diff options
author | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2019-12-29 01:33:36 +0100 |
---|---|---|
committer | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-04-13 08:17:00 +0200 |
commit | 45314ff21ad329593c8ff8c19010cbb290450c82 (patch) | |
tree | d2a1e20f7f43a46288873d07a85deeefa6342638 | |
parent | bd7dea3f4f185a32966d7542837030d843c8518d (diff) |
avformat/matroskaenc: Use random TrackUID
Up until now, the TrackUID of a Matroska track which is supposed to be
random was not random at all: It always coincided with the TrackNumber
which is usually the 1-based index of the corresponding stream in the
array of AVStreams. This has been changed: It is now set via an AVLFG
if AVFMT_FLAG_BITEXACT is not set. Otherwise it is set like it is set
now (the only change happens if an explicit track number has been
chosen via dash_track_number, because the system used in the normal
situation is now used, too). In particular, no FATE tests need to be
updated.
This also fixes a bug in case the dash_track_number option was used:
In this case the TrackUID was set to the provided number, but the tags
were written with a TagTrackUID simply based upon the index, so that
the tags didn't apply to the track they ought to apply to.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
-rw-r--r-- | libavformat/matroskaenc.c | 47 |
1 files changed, 40 insertions, 7 deletions
diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index 58e89b232e..a32351a7c6 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -93,6 +93,7 @@ typedef struct mkv_cues { typedef struct mkv_track { int write_dts; int has_cue; + uint64_t uid; int sample_rate; int64_t sample_rate_offset; int64_t last_timestamp; @@ -1115,8 +1116,7 @@ static int mkv_write_track(AVFormatContext *s, MatroskaMuxContext *mkv, track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0); put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER, mkv->is_dash ? mkv->dash_track_number : i + 1); - put_ebml_uint (pb, MATROSKA_ID_TRACKUID, - mkv->is_dash ? mkv->dash_track_number : i + 1); + put_ebml_uint (pb, MATROSKA_ID_TRACKUID, mkv->tracks[i].uid); put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet) if ((tag = av_dict_get(st->metadata, "title", NULL, 0))) @@ -1569,6 +1569,7 @@ static int mkv_write_tags(AVFormatContext *s) tagp = (s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live ? &tag : NULL; for (i = 0; i < s->nb_streams; i++) { AVStream *st = s->streams[i]; + mkv_track *track = &mkv->tracks[i]; if (st->codecpar->codec_type == AVMEDIA_TYPE_ATTACHMENT) continue; @@ -1577,7 +1578,7 @@ static int mkv_write_tags(AVFormatContext *s) continue; ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, - i + 1, tagp); + track->uid, tagp); if (ret < 0) return ret; if (tagp) { @@ -1783,10 +1784,6 @@ static int mkv_write_header(AVFormatContext *s) version = 4; } - mkv->tracks = av_mallocz_array(s->nb_streams, sizeof(*mkv->tracks)); - if (!mkv->tracks) { - return AVERROR(ENOMEM); - } ebml_header = start_ebml_master(pb, EBML_ID_HEADER, MAX_EBML_HEADER_SIZE); put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1); put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1); @@ -2607,8 +2604,28 @@ static int webm_query_codec(enum AVCodecID codec_id, int std_compliance) return 0; } +static uint64_t mkv_get_uid(const mkv_track *tracks, int i, AVLFG *c) +{ + while (1) { + uint64_t uid; + int k; + uid = (uint64_t)av_lfg_get(c) << 32; + uid |= av_lfg_get(c); + if (!uid) + continue; + for (k = 0; k < i; k++) { + if (tracks[k].uid == uid) + break; + } + if (k == i) + return uid; + } +} + static int mkv_init(struct AVFormatContext *s) { + MatroskaMuxContext *mkv = s->priv_data; + AVLFG c; int i; if (s->nb_streams > MAX_TRACKS) { @@ -2637,7 +2654,23 @@ static int mkv_init(struct AVFormatContext *s) s->internal->avoid_negative_ts_use_pts = 1; } + mkv->tracks = av_mallocz_array(s->nb_streams, sizeof(*mkv->tracks)); + if (!mkv->tracks) { + return AVERROR(ENOMEM); + } + + if (!(s->flags & AVFMT_FLAG_BITEXACT)) + av_lfg_init(&c, av_get_random_seed()); + for (i = 0; i < s->nb_streams; i++) { + mkv_track *track = &mkv->tracks[i]; + + if (s->flags & AVFMT_FLAG_BITEXACT) { + track->uid = i + 1; + } else { + track->uid = mkv_get_uid(mkv->tracks, i, &c); + } + // ms precision is the de-facto standard timescale for mkv files avpriv_set_pts_info(s->streams[i], 64, 1, 1000); } |