linuxgeek: Re: [LINUX_Newbies] more questions about videos thank You to Scott

Good afternoon.

> > > > Questions:
> > > > > Stream #0:0: Video: h264 (High) (H264 / 0x34363248), yuv420p,
> 720x576
> > > >
> > > > Is this the most important line for my problem?
> > >
> > > Yes, that is referring to the codec of the video. (In this case,
x264)
> > *
> > OK
> > so
> > can I do those things:
> >
> > Stream #0:0: Video: h264 (High) (H264 / 0x34363248), yuv420p, 720x576
> > Make the quality of every picture worse by reduce the size of picture?
> >
> > Is it possible to split every ṕicture of a video.
> >
> > Example
> >
> >
> > 11111
> > 22222
> > 33333
> > 44444
> >
> >
> >
> >
> > You can see this picture during 2 minutes video.
> >
> > can ffmpeg do that?
>
> Yes.
> If you want the first two minutes of the video
>
> ffmpeg -i myvideo.avi -t 120 1111.avi
>
> The -t is for time, usually in seconds. (So if you want two minutes, use
> 120.)
>
> Then if you want the next two minutes
>
> ffmpeg -ss 121 myvideo.avi -t 120 2222.avi
*
Thank You. So it is very easy to manipulate movies with ffmpeg.

>
> The -ss is to seek position. It is not exact, but it should be close
> enough for your purpose. It should be before the -i <video-name>
> otherwise, it takes a much longer time.
>
> >
> > or can
> > split ffmpeg
> >
> >
> > 11
> > 22
> > 33
> > 44
> > 55
> >
> I'm not sure what you mean by this.

**

Imagine a picture with two humans.

Now I wanna make two pictures with one human.

>
> >
> > and can I make with ffmpeg out of a 2 minutes video an one hour video
> > by making copy paste 59 times like a time loop?
>
> I've never looked into that. You can make a repeating gif easily enough.
*
OK

> >
> ffmpeg -i input -vf scale=320:-1 -r 10 -f image2pipe -vcodec ppm - |
> convert -delay 5 -loop 0 - output.gif
>
> Which might be easier. Otherwise, I'd probably use a different command.
> My page talks about combining videos into one. The easiest thing to
use is
> mkvtoolnix and use mkvmerge -o myfile file1 + file2 + file3.

*
OK

>
> >
> > I can convert a pic from 300 dpi to 100dpi
> > and can I convert a video to any size or are there some sizes only
> possible?
> >
> There are probably some sizes that wouldn't work, I don't know them by
> heart. :)

*
OK
>
> >
> > Question:
> > Here is a video a.avi with 1 GB
> > now I reduce the size of the picture to 25% and same avi-container.
> >
> > Is now the space for the file 250 MB or less and the sound is the
same?
> >
> > Regards Sophie
>
> Sound would probably be the same, assuming you copy the audio. Do you
mean
> reduce it so it's 25 percent smaller or reduce it 75 percent so that it's
> only 256 MB total size? You will probably lose a lot of quality.
> >

Start is 1 GB
Result is 250 MB.

Question: Where can I find
what size is possible to create a movie or a picture of the movie?

Regards Sophie