[FFmpeg-devel] Bad audio DTSs in MXF clip

Jorge Acereda jacereda at brainstorm.es
Wed Nov 7 11:15:01 CET 2012


On Nov 6, 2012, at 8:21 PM, Michael Niedermayer wrote:

> On Tue, Nov 06, 2012 at 12:05:49PM +0100, Jorge Acereda wrote:
>> Hi,
>> 
>> I've uploaded to the incoming folder a clip (bad_audio_dts.mxf) and a text describing the problem  (bad_audio_dts.txt). 
>> 
>> Looks like in that stream, the audio packet duration is fluctuating between a bit more than the timescale and a bit less. Due to the way libavformat/utils.c:compute_pkt_fields() rounds, it gets alternating durations 0 and 1 and that leads to bad timestamps.
>> 
> 
>> I've included a patch in the text file (just changing the rounding mode to AV_ROUND_NEAR_INF).
>> Is that the right thing to do?
> 
> no, the bug is in the demuxer, it MUST set a timebase that is accurate
> enough to represent the durations reasonable exactly.

OK, so is it something along the lines of this?

-------------- next part --------------
A non-text attachment was scrubbed...
Name: bad_audio_ts_2.patch
Type: application/octet-stream
Size: 790 bytes
Desc: not available
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20121107/0397d400/attachment.obj>
-------------- next part --------------





More information about the ffmpeg-devel mailing list