[FFmpeg-devel] [PATCH] avformat/mov: add ignore_hoov option to ignore hoov atom

[Steven Liu]

Steven Liu <lq at chinaffmpeg.org> 于2021年12月24日周五 14:20写道：
>
>
>
> > 2021年12月24日 上午11:43，zhilizhao(赵志立) <quinkblack at foxmail.com> 写道：
> >
> >
> >
> >> On Dec 23, 2021, at 3:10 PM, Steven Liu <lq at chinaffmpeg.org> wrote:
> >>
> >> Try to get context from the moov atom when the hoov before moov atom,
> >> because the streams info get a possible incorrect when there have both
> >> hoov and moov atom. So add and ignore_hoov option for try to get
> >> moov context by user.
> >>
> >> Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
> >> ---
> >> doc/demuxers.texi  |  6 ++++++
> >> libavformat/isom.h |  2 ++
> >> libavformat/mov.c  | 14 ++++++++++++--
> >> 3 files changed, 20 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/doc/demuxers.texi b/doc/demuxers.texi
> >> index cab8a7072c..d23c118210 100644
> >> --- a/doc/demuxers.texi
> >> +++ b/doc/demuxers.texi
> >> @@ -660,6 +660,11 @@ to demuxing linearly from the beginning. Default is true.
> >> Ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the
> >> timeline described by the edit list. Default is false.
> >>
> >> + at item ignore_hoov
> >> +Ignore hoov atom. The demuxer, by default, use hoov atom when there have hoov before moov atom.
> >> +You can try ignore hoov atom try the moov atom.
> >> +Default is false.
> >> +
> >> @item advanced_editlist
> >> Modify the stream index to reflect the timeline described by the edit list. @code{ignore_editlist}
> >> must be set to false for this option to be effective.
> >> diff --git a/libavformat/isom.h b/libavformat/isom.h
> >> index ef8f19b18c..6aa2b40c94 100644
> >> --- a/libavformat/isom.h
> >> +++ b/libavformat/isom.h
> >> @@ -255,6 +255,7 @@ typedef struct MOVContext {
> >>    AVFormatContext *fc;
> >>    int time_scale;
> >>    int64_t duration;     ///< duration of the longest track
> >> +    int found_hoov;       ///< 'hoov' atom has been found
> >>    int found_moov;       ///< 'moov' atom has been found
> >>    int found_mdat;       ///< 'mdat' atom has been found
> >>    int found_hdlr_mdta;  ///< 'hdlr' atom with type 'mdta' has been found
> >> @@ -273,6 +274,7 @@ typedef struct MOVContext {
> >>    unsigned int nb_chapter_tracks;
> >>    int use_absolute_path;
> >>    int ignore_editlist;
> >> +    int ignore_hoov;
> >>    int advanced_editlist;
> >>    int ignore_chapters;
> >>    int seek_individually;
> >> diff --git a/libavformat/mov.c b/libavformat/mov.c
> >> index 2aed6e80ef..cd775b219f 100644
> >> --- a/libavformat/mov.c
> >> +++ b/libavformat/mov.c
> >> @@ -1159,8 +1159,11 @@ static int mov_read_moov(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >>
> >>    if (c->found_moov) {
> >>        av_log(c->fc, AV_LOG_WARNING, "Found duplicated MOOV Atom. Skipped it\n");
> >> -        avio_skip(pb, atom.size);
> >> -        return 0;
> >> +        if (!c->found_hoov) {
> >> +            avio_skip(pb, atom.size);
> >> +            return 0;
> >> +        }
> >> +        c->found_hoov = 0;
> >>    }
> >>
> >>    if ((ret = mov_read_default(c, pb, atom)) < 0)
> >> @@ -4239,6 +4242,9 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >>    MOVStreamContext *sc;
> >>    int ret;
> >>
> >> +    if (c->found_hoov)
> >> +        return 0;
> >> +
> >
> > Does it break files with only hoov boxes?
> No by default. And Yes if have both hoov and moov.
> Yes it should break if user use ignore_hoov option.
> Add ignore_hoov can be choosed by users.
>
> >
> >>    st = avformat_new_stream(c->fc, NULL);
> >>    if (!st) return AVERROR(ENOMEM);
> >>    st->id = -1;
> >> @@ -7329,6 +7335,8 @@ static int mov_read_default(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> >>                a.size >= 8 &&
> >>                c->fc->strict_std_compliance < FF_COMPLIANCE_STRICT) {
> >>                uint32_t type;
> >> +                if (c->ignore_hoov)
> >> +                    c->found_hoov = 1;
> >>                avio_skip(pb, 4);
> >>                type = avio_rl32(pb);
> >>                if (avio_feof(pb))
> >> @@ -8541,6 +8549,8 @@ static const AVOption mov_options[] = {
> >>        0, 1, FLAGS},
> >>    {"ignore_editlist", "Ignore the edit list atom.", OFFSET(ignore_editlist), AV_OPT_TYPE_BOOL, {.i64 = 0},
> >>        0, 1, FLAGS},
> >> +    {"ignore_hoov", "Ignore the hoov atom.", OFFSET(ignore_hoov), AV_OPT_TYPE_BOOL, {.i64 = 0},
> >> +        0, 1, FLAGS},
> >
> > TBH, add an option is too much effort to workaround such broken files. I prefer
> >
> > a.type == MKTAG('h','o','o','v') && c->fc->strict_std_compliance < FF_COMPLIANCE_UNOFFICIAL
> >
> > But it will break those samples if user doesn't lower strict_std_compliance.
> >
> >>    {"advanced_editlist",
> >>        "Modify the AVIndex according to the editlists. Use this option to decode in the order specified by the edits.",
> >>        OFFSET(advanced_editlist), AV_OPT_TYPE_BOOL, {.i64 = 1},
> >> --
> >> 2.25.0
> >>
> >> _______________________________________________
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> >>
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> >
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>
> Thanks
>
> Steven Liu
>
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