[FFmpeg-trac] #5080(undetermined:new): Excessive HTTP GETs reading MP4 from web server
FFmpeg
trac at avcodec.org
Tue Jan 12 14:15:32 CET 2016
#5080: Excessive HTTP GETs reading MP4 from web server
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Reporter: nealzebub | Owner:
Type: defect | Status: new
Priority: normal | Component:
Version: git-master | undetermined
Keywords: http mov | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
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Comment (by stefang):
You can see from the list of A/V positions that the file has a drift in
multiplexing. By that I mean that while at the beginning of the list the
difference in position between audio and video chunks of the same
timestamp are about 6k (audio with pts 0 at pos 44, video with pts 0 at
pos 6210) this increases towards the end of the list to about 30k (audio
with pts 34.3 at pos 647105, video with pts 34.3 at pos 675027).
I have also seen such files in the wild on numerous occasions but they are
hard to handle nicely. For smaller files as in your case just increasing
the size of some I/O buffers might help. But for movies of hours length
which drift apart by many megabytes the currently employed solution is not
so bad, handling it without additional GETs would require complex code and
would increase buffer size requirements by a lot.
On the content side, such files can be improved by remultiplexing or using
http://linux.die.net/man/3/mp4optimize
--
Ticket URL: <https://trac.ffmpeg.org/ticket/5080#comment:6>
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