[FFmpeg-cvslog] alac: multi-channel decoding support
Andrew D'Addesio
git at videolan.org
Thu Jul 19 23:35:56 CEST 2012
ffmpeg | branch: master | Andrew D'Addesio <modchipv12 at gmail.com> | Mon Jul 9 16:29:49 2012 -0400| [1b3ef155d7033fcca4286d6e34a6c15214cb8bb0] | committer: Justin Ruggles
alac: multi-channel decoding support
Signed-off-by: Justin Ruggles <justin.ruggles at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1b3ef155d7033fcca4286d6e34a6c15214cb8bb0
---
libavcodec/alac.c | 61 +++++++++++++++++++++++++++++++++++++----------------
1 file changed, 43 insertions(+), 18 deletions(-)
diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index 1e37290..8c8e830 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -45,7 +45,7 @@
* 32bit samplerate
*/
-
+#include "libavutil/audioconvert.h"
#include "avcodec.h"
#include "get_bits.h"
#include "bytestream.h"
@@ -53,7 +53,7 @@
#include "mathops.h"
#define ALAC_EXTRADATA_SIZE 36
-#define MAX_CHANNELS 2
+#define MAX_CHANNELS 8
typedef struct {
@@ -64,9 +64,9 @@ typedef struct {
int channels;
/* buffers */
- int32_t *predict_error_buffer[MAX_CHANNELS];
- int32_t *output_samples_buffer[MAX_CHANNELS];
- int32_t *extra_bits_buffer[MAX_CHANNELS];
+ int32_t *predict_error_buffer[2];
+ int32_t *output_samples_buffer[2];
+ int32_t *extra_bits_buffer[2];
uint32_t max_samples_per_frame;
uint8_t sample_size;
@@ -90,6 +90,28 @@ enum RawDataBlockType {
TYPE_END
};
+static const uint8_t alac_channel_layout_offsets[8][8] = {
+ { 0 },
+ { 0, 1 },
+ { 2, 0, 1 },
+ { 2, 0, 1, 3 },
+ { 2, 0, 1, 3, 4 },
+ { 2, 0, 1, 4, 5, 3 },
+ { 2, 0, 1, 4, 5, 6, 3 },
+ { 2, 6, 7, 0, 1, 4, 5, 3 }
+};
+
+static const uint16_t alac_channel_layouts[8] = {
+ AV_CH_LAYOUT_MONO,
+ AV_CH_LAYOUT_STEREO,
+ AV_CH_LAYOUT_SURROUND,
+ AV_CH_LAYOUT_4POINT0,
+ AV_CH_LAYOUT_5POINT0_BACK,
+ AV_CH_LAYOUT_5POINT1_BACK,
+ AV_CH_LAYOUT_6POINT1_BACK,
+ AV_CH_LAYOUT_7POINT1_WIDE_BACK
+};
+
static inline unsigned int decode_scalar(GetBitContext *gb, int k,
int readsamplesize)
{
@@ -249,7 +271,7 @@ static void predictor_decompress_fir_adapt(int32_t *error_buffer,
}
}
-static void decorrelate_stereo(int32_t *buffer[MAX_CHANNELS],
+static void decorrelate_stereo(int32_t *buffer[2],
int numsamples, uint8_t interlacing_shift,
uint8_t interlacing_leftweight)
{
@@ -269,8 +291,8 @@ static void decorrelate_stereo(int32_t *buffer[MAX_CHANNELS],
}
}
-static void append_extra_bits(int32_t *buffer[MAX_CHANNELS],
- int32_t *extra_bits_buffer[MAX_CHANNELS],
+static void append_extra_bits(int32_t *buffer[2],
+ int32_t *extra_bits_buffer[2],
int extra_bits, int numchannels, int numsamples)
{
int i, ch;
@@ -326,7 +348,7 @@ static int decode_element(AVCodecContext *avctx, void *data, int ch_index,
}
if (alac->sample_size > 16) {
for (ch = 0; ch < channels; ch++)
- alac->output_samples_buffer[ch] = (int32_t *)alac->frame.data[ch_index + ch];
+ alac->output_samples_buffer[ch] = (int32_t *)alac->frame.extended_data[ch_index + ch];
}
} else if (output_samples != alac->nb_samples) {
av_log(avctx, AV_LOG_ERROR, "sample count mismatch: %u != %d\n",
@@ -336,11 +358,11 @@ static int decode_element(AVCodecContext *avctx, void *data, int ch_index,
alac->nb_samples = output_samples;
if (is_compressed) {
- int16_t predictor_coef_table[MAX_CHANNELS][32];
- int predictor_coef_num[MAX_CHANNELS];
- int prediction_type[MAX_CHANNELS];
- int prediction_quantitization[MAX_CHANNELS];
- int ricemodifier[MAX_CHANNELS];
+ int16_t predictor_coef_table[2][32];
+ int predictor_coef_num[2];
+ int prediction_type[2];
+ int prediction_quantitization[2];
+ int ricemodifier[2];
interlacing_shift = get_bits(&alac->gb, 8);
interlacing_leftweight = get_bits(&alac->gb, 8);
@@ -419,7 +441,7 @@ static int decode_element(AVCodecContext *avctx, void *data, int ch_index,
switch(alac->sample_size) {
case 16: {
for (ch = 0; ch < channels; ch++) {
- int16_t *outbuffer = (int16_t *)alac->frame.data[ch_index + ch];
+ int16_t *outbuffer = (int16_t *)alac->frame.extended_data[ch_index + ch];
for (i = 0; i < alac->nb_samples; i++)
*outbuffer++ = alac->output_samples_buffer[ch][i];
}}
@@ -462,7 +484,9 @@ static int alac_decode_frame(AVCodecContext *avctx, void *data,
return AVERROR_INVALIDDATA;
}
- ret = decode_element(avctx, data, ch, channels);
+ ret = decode_element(avctx, data,
+ alac_channel_layout_offsets[alac->channels - 1][ch],
+ channels);
if (ret < 0)
return ret;
@@ -484,7 +508,7 @@ static av_cold int alac_decode_close(AVCodecContext *avctx)
ALACContext *alac = avctx->priv_data;
int ch;
- for (ch = 0; ch < alac->channels; ch++) {
+ for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
av_freep(&alac->predict_error_buffer[ch]);
if (alac->sample_size == 16)
av_freep(&alac->output_samples_buffer[ch]);
@@ -497,7 +521,7 @@ static av_cold int alac_decode_close(AVCodecContext *avctx)
static int allocate_buffers(ALACContext *alac)
{
int ch;
- for (ch = 0; ch < alac->channels; ch++) {
+ for (ch = 0; ch < FFMIN(alac->channels, 2); ch++) {
int buf_size = alac->max_samples_per_frame * sizeof(int32_t);
FF_ALLOC_OR_GOTO(alac->avctx, alac->predict_error_buffer[ch],
@@ -588,6 +612,7 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)
avctx->channels);
return AVERROR_PATCHWELCOME;
}
+ avctx->channel_layout = alac_channel_layouts[alac->channels - 1];
if ((ret = allocate_buffers(alac)) < 0) {
av_log(avctx, AV_LOG_ERROR, "Error allocating buffers\n");
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