[FFmpeg-user] Use of tee output with codec copy

[Devin Heitmueller]

Hello,

I've seen various postings related to problems with the use of copy with
the tee output format, but not with any real resolution.  I'm trying to
direct output to both an flv and a UDP output with codec copy, and I've
boiled it down to the following test case (run against today's master).

I originally assumed it was some failure to automatically insert a BSF when
using the tee filter, but I don't see any sign of that.

There's something in ffmpeg that converts "h264 (High) ([27][0][0][0]" into
"h264 (High) ([7][0][0][0] / 0x0007)" when going directly to flv but not
when using tee, but it's not clear to me where in the code that happens.

Any suggestions would be greatly appreciated (I'm happy to provide the
foo.ts file if you can't reproduce it with any other ts that has h.264 in
it).

Thanks,

Devin Heitmueller

=====
./ffmpeg -i foo.ts -map 0:0 -c:v copy -f tee "[f=mpegts]udp://
227.1.1.1:6002?pkt_size=1316|[f=flv]whatever.flv"
ffmpeg version N-96891-g60b1f85b67 Copyright (c) 2000-2020 the FFmpeg
developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.17)
  configuration:
  libavutil      56. 42.100 / 56. 42.100
  libavcodec     58. 73.102 / 58. 73.102
  libavformat    58. 39.101 / 58. 39.101
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 77.100 /  7. 77.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
Input #0, mpegts, from 'foo.ts':
  Duration: 00:00:23.90, start: 1.400000, bitrate: 2531 kb/s
  Program 1
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
    Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B),
yuv420p(tv, bt709, top first), 1920x1080 [SAR 1:1 DAR 16:9], 29.97 fps,
29.97 tbr, 90k tbn, 59.94 tbc
    Stream #0:1[0x101]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
stereo, fltp, 256 kb/s
[flv @ 0x7fe45a804c00] Tag [27][0][0][0] incompatible with output codec id
'27' ([7][0][0][0])
[tee @ 0x7fe45a802200] Slave '[f=flv]whatever.flv': error writing header:
Invalid data found when processing input
[tee @ 0x7fe45a802200] Slave muxer #1 failed, aborting.
Could not write header for output file #0 (incorrect codec parameters ?):
Invalid data found when processing input
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
    Last message repeated 1 times
===================

For reference, this command works fine:
./ffmpeg -i foo.ts -map 0:0 -c:v copy -f flv whatever.flv


-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com