At 2016-11-01T00:56:45-0300, James Almer wrote: > The muxer gets the extradata as created by the encoder only during init(). > Even if the encoder changes it in any way afterwards, it will never make > it to the muxer. That's why packet side data is used for this. > > The reason the encoder used the AVCodecContext extradata to store the > updated Streaminfo before creating the packet side data is most likely > because it was an already allocated buffer. Technically, it's not the > "proper" thing to do, but it also doesn't seem to make a difference.
Makes sense, thanks for the explanation. Updated patch attached with the following changes: - Uses libavcodec/flac.h for the FLAC_STREAMINFO_SIZE and FLAC_METADATA_TYPE_STREAMINFO definitions, per the feedback on the demuxer patch. - Fixes the sample size in bits written to the 'fLaC' audio box. Thanks to Vittorio Giovara for pointing this out.
>From e08e1b5041a331d640d190c39c00bdc61e81243c Mon Sep 17 00:00:00 2001 From: Matthew Gregan <kine...@flim.org> Date: Thu, 20 Oct 2016 17:28:11 +1300 Subject: [PATCH 1/2] Add experimental muxing support for FLAC in ISO BMFF (MP4). Based on the draft spec at https://git.xiph.org/?p=flac.git;a=blob;f=doc/isoflac.txt '-strict -2' is required to create files in this format. Signed-off-by: Matthew Gregan <kine...@flim.org> --- libavformat/isom.c | 2 ++ libavformat/movenc.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 45 insertions(+), 3 deletions(-) diff --git a/libavformat/isom.c b/libavformat/isom.c index ab79e22..aacbe43 100644 --- a/libavformat/isom.c +++ b/libavformat/isom.c @@ -60,6 +60,7 @@ const AVCodecTag ff_mp4_obj_type[] = { { AV_CODEC_ID_EAC3 , 0xA6 }, { AV_CODEC_ID_DTS , 0xA9 }, /* mp4ra.org */ { AV_CODEC_ID_VP9 , 0xC0 }, /* nonstandard, update when there is a standard value */ + { AV_CODEC_ID_FLAC , 0xC1 }, /* nonstandard, update when there is a standard value */ { AV_CODEC_ID_TSCC2 , 0xD0 }, /* nonstandard, camtasia uses it */ { AV_CODEC_ID_VORBIS , 0xDD }, /* nonstandard, gpac uses it */ { AV_CODEC_ID_DVD_SUBTITLE, 0xE0 }, /* nonstandard, see unsupported-embedded-subs-2.mp4 */ @@ -345,6 +346,7 @@ const AVCodecTag ff_codec_movaudio_tags[] = { { AV_CODEC_ID_WMAV2, MKTAG('W', 'M', 'A', '2') }, { AV_CODEC_ID_EVRC, MKTAG('s', 'e', 'v', 'c') }, /* 3GPP2 */ { AV_CODEC_ID_SMV, MKTAG('s', 's', 'm', 'v') }, /* 3GPP2 */ + { AV_CODEC_ID_FLAC, MKTAG('f', 'L', 'a', 'C') }, /* nonstandard */ { AV_CODEC_ID_NONE, 0 }, }; diff --git a/libavformat/movenc.c b/libavformat/movenc.c index 6228192..06f6dc6 100644 --- a/libavformat/movenc.c +++ b/libavformat/movenc.c @@ -33,6 +33,7 @@ #include "avc.h" #include "libavcodec/ac3_parser.h" #include "libavcodec/dnxhddata.h" +#include "libavcodec/flac.h" #include "libavcodec/get_bits.h" #include "libavcodec/put_bits.h" #include "libavcodec/vc1_common.h" @@ -654,6 +655,26 @@ static int mov_write_wfex_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *tra return update_size(pb, pos); } +static int mov_write_dfla_tag(AVIOContext *pb, MOVTrack *track) +{ + int64_t pos = avio_tell(pb); + avio_wb32(pb, 0); + ffio_wfourcc(pb, "dfLa"); + avio_w8(pb, 0); /* version */ + avio_wb24(pb, 0); /* flags */ + + /* Expect the encoder to pass a METADATA_BLOCK_TYPE_STREAMINFO. */ + if (track->par->extradata_size != FLAC_STREAMINFO_SIZE) + return AVERROR_INVALIDDATA; + + /* TODO: Write other METADATA_BLOCK_TYPEs if the encoder makes them available. */ + avio_w8(pb, 1 << 7 | FLAC_METADATA_TYPE_STREAMINFO); /* LastMetadataBlockFlag << 7 | BlockType */ + avio_wb24(pb, track->par->extradata_size); /* Length */ + avio_write(pb, track->par->extradata, track->par->extradata_size); /* BlockData[Length] */ + + return update_size(pb, pos); +} + static int mov_write_chan_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *track) { uint32_t layout_tag, bitmap; @@ -963,8 +984,13 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex avio_wb16(pb, 16); avio_wb16(pb, track->audio_vbr ? -2 : 0); /* compression ID */ } else { /* reserved for mp4/3gp */ - avio_wb16(pb, 2); - avio_wb16(pb, 16); + if (track->par->codec_id == AV_CODEC_ID_FLAC) { + avio_wb16(pb, track->par->channels); + avio_wb16(pb, track->par->bits_per_raw_sample); + } else { + avio_wb16(pb, 2); + avio_wb16(pb, 16); + } avio_wb16(pb, 0); } @@ -1009,6 +1035,8 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex mov_write_extradata_tag(pb, track); else if (track->par->codec_id == AV_CODEC_ID_WMAPRO) mov_write_wfex_tag(s, pb, track); + else if (track->par->codec_id == AV_CODEC_ID_FLAC) + mov_write_dfla_tag(pb, track); else if (track->vos_len > 0) mov_write_glbl_tag(pb, track); @@ -1177,6 +1205,7 @@ static int mp4_get_codec_tag(AVFormatContext *s, MOVTrack *track) else if (track->par->codec_id == AV_CODEC_ID_DIRAC) tag = MKTAG('d','r','a','c'); else if (track->par->codec_id == AV_CODEC_ID_MOV_TEXT) tag = MKTAG('t','x','3','g'); else if (track->par->codec_id == AV_CODEC_ID_VC1) tag = MKTAG('v','c','-','1'); + else if (track->par->codec_id == AV_CODEC_ID_FLAC) tag = MKTAG('f','L','a','C'); else if (track->par->codec_type == AVMEDIA_TYPE_VIDEO) tag = MKTAG('m','p','4','v'); else if (track->par->codec_type == AVMEDIA_TYPE_AUDIO) tag = MKTAG('m','p','4','a'); else if (track->par->codec_id == AV_CODEC_ID_DVD_SUBTITLE) tag = MKTAG('m','p','4','s'); @@ -5019,7 +5048,8 @@ static int mov_write_single_packet(AVFormatContext *s, AVPacket *pkt) trk->start_cts = 0; } - if (trk->par->codec_id == AV_CODEC_ID_MP4ALS) { + if (trk->par->codec_id == AV_CODEC_ID_MP4ALS || + trk->par->codec_id == AV_CODEC_ID_FLAC) { int side_size = 0; uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size); if (side && side_size > 0 && (side_size != par->extradata_size || memcmp(side, par->extradata, side_size))) { @@ -5733,6 +5763,16 @@ static int mov_init(AVFormatContext *s) i, track->par->sample_rate); } } + if (track->mode == MODE_MP4 && + track->par->codec_id == AV_CODEC_ID_FLAC) { + if (s->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) { + av_log(s, AV_LOG_ERROR, + "FLAC in MP4 support is experimental, add " + "'-strict %d' if you want to use it.\n", + FF_COMPLIANCE_EXPERIMENTAL); + return AVERROR_EXPERIMENTAL; + } + } } else if (st->codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE) { track->timescale = st->time_base.den; } else if (st->codecpar->codec_type == AVMEDIA_TYPE_DATA) { -- 2.10.1
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