 +2519,9 @@ int avpicture_layout(const AVPicture* sr
* Calculate the size in bytes that a picture of the given width and height
* would occupy if stored in the given picture format.
*
- * @param pix_fmt The given picture format
- * @param width The width of the image
- * @param height The height of the image
+ * @param pix_fmt the given picture format
+ * @param width the width of the image
+ * @param height the height of the image
* @return Image data size in bytes
*/
int avpicture_get_size(int pix_fmt, int width, int height);
@@ -2544,11 +2547,11 @@ unsigned int avcodec_pix_fmt_to_codec_ta
* other formats. These losses can involve loss of chroma, but also loss of
* resolution, loss of color depth, loss due to the color space conversion, loss
* of the alpha bits or loss due to color quantization.
- * avcodec_get_fix_fmt_loss() informs you on the various types of losses which
- * will occur when converting from one pixel format to another.
+ * avcodec_get_fix_fmt_loss() informs you about the various types of losses
+ * which will occur when converting from one pixel format to another.
*
- * @param[in] dst_pix_fmt Destination pixel format.
- * @param[in] src_pix_fmt Source pixel format.
+ * @param[in] dst_pix_fmt destination pixel format
+ * @param[in] src_pix_fmt source pixel format
* @param[in] has_alpha Whether the source pixel format alpha channel is used.
* @return Combination of flags informing you what kind of losses will occur.
*/
@@ -2561,8 +2564,8 @@ int avcodec_get_pix_fmt_loss(int dst_pix
* may occur. For example, when converting from RGB24 to GRAY, the color
* information will be lost. Similarly, other losses occur when converting from
* some formats to other formats. avcodec_find_best_pix_fmt() searches which of
- * the given pixel formats should be used to undergo the least amount of losses.
- * The pixel formats from which it choses one, are determined by the
+ * the given pixel formats should be used to suffer the least amount of loss.
+ * The pixel formats from which it chooses one, are determined by the
* \p pix_fmt_mask parameter.
*
* @code
@@ -2571,8 +2574,8 @@ int avcodec_get_pix_fmt_loss(int dst_pix
* dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss);
* @endcode
*
- * @param[in] pix_fmt_mask Bitmask determining which pixel format to choose from.
- * @param[in] src_pix_fmt Source pixel format.
+ * @param[in] pix_fmt_mask bitmask determining which pixel format to choose from
+ * @param[in] src_pix_fmt source pixel format
* @param[in] has_alpha Whether the source pixel format alpha channel is used.
* @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
* @return The best pixel format to convert to or -1 if none was found.
@@ -2624,7 +2627,7 @@ void register_avcodec(AVCodec *format);
/**
* Finds an encoder with a matching codec ID.
*
- * @param id CodecID of the requested encoder.
+ * @param id CodecID of the requested encoder
* @return An encoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_encoder(enum CodecID id);
@@ -2632,7 +2635,7 @@ AVCodec *avcodec_find_encoder(enum Codec
/**
* Finds an encoder with the specified name.
*
- * @param name Name of the requested encoder.
+ * @param name name of the requested encoder
* @return An encoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_encoder_by_name(const char *name);
@@ -2640,7 +2643,7 @@ AVCodec *avcodec_find_encoder_by_name(co
/**
* Finds a decoder with a matching codec ID.
*
- * @param id CodecID of the requested decoder.
+ * @param id CodecID of the requested decoder
* @return A decoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_decoder(enum CodecID id);
@@ -2648,7 +2651,7 @@ AVCodec *avcodec_find_decoder(enum Codec
/**
* Finds an decoder with the specified name.
*
- * @param name Name of the requested decoder.
+ * @param name name of the requested decoder
* @return A decoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_decoder_by_name(const char *name);
@@ -2724,7 +2727,7 @@ int avcodec_default_execute(AVCodecConte
* avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
* retrieving a codec.
*
- * @warning This function is not thread save!
+ * @warning This function is not thread safe!
*
* @code
* codec = avcodec_find_decoder(CODEC_ID_H264);
@@ -2737,9 +2740,9 @@ int avcodec_default_execute(AVCodecConte
* exit(1);
* @endcode
*
- * @param avctx The context which will be setup to use the given codec.
+ * @param avctx The context which will be set up to use the given codec.
* @param codec The codec to use within the context.
- * @return Zero on success, a negative value on error.
+ * @return zero on success, a negative value on error
* @see avcodec_alloc_context, avcodec_find_decoder, avcodec_find_encoder
*/
int avcodec_open(AVCodecContext *avctx, AVCodec *codec);
@@ -2753,9 +2756,9 @@ attribute_deprecated int avcodec_decode_
/**
* Decodes an audio frame from \p buf into \p samples.
- * The avcodec_decode_audio2() function decodes a frame of audio from the input
+ * The avcodec_decode_audio2() function decodes an audio frame from the input
* buffer \p buf of size \p buf_size. To decode it, it makes use of the
- * audiocodec which was coupled with \p avctx using avcodec_open(). The
+ * audio codec which was coupled with \p avctx using avcodec_open(). The
* resulting decoded frame is stored in output buffer \p samples. If no frame
* could be decompressed, \p frame_size_ptr is zero. Otherwise, it is the
* decompressed frame size in \e bytes.
@@ -2771,7 +2774,7 @@ attribute_deprecated int avcodec_decode_
* no overreading happens for damaged MPEG streams.
*
* @note You might have to align the input buffer \p buf and output buffer \p
- * samples. The alignment requirements depend on the CPU: on some CPUs it isn't
+ * samples. The alignment requirements depend on the CPU: On some CPUs it isn't
* necessary at all, on others it won't work at all if not aligned and on others
* it will work but it will have an impact on performance. In practice, the
* bitstream should have 4 byte alignment at minimum and all sample data should
@@ -2779,11 +2782,11 @@ attribute_deprecated int avcodec_decode_
* the linesize is not a multiple of 16 then there's no sense in aligning the
* start of the buffer to 16.
*
- * @param avctx The codec context.
- * @param[out] samples The output buffer.
- * @param[in,out] frame_size_ptr The output buffer size in bytes.
- * @param[in] buf The input buffer.
- * @param[in] buf_size The input buffer size in bytes.
+ * @param avctx the codec context
+ * @param[out] samples the output buffer
+ * @param[in,out] frame_size_ptr the output buffer size in bytes
+ * @param[in] buf the input buffer
+ * @param[in] buf_size the input buffer size in bytes
* @return On error a negative value is returned, otherwise the number of bytes
* used or zero if no frame could be decompressed.
*/
@@ -2793,9 +2796,9 @@ int avcodec_decode_audio2(AVCodecContext
/**
* Decodes a video frame from \p buf into \p picture.
- * The avcodec_decode_video() function decodes a frame of video from the input
+ * The avcodec_decode_video() function decodes a video frame from the input
* buffer \p buf of size \p buf_size. To decode it, it makes use of the
- * videocodec which was coupled with \p avctx using avcodec_open(). The
+ * video codec which was coupled with \p avctx using avcodec_open(). The
* resulting decoded frame is stored in \p picture.
*
* @warning The input buffer must be \c FF_INPUT_BUFFER_PADDING_SIZE larger than
@@ -2814,11 +2817,11 @@ int avcodec_decode_audio2(AVCodecContext
* the linesize is not a multiple of 16 then there's no sense in aligning the
* start of the buffer to 16.
*
- * @param avctx The codec context.
+ * @param avctx the codec context
* @param[out] picture The AVFrame in which the decoded video frame will be stored.
- * @param[in] buf The input buffer.
- * @param[in] buf_size The size of the input buffer in bytes.
- * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is non zero.
+ * @param[in] buf the input buffer
+ * @param[in] buf_size the size of the input buffer in bytes
+ * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
* @return On error a negative value is returned, otherwise the number of bytes
* used or zero if no frame could be decompressed.
*/
@@ -2826,9 +2829,9 @@ int avcodec_decode_video(AVCodecContext
int *got_picture_ptr,
uint8_t *buf, int buf_size);
-/* decode a subtitle message. return -1 if error, otherwise return the
- *number of bytes used. If no subtitle could be decompressed,
- *got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */
+/* Decode a subtitle message. Return -1 if error, otherwise return the
+ * number of bytes used. If no subtitle could be decompressed,
+ * got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */
int avcodec_decode_subtitle(AVCodecContext *avctx, AVSubtitle *sub,
int *got_sub_ptr,
const uint8_t *buf, int buf_size);
@@ -2838,17 +2841,17 @@ int avcodec_parse_frame(AVCodecContext *
/**
* Encodes an audio frame from \p samples into \p buf.
- * The avcodec_encode_audio() function encodes a frame of audio from the input
- * buffer \p samples. To encode it, it makes use of the audiocodec which was
+ * The avcodec_encode_audio() function encodes an audio frame from the input
+ * buffer \p samples. To encode it, it makes use of the audio codec which was
* coupled with \p avctx using avcodec_open(). The resulting encoded frame is
* stored in output buffer \p buf.
*
* @note The output buffer should be at least \c FF_MIN_BUFFER_SIZE bytes large.
*
- * @param avctx The codec context.
- * @param[out] buf The output buffer.
- * @param[in] buf_size The output buffer size.
- * @param[in] samples The input buffer containing the samples.
+ * @param avctx the codec context
+ * @param[out] buf the output buffer
+ * @param[in] buf_size the output buffer size
+ * @param[in] samples the input buffer containing the samples
* @return On error a negative value is returned, on succes zero or the number
* of bytes used from the input buffer.
*/
@@ -2857,16 +2860,16 @@ int avcodec_encode_audio(AVCodecContext
/**
* Encodes a video frame from \p pict into \p buf.
- * The avcodec_encode_video() function encodes a frame of video from the input
- * \p pict. To encode it, it makes use of the videocodec which was coupled with
+ * The avcodec_encode_video() function encodes a video frame from the input
+ * \p pict. To encode it, it makes use of the video codec which was coupled with
* \p avctx using avcodec_open(). The resulting encoded bytes representing the
* frame are stored in the output buffer \p buf. The input picture should be
* stored using a specific format, namely \c avctx.pix_fmt.
*
- * @param avctx The codec context.
- * @param[out] buf The output buffer for the bitstream of encoded frame.
- * @param[in] buf_size The size of the outputbuffer in bytes.
- * @param[in] pict The input picture to encode.
+ * @param avctx the codec context
+ * @param[out] buf the output buffer for the bitstream of encoded frame
+ * @param[in] buf_size the size of the output buffer in bytes
+ * @param[in] pict the input picture to encode
* @return On error a negative value is returned, on success zero or the number
* of bytes used from the input buffer.
*/
@@ -2891,7 +2894,7 @@ void avcodec_default_free_buffers(AVCode
/**
* Returns a single letter to describe the given picture type \p pict_type.
*
- * @param[in] pict_type The picture type.
+ * @param[in] pict_type the picture type
* @return A single character representing the picture type.
*/
char av_get_pict_type_char(int pict_type);
@@ -2899,7 +2902,7 @@ char av_get_pict_type_char(int pict_type
/**
* Returns codec bits per sample.
*
- * @param[in] codec_id The codec.
+ * @param[in] codec_id the codec
* @return Number of bits per sample or zero if unknown for the given codec.
*/
int av_get_bits_per_sample(enum CodecID codec_id);
@@ -2913,8 +2916,8 @@ typedef struct AVCodecParserContext {
(incremented by each av_parser_parse()) */
int64_t last_frame_offset; /* offset of the last frame */
/* video info */
- int pict_type; /* XXX: put it back in AVCodecContext */
- int repeat_pict; /* XXX: put it back in AVCodecContext */
+ int pict_type; /* XXX: Put it back in AVCodecContext. */
+ int repeat_pict; /* XXX: Put it back in AVCodecContext. */
int64_t pts; /* pts of the current frame */
int64_t dts; /* dts of the current frame */
@@ -3028,7 +3031,7 @@ void *av_fast_realloc(void *ptr, unsigne
/* for static data only */
/**
- * Frees all static arrays and reset their pointers to 0.
+ * Frees all static arrays and resets their pointers to 0.
* Call this function to release all statically allocated tables.
*/
attribute_deprecated void av_free_static(void);
@@ -3039,7 +3042,7 @@ attribute_deprecated void av_free_static
* @warning Do not use for normal allocation.
*
* @param[in] size The amount of memory you need in bytes.
- * @return Block of memory of the requested size.
+ * @return block of memory of the requested size
*/
attribute_deprecated void *av_mallocz_static(unsigned int size);
@@ -3050,13 +3053,13 @@ void av_picture_copy(AVPicture *dst, con
int pix_fmt, int width, int height);
/**
- * Crop image top and left side
+ * Crop image top and left side.
*/
int av_picture_crop(AVPicture *dst, const AVPicture *src,
int pix_fmt, int top_band, int left_band);
/**
- * Pad image
+ * Pad image.
*/
int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, int pix_fmt,
int padtop, int padbottom, int padleft, int padright, int *color);
@@ -3076,20 +3079,20 @@ extern unsigned int av_xiphlacing(unsign
/* error handling */
#if EINVAL > 0
-#define AVERROR(e) (-(e)) /**< returns a negative error code from a POSIX error code, to return from library functions. */
-#define AVUNERROR(e) (-(e)) /**< returns a POSIX error code from a library function error return value. */
+#define AVERROR(e) (-(e)) /**< Returns a negative error code from a POSIX error code, to return from library functions. */
+#define AVUNERROR(e) (-(e)) /**< Returns a POSIX error code from a library function error return value. */
#else
-/* some platforms have E* and errno already negated. */
+/* Some platforms have E* and errno already negated. */
#define AVERROR(e) (e)
#define AVUNERROR(e) (e)
#endif
#define AVERROR_UNKNOWN AVERROR(EINVAL) /**< unknown error */
-#define AVERROR_IO AVERROR(EIO) /**< i/o error */
-#define AVERROR_NUMEXPECTED AVERROR(EDOM) /**< number syntax expected in filename */
+#define AVERROR_IO AVERROR(EIO) /**< I/O error */
+#define AVERROR_NUMEXPECTED AVERROR(EDOM) /**< Number syntax expected in filename. */
#define AVERROR_INVALIDDATA AVERROR(EINVAL) /**< invalid data found */
#define AVERROR_NOMEM AVERROR(ENOMEM) /**< not enough memory */
#define AVERROR_NOFMT AVERROR(EILSEQ) /**< unknown format */
-#define AVERROR_NOTSUPP AVERROR(ENOSYS) /**< operation not supported */
+#define AVERROR_NOTSUPP AVERROR(ENOSYS) /**< Operation not supported. */
#ifdef __cplusplus
}
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