PR #21001 opened by James Almer (jamrial) URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21001 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/21001.patch
Defined mainly to signal a sample rate with a value that doesn't fit the standard 16bit field for formats that don't report a sample rate within private codec parameters (which in general takes precedence), as is the case for PCM. For those, the spec recommends using AudioSampleEntryV1 to signal their parsing is required. >From 2d5f77c5a2e0fe601eedd804dc67fef7a4708f78 Mon Sep 17 00:00:00 2001 From: James Almer <[email protected]> Date: Fri, 21 Nov 2025 23:06:25 -0300 Subject: [PATCH] avformat/movenc: add support for writing srat box Signed-off-by: James Almer <[email protected]> --- libavformat/movenc.c | 51 +++++++++++++++++++++++++++++++++++++++----- libavformat/movenc.h | 1 + 2 files changed, 47 insertions(+), 5 deletions(-) diff --git a/libavformat/movenc.c b/libavformat/movenc.c index 42c8771496..443ef2866c 100644 --- a/libavformat/movenc.c +++ b/libavformat/movenc.c @@ -161,6 +161,18 @@ static int64_t update_size(AVIOContext *pb, int64_t pos) return curpos - pos; } +static int64_t update_size_and_version(AVIOContext *pb, int64_t pos, int version) +{ + int64_t curpos = avio_tell(pb); + avio_seek(pb, pos, SEEK_SET); + avio_wb32(pb, curpos - pos); /* rewrite size */ + avio_skip(pb, 4); + avio_w8(pb, version); /* rewrite version */ + avio_seek(pb, curpos, SEEK_SET); + + return curpos - pos; +} + static int co64_required(const MOVTrack *track) { if (track->entry > 0 && track->cluster[track->entry - 1].pos + track->data_offset > UINT32_MAX) @@ -1344,6 +1356,18 @@ static int mov_write_pcmc_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *tra return update_size(pb, pos); } +static int mov_write_srat_tag(AVIOContext *pb, MOVTrack *track) +{ + int64_t pos = avio_tell(pb); + avio_wb32(pb, 0); /* size */ + ffio_wfourcc(pb, "srat"); + avio_wb32(pb, 0); /* version & flags */ + + avio_wb32(pb, track->par->sample_rate); + + return update_size(pb, pos); +} + static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContext *mov, MOVTrack *track) { int64_t pos = avio_tell(pb); @@ -1363,6 +1387,10 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex track->par->codec_id == AV_CODEC_ID_QDM2) { version = 1; } + } else if (track->mode == MODE_MP4) { + if (track->par->sample_rate > UINT16_MAX && + (tag == MOV_MP4_IPCM_TAG || tag == MOV_MP4_FPCM_TAG)) + version = 1; } avio_wb32(pb, 0); /* size */ @@ -1395,6 +1423,8 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex avio_wb32(pb, track->sample_size); avio_wb32(pb, get_samples_per_packet(track)); } else { + unsigned sample_rate = track->par->sample_rate; + if (track->mode == MODE_MOV) { avio_wb16(pb, track->par->ch_layout.nb_channels); if (track->par->codec_id == AV_CODEC_ID_PCM_U8 || @@ -1415,6 +1445,9 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex avio_wb16(pb, 16); } avio_wb16(pb, 0); + + while (sample_rate > UINT16_MAX) + sample_rate >>= 1; } avio_wb16(pb, 0); /* packet size (= 0) */ @@ -1425,14 +1458,14 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex else if (track->par->codec_id == AV_CODEC_ID_TRUEHD) avio_wb32(pb, track->par->sample_rate); else - avio_wb16(pb, track->par->sample_rate <= UINT16_MAX ? - track->par->sample_rate : 0); + avio_wb16(pb, sample_rate); if (track->par->codec_id != AV_CODEC_ID_TRUEHD) avio_wb16(pb, 0); /* Reserved */ } if (version == 1) { /* SoundDescription V1 extended info */ + if (track->mode == MODE_MOV) { if (mov_pcm_le_gt16(track->par->codec_id) || mov_pcm_be_gt16(track->par->codec_id)) avio_wb32(pb, 1); /* must be 1 for uncompressed formats */ @@ -1441,6 +1474,7 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex avio_wb32(pb, track->sample_size / track->par->ch_layout.nb_channels); /* Bytes per packet */ avio_wb32(pb, track->sample_size); /* Bytes per frame */ avio_wb32(pb, 2); /* Bytes per sample */ + } } if (track->mode == MODE_MOV && @@ -1489,9 +1523,13 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex if (ret < 0) return ret; - if (track->mode == MODE_MP4 && track->par->codec_type == AVMEDIA_TYPE_AUDIO - && ((ret = mov_write_SA3D_tag(s, pb, track)) < 0)) { + if (track->mode == MODE_MP4) { + ret = mov_write_SA3D_tag(s, pb, track); + if (ret < 0) return ret; + + if (track->par->sample_rate > UINT16_MAX) + mov_write_srat_tag(pb, track); } if (track->mode == MODE_MOV && track->par->codec_type == AVMEDIA_TYPE_AUDIO @@ -1508,6 +1546,9 @@ static int mov_write_audio_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContex ((ret = mov_write_btrt_tag(pb, track)) < 0)) return ret; + if (track->mode == MODE_MP4) + track->entry_version = version; + ret = update_size(pb, pos); return ret; } @@ -3122,7 +3163,7 @@ static int mov_write_stsd_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContext track->last_stsd_index = stsd_index_back; - return update_size(pb, pos); + return update_size_and_version(pb, pos, track->entry_version); } static int mov_write_ctts_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *track) diff --git a/libavformat/movenc.h b/libavformat/movenc.h index 942ad905f7..eb12551ee5 100644 --- a/libavformat/movenc.h +++ b/libavformat/movenc.h @@ -86,6 +86,7 @@ typedef struct MOVFragmentInfo { typedef struct MOVTrack { int mode; + int entry_version; int entry, entry_written; unsigned timescale; uint64_t time; -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
