[FFmpeg-trac] #1224(undetermined:new): dvb-t to rtmp crash.
FFmpeg
trac at avcodec.org
Sat Apr 21 18:36:12 CEST 2012
#1224: dvb-t to rtmp crash.
-------------------------------------+-------------------------------------
Reporter: eregi | Owner:
Type: defect | Status: new
Priority: normal | Component:
Version: unspecified | undetermined
Keywords: | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
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Comment (by Cigaes):
I am afraid that solves it: the only difference between these commands is
the speed of the encoding process: the first is very slow ({{{veryslow}}})
is a dead giveaway) and the second is very fast ({{{ultrafast}}} is a
clue; the very small resolution helps too).
My conclusion is that the problem is that when the encoding command is too
slow, the kernel buffer overflows and causes a read error. Now that I know
that, I can reproduce the problem, and I see, using strace, that read on
the device fails with EOVERFLOW (shame on the MPEG-TS demuxer not to
report it).
You need to tweak your encoding parameters so that encoding is
significantly faster than realtime. You can do the tweaking with a large
enough dump, you just have to look at the {{{fps}}} field in the status
line: it must stay way above 30.
Possible ways: use {{{-vcodec libx264}}} and {{{-preset ultrafast}}};
reduce the resolution.
Depending on your needs and means, upgrading the hardware may or may not
be an option.
Good luck.
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1224#comment:31>
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