Reuben Martin wrote > On Thursday, June 29, 2017 6:56:51 PM CDT shalin wrote: >> Cley Faye wrote >> >> > More to the point, as far as I know, ffmpeg will not do parallel >> treatment >> > on either input or output, as you deduced. It certainly is doable, but >> > don't seem trivial to implement in the ffmpeg CLI tool itself since >> that >> > tool must handle various cases, and introducing (more) special cases >> would >> > add complexity for not much benefits. >> > >> > You should look in using the various ffmpeg libraries directly; with >> that >> > you could probably write it to decode once, encode multiple time. But >> > unless you have shockingly similar settings and unlimited processing >> > power, >> > you'll most likely stall some of your encodings while other catch up >> with >> > them. I don't know how well ffmpeg libraries handle multithreading (I >> > suppose fairly well since most of it's operations are based on context >> > structures) but you'll have to do a fair amount of synchronization by >> > hand. >> >> Thank you for your answer to my original question. So from this, I am >> assuming that ffmpeg in its current form doesn't support output level >> parallelism. Actually I have 'shockingly' similar transcodings to perform >> on >> a given input stream (I need to crop different parts of the input video >> and >> encode them at same bitrate and also cropped parts are same in size for >> each stream). With that each encode should roughly run at the same rate >> and >> I believe multithreading should be really helpful. > > All this is possible but you need to do a lot of reading. Starting with > input > mapping. http://www.ffmpeg.org/ffmpeg-all.html#Advanced-options > > It couldn’t hurt to read up on how anonymous pipes work in a posix shell, > as > well as other shell related concepts.
There's no doubt that I need a lot of reading but I wish you at least read my question properly. It has nothing to do with pipes or shell. It's about running multiple encodes in parallel within single ffmpeg process (option 2 in my question). Simply providing the link doesn't help as it doesn't solve the issue at hand. -- View this message in context: http://www.ffmpeg-archive.org/Using-FFMPEG-to-encode-multiple-outputs-in-parallel-doesn-t-work-tp4680420p4680482.html Sent from the FFmpeg-users mailing list archive at Nabble.com. _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".