|
|
|
|
|
+++
|
|
|
|
|
|
title = 'Converting big videos'
|
|
|
|
|
|
summary = '''I am subscribed to a few mailing lists and I stumbled across
|
|
|
|
|
|
a big video file in one of them recently. Here is a small command-line
|
|
|
|
|
|
command using **ffmpeg** that cut its filesize in half.'''
|
|
|
|
|
|
date = '2023-10-01T10:37:00+0200'
|
|
|
|
|
|
#lastmod = ''
|
|
|
|
|
|
categories = [ 'computerstuff' ]
|
|
|
|
|
|
tags = [ 'openbsd', 'freebsd', 'linux', 'command-line' ]
|
|
|
|
|
|
|
|
|
|
|
|
+++
|
|
|
|
|
|
|
|
|
|
|
|
I don't like big mail attachments but when I see them I try to reduce their filesize
|
|
|
|
|
|
because I think it should be possible to send pictures with good quality but with reduced
|
|
|
|
|
|
filesize.
|
|
|
|
|
|
|
|
|
|
|
|
{{< alert >}}
|
|
|
|
|
|
Whenever I talk about filesizes or video sizes in this post, I want to
|
|
|
|
|
|
send them via email. You can of course have big files with high bitrates,
|
|
|
|
|
|
but forcing the mail recipient to download those in his email client is
|
|
|
|
|
|
just not okay IMHO.
|
|
|
|
|
|
{{< /alert >}}
|
|
|
|
|
|
|
|
|
|
|
|
For this I inspect images and videos with some basic commands.
|
|
|
|
|
|
|
|
|
|
|
|
## Inspecting the video file
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ll Video.MOV
|
|
|
|
|
|
-rw------- 1 dominic dominic 10.7M Sep 23 19:05 Video.MOV
|
|
|
|
|
|
$ file Video.MOV
|
|
|
|
|
|
Video.MOV: ISO Media, Apple QuickTime movie, Apple QuickTime (.MOV/QT)
|
|
|
|
|
|
$ ffmpeg -i Video.MOV
|
|
|
|
|
|
ffmpeg version 4.4.4 Copyright (c) 2000-2023 the FFmpeg developers
|
|
|
|
|
|
built with OpenBSD clang version 13.0.0
|
|
|
|
|
|
configuration: --enable-shared --arch=amd64 --cc=cc --enable-debug --disable-stripping --disable-indev=jack --disable-outdev=sdl2 --enable-fontconfig --enable-frei0r --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libdav1d --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libmp3lame --enable-libopus --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nonfree --enable-openssl --enable-libvidstab --extra-cflags='-I/usr/local/include -I/usr/X11R6/include' --extra-libs='-L/usr/local/lib -L/usr/X11R6/lib' --extra-ldsoflags= --mandir=/usr/local/man --objcc=/usr/bin/false --optflags='-O2 -pipe -g -Wno-redundant-decls'
|
|
|
|
|
|
libavutil 56. 70.100 / 56. 70.100
|
|
|
|
|
|
libavcodec 58.134.100 / 58.134.100
|
|
|
|
|
|
libavformat 58. 76.100 / 58. 76.100
|
|
|
|
|
|
libavdevice 58. 13.100 / 58. 13.100
|
|
|
|
|
|
libavfilter 7.110.100 / 7.110.100
|
|
|
|
|
|
libswscale 5. 9.100 / 5. 9.100
|
|
|
|
|
|
libswresample 3. 9.100 / 3. 9.100
|
|
|
|
|
|
libpostproc 55. 9.100 / 55. 9.100
|
|
|
|
|
|
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Video.MOV':
|
|
|
|
|
|
Metadata:
|
|
|
|
|
|
major_brand : qt
|
|
|
|
|
|
minor_version : 0
|
|
|
|
|
|
compatible_brands: qt
|
|
|
|
|
|
creation_time : 2023-09-23T16:11:17.000000Z
|
|
|
|
|
|
com.apple.quicktime.artwork: <20><>
|
|
|
|
|
|
com.apple.quicktime.is-montage: iMovie
|
|
|
|
|
|
Duration: 00:01:53.23, start: 0.000000, bitrate: 795 kb/s
|
|
|
|
|
|
Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 94 kb/s (default)
|
|
|
|
|
|
Metadata:
|
|
|
|
|
|
creation_time : 2023-09-23T16:11:17.000000Z
|
|
|
|
|
|
handler_name : Core Media Audio
|
|
|
|
|
|
vendor_id : [0][0][0][0]
|
|
|
|
|
|
Stream #0:1(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv, bt709), 568x320, 693 kb/s, 30 fps, 30 tbr, 600 tbn, 1200 tbc (default)
|
|
|
|
|
|
Metadata:
|
|
|
|
|
|
creation_time : 2023-09-23T16:11:17.000000Z
|
|
|
|
|
|
handler_name : Core Media Video
|
|
|
|
|
|
vendor_id : [0][0][0][0]
|
|
|
|
|
|
encoder : H.264
|
|
|
|
|
|
At least one output file must be specified
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
## Converting to a smaller filesize
|
|
|
|
|
|
|
|
|
|
|
|
With default values (for bitrates). Takes about 12 seconds and
|
|
|
|
|
|
creates a 4.4MB big file. I also strip metadata out of the videos, usually.
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ffmpeg -i Video.MOV -acodec aac -vcodec h264 -map_metadata -1 newvideo-default.mp4
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
Another approach would be to specify the bitrates. You probably have to “play” with
|
|
|
|
|
|
these values. For this example I chose 64k for audio and 300k for video. Note, that
|
|
|
|
|
|
the filesize is actually bigger than the example above (with default values). This
|
|
|
|
|
|
took about 16 seconds but creates a file of 5.0MB.
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ffmpeg -i Video.MOV -acodec aac -vcodec h264 -map_metadata -1 -b:a 64k -b:v 300k newvideo-64k-300k.mp4
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
## Also convert the video size
|
|
|
|
|
|
|
|
|
|
|
|
When we inspected the file above we notices a video size of 568×320.
|
|
|
|
|
|
We will reduce this now to 240 on the shorter side and we will get a
|
|
|
|
|
|
new file that is 3.2MB big.
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ffmpeg -i Video.MOV -acodec aac -vcodec h264 -map_metadata -1 -filter:v scale=-1:240 newvideo-default-resized.mp4
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
We can improve this by reducing the audio bitrate to 32kb/s (going
|
|
|
|
|
|
further down did not reduce the file much).
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ffmpeg -i Video.MOV -acodec aac -vcodec h264 -map_metadata -1 -filter:v scale=-1:240 -b:a 32k newvideo-default-resized-32k.mp4
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
Another look into the last converted file:
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ffmpeg -i newvideo-default-resized-32k.mp4
|
|
|
|
|
|
ffmpeg version 4.4.4 Copyright (c) 2000-2023 the FFmpeg developers
|
|
|
|
|
|
built with OpenBSD clang version 13.0.0
|
|
|
|
|
|
configuration: --enable-shared --arch=amd64 --cc=cc --enable-debug --disable-stripping --disable-indev=jack --disable-outdev=sdl2 --enable-fontconfig --enable-frei0r --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libdav1d --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libmp3lame --enable-libopus --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nonfree --enable-openssl --enable-libvidstab --extra-cflags='-I/usr/local/include -I/usr/X11R6/include' --extra-libs='-L/usr/local/lib -L/usr/X11R6/lib' --extra-ldsoflags= --mandir=/usr/local/man --objcc=/usr/bin/false --optflags='-O2 -pipe -g -Wno-redundant-decls'
|
|
|
|
|
|
libavutil 56. 70.100 / 56. 70.100
|
|
|
|
|
|
libavcodec 58.134.100 / 58.134.100
|
|
|
|
|
|
libavformat 58. 76.100 / 58. 76.100
|
|
|
|
|
|
libavdevice 58. 13.100 / 58. 13.100
|
|
|
|
|
|
libavfilter 7.110.100 / 7.110.100
|
|
|
|
|
|
libswscale 5. 9.100 / 5. 9.100
|
|
|
|
|
|
libswresample 3. 9.100 / 3. 9.100
|
|
|
|
|
|
libpostproc 55. 9.100 / 55. 9.100
|
|
|
|
|
|
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'newvideo-default-resized-32k.mp4':
|
|
|
|
|
|
Metadata:
|
|
|
|
|
|
major_brand : isom
|
|
|
|
|
|
minor_version : 512
|
|
|
|
|
|
compatible_brands: isomiso2avc1mp41
|
|
|
|
|
|
encoder : Lavf58.76.100
|
|
|
|
|
|
Duration: 00:01:53.24, start: 0.000000, bitrate: 140 kb/s
|
|
|
|
|
|
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 426x240, 100 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
|
|
|
|
|
|
Metadata:
|
|
|
|
|
|
handler_name : VideoHandler
|
|
|
|
|
|
vendor_id : [0][0][0][0]
|
|
|
|
|
|
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 31 kb/s (default)
|
|
|
|
|
|
Metadata:
|
|
|
|
|
|
handler_name : SoundHandler
|
|
|
|
|
|
vendor_id : [0][0][0][0]
|
|
|
|
|
|
At least one output file must be specified
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
## How to find the best values
|
|
|
|
|
|
|
|
|
|
|
|
The best option is probably to get routined. Convert some videos and look what
|
|
|
|
|
|
changes (video and audio quality, filesize). Also try to trim them if you need to.
|
|
|
|
|
|
Have a look at the [manpages of ffmpeg][1] (switches `-t`, `-to`, `-ss`).
|
|
|
|
|
|
|
|
|
|
|
|
[1]: https://ffmpeg.org/ffmpeg.html
|
|
|
|
|
|
|
|
|
|
|
|
I guess a short video where someone is talking and explaining something does
|
|
|
|
|
|
not always need high bitrates. This is like a slideshow where someone is talking
|
|
|
|
|
|
in the background.
|
|
|
|
|
|
|
|
|
|
|
|
If you want to share music you might use higher bitrates. The classic mp3 files
|
|
|
|
|
|
sounded quite good with 192kb/s or even 320kb/s but I think 128kb/s should
|
|
|
|
|
|
also be fine. For aac files I'd probably try 96kb/s first and then increase or
|
|
|
|
|
|
decrease on another run and look if the filesize improves.
|
|
|
|
|
|
|
|
|
|
|
|
It basically makes no sense reducing much of a bitrate if the filesize stays nearly
|
|
|
|
|
|
the same in the end (as long as you can't see or hear much difference).
|
|
|
|
|
|
|
|
|
|
|
|
## Some values for reference
|
|
|
|
|
|
|
|
|
|
|
|
The filename suggest the used bitrates and options.
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ll Video.MOV newvideo-*
|
|
|
|
|
|
-rw------- 1 dominic dominic 10.7M Sep 23 19:05 Video.MOV
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 5.0M Oct 1 09:48 newvideo-64k-300k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 6.4M Oct 1 09:40 newvideo-64k-400k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 1.8M Oct 1 10:04 newvideo-default-resized-16k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 1.8M Oct 1 10:03 newvideo-default-resized-24k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 1.9M Oct 1 10:01 newvideo-default-resized-32k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 3.2M Oct 1 09:54 newvideo-default-resized.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 4.4M Oct 1 09:43 newvideo-default.mp4
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
```console
|
|
|
|
|
|
$ ls -l Video.MOV newvideo-*
|
|
|
|
|
|
-rw------- 1 dominic dominic 11254505 Sep 23 19:05 Video.MOV
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 5290645 Oct 1 09:48 newvideo-64k-300k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 6705317 Oct 1 09:40 newvideo-64k-400k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 1844227 Oct 1 10:04 newvideo-default-resized-16k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 1869904 Oct 1 10:03 newvideo-default-resized-24k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 1991368 Oct 1 10:01 newvideo-default-resized-32k.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 3382468 Oct 1 09:54 newvideo-default-resized.mp4
|
|
|
|
|
|
-rw-r--r-- 1 dominic dominic 4647129 Oct 1 09:43 newvideo-default.mp4
|
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
## Related content (optimizing images)
|
|
|
|
|
|
|
|
|
|
|
|
I've created a similar post for images in 2020:
|
|
|
|
|
|
[Optimizing PNG images]({{< ref "2020-01-20-optimizing-png-images/" >}})
|
|
|
|
|
|
(there is also some info on JPG files).
|
|
|
|
|
|
|
