[FFmpeg-trac] #3823(avformat:new): RTP encoding of MJPEG from Trendnet TV-IP651WI (IP cam) gives undecodable stream

[FFmpeg]

#3823: RTP encoding of MJPEG from Trendnet TV-IP651WI (IP cam) gives undecodable
stream
-------------------------------------+------------------------------------
             Reporter:  Krieger      |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  avformat
              Version:  unspecified  |               Resolution:
             Keywords:  mjpeg rtp    |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+------------------------------------

Comment (by Krieger):

 When i try to RTPize a yuv422p MJPEG-encoded stream generated by ffmpeg
 itself, i get clear errors:

 {{{
  $ ffmpeg -f lavfi -i testsrc -pix_fmt yuv422p -vcodec mjpeg -f rtp
 rtp://127.0.0.1:6666
 ffmpeg version N-65153-gad99837 Copyright (c) 2000-2014 the FFmpeg
 developers
   built on Aug  1 2014 16:44:34 with gcc 4.7.3 (Gentoo 4.7.3-r1 p1.4,
 pie-0.5.5)
   configuration: --enable-libfreetype --enable-gpl --enable-libx264
 --enable-openssl --enable-nonfree
   libavutil      52. 94.100 / 52. 94.100
   libavcodec     55. 71.100 / 55. 71.100
   libavformat    55. 50.100 / 55. 50.100
   libavdevice    55. 13.102 / 55. 13.102
   libavfilter     4. 11.102 /  4. 11.102
   libswscale      2.  6.100 /  2.  6.100
   libswresample   0. 19.100 /  0. 19.100
   libpostproc    52.  3.100 / 52.  3.100
 Input #0, lavfi, from 'testsrc':
   Duration: N/A, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240
 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
 Incompatible pixel format 'yuv422p' for codec 'mjpeg', auto-selecting
 format 'yuvj422p'
 [swscaler @ 0x2a54fa0] deprecated pixel format used, make sure you did set
 range correctly
 Output #0, rtp, to 'rtp://127.0.0.1:6666':
   Metadata:
     encoder         : Lavf55.50.100
     Stream #0:0: Video: mjpeg, yuvj422p, 320x240 [SAR 1:1 DAR 4:3],
 q=2-31, 200 kb/s, 25 fps, 90k tbn, 25 tbc
     Metadata:
       encoder         : Lavc55.71.100 mjpeg
 Stream mapping:
   Stream #0:0 -> #0:0 (rawvideo (native) -> mjpeg (native))
 SDP:
 v=0
 o=- 0 0 IN IP4 127.0.0.1
 s=No Name
 c=IN IP4 127.0.0.1
 t=0 0
 a=tool:libavformat 55.50.100
 m=video 6666 RTP/AVP 26
 b=AS:200

 Press [q] to stop, [?] for help
 [rtp @ 0x2a68b80] Only 1x1 chroma blocks are supported. Aborted!
     Last message repeated 409 times
 [rtp @ 0x2a68b80] Only 1x1 chroma blocks are supported. Aborted!ate=
 0.0kbits/s
     Last message repeated 407 times
 [rtp @ 0x2a68b80] Only 1x1 chroma blocks are supported. Aborted!ate=
 0.0kbits/s
     Last message repeated 368 times
 }}}

 Does it mean that yuv422p is not supported by FFmpeg's MJPEG RTP
 packetizing code (and in the case of camera stream this error is not shown
 because of some confusion or extra data coming from HTTP)?

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3823#comment:1>
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