[FFmpeg-trac] #9880(undetermined:new): RealMedia video file converts initial frame only

[FFmpeg]

#9880: RealMedia video file converts initial frame only
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             Reporter:  Anthony      |                    Owner:  (none)
  Kleine                             |
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  rv10 rmdec   |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Description changed by Anthony Kleine:

Old description:

> -I am attempting to convert a RealMedia video file, using the RealVideo
> 1.0 codec, to a standard format such as AVI. The following bug occurs
> with this file regardless of the output format.
> -The latest official RealPlayer can play the video, but nothing else can
> play or convert it. Everything else gets stuck on the initial frame of
> the video, continuing to play the audio. I've tried converting with
> ffmpeg, MEncoder (with the RealPlayer binaries,) and VirtualDub2. It
> won't play in MPC-BE or VLC, either. ffmpeg outputs several errors.
> -A command line demonstrating the issue is `ffmpeg -i
> initial_frame_only.rm initial_frame_only.avi`
> -Note that this video is from a 1997 RealPlayer livestream, and as such
> it has a very low resolution and framerate (one frame every two seconds,)
> which may be related to the error cause. It is possible the video is
> corrupted, because other RealVideo 1.0 videos convert fine for me.
> However, because RealPlayer is able to play this file through to the end,
> I imagine it should be possible for ffmpeg to also be resilient against
> the problem.
>         -As far as I can tell, the error is in libavcodec, which is used
> for this conversion - the official RealPlayer binaries seem to be ignored
> for RealVideo 1.0.
>         -I did a little investigation in a debugger. It seems to be
> reading an MPEG slice from the wrong position in the file, effectively
> reading erroneous data. Although the error messages are from
> libavcodec\rv10.c, I strongly suspect the root error cause occurs before,
> in libavformat\rmdec.c. Having no former familiarity with the stucture of
> ffmpeg or the RealMedia format, I am a bit lost trying to debug the issue
> myself.
> -I will upload initial_frame_only.rm to the VideoLAN File Uploader.
> -I will include the full, uncut log file in replies to this post because
> it is over 262144 characters long and cannot be included in this
> description. Apologies if this is not the correct way to do this.

New description:

 -I am attempting to convert a RealMedia video file, using the RealVideo
 1.0 codec, to a standard format such as AVI. The following bug occurs with
 this file regardless of the output format.
 -The latest official RealPlayer can play the video, but nothing else can
 play or convert it. Everything else gets stuck on the initial frame of the
 video, continuing to play the audio. I've tried converting with ffmpeg,
 MEncoder (with the RealPlayer binaries,) and VirtualDub2. It won't play in
 MPC-BE or VLC, either. ffmpeg outputs several errors.
 -A command line demonstrating the issue is `ffmpeg -i
 initial_frame_only.rm initial_frame_only.avi`
 -Note that this video is from a 1997 RealPlayer livestream, and as such it
 has a very low resolution and framerate (one frame every two seconds,)
 which may be related to the error cause. It is possible the video is
 corrupted, because other RealVideo 1.0 videos convert fine for me.
 However, because RealPlayer is able to play this file through to the end,
 I imagine it should be possible for ffmpeg to also be resilient against
 the problem.
         -As far as I can tell, the error is in libavcodec, which is used
 for this conversion - the official RealPlayer binaries seem to be ignored
 for RealVideo 1.0.
         -I did a little investigation in a debugger. It seems to be
 reading an MPEG slice from the wrong position in the file, effectively
 reading erroneous data. Although the error messages are from
 libavcodec\rv10.c, I strongly suspect the root error cause occurs before,
 in libavformat\rmdec.c. Having no former familiarity with the stucture of
 ffmpeg or the RealMedia format, I am a bit lost trying to debug the issue
 myself.
 -I will upload initial_frame_only.rm to the VideoLAN File Uploader.
 -I have attached the full, uncut log file to this post because it is over
 262144 characters long and cannot be included in this description.

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Ticket URL: <https://trac.ffmpeg.org/ticket/9880#comment:1>
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