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mlp: Parse TrueHD decoder channel modifiers and set the AVMatrixEncoding for each substream.

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This commit is contained in:
Tim Walker 2013-12-11 02:03:32 +00:00
parent 30d70e79a6
commit 4b7f1a7ced
4 changed files with 61 additions and 2 deletions
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10
libavcodec/mlp.h
View File

@ -124,4 +124,14 @@ static inline uint8_t xor_32_to_8(uint32_t value)
return value;
}
typedef enum THDChannelModifier {
THD_CH_MODIFIER_NOTINDICATED = 0x0,
THD_CH_MODIFIER_STEREO = 0x0, // Stereo (not Dolby Surround)
THD_CH_MODIFIER_LTRT = 0x1, // Dolby Surround
THD_CH_MODIFIER_LBINRBIN = 0x2, // Dolby Headphone
THD_CH_MODIFIER_MONO = 0x3, // Mono or Dual Mono
THD_CH_MODIFIER_NOTSURROUNDEX = 0x1, // Not Dolby Digital EX
THD_CH_MODIFIER_SURROUNDEX = 0x2, // Dolby Digital EX
} THDChannelModifier;
#endif /* AVCODEC_MLP_H */

7
libavcodec/mlp_parser.c
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@ -169,13 +169,16 @@ int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
mh->group1_samplerate = mlp_samplerate(ratebits);
mh->group2_samplerate = 0;
skip_bits(gb, 8);
skip_bits(gb, 4);
mh->channel_modifier_thd_stream0 = get_bits(gb, 2);
mh->channel_modifier_thd_stream1 = get_bits(gb, 2);
channel_arrangement = get_bits(gb, 5);
mh->channels_thd_stream1 = truehd_channels(channel_arrangement);
mh->channel_layout_thd_stream1 = truehd_layout(channel_arrangement);
skip_bits(gb, 2);
mh->channel_modifier_thd_stream2 = get_bits(gb, 2);
channel_arrangement = get_bits(gb, 13);
mh->channels_thd_stream2 = truehd_channels(channel_arrangement);

4
libavcodec/mlp_parser.h
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@ -39,6 +39,10 @@ typedef struct MLPHeaderInfo
int group1_samplerate; ///< Sample rate of first substream
int group2_samplerate; ///< Sample rate of second substream (MLP only)
int channel_modifier_thd_stream0; ///< Channel modifier for substream 0 of TrueHD sreams ("2-channel presentation")
int channel_modifier_thd_stream1; ///< Channel modifier for substream 1 of TrueHD sreams ("6-channel presentation")
int channel_modifier_thd_stream2; ///< Channel modifier for substream 2 of TrueHD sreams ("8-channel presentation")
int channels_mlp; ///< Channel count for MLP streams
int channels_thd_stream1; ///< Channel count for substream 1 of TrueHD streams ("6-channel presentation")
int channels_thd_stream2; ///< Channel count for substream 2 of TrueHD streams ("8-channel presentation")

42
libavcodec/mlpdec.c
View File

@ -60,6 +60,8 @@ typedef struct SubStream {
uint8_t ch_assign[MAX_CHANNELS];
/// The channel layout for this substream
uint64_t ch_layout;
/// The matrix encoding mode for this substream
enum AVMatrixEncoding matrix_encoding;
/// Channel coding parameters for channels in the substream
ChannelParams channel_params[MAX_CHANNELS];
@ -374,6 +376,46 @@ static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb)
m->substream[substr].ch_layout = mh.channel_layout_thd_stream1;
}
/* Parse the TrueHD decoder channel modifiers and set each substream's
* AVMatrixEncoding accordingly.
*
* The meaning of the modifiers depends on the channel layout:
*
* - THD_CH_MODIFIER_LTRT, THD_CH_MODIFIER_LBINRBIN only apply to 2-channel
*
* - THD_CH_MODIFIER_MONO applies to 1-channel or 2-channel (dual mono)
*
* - THD_CH_MODIFIER_SURROUNDEX, THD_CH_MODIFIER_NOTSURROUNDEX only apply to
* layouts with an Ls/Rs channel pair
*/
for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
m->substream[substr].matrix_encoding = AV_MATRIX_ENCODING_NONE;
if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {
if (mh.num_substreams > 2 &&
mh.channel_layout_thd_stream2 & AV_CH_SIDE_LEFT &&
mh.channel_layout_thd_stream2 & AV_CH_SIDE_RIGHT &&
mh.channel_modifier_thd_stream2 == THD_CH_MODIFIER_SURROUNDEX)
m->substream[2].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;
if (mh.num_substreams > 1 &&
mh.channel_layout_thd_stream1 & AV_CH_SIDE_LEFT &&
mh.channel_layout_thd_stream1 & AV_CH_SIDE_RIGHT &&
mh.channel_modifier_thd_stream1 == THD_CH_MODIFIER_SURROUNDEX)
m->substream[1].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;
if (mh.num_substreams > 0)
switch (mh.channel_modifier_thd_stream0) {
case THD_CH_MODIFIER_LTRT:
m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
break;
case THD_CH_MODIFIER_LBINRBIN:
m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;
break;
default:
break;
}
}
return 0;
}