[FFmpeg-trac] #1486(undetermined:new): stalls / pauses in video every 30 seconds.
FFmpeg
trac at avcodec.org
Tue Jun 26 21:32:21 CEST 2012
#1486: stalls / pauses in video every 30 seconds.
-------------------------------------+-------------------------------------
Reporter: TroyWorks | Type: defect
Status: new | Priority: normal
Component: | Version:
undetermined | unspecified
Keywords: | Blocked By:
pause,stall,freeze,capture,xllgrab,xvfb| Reproduced by developer: 0
Blocking: |
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
We are using fllgrab for screencapture in the cloud.
Every 30 seconds for about 1-2 seconds in duration, are pauses in only the
video. Audio and Audio Video sync is perfectly fine despite stalls.
EXAMPLEs: with a four color frame counter drop frame test case
WITH lossless x264 dropped frames around 25-26 and significant stall
errors at 30 and 60 seconds
http://66.220.0.170/XFG4.mkv
We get this trying even different options, like keyframes, bitrate.
WITH flashsrv, which shows similar pause around 23 and 53 seconds, and
indicates it's not a libx264 specific issue.
flashsrv http://66.220.0.170/out.mov
This is running on an instance with 16 vcpu + 16gb ram, on the Amazon AWS
there is no noticeable background process that we can see at least that
would explain
It happens regardless if it's debian, or ubuntu.
How to reproduce:
Using XVFB open chrome with this test
http://www.troyworks.com/clients/sb/fourframe.html
START CAPTURE USING:
ffmpeg -f alsa -ac 2 -i pulse -f x11grab -r 30 -s 1024x768 -i :0.0
-acodec libvorbis -ar 44100 -vcodec libx264 -preset ultrafast -gp 0
-threads 0 ffg4.mkv
VERSION
ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers
built on Jun 26 2012 12:42:06 with gcc 4.7.1
configuration: --arch=x86_64 --enable-avfilter --enable-vdpau --enable-
bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-
libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-
stripping --enable-gpl --enable-postproc --enable-swscale --enable-x11grab
--enable-libdc1394 --enable-shared --disable-static --enable-libx264
--enable-libvpx --enable-libmp3lame --enable-libfaac --enable-nonfree
--enable-libopencore-amrwb --enable-libopencore-amrnb --enable-version3
BUILT ON
Ubuntu (several versions) and Debian, with hardware accelerated
virtualization (HVM). We've also tried several xwindows and xvfb/xenth
with same issue.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1486>
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