[FFmpeg-devel] [PATCH] HAM6/HAM8 support for IFF demuxer/decoder
Stefano Sabatini
stefano.sabatini-lala at poste.it
Thu Apr 21 18:13:53 CEST 2011
On date Wednesday 2011-04-20 13:56:56 +0200, Sebastian Vater encoded:
> Hello folks!
>
> I just finished the new IFF demuxer/decoder patch which adds IFF HAM6/HAM8
> support.
> It now uses the new avio interface instead of the old ones.
>
> In the meanwhile I'll continue with the IFF-ANIM support. Should be ready
> tonight, too.
>
> IFF-HAM files for testing should be on the ftp. If not, just tell me, I'll
> upload some in that case.
Please remember the name of the files and/or their location.
> --
>
> Best regards,
> :-) Basty/CDGS (-:
> diff --git a/libavcodec/iff.c b/libavcodec/iff.c
> index e64ce1e..2467781 100644
> --- a/libavcodec/iff.c
> +++ b/libavcodec/iff.c
> @@ -30,10 +30,72 @@
> #include "avcodec.h"
> #include "get_bits.h"
>
> +// TODO: masking bits
> +typedef enum {
> + MASK_NONE,
> + MASK_HAS_MASK,
> + MASK_HAS_TRANSPARENT_COLOR,
> + MASK_LASSO
> +} mask_type;
> +
> +/**
> + * Gets the actual extra data after video preperties which contains
> + * the raw CMAP palette data beyond the IFF extra context.
Nit+++: Get -> use impersonal form
> + *
> + * @param avctx the AVCodecContext where to extract raw palette data from
> + * @return pointer to raw CMAP palette data
> + */
> +static av_always_inline uint8_t *get_palette_data(const AVCodecContext *const avctx) {
> + return avctx->extradata + AV_RB16(avctx->extradata);
> +}
Is this really required? Can't you simply cache these values in the
IFF context?
> +/**
> + * Gets the size of CMAP palette data beyond the IFF extra context.
Nit+++: Gets -> get (here and below)
> + * Please note that any value < 2 of IFF extra context or
> + * raw extradata < 0 is considered as illegal extradata.
> + *
> + * @param avctx the AVCodecContext where to extract palette data size from
> + * @return size of raw palette data in bytes
> + */
> +static av_always_inline int get_palette_size(const AVCodecContext *const avctx) {
> + return avctx->extradata_size - AV_RB16(avctx->extradata);
> +}
>
> +/**
> + * Gets the actual raw image data after video properties which
> + * contains the raw image data beyond the IFF extra context.
> + *
> + * @param avpkt the AVPacket where to extract raw image data from
> + * @return pointer to raw image data
> + */
> +static av_always_inline uint8_t *get_image_data(const AVPacket *const avpkt) {
> + return avpkt->data + AV_RB16(avpkt->data);
> +}
> +
> +/**
> + * Gets the size of raw image data beyond the IFF extra context.
> + * Please note that any value < 2 of either IFF extra context
> + * or raw image data is considered as an illegal packet.
> + *
> + * @param avpkt the AVPacket where to extract image data size from
> + * @return size of raw image data in bytes
> + */
> +static av_always_inline int get_image_size(const AVPacket *const avpkt) {
> + return avpkt->size - AV_RB16(avpkt->data);
> +}
Same: this looks weird to me, you can save the image_data/size/offset
in the functions using it and avoid this confusing indirection level,
but maybe I'm missing something.
Or in other words: why these get_* functions when you can access the
required data when you need it?
> typedef struct {
> AVFrame frame;
> int planesize;
> uint8_t * planebuf;
> + uint8_t * ham_buf; ///< temporary buffer for planar to chunky conversation
> + uint32_t *ham_palbuf; ///< HAM decode table
> + unsigned compression; ///< delta compression method used
> + unsigned bpp; ///< bits per plane to decode (differs from bits_per_coded_sample if HAM)
> + unsigned ham; ///< 0 if non-HAM or number of hold bits (6 for bpp > 6, 4 otherwise)
> + unsigned flags; ///< 1 for EHB, 0 is no extra half darkening
> + unsigned transparency; ///< TODO: transparency color index in palette
> + unsigned masking; ///< TODO: masking method used
> int init; // 1 if buffer and palette data already initialized, 0 otherwise
> } IffContext;
>
> @@ -122,6 +184,7 @@ static av_always_inline uint32_t gray2rgb(const uint32_t x) {
> static int ff_cmap_read_palette(AVCodecContext *avctx, uint32_t *pal)
> {
> int count, i;
> + const uint8_t *const extradata = get_palette_data(avctx);
>
> if (avctx->bits_per_coded_sample > 8) {
> av_log(avctx, AV_LOG_ERROR, "bit_per_coded_sample > 8 not supported\n");
> @@ -130,10 +193,10 @@ static int ff_cmap_read_palette(AVCodecContext *avctx, uint32_t *pal)
>
> count = 1 << avctx->bits_per_coded_sample;
> // If extradata is smaller than actually needed, fill the remaining with black.
> - count = FFMIN(avctx->extradata_size / 3, count);
> + count = FFMIN(get_palette_size(avctx) / 3, count);
> if (count) {
> for (i=0; i < count; i++) {
> - pal[i] = 0xFF000000 | AV_RB24( avctx->extradata + i*3 );
> + pal[i] = 0xFF000000 | AV_RB24(extradata + i*3);
> }
> } else { // Create gray-scale color palette for bps < 8
> count = 1 << avctx->bits_per_coded_sample;
> @@ -145,15 +208,123 @@ static int ff_cmap_read_palette(AVCodecContext *avctx, uint32_t *pal)
> return 0;
> }
>
> +/**
> + * Extracts the IFF extra context and updates internal
> + * decoder structures.
> + *
> + * @param avctx the AVCodecContext where to extract extra context to
> + * @param avpkt the AVPacket to extract extra context from or NULL to use avctx
> + * @return 0 in case of success, a negative error code otherwise
> + */
> +static int extract_header(AVCodecContext *const avctx,
> + const AVPacket *const avpkt) {
Nit+++: place "{" in the following line
> + const uint8_t *buf;
> + unsigned buf_size;
> + IffContext *s = avctx->priv_data;
> + if (avpkt) {
> + if (avpkt->size < 2)
> + return AVERROR_INVALIDDATA;
> + buf = avpkt->data;
> + buf_size = bytestream_get_be16(&buf);
getting image offset (first two bytes of pkt.data)
> + if (buf_size <= 1 || get_image_size(avpkt) <= 1) {
> + av_log(avctx, AV_LOG_ERROR,
> + "Invalid image size received: %u -> image data offset: %d\n",
> + buf_size, get_image_size(avpkt));
Confusing error message, it is not clear what's the image size and
what the offset, I suggest:
"Invalid image size %u and/or image data offset %d received\n", get_image_size(avpkt), buf_size
buf_size doesn't seem a particularly good name, also I'm not convinced
of the get_image_* stuff.
> + return AVERROR_INVALIDDATA;
> + }
> + } else {
> + if (avctx->extradata_size < 2)
> + return AVERROR_INVALIDDATA;
> + buf = avctx->extradata;
> + buf_size = bytestream_get_be16(&buf);
> + if (buf_size <= 1 || get_palette_size(avctx) < 0) {
> + av_log(avctx, AV_LOG_ERROR,
> + "Invalid palette size received: %u -> palette data offset: %d\n",
> + buf_size, get_palette_size(avctx));
> + return AVERROR_INVALIDDATA;
> + }
> + }
Same considerations as above.
> + if (buf_size > 8) {
> + s->compression = bytestream_get_byte(&buf);
> + s->bpp = bytestream_get_byte(&buf);
> + s->ham = bytestream_get_byte(&buf);
> + s->flags = bytestream_get_byte(&buf);
> + s->transparency = bytestream_get_be16(&buf);
> + s->masking = bytestream_get_byte(&buf);
> + if (s->masking == MASK_HAS_TRANSPARENT_COLOR) {
> + av_log(avctx, AV_LOG_ERROR, "Transparency not supported\n");
> + return AVERROR_PATCHWELCOME;
> + } else if (s->masking != MASK_NONE) {
> + av_log(avctx, AV_LOG_ERROR, "Masking not supported\n");
> + return AVERROR_PATCHWELCOME;
> + }
> + if (!s->bpp || s->bpp > 32) {
For non-flags I prefer: if (s->bpp == 0), but this is pure nitpick.
> + av_log(avctx, AV_LOG_ERROR, "Invalid number of bitplanes: %u\n", s->bpp);
> + return AVERROR_INVALIDDATA;
> + } else if (s->ham >= 8) {
> + av_log(avctx, AV_LOG_ERROR, "Invalid number of hold bits for HAM: %u\n", s->ham);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + av_freep(&s->ham_buf);
> + av_freep(&s->ham_palbuf);
> +
> + if (s->ham) {
> + int i, count = FFMIN(get_palette_size(avctx) / 3, 1 << s->ham);
> + const uint8_t *const extradata = get_palette_data(avctx);
poor name, please use palette_data or something like that
> + s->ham_buf = av_malloc((s->planesize * 8) + FF_INPUT_BUFFER_PADDING_SIZE);
> + if (!s->ham_buf)
> + return AVERROR(ENOMEM);
> +
> + s->ham_palbuf = av_malloc((8 * (1 << s->ham) * sizeof (uint32_t)) + FF_INPUT_BUFFER_PADDING_SIZE);
Nit: sizeof (uint32_t) -> 4, here and below
> + if (!s->ham_palbuf) {
> + av_freep(&s->ham_buf);
> + return AVERROR(ENOMEM);
> + }
> +
> + if (count) { // HAM with color palette attached
> + // prefill with black and palette and set HAM take direct value mask to zero
> + memset(s->ham_palbuf, 0, (1 << s->ham) * 2 * sizeof (uint32_t));
> + for (i=0; i < count; i++) {
> + s->ham_palbuf[i*2+1] = AV_RL24(extradata + i*3);
> + }
> + count = 1 << s->ham;
> + } else { // HAM with grayscale color palette
> + count = 1 << s->ham;
> + for (i=0; i < count; i++) {
> + s->ham_palbuf[i*2] = 0; // take direct color value from palette
> + s->ham_palbuf[i*2+1] = av_le2ne32(gray2rgb((i * 255) >> s->ham));
> + }
> + }
> + for (i=0; i < count; i++) {
> + uint32_t tmp = i << (8 - s->ham);
> + tmp |= tmp >> s->ham;
> + s->ham_palbuf[(i+count)*2] = 0x00FFFF; // just modify blue color component
> + s->ham_palbuf[(i+count*2)*2] = 0xFFFF00; // just modify red color component
> + s->ham_palbuf[(i+count*3)*2] = 0xFF00FF; // just modify green color component
> + s->ham_palbuf[(i+count)*2+1] = tmp << 16;
> + s->ham_palbuf[(i+count*2)*2+1] = tmp;
> + s->ham_palbuf[(i+count*3)*2+1] = tmp << 8;
> + }
> + } else if (s->flags & 1) { // EHB (ExtraHalfBrite) color palette
> + av_log(avctx, AV_LOG_ERROR, "ExtraHalfBrite (EHB) mode not supported\n");
> + return AVERROR_PATCHWELCOME;
> + }
> + }
> +
> + return 0;
> +}
> +
> static av_cold int decode_init(AVCodecContext *avctx)
> {
> IffContext *s = avctx->priv_data;
> int err;
>
> if (avctx->bits_per_coded_sample <= 8) {
> - avctx->pix_fmt = (avctx->bits_per_coded_sample < 8 ||
> - avctx->extradata_size) ? PIX_FMT_PAL8
> - : PIX_FMT_GRAY8;
> + avctx->pix_fmt = (avctx->bits_per_coded_sample < 8) ||
> + (avctx->extradata_size >= 2 && get_palette_size(avctx)) ? PIX_FMT_PAL8
> + : PIX_FMT_GRAY8;
> } else if (avctx->bits_per_coded_sample <= 32) {
> avctx->pix_fmt = PIX_FMT_BGR32;
> } else {
> @@ -167,6 +338,10 @@ static av_cold int decode_init(AVCodecContext *avctx)
> if (!s->planebuf)
> return AVERROR(ENOMEM);
>
> + s->bpp = avctx->bits_per_coded_sample;
nit: avctx->bits_per_coded_sample -> s->bpp change could be put in a
separate patch.
> +
> + if ((err = extract_header(avctx, NULL)) < 0)
> + return err;
> s->frame.reference = 1;
>
> return 0;
> @@ -214,6 +389,39 @@ static void decodeplane32(uint32_t *dst, const uint8_t *buf, int buf_size, int p
> } while (--buf_size);
> }
>
> +#define DECODE_HAM_PLANE32(x) \
> + first = buf[x] << 1; \
> + second = buf[(x)+1] << 1; \
> + delta &= pal[first++]; \
> + delta |= pal[first]; \
> + dst[x] = delta; \
> + delta &= pal[second++]; \
> + delta |= pal[second]; \
> + dst[(x)+1] = delta
> +
> +/**
> + * Converts one line of HAM6/8-encoded chunky buffer to 24bpp.
nit: Convert
> + *
> + * @param dst the destination 24bpp buffer
> + * @param buf the source 8bpp chunky buffer
> + * @param pal the HAM decode table
> + * @param buf_size the plane size in bytes
> + */
> +static void decode_ham_plane32(uint32_t *dst, const uint8_t *buf,
> + const uint32_t *const pal, unsigned buf_size)
> +{
> + uint32_t delta = 0;
> + do {
> + uint32_t first, second;
> + DECODE_HAM_PLANE32(0);
> + DECODE_HAM_PLANE32(2);
> + DECODE_HAM_PLANE32(4);
> + DECODE_HAM_PLANE32(6);
> + buf += 8;
> + dst += 8;
> + } while (--buf_size);
> +}
> +
> /**
> * Decode one complete byterun1 encoded line.
> *
> @@ -250,11 +458,14 @@ static int decode_frame_ilbm(AVCodecContext *avctx,
> AVPacket *avpkt)
> {
> IffContext *s = avctx->priv_data;
> - const uint8_t *buf = avpkt->data;
> - int buf_size = avpkt->size;
> + const uint8_t *buf = avpkt->size >= 2 ? get_image_data(avpkt) : NULL;
> + const int buf_size = avpkt->size >= 2 ? get_image_size(avpkt) : 0;
> const uint8_t *buf_end = buf+buf_size;
> int y, plane, res;
>
> + if ((res = extract_header(avctx, avpkt)) < 0)
> + return res;
> +
> if (s->init) {
> if ((res = avctx->reget_buffer(avctx, &s->frame)) < 0) {
> av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
> @@ -274,16 +485,26 @@ static int decode_frame_ilbm(AVCodecContext *avctx,
> for(y = 0; y < avctx->height; y++ ) {
> uint8_t *row = &s->frame.data[0][ y*s->frame.linesize[0] ];
> memset(row, 0, avctx->width);
> - for (plane = 0; plane < avctx->bits_per_coded_sample && buf < buf_end; plane++) {
> + for (plane = 0; plane < s->bpp && buf < buf_end; plane++) {
> decodeplane8(row, buf, FFMIN(s->planesize, buf_end - buf), plane);
> buf += s->planesize;
> }
> }
> + } else if (s->ham) { // HAM to PIX_FMT_BGR32
> + for (y = 0; y < avctx->height; y++) {
> + uint8_t *row = &s->frame.data[0][ y*s->frame.linesize[0] ];
> + memset(s->ham_buf, 0, avctx->width);
> + for (plane = 0; plane < s->bpp && buf < buf_end; plane++) {
> + decodeplane8(s->ham_buf, buf, FFMIN(s->planesize, buf_end - buf), plane);
> + buf += s->planesize;
> + }
> + decode_ham_plane32((uint32_t *) row, s->ham_buf, s->ham_palbuf, s->planesize);
> + }
> } else { // PIX_FMT_BGR32
> for(y = 0; y < avctx->height; y++ ) {
> uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
> memset(row, 0, avctx->width << 2);
> - for (plane = 0; plane < avctx->bits_per_coded_sample && buf < buf_end; plane++) {
> + for (plane = 0; plane < s->bpp && buf < buf_end; plane++) {
> decodeplane32((uint32_t *) row, buf, FFMIN(s->planesize, buf_end - buf), plane);
> buf += s->planesize;
> }
> @@ -295,6 +516,13 @@ static int decode_frame_ilbm(AVCodecContext *avctx,
> memcpy(row, buf, FFMIN(avctx->width, buf_end - buf));
> buf += avctx->width + (avctx->width % 2); // padding if odd
> }
> + } else { // IFF-PBM: HAM to PIX_FMT_BGR32
> + for (y = 0; y < avctx->height; y++) {
> + uint8_t *row = &s->frame.data[0][ y*s->frame.linesize[0] ];
> + memcpy(s->ham_buf, buf, FFMIN(avctx->width, buf_end - buf));
> + buf += avctx->width + (avctx->width & 1); // padding if odd
> + decode_ham_plane32((uint32_t *) row, s->ham_buf, s->ham_palbuf, avctx->width);
> + }
> }
>
> *data_size = sizeof(AVFrame);
> @@ -307,11 +535,13 @@ static int decode_frame_byterun1(AVCodecContext *avctx,
> AVPacket *avpkt)
> {
> IffContext *s = avctx->priv_data;
> - const uint8_t *buf = avpkt->data;
> - int buf_size = avpkt->size;
> + const uint8_t *buf = avpkt->size >= 2 ? get_image_data(avpkt) : NULL;
> + const int buf_size = avpkt->size >= 2 ? get_image_size(avpkt) : 0;
> const uint8_t *buf_end = buf+buf_size;
> int y, plane, res;
>
> + if ((res = extract_header(avctx, avpkt)) < 0)
> + return res;
> if (s->init) {
> if ((res = avctx->reget_buffer(avctx, &s->frame)) < 0) {
> av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
> @@ -331,26 +561,42 @@ static int decode_frame_byterun1(AVCodecContext *avctx,
> for(y = 0; y < avctx->height ; y++ ) {
> uint8_t *row = &s->frame.data[0][ y*s->frame.linesize[0] ];
> memset(row, 0, avctx->width);
> - for (plane = 0; plane < avctx->bits_per_coded_sample; plane++) {
> + for (plane = 0; plane < s->bpp; plane++) {
> buf += decode_byterun(s->planebuf, s->planesize, buf, buf_end);
> decodeplane8(row, s->planebuf, s->planesize, plane);
> }
> }
> + } else if (s->ham) { // HAM to PIX_FMT_BGR32
> + for (y = 0; y < avctx->height ; y++) {
> + uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
> + memset(s->ham_buf, 0, avctx->width);
> + for (plane = 0; plane < s->bpp; plane++) {
> + buf += decode_byterun(s->planebuf, s->planesize, buf, buf_end);
> + decodeplane8(s->ham_buf, s->planebuf, s->planesize, plane);
> + }
> + decode_ham_plane32((uint32_t *) row, s->ham_buf, s->ham_palbuf, s->planesize);
> + }
> } else { //PIX_FMT_BGR32
> for(y = 0; y < avctx->height ; y++ ) {
> uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
> memset(row, 0, avctx->width << 2);
> - for (plane = 0; plane < avctx->bits_per_coded_sample; plane++) {
> + for (plane = 0; plane < s->bpp; plane++) {
> buf += decode_byterun(s->planebuf, s->planesize, buf, buf_end);
> decodeplane32((uint32_t *) row, s->planebuf, s->planesize, plane);
> }
> }
> }
> - } else {
> + } else if (avctx->pix_fmt == PIX_FMT_PAL8 || avctx->pix_fmt == PIX_FMT_GRAY8) { // IFF-PBM
^^^^^^^
> for(y = 0; y < avctx->height ; y++ ) {
> uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
> buf += decode_byterun(row, avctx->width, buf, buf_end);
> }
> + } else { // IFF-PBM: HAM to PIX_FMT_BGR32
^^^^^^^
If these are sub-cases of IFF-PBM please specify it more explicitely
(e.g. IFF-PBM PAL8/GRAY, IFF-PBM: HAM to ...)
> + for (y = 0; y < avctx->height ; y++) {
> + uint8_t *row = &s->frame.data[0][y*s->frame.linesize[0]];
> + buf += decode_byterun(s->ham_buf, avctx->width, buf, buf_end);
> + decode_ham_plane32((uint32_t *) row, s->ham_buf, s->ham_palbuf, avctx->width);
> + }
> }
>
> *data_size = sizeof(AVFrame);
> @@ -364,6 +610,8 @@ static av_cold int decode_end(AVCodecContext *avctx)
> if (s->frame.data[0])
> avctx->release_buffer(avctx, &s->frame);
> av_freep(&s->planebuf);
> + av_freep(&s->ham_buf);
> + av_freep(&s->ham_palbuf);
> return 0;
> }
>
> diff --git a/libavformat/iff.c b/libavformat/iff.c
> index 2494212..da4e858 100644
> --- a/libavformat/iff.c
> +++ b/libavformat/iff.c
> @@ -29,6 +29,7 @@
> * http://wiki.multimedia.cx/index.php?title=IFF
> */
>
> +#include "libavcodec/bytestream.h"
> #include "libavutil/intreadwrite.h"
> #include "avformat.h"
>
> @@ -40,6 +41,7 @@
> #define ID_PBM MKTAG('P','B','M',' ')
> #define ID_ILBM MKTAG('I','L','B','M')
> #define ID_BMHD MKTAG('B','M','H','D')
> +#define ID_CAMG MKTAG('C','A','M','G')
> #define ID_CMAP MKTAG('C','M','A','P')
>
> #define ID_FORM MKTAG('F','O','R','M')
> @@ -60,6 +62,16 @@
>
> #define PACKET_SIZE 1024
>
> +/**
> + * This number of bytes if added at the beginning of each AVPacket
> + * which contain additional information about video properties
> + * which has to be shared between demuxer and decoder.
> + * This number may change between frames, e.g. the demuxer might
> + * set it to smallest possible size of 2 to indicate that there's
> + * no extradata changing in this frame.
> + */
> +#define IFF_EXTRA_VIDEO_SIZE 9
> +
> typedef enum {
> COMP_NONE,
> COMP_FIB,
> @@ -76,6 +88,12 @@ typedef struct {
> uint32_t body_size;
> uint32_t sent_bytes;
> uint32_t audio_frame_count;
> + unsigned compression; ///< delta compression method used
> + unsigned bpp; ///< bits per plane to decode (differs from bits_per_coded_sample if HAM)
> + unsigned ham; ///< 0 if non-HAM or number of hold bits (6 for bpp > 6, 4 otherwise)
> + unsigned flags; ///< 1 for EHB, 0 is no extra half darkening
> + unsigned transparency; ///< transparency color index in palette
> + unsigned masking; ///< masking method used
> } IffDemuxContext;
>
>
> @@ -126,8 +144,12 @@ static int iff_read_header(AVFormatContext *s,
> IffDemuxContext *iff = s->priv_data;
> AVIOContext *pb = s->pb;
> AVStream *st;
> + uint8_t *buf;
> uint32_t chunk_id, data_size;
> int compression = -1;
> + uint32_t screenmode = 0;
> + unsigned transparency = 0;
> + unsigned masking = 0; // no mask
>
> st = av_new_stream(s, 0);
> if (!st)
> @@ -171,12 +193,18 @@ static int iff_read_header(AVFormatContext *s,
> st->codec->channels = (avio_rb32(pb) < 6) ? 1 : 2;
> break;
>
> + case ID_CAMG:
> + if (data_size < 4)
> + return AVERROR_INVALIDDATA;
> + screenmode = avio_rb32(pb);
> + break;
> +
> case ID_CMAP:
> - st->codec->extradata_size = data_size;
> - st->codec->extradata = av_malloc(data_size);
> + st->codec->extradata_size = data_size + IFF_EXTRA_VIDEO_SIZE;
> + st->codec->extradata = av_malloc(data_size + IFF_EXTRA_VIDEO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
> if (!st->codec->extradata)
> return AVERROR(ENOMEM);
> - if (avio_read(pb, st->codec->extradata, data_size) < 0)
> + if (avio_read(pb, st->codec->extradata + IFF_EXTRA_VIDEO_SIZE, data_size) < 0)
> return AVERROR(EIO);
> break;
>
> @@ -188,12 +216,15 @@ static int iff_read_header(AVFormatContext *s,
> st->codec->height = avio_rb16(pb);
> avio_skip(pb, 4); // x, y offset
> st->codec->bits_per_coded_sample = avio_r8(pb);
> - if (data_size >= 11) {
> - avio_skip(pb, 1); // masking
> + if (data_size >= 10)
> + masking = avio_r8(pb);
> + if (data_size >= 11)
> compression = avio_r8(pb);
> + if (data_size >= 14) {
> + avio_skip(pb, 1); // padding
> + transparency = avio_rb16(pb);
> }
> if (data_size >= 16) {
> - avio_skip(pb, 3); // paddding, transparent
> st->sample_aspect_ratio.num = avio_r8(pb);
> st->sample_aspect_ratio.den = avio_r8(pb);
> }
> @@ -253,6 +284,31 @@ static int iff_read_header(AVFormatContext *s,
> break;
>
> case AVMEDIA_TYPE_VIDEO:
> + iff->compression = compression;
> + iff->bpp = st->codec->bits_per_coded_sample;
> + if ((screenmode & 0x800 /* Hold And Modify */) && iff->bpp <= 8) {
> + iff->ham = iff->bpp > 6 ? 6 : 4;
> + st->codec->bits_per_coded_sample = 24;
> + }
> + iff->flags = (screenmode & 0x80 /* Extra HalfBrite */) && iff->bpp <= 8;
> + iff->masking = masking;
> + iff->transparency = transparency;
> +
> + if (!st->codec->extradata) {
> + st->codec->extradata_size = IFF_EXTRA_VIDEO_SIZE;
> + st->codec->extradata = av_malloc(IFF_EXTRA_VIDEO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
> + if (!st->codec->extradata)
> + return AVERROR(ENOMEM);
> + }
> + buf = st->codec->extradata;
> + bytestream_put_be16(&buf, IFF_EXTRA_VIDEO_SIZE);
> + bytestream_put_byte(&buf, iff->compression);
> + bytestream_put_byte(&buf, iff->bpp);
> + bytestream_put_byte(&buf, iff->ham);
> + bytestream_put_byte(&buf, iff->flags);
> + bytestream_put_be16(&buf, iff->transparency);
> + bytestream_put_byte(&buf, iff->masking);
I confess I have not much experience with this way of passing data
from the demuxer to the decoder, and I remember it was already
discussed, but isn't this ABI fragile, isn't this creating a lavc/lavf
coupling?
> +
> switch (compression) {
> case BITMAP_RAW:
> st->codec->codec_id = CODEC_ID_IFF_ILBM;
> @@ -293,7 +349,15 @@ static int iff_read_packet(AVFormatContext *s,
> }
> interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
> } else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
> - ret = av_get_packet(pb, pkt, iff->body_size);
> + uint8_t *buf;
> +
> + if (av_new_packet(pkt, iff->body_size + 2) < 0) {
> + return AVERROR(ENOMEM);
> + }
nit++: here you can skip "{" and "}"
[...]
--
FFmpeg = Fast and Faithful Magical Power Elegant God
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