Module: libav Branch: master Commit: 8071dca3d595a4fc5f9b3ee9f667e2c3e4a35517
Author: Moritz Bunkus <mor...@bunkus.org> Committer: Luca Barbato <lu_z...@gentoo.org> Date: Fri Sep 14 22:26:14 2012 +0200 matroska: implement support for ALAC Support Matroska native formatting. On demuxing reconstruct the 36-bytes QuickTime atom that the ALAC decoder expects by prepending the "atom size", "tag" and "tag version" fields missing from the Matroska's CodecPrivate element. On muxing remove the initial 12 bytes Sample files are available: http://www.bunkus.org/videotools/mkvtoolnix/samples/alac/alac-in-matroska.mka and the CoreAudio file it was created from with today's mkvmerge: http://www.bunkus.org/videotools/mkvtoolnix/samples/alac/alac-in-matroska-source.caf Signed-off-by: Luca Barbato <lu_z...@gentoo.org> --- libavformat/matroska.c | 1 + libavformat/matroskadec.c | 13 +++++++++++++ libavformat/matroskaenc.c | 10 ++++++++++ 3 files changed, 24 insertions(+), 0 deletions(-) diff --git a/libavformat/matroska.c b/libavformat/matroska.c index d2d07a8..652e4d0 100644 --- a/libavformat/matroska.c +++ b/libavformat/matroska.c @@ -24,6 +24,7 @@ const CodecTags ff_mkv_codec_tags[]={ {"A_AAC" , AV_CODEC_ID_AAC}, {"A_AC3" , AV_CODEC_ID_AC3}, + {"A_ALAC" , AV_CODEC_ID_ALAC}, {"A_DTS" , AV_CODEC_ID_DTS}, {"A_EAC3" , AV_CODEC_ID_EAC3}, {"A_FLAC" , AV_CODEC_ID_FLAC}, diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index ff2a6c2..69a8c7f 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -1528,6 +1528,19 @@ static int matroska_read_header(AVFormatContext *s) extradata_size = 5; } else extradata_size = 2; + } else if (codec_id == AV_CODEC_ID_ALAC && track->codec_priv.size) { + /* Only ALAC's magic cookie is stored in Matroska's track headers. + Create the "atom size", "tag", and "tag version" fields the + decoder expects manually. */ + extradata_size = 12 + track->codec_priv.size; + extradata = av_mallocz(extradata_size + FF_INPUT_BUFFER_PADDING_SIZE); + if (extradata == NULL) + return AVERROR(ENOMEM); + AV_WB32(extradata, extradata_size); + memcpy(&extradata[4], "alac", 4); + AV_WB32(&extradata[8], 0); + memcpy(&extradata[12], track->codec_priv.data, + track->codec_priv.size); } else if (codec_id == AV_CODEC_ID_TTA) { extradata_size = 30; extradata = av_mallocz(extradata_size); diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index 9d9c223..521f6b5 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -475,6 +475,16 @@ static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb, AVCodecCo ret = ff_flac_write_header(dyn_cp, codec, 1); else if (codec->codec_id == AV_CODEC_ID_H264) ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size); + else if (codec->codec_id == AV_CODEC_ID_ALAC) { + if (codec->extradata_size < 36) { + av_log(s, AV_LOG_ERROR, + "Invalid extradata found, ALAC expects a 36-byte " + "QuickTime atom."); + ret = AVERROR_INVALIDDATA; + } else + avio_write(dyn_cp, codec->extradata + 12, + codec->extradata_size - 12); + } else if (codec->extradata_size) avio_write(dyn_cp, codec->extradata, codec->extradata_size); } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) { _______________________________________________ libav-commits mailing list libav-commits@libav.org https://lists.libav.org/mailman/listinfo/libav-commits
