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Old 19th December 2018, 05:26   #21  |  Link
BLKMGK
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Quote:
Originally Posted by Blue_MiSfit View Post
set open-gop=0 (in ffmpeg speak, --open-gop=0 in x265 binary speak) to make all GOPs closed.
I think x265 does it slightly differently but you set me on the right path after I had troubles with ffmpeg, thank you! I used --no-open-gop and it seemed to like it, much experimentation left to do. Does closing gop structures impact encoding efficiency? Seemed to run across some information that sounded like it might. Appreciate the help!

Quote:
--open-gop, --no-open-gop
Enable open GOP, allow I-slices to be non-IDR. Default enabled
For black borders the following website had some good info using ffplay.

http://www.renevolution.com/ffmpeg/2...-cropping.html
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Old 22nd December 2018, 22:38   #22  |  Link
BLKMGK
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Originally Posted by Blue_MiSfit View Post
Interesting - so I could encode 30 second chunks but have each include a few seconds of the prior chunk in the rate control. Neat!
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Originally Posted by Selur View Post
about chunked encoding: Would this be a good start for additional multi-threading option? Like 'virtually' splitting the source in chunks and encode them in parallel without having to physically split the source on systems where the cpu usage isn't that high?
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Originally Posted by benwaggoner View Post
it could be, for cases where you have a lot of unused RAM or cores. People have already done scripts or apps using the .dll for that.
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Originally Posted by Blue_MiSfit View Post
Yep, absolutely. This is how you encode super fast using tons of machines e.g. in the cloud
Reading this exchange I built a script to do exactly this but was pretty puzzled by some of the results I was seeing. Turns out "chunk" starts at the beginning of the file with it's encoding even if you've specified a starting frame deep into the source video. It will merrily encode and throw away the work until it hits the starting frame, save frames until it hits the provided end frame, and then quit. I had expected I could give it a start frame and it would read back to a keyframe to begin encoding and then spit out the frames I specified - it does NOT in my testing Judging from the conversation here it sounds like I wasn't the only one confused, I'm pretty bummed...

Edit: My previous test was cropping and I decided to drop that to see if it impacted the behavior. I changed to a much earlier portion of the source (frame 2000) and encoded only 500 frames. When it hit the end frame at 2500 it kept running until I broke it. Aborted input at frame 108145 output frame 501, it seems that it also doesn't stop encoding at the chunk end frame either - it seems previously I'd used a point near the end of the video. I'm really confused as to how this function is used and hope I've simply screwed something up.

Last edited by BLKMGK; 22nd December 2018 at 23:01.
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