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Cutting an AVI file down to size

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  Cutting an AVI file down to size Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2019-07-03 05:29 +0000
    Re: Cutting an AVI file down to size dillinger <dillinger@invalid.not> - 2019-07-03 07:59 +0200
    Re: Cutting an AVI file down to size "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2019-07-03 02:21 -0400
      Re: Cutting an AVI file down to size The Natural Philosopher <tnp@invalid.invalid> - 2019-07-03 09:22 +0100
    Re: Cutting an AVI file down to size The Natural Philosopher <tnp@invalid.invalid> - 2019-07-03 09:18 +0100
    Re: Cutting an AVI file down to size Rich <rich@example.invalid> - 2019-07-03 11:16 +0000
    Re: Cutting an AVI file down to size queequeg@trust.no1 (Queequeg) - 2019-07-03 12:59 +0000
      Re: Cutting an AVI file down to size Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2019-07-03 16:16 +0000
        Re: Cutting an AVI file down to size Andreas Kohlbach <ank@spamfence.net> - 2019-07-03 15:27 -0400
          Re: Cutting an AVI file down to size Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2019-07-03 21:49 +0000
            Re: Cutting an AVI file down to size not@telling.you.invalid (Computer Nerd Kev) - 2019-07-04 00:29 +0000
              Re: Cutting an AVI file down to size Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2019-07-04 08:53 +0000
                Re: Cutting an AVI file down to size "Carlos E.R." <robin_listas@es.invalid> - 2019-07-04 15:41 +0200
            Re: Cutting an AVI file down to size queequeg@trust.no1 (Queequeg) - 2019-07-04 08:08 +0000
    Re: Cutting an AVI file down to size "F. Russell" <fr@random.info> - 2019-07-06 18:42 +0000

#27533 — Cutting an AVI file down to size

This might not be the right place to post this, but I am in the
process of converting a friend's laptop from Windows 10 to Linux.
While copying over her files, I came across a .avi file that is
14 gigabytes in size.  That's right, gigabytes - enough data to
fill three DVDs to bursting.  The file plays fine - it's a home-shot
video which is 13 minutes long.  Something is very wrong, obviously.

Is there some way of stripping out what must be a lot of extraneous
data and reducing the video to a reasonable size (e.g. under 100MB)?
One suggestion I came across was to use mencoder, although this is
primarily to clean up errors in the file.  The result came out only
a few bytes smaller.

How can I get the file down to a reasonable size?  And how did it
get so bloated in the first place?

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  Fight low-contrast text in web pages!  http://contrastrebellion.com

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#27534

On 7/3/19 7:29 AM, Charlie Gibbs wrote:
> This might not be the right place to post this, but I am in the
> process of converting a friend's laptop from Windows 10 to Linux.
> While copying over her files, I came across a .avi file that is
> 14 gigabytes in size.  That's right, gigabytes - enough data to
> fill three DVDs to bursting.  The file plays fine - it's a home-shot
> video which is 13 minutes long.  Something is very wrong, obviously.
> 
> Is there some way of stripping out what must be a lot of extraneous
> data and reducing the video to a reasonable size (e.g. under 100MB)?
> One suggestion I came across was to use mencoder, although this is
> primarily to clean up errors in the file.  The result came out only
> a few bytes smaller.
> 
> How can I get the file down to a reasonable size?

Have a look at avidemux, and experiment a bit.
>  And how did it get so bloated in the first place?
> 

This is probably the result of using no compression at all.

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#27535

On Wed, 03 Jul 2019 01:29:25 -0400, Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:

> This might not be the right place to post this, but I am in the
> process of converting a friend's laptop from Windows 10 to Linux.
> While copying over her files, I came across a .avi file that is
> 14 gigabytes in size.  That's right, gigabytes - enough data to
> How can I get the file down to a reasonable size?  And how did it
> get so bloated in the first place?

The avi file type is a container not actually a video format. First step
is to figure out why it's so large, which will likely be due to a large
frame size, high frames per second.

What's the output of the file command for that file?

Shrinking it will likely involve converting it to a container that does
support compression, and may also involve reducing the frame size, rate,
bits per pixel for color, audio bits per second for fidelity, etc.

It's been a long time since I did any video conversions or editing. You
will want a very powerful system with a good cooling system, as it's very
cpu/gpu/ram intensive. Keeping audio and video tracks in sync is not easy
when doing the conversions, so expect lots of trial and error. I'd start by
extracting the first minute or less, and experimenting with that till you
find the settings that work.

See https://en.wikipedia.org/wiki/List_of_video_editing_software#Active_and_stable
for software that can handle the conversion.
https://en.wikipedia.org/wiki/Comparison_of_video_container_formats for
the various container formats.

What do you want to do with the video after reducing it's size? Play it
on a dvd player, just on computers, on a phone, etc.

I've not currently subscribed to any of the newsgroups where video editing
and conversion is discussed, so don't know of any that are still active,
but the above comments and links may help get you started.

Regards, Dave Hodgins

-- 
Change dwhodgins@nomail.afraid.org to davidwhodgins@teksavvy.com for
email replies.

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#27537

On 03/07/2019 07:21, David W. Hodgins wrote:
> On Wed, 03 Jul 2019 01:29:25 -0400, Charlie Gibbs 
> <cgibbs@kltpzyxm.invalid> wrote:
> 
>> This might not be the right place to post this, but I am in the
>> process of converting a friend's laptop from Windows 10 to Linux.
>> While copying over her files, I came across a .avi file that is
>> 14 gigabytes in size.  That's right, gigabytes - enough data to
>> How can I get the file down to a reasonable size?  And how did it
>> get so bloated in the first place?
> 
> The avi file type is a container not actually a video format. First step
> is to figure out why it's so large, which will likely be due to a large
> frame size, high frames per second.
> 
> What's the output of the file command for that file?
> 
> Shrinking it will likely involve converting it to a container that does
> support compression, and may also involve reducing the frame size, rate,
> bits per pixel for color, audio bits per second for fidelity, etc.
> 
> It's been a long time since I did any video conversions or editing. You
> will want a very powerful system with a good cooling system, as it's very
> cpu/gpu/ram intensive. Keeping audio and video tracks in sync is not easy
> when doing the conversions, so expect lots of trial and error. I'd start by
> extracting the first minute or less, and experimenting with that till you
> find the settings that work.
> 
> See 
> https://en.wikipedia.org/wiki/List_of_video_editing_software#Active_and_stable 
> 
> for software that can handle the conversion.
> https://en.wikipedia.org/wiki/Comparison_of_video_container_formats for
> the various container formats.
> 
> What do you want to do with the video after reducing it's size? Play it
> on a dvd player, just on computers, on a phone, etc.
> 
> I've not currently subscribed to any of the newsgroups where video editing
> and conversion is discussed, so don't know of any that are still active,
> but the above comments and links may help get you started.
> 
> Regards, Dave Hodgins
> 
Overly alarmist.

Try running handbrake over it first and see if the result is acceptable.

I run that on a very inexpoesive quad core CPU with only 8GB RAM. Sure 
CPU maxes out, and core temps climb, but it just takes longer is all.

You dont NEED a massively powerful CPU to convert.It just speeds up 
stuff.  I get arounbd 150fps rates.




-- 
"I am inclined to tell the truth and dislike people who lie consistently.
This makes me unfit for the company of people of a Left persuasion, and 
all women"

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#27536

On 03/07/2019 06:29, Charlie Gibbs wrote:
> This might not be the right place to post this, but I am in the
> process of converting a friend's laptop from Windows 10 to Linux.
> While copying over her files, I came across a .avi file that is
> 14 gigabytes in size.  That's right, gigabytes - enough data to
> fill three DVDs to bursting.  The file plays fine - it's a home-shot
> video which is 13 minutes long.  Something is very wrong, obviously.
> 
> Is there some way of stripping out what must be a lot of extraneous
> data and reducing the video to a reasonable size (e.g. under 100MB)?
> One suggestion I came across was to use mencoder, although this is
> primarily to clean up errors in the file.  The result came out only
> a few bytes smaller.
> 
> How can I get the file down to a reasonable size?  And how did it
> get so bloated in the first place?
> 

Try 'handbraking' it down to an MP4 or thereabouts


-- 
"I am inclined to tell the truth and dislike people who lie consistently.
This makes me unfit for the company of people of a Left persuasion, and 
all women"

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#27538

Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
> While copying over her files, I came across a .avi file that is 14 
> gigabytes in size.  That's right, gigabytes - enough data to fill 
> three DVDs to bursting.  The file plays fine - it's a home-shot video 
> which is 13 minutes long.

> Something is very wrong, obviously.

Not necessarily.  It may have no compression, or an older, weak, 
compression algorithm applied to the video frames.

> Is there some way of stripping out what must be a lot of extraneous 
> data and reducing the video to a reasonable size (e.g.  under 100MB)?

Yes, re-encoding the video using a more modern compression algorithm.  
But there is not likely "extraneous data" as in "junk" or "padding" as 
is implied by your sentence.  It is much more likely, esp.  given the 
.avi container, to be uncompressed or only compressed with an older 
weaker algorithm.

> How can I get the file down to a reasonable size?

First question - why do you care?  If your friend is fine with it as it 
is, then is there any reason to be concerned.

> And how did it get so bloated in the first place?

Most likely weak or no compression.  Raw digital video consumes huge 
amounts of space.  And older digital video cameras only did weak (but 
easy to perform in real time) compression while recording.

If you are really intent on trying to shrink it, then as another poster 
mentioned, try re-encoding it using handbrake and see what results.  
But note, it is very easy to make an ugly mess of the video by choosing 
the wrong settings, so don't remove the original until your friend is 
satisfied with the quality of the re-compressed file.

Also, you might get better, more technical answers from somewhere in 
the alt.video.* hierarchy or the rec.video.* hierarchy, assuming there 
is any traffic in either.

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#27540

Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:

> 14 gigabytes in size.  That's right, gigabytes - enough data to
> fill three DVDs to bursting.  The file plays fine - it's a home-shot
> video which is 13 minutes long.  Something is very wrong, obviously.

The size is similar to what it would be if the video was 640x480@25fps 
and not compressed at all.

Just try converting it with avconv.

-- 
https://www.youtube.com/watch?v=9lSzL1DqQn0

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#27542

On 2019-07-03, Queequeg <queequeg@trust.no1> wrote:

> Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
>
>> 14 gigabytes in size.  That's right, gigabytes - enough data to
>> fill three DVDs to bursting.  The file plays fine - it's a home-shot
>> video which is 13 minutes long.  Something is very wrong, obviously.
>
> The size is similar to what it would be if the video was 640x480@25fps 
> and not compressed at all.

$ dc
640 480 3 25 780 * * * * p
17971200000

Holy crap!  It's easy to forget just how many pixels we're throwing around.

> Just try converting it with avconv.

$ avconv -codecs | wc
    424    2647   24437

So many choices... and I presume most video players only understand a few.
Is there some sort of guide to codecs that would help me decide which to
use?

Thanks to everyone for your help.  Maybe, as some of you have suggested,
I should just leave the file as is unless my friend really wants it
compressed enough to send to someone.

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  Fight low-contrast text in web pages!  http://contrastrebellion.com

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#27543

On 3 Jul 2019 16:16:13 GMT, Charlie Gibbs wrote:
>
> On 2019-07-03, Queequeg <queequeg@trust.no1> wrote:
>
>> Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
>>
>>> 14 gigabytes in size.  That's right, gigabytes - enough data to
>>> fill three DVDs to bursting.  The file plays fine - it's a home-shot
>>> video which is 13 minutes long.  Something is very wrong, obviously.
>>
>> The size is similar to what it would be if the video was 640x480@25fps 
>> and not compressed at all.
>
> $ dc
> 640 480 3 25 780 * * * * p
> 17971200000
>
> Holy crap!  It's easy to forget just how many pixels we're throwing around.

Not sure how you get this number. What is 3, 25 and 780?

And what is actually inside this AVI container? Often

file filename.avi

tells you.

>> Just try converting it with avconv.
>
> $ avconv -codecs | wc
>     424    2647   24437
>
> So many choices... and I presume most video players only understand a few.
> Is there some sort of guide to codecs that would help me decide which to
> use?

I say generic MP4 or MKV. That's what I use when I use a machine emulator
and record the session. Two minutes result in a AVI file with 1.5 GB
because it's uncompressed.

> Thanks to everyone for your help.  Maybe, as some of you have suggested,
> I should just leave the file as is unless my friend really wants it
> compressed enough to send to someone.

Yes.
-- 
Andreas

My random thoughts and comments
https://news-commentaries.blogspot.com/

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#27544

On 2019-07-03, Andreas Kohlbach <ank@spamfence.net> wrote:

> On 3 Jul 2019 16:16:13 GMT, Charlie Gibbs wrote:
>>
>> On 2019-07-03, Queequeg <queequeg@trust.no1> wrote:
>>
>>> Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
>>>
>>>> 14 gigabytes in size.  That's right, gigabytes - enough data to
>>>> fill three DVDs to bursting.  The file plays fine - it's a home-shot
>>>> video which is 13 minutes long.  Something is very wrong, obviously.
>>>
>>> The size is similar to what it would be if the video was 640x480@25fps 
>>> and not compressed at all.
>>
>> $ dc
>> 640 480 3 25 780 * * * * p
>> 17971200000
>>
>> Holy crap!  It's easy to forget just how many pixels we're throwing around.
>
> Not sure how you get this number. What is 3, 25 and 780?

Wild guesses: 3 bytes per pixel, 25 frames per second, 780 seconds duration.
It came out pretty close; the file size is 14,262,080,000 bytes.

> And what is actually inside this AVI container? Often
>
> file filename.avi
>
> tells you.

Aha.  file is smarter than I thought:
RIFF (little-endian) data, AVI, 640 x 480, 30.00 fps,
video:, audio: uncompressed PCM (stereo, 44100 Hz)

>>> Just try converting it with avconv.
>>
>> $ avconv -codecs | wc
>>     424    2647   24437
>>
>> So many choices... and I presume most video players only understand a few.
>> Is there some sort of guide to codecs that would help me decide which to
>> use?
>
> I say generic MP4 or MKV. That's what I use when I use a machine emulator
> and record the session. Two minutes result in a AVI file with 1.5 GB
> because it's uncompressed.

I'll give that a try if the owner cares.

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  Fight low-contrast text in web pages!  http://contrastrebellion.com

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#27545

Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
> On 2019-07-03, Andreas Kohlbach <ank@spamfence.net> wrote:
> 
>> On 3 Jul 2019 16:16:13 GMT, Charlie Gibbs wrote:
>>>
>>> On 2019-07-03, Queequeg <queequeg@trust.no1> wrote:
>>>
>>>> Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
>>>>
>>>>> 14 gigabytes in size.  That's right, gigabytes - enough data to
>>>>> fill three DVDs to bursting.  The file plays fine - it's a home-shot
>>>>> video which is 13 minutes long.  Something is very wrong, obviously.
>>>>
>>>> The size is similar to what it would be if the video was 640x480@25fps 
>>>> and not compressed at all.
>>>
>>> $ dc
>>> 640 480 3 25 780 * * * * p
>>> 17971200000
>>>
>>> Holy crap!  It's easy to forget just how many pixels we're throwing around.
>>
>> Not sure how you get this number. What is 3, 25 and 780?
> 
> Wild guesses: 3 bytes per pixel, 25 frames per second, 780 seconds duration.
> It came out pretty close; the file size is 14,262,080,000 bytes.

Uncompressed video can be reduced in size without losing any
information (picture quality) using Huffman encoding (and variations
upon its theme). The output will still be GBs in size though, so if
you're wanting to save disk space or the video is likely to be moved
about onto other devices, a lossy encoding scheme is recommended.

The AVI container can be used for all sorts of video and audio
formats, including Huffman encoding and MPEG4. I use it for
everything personally, others may have their own preference
(such as MP4 container for MPEG4/h264 video + AAC audio, which
seems to be dominate with the videos that I download from the
web).

>> And what is actually inside this AVI container? Often
>>
>> file filename.avi
>>
>> tells you.
> 
> Aha.  file is smarter than I thought:
> RIFF (little-endian) data, AVI, 640 x 480, 30.00 fps,
> video:, audio: uncompressed PCM (stereo, 44100 Hz)

It's not telling about the video, but running ffprobe should reveal
full details about the file. The conversion software will detect it
automatically anyway (it's part of the same project as the ffprobe
program).

>>>> Just try converting it with avconv.
>>>
>>> $ avconv -codecs | wc
>>>     424    2647   24437
>>>
>>> So many choices... and I presume most video players only understand a few.
>>> Is there some sort of guide to codecs that would help me decide which to
>>> use?

For starters, many/most of the codecs listed are only supported for
decoding, not encoding, so rule that out. The AVI container is very
compatible, or you could follow the MP4 trend noted above. For best
compatibility, you can choose between standard MPEG4 (Xvid), or h264
for better compression/quality.

I use Xvid in AVI because it's compatible with everything and I use
some old software/hardware that doesn't like h264. But both are
likely to work fine for modern devices. As is the MP4 container.

For audio compression, I always use MP3. AAC seems to be common these
days, but for the above reason and because audio file size is a lesser
concern, I haven't looked into it. MP3 96Kbit/s is indistinguishable
quality compared to uncompressed according to my ears, others have
their own views and I would go up to at least 128Kbit/s for something
that other people will watch.

>> I say generic MP4 or MKV. That's what I use when I use a machine emulator
>> and record the session. Two minutes result in a AVI file with 1.5 GB
>> because it's uncompressed.
> 
> I'll give that a try if the owner cares.

There's not really a generic MP4 or MKV because they're continer
formats, and it won't help with what options to throw at the encoder
(it may copy the same video/audio data into the different container,
resulting in near identical file size). I would use Xvid MPEG4 and
MP3 audio, as a personal preference (according to factors noted
above).

Something like:
avconv -i input.avi -f avi -acodec mp3 -vcodec mpeg4 -vtag XVID output.avi

That will automatically work out the compression settings, which will
affect quality. You can adjust quality by either increasing the audio
and video bitrate (for respective changes), or use the "video
quantizer scale" settings. Exact values depend on the resolution (or
sampling frequency for audio) and compression formats. If the default
doesn't work, I suggest looking at the video/audio bitrate value and
maybe just doubling it. I don't have my video encoding notes on the
PC that I'm posting from so I can't gave any suggestions for exact
figures.

And don't delete the original file until you've got it perfect. Each
lossy conversion adds more rubbish to the video (unlike lossless
Huffman encoding), so you don't want to use a compressed file as
input for another compression (even if you want it smaller).

P.S. rec.video.desktop is a good group to post in for this sort of
     question, even though it's low traffic.

-- 
__          __
#_ < |\| |< _#

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#27549

On 2019-07-04, Computer Nerd Kev <not@telling.you.invalid> wrote:

<long detailed description snipped>

Wow!  There's a lot of reading there.  Thanks for the pointers.

-- 
/~\  cgibbs@kltpzyxm.invalid (Charlie Gibbs)
\ /  I'm really at ac.dekanfrus if you read it the right way.
 X   Top-posted messages will probably be ignored.  See RFC1855.
/ \  Fight low-contrast text in web pages!  http://contrastrebellion.com

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#27551

On 04/07/2019 10.53, Charlie Gibbs wrote:
> On 2019-07-04, Computer Nerd Kev <not@telling.you.invalid> wrote:
> 
> <long detailed description snipped>
> 
> Wow!  There's a lot of reading there.  Thanks for the pointers.

Test the results not only on the computer, but also on the TV directly.
People often watch videos on other devices which are mores restrictive
on what they can play. Say, for instance, a Google Chromecast.


-- 
Cheers, Carlos.

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#27548

Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:

>>> $ dc
>>> 640 480 3 25 780 * * * * p
>>> 17971200000
>>>
>>> Holy crap!  It's easy to forget just how many pixels we're throwing around.
>>
>> Not sure how you get this number. What is 3, 25 and 780?
> 
> Wild guesses: 3 bytes per pixel, 25 frames per second, 780 seconds duration.
> It came out pretty close; the file size is 14,262,080,000 bytes.

Still seems a bit compressed :)

If one second is 640*480*30*3+44100*2*2 (audio + video) and we forget 
about the header and metadata, then we have 27824400 bytes per second 
and 512.5 seconds (8.5 minutes).

Adjusting it to 2 bytes per pixel (5-6-5 encoding?) gives 12.77 minutes.

$ echo '14262080000/(640*480*30*2+44100*2*2)/60' | bc -ql
12.77387273131130743821

I think that merely compressing it with zip / 7zip / gzip / bzip2 could 
reduce the file size significantly.

-- 
https://www.youtube.com/watch?v=9lSzL1DqQn0

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#27560

On Wed, 03 Jul 2019 05:29:25 +0000, Charlie Gibbs wrote:

> 
> Is there some way of stripping out what must be a lot of extraneous
> data and reducing the video to a reasonable size (e.g. under 100MB)?
> 

ffmpeg -i file.avi -vcodec h264_nvenc -preset slow file.mp4

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