static int pcm_bluray_parse_header(AVCodecContext *avctx, const uint8_t *header) { static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 }; static const uint32_t channel_layouts[16] = { 0, AV_CH_LAYOUT_MONO, 0, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_SURROUND, AV_CH_LAYOUT_2_1, AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_2_2, AV_CH_LAYOUT_5POINT0, AV_CH_LAYOUT_5POINT1, AV_CH_LAYOUT_7POINT0, AV_CH_LAYOUT_7POINT1, 0, 0, 0, 0 }; static const uint8_t channels[16] = { 0, 1, 0, 2, 3, 3, 4, 4, 5, 6, 7, 8, 0, 0, 0, 0 }; uint8_t channel_layout = header[2] >> 4; if (avctx->debug & FF_DEBUG_PICT_INFO) av_dlog(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n", header[0], header[1], header[2], header[3]); /* get the sample depth and derive the sample format from it */ avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6]; if (!avctx->bits_per_coded_sample) { av_log(avctx, AV_LOG_ERROR, "unsupported sample depth (0)\n"); return -1; } avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 : AV_SAMPLE_FMT_S32; if (avctx->sample_fmt == AV_SAMPLE_FMT_S32) avctx->bits_per_raw_sample = avctx->bits_per_coded_sample; /* get the sample rate. Not all values are known or exist. */ switch (header[2] & 0x0f) { case 1: avctx->sample_rate = 48000; break; case 4: avctx->sample_rate = 96000; break; case 5: avctx->sample_rate = 192000; break; default: avctx->sample_rate = 0; av_log(avctx, AV_LOG_ERROR, "unsupported sample rate (%d)\n", header[2] & 0x0f); return -1; } /* * get the channel number (and mapping). Not all values are known or exist. * It must be noted that the number of channels in the MPEG stream can * differ from the actual meaningful number, e.g. mono audio still has two * channels, one being empty. */ avctx->channel_layout = channel_layouts[channel_layout]; avctx->channels = channels[channel_layout]; if (!avctx->channels) { av_log(avctx, AV_LOG_ERROR, "unsupported channel configuration (%d)\n", channel_layout); return -1; } avctx->bit_rate = avctx->channels * avctx->sample_rate * avctx->bits_per_coded_sample; if (avctx->debug & FF_DEBUG_PICT_INFO) av_dlog(avctx, "pcm_bluray_parse_header: %d channels, %d bits per sample, %d kHz, %d kbit\n", avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate, avctx->bit_rate); return 0; }