[FFmpeg-user] How to drop frames to limit memory usage (or keep latency low)?

[Carl Zwanzig]

On 4/3/2018 8:55 PM, Adam Nielsen wrote:

> I've had a look through the manpage but I can't find any options that
> can do this.  The -r and -vsync options seem to only drop frames to
> match a constant framerate (rather than trying to minimise latency) and
> -frame_drop_threshold looks to be similar, keeping up with timestamps
> rather than affecting latency.

Do you -need- full-rate motion?

It sounds like you need to drop frames to match a constant FR that you then 
transcode. You might be able to use the framestep filter to discard every 
other frame, transcode, then use -r to set the desired output rate which 
will dup frames to fill the time. (I have not tried this myself.)

There's a some vaguely apropos answer regarding framestep at 
https://video.stackexchange.com/questions/16552/4x-resample-videoframes-using-ffmpeg.

Later,

z!