int ff_put_wav_header(AVIOContext *pb, AVCodecContext *enc) { int bps, blkalign, bytespersec; int hdrsize = 18; int waveformatextensible; uint8_t temp[256]; uint8_t *riff_extradata= temp; uint8_t *riff_extradata_start= temp; if(!enc->codec_tag || enc->codec_tag > 0xffff) return -1; waveformatextensible = (enc->channels > 2 && enc->channel_layout) || enc->sample_rate > 48000 || av_get_bits_per_sample(enc->codec_id) > 16; if (waveformatextensible) { avio_wl16(pb, 0xfffe); } else { avio_wl16(pb, enc->codec_tag); } avio_wl16(pb, enc->channels); avio_wl32(pb, enc->sample_rate); if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3 || enc->codec_id == CODEC_ID_GSM_MS) { bps = 0; } else if (enc->codec_id == CODEC_ID_ADPCM_G726) { bps = 4; } else { if (!(bps = av_get_bits_per_sample(enc->codec_id))) bps = 16; // default to 16 } if(bps != enc->bits_per_coded_sample && enc->bits_per_coded_sample){ av_log(enc, AV_LOG_WARNING, "requested bits_per_coded_sample (%d) and actually stored (%d) differ\n", enc->bits_per_coded_sample, bps); } if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3) { blkalign = enc->frame_size; //this is wrong, but it seems many demuxers do not work if this is set correctly //blkalign = 144 * enc->bit_rate/enc->sample_rate; } else if (enc->codec_id == CODEC_ID_AC3) { blkalign = 3840; //maximum bytes per frame } else if (enc->codec_id == CODEC_ID_ADPCM_G726) { // blkalign = 1; } else if (enc->block_align != 0) { /* specified by the codec */ blkalign = enc->block_align; } else blkalign = enc->channels*bps >> 3; if (enc->codec_id == CODEC_ID_PCM_U8 || enc->codec_id == CODEC_ID_PCM_S24LE || enc->codec_id == CODEC_ID_PCM_S32LE || enc->codec_id == CODEC_ID_PCM_F32LE || enc->codec_id == CODEC_ID_PCM_F64LE || enc->codec_id == CODEC_ID_PCM_S16LE) { bytespersec = enc->sample_rate * blkalign; } else { bytespersec = enc->bit_rate / 8; } avio_wl32(pb, bytespersec); /* bytes per second */ avio_wl16(pb, blkalign); /* block align */ avio_wl16(pb, bps); /* bits per sample */ if (enc->codec_id == CODEC_ID_MP3) { hdrsize += 12; bytestream_put_le16(&riff_extradata, 1); /* wID */ bytestream_put_le32(&riff_extradata, 2); /* fdwFlags */ bytestream_put_le16(&riff_extradata, 1152); /* nBlockSize */ bytestream_put_le16(&riff_extradata, 1); /* nFramesPerBlock */ bytestream_put_le16(&riff_extradata, 1393); /* nCodecDelay */ } else if (enc->codec_id == CODEC_ID_MP2) { hdrsize += 22; bytestream_put_le16(&riff_extradata, 2); /* fwHeadLayer */ bytestream_put_le32(&riff_extradata, enc->bit_rate); /* dwHeadBitrate */ bytestream_put_le16(&riff_extradata, enc->channels == 2 ? 1 : 8); /* fwHeadMode */ bytestream_put_le16(&riff_extradata, 0); /* fwHeadModeExt */ bytestream_put_le16(&riff_extradata, 1); /* wHeadEmphasis */ bytestream_put_le16(&riff_extradata, 16); /* fwHeadFlags */ bytestream_put_le32(&riff_extradata, 0); /* dwPTSLow */ bytestream_put_le32(&riff_extradata, 0); /* dwPTSHigh */ } else if (enc->codec_id == CODEC_ID_GSM_MS || enc->codec_id == CODEC_ID_ADPCM_IMA_WAV) { hdrsize += 2; bytestream_put_le16(&riff_extradata, enc->frame_size); /* wSamplesPerBlock */ } else if(enc->extradata_size){ riff_extradata_start= enc->extradata; riff_extradata= enc->extradata + enc->extradata_size; hdrsize += enc->extradata_size; } else if (!waveformatextensible){ hdrsize -= 2; } if(waveformatextensible) { /* write WAVEFORMATEXTENSIBLE extensions */ hdrsize += 22; avio_wl16(pb, riff_extradata - riff_extradata_start + 22); /* 22 is WAVEFORMATEXTENSIBLE size */ avio_wl16(pb, enc->bits_per_coded_sample); /* ValidBitsPerSample || SamplesPerBlock || Reserved */ avio_wl32(pb, enc->channel_layout); /* dwChannelMask */ avio_wl32(pb, enc->codec_tag); /* GUID + next 3 */ avio_wl32(pb, 0x00100000); avio_wl32(pb, 0xAA000080); avio_wl32(pb, 0x719B3800); } else if(riff_extradata - riff_extradata_start) { avio_wl16(pb, riff_extradata - riff_extradata_start); } avio_write(pb, riff_extradata_start, riff_extradata - riff_extradata_start); if(hdrsize&1){ hdrsize++; avio_w8(pb, 0); } return hdrsize; }