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ac3dec: reorder output channels to SMPTE channel order

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Originally committed as revision 18542 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2009-04-17 08:43:04 +00:00
parent 8b5ec0875c
commit 95f3019a51
3 changed files with 23 additions and 7 deletions
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4
libavcodec/ac3dec.c
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@ -1233,6 +1233,7 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
AC3DecodeContext *s = avctx->priv_data;
int16_t *out_samples = (int16_t *)data;
int blk, ch, err;
const uint8_t *channel_map;
/* initialize the GetBitContext with the start of valid AC-3 Frame */
if (s->input_buffer) {
@ -1321,6 +1322,7 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
}
/* decode the audio blocks */
channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
for (blk = 0; blk < s->num_blocks; blk++) {
const float *output[s->out_channels];
if (!err && decode_audio_block(s, blk)) {
@ -1328,7 +1330,7 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
err = 1;
}
for (ch = 0; ch < s->out_channels; ch++)
output[ch] = s->output[ch];
output[ch] = s->output[channel_map[ch]];
s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
out_samples += 256 * s->out_channels;
}

25
libavcodec/ac3tab.c
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@ -79,21 +79,34 @@ const uint8_t ff_ac3_channels_tab[8] = {
2, 1, 2, 3, 3, 4, 4, 5
};
#define COMMON_CHANNEL_MAP \
{ { 0, 1, }, { 0, 1, 2, } },\
{ { 0, }, { 0, 1, } },\
{ { 0, 1, }, { 0, 1, 2, } },\
{ { 0, 2, 1, }, { 0, 2, 1, 3, } },\
{ { 0, 1, 2, }, { 0, 1, 3, 2, } },\
{ { 0, 2, 1, 3, }, { 0, 2, 1, 4, 3, } },
/**
* Table to remap channels from SMPTE order to AC-3 order.
* [channel_mode][lfe][ch]
*/
const uint8_t ff_ac3_enc_channel_map[8][2][6] = {
{ { 0, 1, }, { 0, 1, 2, } },
{ { 0, }, { 0, 1, } },
{ { 0, 1, }, { 0, 1, 2, } },
{ { 0, 2, 1, }, { 0, 2, 1, 3, } },
{ { 0, 1, 2, }, { 0, 1, 3, 2, } },
{ { 0, 2, 1, 3, }, { 0, 2, 1, 4, 3, } },
COMMON_CHANNEL_MAP
{ { 0, 1, 2, 3, 4, }, { 0, 1, 3, 4, 2, } },
{ { 0, 2, 1, 3, 4, }, { 0, 2, 1, 4, 5, 3 } },
};
/**
* Table to remap channels from from AC-3 order to SMPTE order.
* [channel_mode][lfe][ch]
*/
const uint8_t ff_ac3_dec_channel_map[8][2][6] = {
COMMON_CHANNEL_MAP
{ { 0, 1, 2, 3, 4, }, { 0, 1, 4, 2, 3, } },
{ { 0, 2, 1, 3, 4, }, { 0, 2, 1, 5, 3, 4 } },
};
/* possible frequencies */
const uint16_t ff_ac3_sample_rate_tab[3] = { 48000, 44100, 32000 };

1
libavcodec/ac3tab.h
View File

@ -27,6 +27,7 @@
extern const uint16_t ff_ac3_frame_size_tab[38][3];
extern const uint8_t ff_ac3_channels_tab[8];
extern const uint8_t ff_ac3_enc_channel_map[8][2][6];
extern const uint8_t ff_ac3_dec_channel_map[8][2][6];
extern const uint16_t ff_ac3_sample_rate_tab[3];
extern const uint16_t ff_ac3_bitrate_tab[19];
extern const int16_t ff_ac3_window[256];