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How to record a specific window using FFmpeg?
It is ugly and only works with gnu awk, but I have not found a better way yet to parse the window geometry into a custom format. and should also work under windows and with dshow, I believe.
How to set real time buffer in FFmpeg?
Use the ffmpeg command and optionally set the real-time buffer: Set the format to “dshow”. To avoid a few frame rate problems if want something other than the default it is a good idea to set it before declaring the video input: Now choose the video input source.
Do you support parallelism on the output of FFmpeg?
For instance different formats/different bitrates? Does it support parallelism on the output? The ffmpeg documentation has been updated with lots more information about this and options depend on the version of ffmpeg you use: http://ffmpeg.org/trac/ffmpeg/wiki/Creating%20multiple%20outputs
What happens if you leave out probesize in FFmpeg?
If you leave out the probesize option, ffmpeg will, by default, set the probesize to 5M. max_interleave_delta option prevents ffmpeg forcing output. If ffmpeg forces output, a message will appear in your log, e.g.: [mp4 @ 00000199f7512040] Delay between the first packet and last packet in the muxing queue is 10007271 > 10000000: forcing output
How to set audio to 30fps in FFmpeg?
The option: video=”Decklink Video Capture”:audio=”Decklink Audio Capture” tells ffmpeg to use those device as input, but by specifying them in this fashion, the lag between audio and video will be substantially less (and/or gone). -r 30 forces the output to be 30fps instead of the 60fps in source.
What are the acodec copy and Vcodec copies in FFmpeg?
The -acodec copy and -vcodec copy are there to ensure that the streams are taken as is, instead of doing any compression/transcoding. The only thing left to do (which is a work in progress atm) is creating a c# gui for this.
How to force ffmpeg to use constant bitrate?
-preset ultrafast means we dont have any patience, so use as little compression as possible. This causes a high bitrate, but that’s fine for my purpose. -f mpegts option tells ffmpeg to use MPEG-TS packets, this will “force” ffmpeg to use a constant bitrate mpeg format, since mpeg itself is normally variable bitrate.