Not stable fps in delivery rtmp stream
|Reported by:||Pavlo||Owned by:|
|Blocking:||Reproduced by developer:||no|
|Analyzed by developer:||no|
Summary of the bug:
When flipping a thread with a given fps using the -vf "fps = 30" filter at the output when delivered, the value of fps fluctuates from 20 to 50-60 peaks.
The delivery of frames is controlled by ffprobe, which displays video frames and the code on JS counts the number of frames that came in a second.
This behavior is observed only with non-stable input stream, provided uniform and stable flow of this problem at the output ffmpeg is not observed.
Also, if we analyze Freeman by comparing the pkt_pts_time of received frames, the value of fps remains stable and equal to 30, as specified in the command.
For video analysis, use the module "video-quality-tools"
How to reproduce:
- Emulate the incoming stream with delays in delivery
- Accept ffmpeg input at this prompt
- Output stream also will not have stable fps
% ffmpeg -i rtmp://localhost/myapp/myStream -s 1280x720 -aspect 16:9 \ -c:a aac -b:a 64k -ac 2 -ar 44100 -c:v libx264 -b:v 1500k -minrate 1500k \ -maxrate 1500k -bufsize 700k -profile:v main -level 4.0 -vf "fps=30,format=yuv420p" \ -x264opts "keyint=60:min-keyint=60:no-scenecut" -preset veryfast \ -tune zerolatency -threads 0 -f flv rtmp://localhost/myapp/myStream1 ffmpeg version 3.4.2 Copyright (c) 2000-2018 the FFmpeg developers built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.9) 20160609
Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.