[gst-devel] problem when playing an mpeg4 video

[Sedji Gaouaou]

Hi
>
>    Is your decoder outputting properly timestamped buffers ? Replace
> "ximagesink display=:0.0" with "fakesink sync=True" and use the '-v'
> argument of gst-launch.
>
>    With that you will be able to see the timestamp/durations of the
> buffers entering fakesink. You should normally see continuously
> increasing value.
>

I will try that to check the timestamp of each frame.
>>
>> It works for a while, but at some point I have this error:
>>
>> WARNING: from element /GstPipeline:pipeline0/GstXImageSink:ximagesink0:
>> A lot of buffers are being dropped.
>> Additional debug info:
>> gstbasesink.c(2572): gst_base_sink_is_too_late ():
>> /GstPipeline:pipeline0/GstXImageSink:ximagesink0:
>> There may be a timestamping problem, or this computer is too slow.
>>
>> I am using the gstreamer_0.10.25.
>>
>> I have noticed that this message comes from the gstbasesink.c, and I
>> also noticed that if I change the timestamp of my decoded frame to
>> "GST_CLOCK_TIME_NONE", then I don't see the problem anymore(but of
>> course the file is played in fast forward...)
>
>    If it manages to play it that fast in this case... that means your
> decoder is fast enough, which points even more to the fact that the
> buffers coming out from your decoder are wrongly timestamped.
>
>>

The point I don't understand then, is why the file is correctly played 
for a while and all of a sudden I have some errors.
For instance the file last about 20 minutes, I have errors towards the 
15th min.

I was first thinking that maybe some buffers were overwritten and so the 
displayed missed some frames. In that case if the timestamp were set to 
GST_CLOCK_TIME_NONE, then any overwritten buffers will not cause any 
problems...

But I am not really sure, it is just a guess...