[FFmpeg-trac] #3823(avformat:closed): RTP encoding of MJPEG from Trendnet TV-IP651WI (IP cam) gives undecodable stream
FFmpeg
trac at avcodec.org
Thu Jul 16 09:18:13 CEST 2015
#3823: RTP encoding of MJPEG from Trendnet TV-IP651WI (IP cam) gives undecodable
stream
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Reporter: Krieger | Owner:
Type: defect | Status: closed
Priority: normal | Component: avformat
Version: git-master | Resolution: invalid
Keywords: mjpeg rtp | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Comment (by cehoyos):
Replying to [comment:9 cehoyos]:
> The samplevideo.mjpeg sample cannot be sent over rtp because it uses
non-standard Huffman tables which the rfc also doesn't allow. A patch was
just merged that prints an error now instead of silently sending an
invalid stream.
> My guess is that dump.mkv had the same issue.
My guess was correct, this was sent:
{{{
[mjpeg @ 0x38d3d20] marker=c4 avail_size_in_buf=15220
[mjpeg @ 0x38d3d20] class=0 index=0 nb_codes=10
[mjpeg @ 0x38d3d20] class=1 index=0 nb_codes=249
[mjpeg @ 0x38d3d20] class=0 index=1 nb_codes=10
[mjpeg @ 0x38d3d20] class=1 index=1 nb_codes=249
}}}
And this is what the decoder on the receiving side sees:
{{{
[mjpeg @ 0x7f3810001960] marker=c4 avail_size_in_buf=15010
[mjpeg @ 0x7f3810001960] class=0 index=0 nb_codes=12
[mjpeg @ 0x7f3810001960] class=0 index=1 nb_codes=12
[mjpeg @ 0x7f3810001960] class=1 index=0 nb_codes=251
[mjpeg @ 0x7f3810001960] class=1 index=1 nb_codes=251
}}}
Thanks to the original debug output!
> There is still an issue with quantisation tables (that I will try to
fix) but it isn't easy to trigger because of above issues.
Should be fixed in 9901e5318730ad5f9fb3272aa370e7affe168ddb
I attached a sample that allows testing with jpeg 4:2:2.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/3823#comment:10>
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