[FFmpeg-devel] [PATCH] lavf/vc1test: fix vc1test can't probe some RCV file.

[mypopy at gmail.com]

On Fri, Oct 12, 2018 at 5:19 PM Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:

> 2018-10-12 4:37 GMT+02:00, Jun Zhao <mypopydev at gmail.com>:
> > case 1:
> > use the hexdump -C SMM0005.rcv get:
> >                      size              skip (size - 4)
> >                       |                        |
> >                       V                        V
> > 00000000  18 00 00 c5 05 00 00 00  4d f1 0a 11 00 e0 01 00
> > 00000010  00 d0 02 00 00 0c 00 00  00 88 13 00 00 c0 65 52
> >                          ^
> >                        |
> >                    size + 16
> > case 2:
> > same the command for SMM0015.rcv get:
> >                     size
> >                       |
> >                       V
> > 00000000  19 00 00 c5 04 00 00 00  41 f3 80 01 40 02 00 00
> > 00000010  d0 02 00 00 0c 00 00 00  00 00 00 10 00 00 00 00
> >                       ^
> >                     |
> >                  size + 16
> >
> > There are different the RCV file format for VC-1, vc1test
> > just handle the case 2 now, this fix will support the case 1.
> > (Both of test clips come from: RP 228:2008 - SMPTE
> > Recommended Practice - VC-1 Decoder and Bitstream Conformance).
> >
> > Signed-off-by: Jun Zhao <jun.zhao at intel.com>
> > Signed-off-by: Yan, FengX <fengx.yan at intel.com>
> > ---
> >  libavformat/vc1test.c |   13 +++++++++++--
> >  1 files changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/libavformat/vc1test.c b/libavformat/vc1test.c
> > index a801f4b..38eb1a4 100644
> > --- a/libavformat/vc1test.c
> > +++ b/libavformat/vc1test.c
> > @@ -34,9 +34,13 @@
> >
> >  static int vc1t_probe(AVProbeData *p)
> >  {
> > +    int size;
> > +
> >      if (p->buf_size < 24)
> >          return 0;
> > -    if (p->buf[3] != 0xC5 || AV_RL32(&p->buf[4]) != 4 ||
> > AV_RL32(&p->buf[20]) != 0xC)
> > +
> > +    size = AV_RL32(&p->buf[4]);
> > +    if (p->buf[3] != 0xC5 || AV_RL32(&p->buf[size+16]) != 0xC)
> >          return 0;
> >
> >      return AVPROBE_SCORE_EXTENSION;
> > @@ -48,10 +52,12 @@ static int vc1t_read_header(AVFormatContext *s)
> >      AVStream *st;
> >      int frames;
> >      uint32_t fps;
> > +    int size;
> >
> >      frames = avio_rl24(pb);
> > -    if(avio_r8(pb) != 0xC5 || avio_rl32(pb) != 4)
>
> (Maybe it is enough to only change the "!= 4" here?)
>
> Maybe   avio_rl32(pb) >= 4 ?

> > +    if (avio_r8(pb) != 0xC5)
> >          return AVERROR_INVALIDDATA;
>
> > +    size = avio_rl32(pb);
> >
> >      /* init video codec */
> >      st = avformat_new_stream(s, NULL);
> > @@ -63,6 +69,8 @@ static int vc1t_read_header(AVFormatContext *s)
> >
> >      if (ff_get_extradata(s, st->codecpar, pb, VC1_EXTRADATA_SIZE) < 0)
> >          return AVERROR(ENOMEM);
> > +
> > +    avio_skip(pb, size - 4);
>
> I may miss something but this looks as if you pass an unchecked
> value to avio_skip.
>
> Will add a check before the avio_skip.


> >      st->codecpar->height = avio_rl32(pb);
> >      st->codecpar->width = avio_rl32(pb);
> >      if(avio_rl32(pb) != 0xC)
>
> > @@ -114,5 +122,6 @@ AVInputFormat ff_vc1t_demuxer = {
> >      .read_probe     = vc1t_probe,
> >      .read_header    = vc1t_read_header,
> >      .read_packet    = vc1t_read_packet,
> > +     .extensions    = "rcv",
>
> This is an unrelated change that should not be part of this patch.
>
Will split to the other patch for this change.

>
> Carl Eugen
> _______________________________________________
>