does the repo have an app that can edit these file types?
if there's nothing in the repo, can i download an app that edits mp4 or mkv?

i'm looking for something *simple*, since i only need to chop 20-second
segments out of mp4/mkv files and then save them.

On 10/19/2022 7:14 PM, Dr. Noah Bodie wrote:
> does the repo have an app that can edit these file types?
> if there's nothing in the repo, can i download an app that edits mp4 or mkv?
>
> i'm looking for something *simple*, since i only need to chop 20-second segments out of mp4/mkv files and then save them.

The container and codec issue, is handled by ffmpeg and/or libAV.

It's only when a program is so old, it's never heard of MP4, that
MP4 is not supported. Like, a really old copy of "AVIdemux"
would never have heard of an MP4. It's possible more modern
versions would have containers other than AVI, added as
a form of support.

https://en.wikipedia.org/wiki/MP4_file_format

" Like most modern container formats..."

But generally, anything that calls upon FFMPEG, is going to
support an MP4 container or an MKV container.

Only certain CODECs work with certain containers. That means,
you can't preserve a CODEC and just arbitrarily change the
container as such. The container is the metadata, describing
frame rate, color space, or other types of junk. The CODEC
is the coder/decoder that converts the video packets, into
frames on your screen.

*******

If I look through a list like this (scroll down past the advert):

https://filmora.wondershare.com/video-editor/free-linux-video-editor.html

"Avidemux is a free, open-source video editing software designed mainly
for simple cutting, splitting, merging, filtering, encoding, etc. It is
a cross-platform free video editing software and supports various
file formats with different codecs such as AVI, MPEG, MP4, ASF, etc"

I would be attracted to AVIdemux. Because it does not have a conventional
interface and lacks the "Adobe Premiere" look and feel the others have.
Non Linear Editing (NLE) owes a lot to Premiere for a particular
time line feature set. Most video editing products try to copy
Adobe Premiere in a sense, just like GIMP aspires to be Adobe Photoshop
complete with those silly floating palettes.

In AVIDemux, try opening the video, set the audio to "Copy", the video
to "Copy", then see if you can cut stuff out. Some operations don't
work with a plain copy operation, so you have to enable the
re-rendering by selecting the same format as you started with.
There are certain audio formats, that can be arbitrarily snipped
and perhaps a Copy setting would work with that.

Back when AVIDemux aupported only AVI, and it wasn't cross-platform,
it was pretty well bullet-proof. When it was extended, it went
through a period of instability (I had to dump it, on more than one
occasion). You'll be able to tell us after you're
done, whether it successfully passed through this phase or not :-)

When you edit video, the video frames are arranged in groups.
A group of pictures is a GOP. At 24 FPS, a GOP might be 12 frames.
At 30FPS, a GOP might be 15 frames (0.5 seconds). The maximum GOP allowed,
is on the order of 600 frames (don't do that). At the end of every GOP,
is a "fully rendered frame". Every pixel is spelled out. The other
13 or 14 frames, are "delta" frames, and fewer pixels changes are defined
in such frames.

This has consequences for editing, in that only a few
editors support lossless snipping on individual frames, whereas
other editors might move the cursor in 0.5 second steps (if
you don't want to re-render). If a video is re-encoded, then
this all gets straightened out, but the quality suffers a
bit from the recompression step. For the work you're doing,
you might not care about this, but at least be aware that the
way video is encoded (in groups of frames), matters. It makes
a difference to what is possible when you're in a hurry to get
results. Re-rendering a video can take a bit of time. Like an hour.
If you can make an edit, without re-rendering, the job is done
real fast.

Paul

On 20/10/2022 00:14, Dr. Noah Bodie wrote:
> does the repo have an app that can edit these file types?
> if there's nothing in the repo, can i download an app that edits mp4
> or mkv?
>
> i'm looking for something *simple*, since i only need to chop
> 20-second segments out of mp4/mkv files and then save them.

I am not sure about simple but there is an App you could try:

<https://kdenlive.org/en/>
<https://kdenlive.org/en/download/>

On 10/19/2022 09:37 PM, Paul wrote:

> https://filmora.wondershare.com/video-editor/free-linux-video-editor.html
>
> "Avidemux is a free, open-source video editing software designed mainly
> for simple cutting, splitting, merging, filtering, encoding, etc.
> It is a cross-platform free video editing software and supports various
> file formats with different codecs such as AVI, MPEG, MP4, ASF, etc"

I will try the CLI version and if it's like "MP3Splt" then that will be
great.

On 10/19/22 17:37, Paul wrote:
> Back when AVIDemux aupported only AVI, and it wasn't cross-platform,
> it was pretty well bullet-proof. When it was extended, it went
> through a period of instability (I had to dump it, on more than one
> occasion). You'll be able to tell us after you're
> done, whether it successfully passed through this phase or not :-)

I use Avidemux quite a lot. It supports opening/saving to/from any video
format I've thrown at it. And it's quite stable to me.

On 20/10/2022 00:14, Dr. Noah Bodie wrote:
> does the repo have an app that can edit these file types?
> if there's nothing in the repo, can i download an app that edits mp4 or mkv?
>
> i'm looking for something *simple*, since i only need to chop 20-second
> segments out of mp4/mkv files and then save them.

No idea about mkv, but VLC can edit (extract copy/paste) mp4 files.

--

Jeff

On 20/10/2022 08:12, Jeff Layman wrote:
> On 20/10/2022 00:14, Dr. Noah Bodie wrote:
>> does the repo have an app that can edit these file types?
>> if there's nothing in the repo, can i download an app that edits mp4 or mkv?
>>
>> i'm looking for something *simple*, since i only need to chop 20-second
>> segments out of mp4/mkv files and then save them.
>
> No idea about mkv, but VLC can edit (extract copy/paste) mp4 files.

....copy/SAVE mp4 files!

--

Jeff

On 10/19/2022 10:48 PM, stepore wrote:
> On 10/19/22 17:37, Paul wrote:
> > Back when AVIDemux aupported only AVI, and it wasn't cross-platform,
> > it was pretty well bullet-proof. When it was extended, it went
> > through a period of instability (I had to dump it, on more than one
> > occasion). You'll be able to tell us after you're
> > done, whether it successfully passed through this phase or not :-)
>
> I use Avidemux quite a lot. It supports opening/saving to/from any video format I've thrown at it. And it's quite stable to me.

https://www.fosshub.com/Avidemux.html

"AppImage for recent Linux" <=== what I tested

Name: avidemux_2.8.1.appImage
Size: 44945384 bytes (42 MiB)
SHA256: 4E685FBAD0B59D007C5A23AB5FD47948EA5979601E693521F7B842EDD4D768A3

On the target machine, check in synaptic that libfuse2 is installed.
it was on mine, and I don't think I did that. Then, just execute it.

chmod 755 avidemux_2.8.1.appImage
../avidemux_2.8.1.appImage # not as root of course... as user

I fed it a 6GB .mp4, snipped a couple hours out
of it, and the five minute resulting video saved
in no time. Implying either acceleration was available,
or more likely, it snipped on non-GOP boundaries.

I would use ffprobe and examine where I did the snip, to check
for the "rhythm" of the groups of pictures, and whether or not
the cut disrupted that, to see what kind of lossless cut was done.
This is the sort of topic, if you intend to do a lot of this,
you really need to understand the "quality" of the tool you're
using, and how much trouble they've gone to, to do the cut
in the way this one seems to have been done. I don't
think my video card is fast enough to output 200MB of .mp4 in
a split second, so I don't think it's a re-render.

But as far as playback goes, while my cut was "abrupt", there
did not seem to be much impact from it.

And it does have "fade" capability, it's just that for me, this is
new to avidemux (compared to my usual ancient version)
and I don't know how to use it yet.

[Picture]

https://i.postimg.cc/T3HQDXCP/avidemux-281-effects.jpg

But generally speaking, for a five minute test, impressive.
No wibbling when I fed it the .mp4 (it used to moan when
you fed it non-avi stuff). It read the file at warp speed
(could be using video card for that). The interface was its usual
solid self. But I would need to do a lot more work in there,
to develop some idea how technical sound it is. Some ffprobe work,
look at the packets, plot packet size versus frame number. Then
you can see whether it snipped, mid-GOP.

Paul

On 10/20/22 05:43, Paul wrote:
<snip>
> But generally speaking, for a five minute test, impressive.

Ya, my usage is super simple. I cut, snip, resize, maybe change frame
rate, transcode, etc. Nothing complicated. And most of my videos are <
1-2GB. For that use case it's been extremely solid.

In alt.os.linux.ubuntu Dr. Noah Bodie <noah@bodie.not> wrote:

> I will try the CLI version and if it's like "MP3Splt" then that will be
> great.

For dealing with MP4 and MKV containers there are also *mp4box* (within
"gpac" package) and *mkvtoolnix* accordingly. Both packages comprise very
powerfull CLI programs.