RealMedia video file converts initial frame only

[Anthony Kleine]

-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.

[compn]

hmm. did mplayer ever have a binary rv10 decoder ?

i have these entries in my personal codecs.conf but maybe they were removed long long long ago? also i could not get them to work. i'll fight with it some more later.

videocodec rv10win

info "Win32 RealPlayer 8 RV10"
status working
fourcc RV10,rv10
fourcc RV13,rv13
driver realvid
dll "drv13260.dll"
out I420

videocodec rv10w

info "Win32 RealPlayer 10 RV10"
status working
fourcc RV10,rv10
fourcc RV13,rv13
driver realvid
dll "drv1.dll"
out I420

[Anthony Kleine]

Replying to compn:

hmm. did mplayer ever have a binary rv10 decoder ?

i have these entries in my personal codecs.conf but maybe they were removed long long long ago? also i could not get them to work. i'll fight with it some more later.

videocodec rv10win

info "Win32 RealPlayer 8 RV10"
status working
fourcc RV10,rv10
fourcc RV13,rv13
driver realvid
dll "drv13260.dll"
out I420

videocodec rv10w

info "Win32 RealPlayer 10 RV10"
status working
fourcc RV10,rv10
fourcc RV13,rv13
driver realvid
dll "drv1.dll"
out I420

Well, according to this source, which is not official documentation as far as I can tell, (EDIT: it is and says right at the top of the page) and may be out of date - but seems to be supported by the results - MPlayer only uses the RealPlayer binaries for RV30 and RV40. This video is RV10 which uses libavcodec. I don't understand why it is the case we can't choose though, since binaries are provided for RV10 and RV20.

​https://www.irya.unam.mx/computo/sites/manuales/mplayer/index.html#realvideo