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TheSamsai / Castawesome

A GUI wrapper for FFmpeg and avconv for Livestreaming
GNU General Public License v3.0
49 stars 3 forks source link

rc buffer underflow issue #4

Open askmeaboutlo0m opened 9 years ago

askmeaboutlo0m commented 9 years ago

When using the flv video codec, the consoles prints a lot of angry red messages like [flv @ 0x1d65ec0] rc buffer underflow.

Trying to fix my issue, I came across this thread on FFmpeg-user. It appears to be that the parameters passed to avconv don't work properly for most codecs, only h264 and related ones from my sporadic testing.

Removing the -maxrate and -bufsize parameters from the command line seems to work for both flv and h264 and its friends, but I haven't tested it long term.

TheSamsai commented 9 years ago

As far as I know -maxrate is required for the livestream to count as a CBR (constant bitrate) livestream which is pretty much a requirement for sites like Twitch.tv. It might work just fine but there could be some problems caused by that. I might remember incorrectly but I believe I had to add those arguments to get Twitch working a while back.

askmeaboutlo0m commented 9 years ago

I expected as much, I guess it only breaks codecs that don't support CBR.

The ideal way to solve this would be to somehow ask avconv what parameters the codec supports I guess, maybe from that it could be figured out if -maxrate and -bufsize should be used or not. Not sure if that's possible though.

Otherwise, I guess the codecs need to manually sorted into which ones support CBR and which ones don't.