How do you create a webm from a time section of a video?

How do you create a webm from a time section of a video?

I know it's ffmpeg but you need special commands to re-keyframe it - what's the exact command line to create the best webm?

Other urls found in this thread:

superuser.com/questions/908280/what-is-the-correct-way-to-fix-keyframes-in-ffmpeg-for-dash
wiki.installgentoo.com/index.php/WebM
ffmpeg.org/ffmpeg.html
trac.ffmpeg.org/wiki/Seeking
twitter.com/NSFWRedditImage

Google it.
That's how I learned to make webms and you should be able too.

man ffmpeg

this is a useless reply

googling gives stuff like this superuser.com/questions/908280/what-is-the-correct-way-to-fix-keyframes-in-ffmpeg-for-dash

>wah I am too retarded to google
Here is what I got:
wiki.installgentoo.com/index.php/WebM

this has some useful information that I'll use (the two pass thing) so thank you for that. but it doesn't say what to do about keyframes which is the thing I'm asking about.

Its in the -ss section

I prefer using "-to" to use specific time stamps.
ffmpeg -ss 00:00:00.000 -to 00:00:01.000

I know this and I'm using this but ahhh, theres no point trying to explain this to you guys

>use specific time stamps.
ffmpeg.org/ffmpeg.html
If you have two time stamps you can use -to instead of -t.
-t only requires the starting time stamp while the second time value is the duration of the clip.

Not cutting in the right places?
Use webm for retards.

> Requires .NET Framework 4.5
I don't want this, am on linux.
i guess I'll investigate the source and see how they do it.

sauce?

Was that the problem though?

I just use mpv and screenshot to get the exact time stamps. Needs to be set up in the config to show the config file
screenshot-template=~/snapshots/%f_snapshot_%wH.%wM.%wS.%wT_[%tY.%tm.%td_%tH.%tM.%tS]

this is an awesome trick, thank you! I might make a wrapper based around this once I figure out the right command line

mind me asking how you use the timestamps? -ss and -to doesn't seem to be the correct flags

'input.mkv_snapshot_00.15.06.762_[2016.09.03_20.51.14].jpg'
'input.mkv_snapshot_00.15.11.559_[2016.09.03_20.51.20].jpg'
$ ffmpeg -i input.mkv -ss 00.15.06.762 -to 00.15.11.559 -c:v libvpx-vp9 -b:v 0 -crf 30 -speed 0 -threads 6 -tile-columns 6 -frame-parallel 1 -c:a libopus -b:a 96k out.webm
Invalid duration specification for ss: 00.15.06.762


also any suggestions to changes to the command line? I was recommended not to use two pass

should be 00:00:00:00
If you don't use the exact timestamps, is that why it sometimes gets fucked when I cut videos with ffmpeg?

this explains the issue with keyframse i was originally asking about

-ss position (input/output)
When used as an input option (before -i), seeks in this input file to position. Note that in most formats it is not possible to seek exactly, so ffmpeg will seek to the closest seek point before position. When transcoding and -accurate_seek is enabled (the default), this extra segment between the seek point and position will be decoded and discarded. When doing stream copy or when -noaccurate_seek is used, it will be preserved.

When used as an output option (before an output filename), decodes but discards input until the timestamps reach position.

Like I posted before:
ffmpeg -ss 00:00:00.000 -to 00:00:01.000
You need to change them to colons except for the third one.
I use 00:00:00.000
They have to be exact if you want the precise frames.
You can use the comma and period keys in mpv to move frame by frame in the video.

Also here is an example of how I make webms
ffmpeg -i ~/Videos/video.mp4 -ss 00:01:21.614 -to 00:01:28.488 -crf 4 -b:v 2000K -vf scale=-1:720 -an -metadata title="Video title for source fags" webm_name.webm

2000K can be substituded with 2M and reduced to 500k for a smaller size.

thank you very much! I found that putting -ss before -i speeds up conversion by a LOT... but it requires me to subtract the timestamps which is "awesome".

my command had -crf 30, -crf 4 I'll look into what that is about.

mine -b:v 0 yours -b:v 2000K, hmm..

>google
>trusting the search engine jew

You know what I meant. No one says "startpage it" or "duckduckgo it"

it's better to just not post than tell people to google things

Its better to never make threads that ca be answered by a search engine result.

is someone booty bothered?

No, are you?

trac.ffmpeg.org/wiki/Seeking