RTP should have payload type 33 when used with MPEGTS

[nunojpg]

When RTP is sending a MPEGTS payload it should report it properly.

Otherwise the clients require a SDP, which is completely unnecessary.

The correct RTP payload type is 33 - MP2T - MPEG-2 transport stream Video.

nuno@ground3:~$ ffmpeg -i Desktop/sample1.mp4 -f mpegts rtp://127.0.0.1:5004
ffmpeg version N-62130-g8348bd1 Copyright (c) 2000-2014 the FFmpeg developers
  built on Apr  4 2014 17:04:57 with gcc 4.7 (Ubuntu/Linaro 4.7.3-1ubuntu1)
  configuration: --enable-libx264 --enable-gpl --enable-libfaac --enable-nonfree
  libavutil      52. 73.100 / 52. 73.100
  libavcodec     55. 56.108 / 55. 56.108
  libavformat    55. 36.101 / 55. 36.101
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  6.100 /  2.  6.100
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Desktop/sample1.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 0
    compatible_brands: isom3gp4
    creation_time   : 2013-08-15 12:05:34
  Duration: 00:00:40.13, start: 0.000000, bitrate: 17062 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 16934 kb/s, 29.88 fps, 30 tbr, 90k tbn, 180k tbc (default)
    Metadata:
      creation_time   : 2013-08-15 12:05:34
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 123 kb/s (default)
    Metadata:
      creation_time   : 2013-08-15 12:05:34
      handler_name    : SoundHandle
Output #0, mpegts, to 'rtp://127.0.0.1:5004':
  Metadata:
    major_brand     : isom
    minor_version   : 0
    compatible_brands: isom3gp4
    encoder         : Lavf55.36.101
    Stream #0:0(eng): Video: mpeg2video, yuv420p, 1920x1080, q=2-31, 200 kb/s, 90k tbn, 30 tbc (default)
    Metadata:
      creation_time   : 2013-08-15 12:05:34
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s (default)
    Metadata:
      creation_time   : 2013-08-15 12:05:34
      handler_name    : SoundHandle
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> mpeg2video)
  Stream #0:1 -> #0:1 (aac -> mp2)
Press [q] to stop, [?] for help
frame= 1204 fps= 57 q=31.0 Lsize=   12626kB time=00:00:40.33 bitrate=2564.5kbits/s dup=5 drop=0    
video:10918kB audio:626kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 9.366050%

nuno@ground3:~$ ffplay rtp://127.0.0.1:5004
ffplay version N-62130-g8348bd1 Copyright (c) 2003-2014 the FFmpeg developers
  built on Apr  4 2014 17:04:57 with gcc 4.7 (Ubuntu/Linaro 4.7.3-1ubuntu1)
  configuration: --enable-libx264 --enable-gpl --enable-libfaac --enable-nonfree
  libavutil      52. 73.100 / 52. 73.100
  libavcodec     55. 56.108 / 55. 56.108
  libavformat    55. 36.101 / 55. 36.101
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  6.100 /  2.  6.100
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
[rtp @ 0x7f200c0008c0] Unsupported RTP version packet received0/0   
[rtp @ 0x7f200c0008c0] Unable to receive RTP payload type 65 without an SDP file describing it
Input #0, rtp, from 'rtp://127.0.0.1:5004':
  Duration: N/A, bitrate: N/A
Failed to open file 'rtp://127.0.0.1:5004' or configure filtergraph

[thovo]

Your cmd line is wrong. It explicitly requests for an mpeg TS as output - not an RTP output stream.

[nunojpg]

Replying to thovo:

Your cmd line is wrong. It explicitly requests for an mpeg TS as output - not an RTP output stream.

Actual ouput: RTP carrying MPEG-TS.
Actual payload type: not 33.
Bug.

The cmd line being eventually wrong does not change that this demonstrates a bug. It might not produce the result I would expect though.

But what would be the right cmd line? If I don't explicitly set it to MPEG-TS then it is streaming a naked video over RTP, while I want it to stream video and audio encapsulated MPEG-TS with RTP.

[thovo]

You have to decide between MPEG-TS and RTP as outer format for your stream. Both are not possible at the same time and data flow.

If you need this kind of packetizing sheme, you could add another ticket labelled "Support for RTP/MPEGTS packetizing". And I think a patch for this would be welcome.

[nunojpg]

Could you please explain what kind of format is being sent when I use it in this unsupported way?

ffmpeg -i Desktop/sample1.mp4 -f mpegts rtp://127.0.0.1:5004

Since my ticket still reports a bug, but if this is unsupported, the bug could be formally fixed by throwing a error message and returning when the user requests this unsupported operation.

[Carl Eugen Hoyos]

Martin Storsjö committed a patch that shows a warning now for the original command line since 5ab46704

[Andrey Zholos]

For anyone looking for the correct command to send an MPEG2 Transport Stream over RTP, it's

ffmpeg -re -i input.avi -f rtp_mpegts -acodec mp3 rtp://127.0.0.1:5004