Reuben Martin
Forum Replies Created
-
This entirely depends on what format you are trying to change the metadata on.
-
You can’t just trim h264 video at arbitrary points in the stream without re-encoding it. The exception is if you trim it on a keyframe. Or if the video is Intra-frame only in which case every frame is a key-frame.
-
Yes.
-
It can also be built with libaacplus if you want to encode HE-AAC (a.k.a AAC+). However most publicly available builds of ffmpeg are not build with this library enabled. Same goes for libfaac. If you want to use either of those two encoders, you will probably need to compile them yourself.
-
It’s failing because the input streams are garbage. (Or the build of ffmpeg you are using is broken)
I’m not really sure why you are re-encoding anyway. Those stream formats (h264 and aac) from the source are perfectly valid for mov files. Just remux them.
ffmpeg -i input.avi -vcodec copy -acodec copy -f mov output.mov -
Get rid of the “-b” option when using crf. The b option is when you are trying to achieve a specific bitrate. This is really only needed when there are external limitations requiring you to limit the bitrate. CRF targets a specific quality and adjusts bitrate as needed to maintain that quality. The two are working with very different, and often conflicting, goals; it doesn’t make much sense to specify both.
-
There’s no easy answer to that. Overhead depends on quite a few factors, such as frame size, frame rate, options used, among other factors. That said baseline takes a lot less work to compress than high profile, with the trade off of larger file size (or in your case higher streaming bitrate).
You would probably be best off experimenting with the baseline profile to see what provides the most optimal outcome for whatever you are trying to do.
-
There’s all kinds of things you can do; but without knowing what you want to achieve, nobody can help you.
What is your goal? Speed, minimal file size, best quality, device compatibility, something else?
-
I think your right. I created a test file with a video and a 16 channel audio stream. I created it with ffmpeg btw. It can _create_ the 16 channel audio stream, but the filter subsystem doesn’t like it when I feed it back in to try to split the channels out. Gives errors about invalid channel layout.
Hopefully the developers will make a matrix filter in the future to be able to map any input:stream:channel to any output:stream:channel that isn’t constrained by channel layout presets.
-
yuck. You’re right, I just looked it up. Can’t handle more than 8 channels. Try using map-channel.
ffmpeg -i input.mov -map 0:0 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map 0:1 -map_channel 0.1.0:0.1 -map_channel 0.1.1:0.2 -map_channel 0.1.2:0.3 -map_channel 0.1.3:0.4 -map_channel 0.1.4:0.5 -map_channel 0.1.5:0.6 -map_channel 0.1.6:0.7 -map_channel 0.1.7:0.8 -map_channel 0.1.8:0.9 -map_channel 0.1.9:0.10 -map_channel 0.1.10:0.11 -map_channel 0.1.11:0.12 -map_channel 0.1.12:0.13 -map_channel 0.1.13:0.14 -vcodec copy -acodec pcm_s16be output.movVery long, and don’t have anything to test it with. But should be close to something like that.