Hallo,
mkfifo creates a file where one file/process reads it's content, and
another process puts data into. You need is when program data can't pipe
direct to each other. So you create the named pipe. You start afterwards
the process that reads the data and as last step you put the data into it.
The commands for the video would than be in one terminal window:
> mkfifo stream.yuv
> cat stream.yuv │ yuvscaler -O SVCD │ mpeg2enc -f 4 -o video_svcd.m2v &
> mplayer -nosound -noframedrop -vo yuv4mpeg ezcap0001.avi
Don't forget to add the & in the 2nd line to start the process in the
background. You don't need to start mplayer in the background.
For audio:
> mplayer -vo null -ao pcm:file=audio.wav ezcap0001.avi
> cat audio.wav │ mp2enc -v 2 -V -o sound.mp2
Afterwards mutiplex the files together with:
mplex -f 4 sound.mp2 video_svcd.m2v -o SVCD.mpg
You have then a encoded MPEG file with ist suitable for SVCD. You need
to change the commands for you need.
What do you want with the AVI file ?
If you encounter errors please add the output to the mail.
Janos G. Komaromi wrote:
Hi Bernie, thanks for your answer. Sorry, I have not been doing video
edits lately, so I need a little more help. Lat time I used Cinelerra
for video edit on my old FC-3 desktop.
I tried
Quote
mkfifo stream.yuv
>cat stream.yuv │ yuvdenoise │ yuvscaler -O SVCD │ mpeg2enc -f 4 -o
video_svcd.m2v
>mplayer -nosound -noframedrop -vo yuv4mpeg anyfile.mpg
For Audio:
>mplayer -vo null -ao pcm:file=anyfile.wav anyfile.mpg
> cat anyfile.wav │ mp2enc -v 2 -V -o sound.mp2
Unquote
but did not get far.
My video clip is "ezcap0001.avi" as shown in DETAILS below. What are
the exact commands I need to issue? How do I make the "stream.yuv"? If
I just issue the command "mkfifo stream.yuv" it creates a zero byte
pipe file that the next command uses: "cat stream.yuv | yuvdenoise....
etc", but it does not do anything. And what is the "anyfile.mpg"
output? Is it the file that can be edited with glav? If it is only the
picture content of my video how the edited version will be synchronized
with the unedited sound part of the original clip?
Sorry, these may be stupid questions but I'd like to understand the
whole thing better. OK, there is the RTFM principle, and I read MJPEG
HOWTO document 4.1 through 4.3 but still don't know how to edit my
"ezcap0001.avi" video file with glav.
PLease, explain - Janos
P.S. tried other opensource linux video editors on my Gentoo machine,
but openshot does not run, and could not compile flowblade yet. I like
the simplicity of your glav.
On Thu, 2022-09-29 at 19:20 +0200, Bernhard Praschinger wrote:
...
DETAILS:
janos@andraslinux ~/tmp $ lavplay -p S -v 2 ezcap0001.avi
lavplay2.2.1
lavtools version 2.2.1
--DEBUG: [lavplay] Opening video file ezcap0001.avi ...
**ERROR: [lavplay] Error opening ezcap0001.avi
janos@andraslinux ~/tmp $ file ezcap0001.avi
ezcap0001.avi: RIFF (little-endian) data, AVI, 800 x 592, 30.00
fps,
video: XviD, audio: MPEG-1 Layer 3 (stereo, 44100 Hz)
janos@andraslinux ~/tmp $ ffprobe ezcap0001.avi
ffprobe version 4.4.2 Copyright (c) 2007-2021 the FFmpeg developers
built with gcc 11.3.0 (Gentoo 11.3.0 p4)
...
Input #0, avi, from 'ezcap0001.avi':
Duration: 01:48:51.67, start: 0.000000, bitrate: 967 kb/s
Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID /
0x44495658), yuv420p, 800x592 [SAR 1:1 DAR 50:37], 896 kb/s, 30
fps, 30
tbr, 30 tbn, 30 tbc Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055),
44100 Hz, stereo, fltp, 64 kb/sThe mjpegtools can only handle a few
AVI Codecs. For example: dvvideo
and mjpeg it can't decode the encoded MPEG4
I don't know if ffmpeg can decode it in a format the mjpegtools
understand. But mplayer can (should) do it, here is are example
commands
for video:
>mkfifo stream.yuv
>cat stream.yuv │ yuvdenoise │ yuvscaler -O SVCD │ mpeg2enc -f 4 -o
video_svcd.m2v
>mplayer -nosound -noframedrop -vo yuv4mpeg anyfile.mpg
For Audio:
>mplayer -vo null -ao pcm:file=anyfile.wav anyfile.mpg
> cat anyfile.wav │ mp2enc -v 2 -V -o sound.mp2
You find a section in the: mjpegtools manpage called: Decoding
streams
with mplayer that should explain it in more detail. I hope the
program
auf hoffentlich bald,
Berni the Chaos of Woodquarter
Email: bernh...@griesbach.at
www: http://www.lysator.liu.se/~gz/bernhard
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