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bnnm 2022-12-07 21:30:38 +01:00
parent 32451ed096
commit 1f4a29d29a
1 changed files with 19 additions and 7 deletions
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26
src/coding/ffmpeg_decoder_custom_opus.c
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@ -500,11 +500,22 @@ static size_t make_opus_header(uint8_t* buf, int buf_size, opus_config *cfg) {
size_t header_size = 0x13;
int mapping_family = 0;
/* special multichannel config */
/* Opus can't play a Nch file unless the channel mapping is properly configured (not implicit).
* A 8ch file may be 2ch+2ch+1ch+1ch+2ch; this is defined with a "channel mapping":
* - mapping family:
* 0 = standard (single stream mono/stereo, >2ch = error, and table MUST be ommited)
* 1 = standard multichannel (1..8ch), using Vorbis channel layout (needs table)
* 255 = undefined (1..255ch) application defined (needs table)
* - mapping table:
* - stream count: internal opus streams (>= 1), of 1/2ch
* - coupled count: internal stereo streams (<= streams)
* - mappings: one byte per channel with the channel position (0..Nch), or 255 (silence)
*/
/* set mapping family */
if (cfg->channels > 2 || cfg->stream_count > 1) {
/* channel config: 0=standard (single stream mono/stereo), 1=vorbis, 255: not defined */
mapping_family = 1;
header_size += 0x01+0x01+cfg->channels;
mapping_family = 1; //todo test 255
header_size += 0x01 + 0x01 + cfg->channels; /* table size */
}
if (cfg->skip < 0) {
@ -526,14 +537,15 @@ static size_t make_opus_header(uint8_t* buf, int buf_size, opus_config *cfg) {
put_u16le(buf+0x10, 0); /* output gain */
put_u8 (buf+0x12, mapping_family);
/* set mapping table */
if (mapping_family > 0) {
int i;
/* internal mono/stereo streams (N mono/stereo streams that make M channels) */
/* total streams (mono/stereo) */
put_u8(buf+0x13, cfg->stream_count);
/* joint stereo streams (rest would be mono, so 6ch can be 2ch+2ch+1ch+1ch = 2 coupled in 4 streams */
/* stereo streams (6ch can be 2ch+2ch+1ch+1ch = 2 coupled in 4 streams) */
put_u8(buf+0x14, cfg->coupled_count);
/* mapping per channel (order of channels, ex: 0x000104050203) */
/* mapping per channel (order of channels, ex: 00 01 04 05 02 03) */
for (i = 0; i < cfg->channels; i++) {
put_u8(buf+0x15+i, cfg->channel_mapping[i]);
}