[FFmpeg-user] Streaming a static image fails

Tue May 21 09:29:13 EEST 2024

2024년 5월 21일 (화) 오전 1:26, Deon Stoltz <deon at tech-source.co.za>님이 작성:
>
> I need to stream a static image with information on a network to Tv's.
>
> ffmpeg does convert the image to a transport stream but VLC refuse to
> play it as well the TV's. ffplay does play it but complains about
> invalid frame dimensions. I therefore added the frame size but it has no
> effect. Note that the error is still reported in ffplay.
>
>   I upgraded to the latest version of ffmpeg (compiled in a subdir
> because  Mint version is old and the .deb file did not want to install).
> Any idea what could be the reason?
>
> Cmd used:
>
> ./ffmpeg -y -stream_loop -1 -r 25/1  -i text2.png  -f mpegts -s 800x600
> udp://239.1.250.12:1234
> ffmpeg version N-115265-g7e59f02c14 Copyright (c) 2000-2024 the FFmpeg
> developers
>    built with gcc 11 (Ubuntu 11.4.0-1ubuntu1~22.04)
>    configuration:
>    libavutil      59. 17.100 / 59. 17.100
>    libavcodec     61.  5.104 / 61.  5.104
>    libavformat    61.  3.103 / 61.  3.103
>    libavdevice    61.  2.100 / 61.  2.100
>    libavfilter    10.  2.101 / 10.  2.101
>    libswscale      8.  2.100 /  8.  2.100
>    libswresample   5.  2.100 /  5.  2.100
> Input #0, png_pipe, from 'text2.png':
>    Duration: N/A, bitrate: N/A
>    Stream #0:0: Video: png, pal8(pc, gbr/unknown/unknown), 800x600 [SAR
> 3780:3780 DAR 4:3], 25 fps, 25 tbr, 25 tbn
> Stream mapping:
>    Stream #0:0 -> #0:0 (png (native) -> mpeg2video (native))
> Press [q] to stop, [?] for help
> Output #0, mpegts, to 'udp://239.1.250.12:1234':
>    Metadata:
>      encoder         : Lavf61.3.103
>    Stream #0:0: Video: mpeg2video (Main), yuv420p(progressive), 800x600
> [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25 fps, 90k tbn
>        Metadata:
>          encoder         : Lavc61.5.104 mpeg2video
>        Side data:
>          cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay:
N/A
> [out#0/mpegts @ 0x557c16e53ac0] video:48400KiB audio:0KiB subtitle:0KiB
> other streams:0KiB global headers:0KiB muxing overhead: 15.095825%
> frame=20140 fps=1059 q=31.0 Lsize=   55707KiB time=00:13:25.56 bitrate=
> 566.5kbits/s speed=42.4x
> Exiting normally, received signal 2.
>
> Receiving side:
>
> ffplay udp://239.1.250.12:1234
> ffplay version 4.4.2-0ubuntu0.22.04.1 Copyright (c) 2003-2021 the FFmpeg
> developers
>    built with gcc 11 (Ubuntu 11.2.0-19ubuntu1)
>    configuration: --prefix=/usr --extra-version=0ubuntu0.22.04.1
> --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu
> --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl
> --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom
> --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca
> --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite
> --enable-libfontconfig --enable-libfreetype --enable-libfribidi
> --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame
> --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt
> --enable-libopus --enable-libpulse --enable-librabbitmq
> --enable-librubberband --enable-libshine --enable-libsnappy
> --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh
> --enable-libtheora --enable-libtwolame --enable-libvidstab
> --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265
> --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq
> --enable-libzvbi --enable-lv2 --enable-omx --enable-openal
> --enable-opencl --enable-opengl --enable-sdl2 --enable-pocketsphinx
> --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm
> --enable-libiec61883 --enable-chromaprint --enable-frei0r
> --enable-libx264 --enable-shared
>    libavutil      56. 70.100 / 56. 70.100
>    libavcodec     58.134.100 / 58.134.100
>    libavformat    58. 76.100 / 58. 76.100
>    libavdevice    58. 13.100 / 58. 13.100
>    libavfilter     7.110.100 /  7.110.100
>    libswscale      5.  9.100 /  5.  9.100
>    libswresample   3.  9.100 /  3.  9.100
>    libpostproc    55.  9.100 / 55.  9.100
> [mpeg2video @ 0x7f77d8029e40] Invalid frame dimensions 0x0. f=0/0
> [mpeg2video @ 0x7f77d8029e40] Invalid frame dimensions 0x0. f=0/0
>      Last message repeated 3 times
> Input #0, mpegts, from 'udp://239.1.250.12:1234': sq=    0B f=0/0
>    Duration: N/A, start: 6196.600000, bitrate: N/A
>    Program 1
>      Metadata:
>        service_name    : Service01
>        service_provider: FFmpeg
>    Stream #0:0[0x100]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
> yuv420p(tv, progressive), 800x600 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 90k
> tbn, 50 tbc
>      Side data:
>        cpb: bitrate max/min/avg: 0/0/0 buffer size: 49152 vbv_delay: N/A
>
> Any help appreciated.
>
After a few search, I found the solution.
First, according to
https://superuser.com/questions/1361198/vlc-3-can-not-play-certain-udp-streams,
you should make udp packets with size 1316, by setting the address udp://
239.1.250.12:1234?pkt_size=1316
Second, vlc should play udp://@239.1.250.12:1234. Without the @, vlc won't
succeed to play the stream.
Hope these help you.
Kim Syehoon
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