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.

[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