/demo/ - WebM test board

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File: 1379452234979.webm (2.37 MB, 1680x1050, capture.webm)

 No.16[View All]

ITT: ways of extracting clips from videos and editing them.

Here's a screen capture showing how to use ffmpeg and Avidemux to cut and crop a clip from a video. I've sped the action up by a factor of 2 so it's easier to watch.

I start by using converting the video into a format I know Avidemux can read. This isn't always necessary (and, in fact, wasn't in this case), but I wanted to show it anyway. To avoid having to convert the whole video, I start by opening it and finding the approximate time of the clip I want.

Then I invoke ffmpeg at the command prompt to convert the video:

ffmpeg -ss 20:40 -i source.mp4 -t 20 -pix_fmt yuv420p -c:v ffvhuff -an tmp1.mkv

To break this down:
> -ss 20:40
start at 20 minutes, 40 seconds
> -i source.mp4
input file is source.mp4
> -t 20
convert 20 seconds of video
> -pix_fmt yuv420p
8-bit YUV color with 4:2:0 chroma subsampling, the same as what's used in the VP8 format which is what we want at the end
> -c:v ffvhuff
Convert the video to the ffvhuff format. This is lossless format, meaning we don't lose quality by converting to it, but the files are very large.
> -an
no audio
> tmp1.mkv
the output file

96 posts and 65 image replies omitted. Click reply to view.


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hmm les see


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i did these and these is my first webm ever
i make 2 one VP8 (q=10) + Vorbis and the other VP8 (q=20) + Vorbis

what you think

and how yo make loop
and can i make it with out audio


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Is this Tera?


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Testing Webm


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new test


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A note to anyone reading this in 2017: FFmpeg now supports a proper constant-quality mode with -crf 10 -b:v 0. This should replace the -qmin 10 -qmax 10 thing.


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[spoiler] asdsadasd [/spoiler]


File: 1487514065492.webm (6.66 MB, 1920x1080, testinglimitations.webm)



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