DECKLINK: Video and Audio misbehaving

[Pablo Llorach]

Summary of the bug:

Receiving a UDP feed on my server and process it with ffmpeg, and then save it to a file and then forwardit to the SDI, but i receive errors saying there is no enough buffered video and audio.

How to reproduce:

root@video-mvd-tec:/home/tecnico# /home/tecnico/FFmpeg/ffmpeg –i udp://192.168.1.20:5004?overrun_nonfatal=1&fifo_size=50000000" -acodec aac -ab 192k -vcodec libx264 -preset ultrafast -s 1920x1080 -r 25 -f mpegts /home/tecnico/Escritorio/test-live2.avi -acodec pcm_s16le -ab 192k -ac 2 -vcodec v210 -s 1920x1080 -r 25 -f decklink 'DeckLink SDI (1)' -acodec pcm_s16le -ab 192k -ac 2 -vcodec v210 -s 1920x1080 -r 25 -f decklink 'DeckLink SDI (2)'

/home/tecnico/FFmpeg/ffmpeg -i "udp://192.168.1.20:5004?overrun_nonfatal=1&fifo_size=50000000" -acodec aac -ab 192k -vcodec libx264 -preset ultrafast -s 1920x1080 -r 25 -profile:v 3 -acodec pcm_s16be -ac 2 -ar 48000 /home/tecnico/Escritorio/test-live2.mov -acodec pcm_s16le -ab 192k -ac 2 -vcodec v210 -s 1920x1080 -r 25 -f decklink 'DeckLink SDI (1)' -acodec pcm_s16le -ab 192k -ac 2 -vcodec v210 -s 1920x1080 -r 25 -f decklink 'DeckLink SDI (2)'

Log

[decklink @ 0x260dc40] There's no buffered audio. Audio will misbehave!

[decklink @ 0x260dc40] There are not enough buffered video frames. Video may misbehave!

% ffmpeg -i input ... output
ffmpeg version 4.1
built on ... Ubuntu Server 16.04

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Marton Balint]

This just means that your PC is not fast enough, or A-V is getting out of sync due to lost packets. You should optimize your command line, use 8 bit only (uyvy422 pixel format) and drive only 1 decklink output, see if that works.