[FFmpeg-trac] #4158(undetermined:reopened): Audio Stream loss after codec change
FFmpeg
trac at avcodec.org
Thu May 12 20:37:18 CEST 2016
#4158: Audio Stream loss after codec change
-------------------------------------+-------------------------------------
Reporter: jimbob | Owner:
Type: defect | Status: reopened
Priority: normal | Component:
Version: git-master | undetermined
Keywords: | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
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Changes (by jimbob):
* status: closed => reopened
* resolution: needs_more_info =>
Comment:
cehoyos,
I checked bug reports for this bug but was unable to correct it (except
reported for an older version): See #3553, and
https://ffmpeg.org/pipermail/ffmpeg-user/2013-May/015184.html. I don't
suspect these issues are related.
I have two sample videos now. Only 5 minutes each. I just happened to get
lucky and noticed it shortly after restarting the stream. Thankfully I
have multiple copies of this problem, it seems to affect both video output
as well as video 'input'. Time of occurrence is roughly between 3 minutes
to the end of the video. Skipping it in VLC has no effect on the fact that
audio is not present; nor is it restored.
Version: FFMPEG 2.8-static and FFMPEG 2.4.2
Original parameters:
/home/user/ffmpeg_run/ffmpeg -i
"udp://239.175.2.61:5000?overrun_nonfatal=1" -vf yadif -map 0 -c:a copy
-vcodec libx264 -b:v 5000k -bufsize 12000k -g 60 -preset superfast -tune
zerolatency -f "mpegts udp://239.175.4.61:5000?pkt_size=1316&ttl=10"
/home/user/ffmpeg_run/ffmpeg -i
"udp://239.175.2.61:5000?overrun_nonfatal=1" -y -f mpegts WGN-input.raw
/home/user/ffmpeg_run/ffmpeg -i
"udp://239.175.4.61:5000?pkt_size=1316&ttl=10" -y -f mpegts WGN-output.raw
Background:
We receive the stream from an authorized satellite receiver via unicast,
it hits a multicast server; this then broadcasts the output which is
received by these transcoding servers. We are confident that this issue is
not a problem with the multicast server because we can tune into the
stream without any problem after the audio has been "muted" after it
passes the ffmpeg processes. This issue has been omnipresent since version
2.4 and earlier.
Please feel free to pass input.raw and output.raw through the latest
ffmpeg build to see if it corrects the problem: I have a feeling that it
doesn't.
I have uploaded WGN-PUT.txt to your file server, as well as the input and
output files respectively. The only real output to the screen is the
message in WGN-PUT.txt.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/4158#comment:4>
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