Opened 3 years ago

Closed 2 years ago

#6236 closed defect (needs_more_info)

FFmpeg bandwidth skyrockets upon scene change after the scene has been identical for 5 minutes.

Reported by: adamfenn28 Owned by:
Priority: normal Component: undetermined
Version: unspecified Keywords:
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


Summary of the bug:

When RTMP streaming with FFmpeg, using either videotoolbox or x264, and streaming a static image for 5 or more minutes, before a scene change to a different image or motion video, FFmpeg will suddenly produce huge frames upon the scene change, resulting in 2-3x the configured bit rate, for 60 seconds. If the scene is left consistent for longer than 5 minutes, the impact will last for longer than 60 seconds.

How to reproduce:

Stream with FFmpeg using x264 or videotoolbox, and stream a static image for 5 minutes. Observer the output bit rate and output frame size. Then change the scene to a video. The frame size and bit rate will skyrocket. Wait 60 seconds. Continue to observe the bitrate and frame size. They will be reduced.

This is using ffmpeg version 3.2

Change History (2)

comment:1 Changed 3 years ago by cehoyos

Please test current FFmpeg git and provide the command line you tested together with the complete, uncut console output to make this a valid ticket.
Note that neither x264 nor videotoolbox are implemented within the FFmpeg project though, so if there is an issue, we will not be able to fix it.

comment:2 Changed 2 years ago by cehoyos

  • Resolution set to needs_more_info
  • Status changed from new to closed
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