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This article mainly shows you "how to use the FFmpeg command in linux". The content is simple and clear. I hope it can help you solve your doubts. Let the editor lead you to study and learn how to use the FFmpeg command in linux.

FFmpeg command

The typical syntax of the FFmpeg command is:

Ffmpeg [Global options] {[input File options]-I enter _ url_ address}. {[output File options] output _ url_ address}.

Now we will look at some important and useful FFmpeg commands.

1. Get audio / video file information

To display the details of your media file, run:

$ffmpeg-I video.mp4

Sample output:

Ffmpeg version n4.1.3 Copyright (c) 2000-2019 the FFmpeg developersbuilt with gcc 8.2.1 (GCC) 20181127configuration:-- prefix=/usr-- disable-debug-- disable-static-- disable-stripping-- enable-fontconfig-- enable-gmp-- enable-gnutls-- enable-gpl-- enable-ladspa-- enable-libaom-- enable-libass-- enable-libbluray-enable-libdrm-- enable-libfreetype-- enable-libfribidi-- enable-libgsm-enable-libiec61883-- enable-libjack -- enable-libmodplug-- enable-libmp3lame-- enable-libopencore_amrnb-- enable-libopencore_amrwb-- enable-libopenjpeg-- enable-libopus-- enable-libpulse-- enable-libsoxr-- enable-libspeex-- enable-libssh-- enable-libtheora-- enable-libv4l2-- enable-libvidstab-- enable-libvorbis-- enable-libvpx-- enable-libwebp-- enable-libx264-enable-libx265-- enable-libxcb-- enable-libxml2-- enable-libxvid-- enable-nvdec-enable-nvenc-- -enable-omx-- enable-shared-- enable-version3libavutil 56. 22.100 / 56. 22.100libavcodec 58. 35.100 / 58. 35.100libavformat 58. 20.100 / 58. 20.100libavdevice 58. 5.100 / 58. 5.100libavfilter 7. 40.101 / 7. 40.101libswscale 5. 3.100 / 5. 3.100libswresample 3. 3.100 / 3. 3.100libpostproc 55. 3.100 / 55. 3.100Input # 0, mov,mp4,m4a,3gp,3g2,mj2, from 'video.mp4':Metadata:major_brand: isomminor_version: 512compatible_brands: isomiso2avc1mp41encoder: Lavf58.20.100Duration: 00 kb/sStream # 0:0 (und): Video: h364 (High) (avc1 / 0x31637661), yuv420p (tv, smpte170m/bt470bg/smpte170m), 1920x1080 [SAR 1:1 DAR 16:9], 318 kb/s, 30 fps, 30 tbr, 15360 tbn 60 tbc (default) Metadata:handler_name: ISO Media file produced by Google Inc. Created on: 04/08/2019.Stream # 0:1 (eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 128 kb/s (default) Metadata:handler_name: ISO Media file produced by Google Inc. Created on: 04/08/2019.At least one output file must be specified

As you can see in the output above, FFmpeg displays the media file information, as well as FFmpeg details, such as version, configuration details, copyright tags, build parameters, library options, and so on.

If you don't want to see FFmpeg slogans and other details, but just want to see media file information, use the-hide_banner flag, like below.

$ffmpeg-I video.mp4-hide_banner

Sample output:

Use FFMpeg to view audio and video file information.

Did you see that? For now, it only displays media file details.

2. Convert video files to different formats

FFmpeg is a powerful audio and video converter, so it can convert media files between different formats. For example, to convert a mp4 file to an avi file, run:

$ffmpeg-I video.mp4 video.avi

Similarly, you can convert media files to any format you choose.

For example, to convert video from YouTube flv format to mpeg format, run:

$ffmpeg-I video.flv video.mpeg

If you want to maintain the quality of your source video files, use the-qscale 0 parameter:

$ffmpeg-I input.webm-qscale 0 output.mp4

To check the list of supported formats for FFmpeg, run:

$ffmpeg-formats3, converting video files to audio files

I convert a video file to an audio file by specifying the output format, such as .mp3, or .ogg, or any other audio format.

The above command converts input.mp4 video files to output.mp3 audio files.

$ffmpeg-I input.mp4-vn output.mp3

In addition, you can also use a variety of audio transcoding options for the output file, as shown below.

$ffmpeg-I input.mp4-vn-ar 44100-ac 2-ab 320-f mp3 output.mp3

Here,

-vn-indicates that we have disabled video recording in the output file.

-ar-sets the audio frequency of the output file. The commonly used values are 22050 Hz, 44100 Hz, 48000 Hz.

-ac-sets the number of audio channels.

-ab-indicates the audio bit rate.

-f-output file format. In our example, it is in mp3 format.

4. Change the resolution of the video file

If you want to set a video file to the specified resolution, you can use the following command:

$ffmpeg-I input.mp4-filter:v scale=1280:720-CRAV a copy output.mp4

Or

$ffmpeg-I input.mp4-s 1280x720-CMV a copy output.mp4

The above command sets the resolution of the given video file to 1280 × 720.

Similarly, to convert the above file to the size of 640 × 480, run:

$ffmpeg-I input.mp4-filter:v scale=640:480-CRAV a copy output.mp4

Or

$ffmpeg-I input.mp4-s 640x480-CMV a copy output.mp4

This technique will help you scale your video files to smaller display devices, such as tablets and phones.

5. Compress video files

It is always a good idea to reduce the size of media files to a smaller size to save hardware space.

The following command compresses and reduces the size of the output file.

$ffmpeg-I input.mp4-vf scale=1280:-1-CV libx264-preset veryslow-crf 24 output.mp4

Please note that if you try to reduce the size of the video file, you will lose video quality. If 24 is too aggressive, you can lower the-crf value to or lower.

You can also use the following options to convert the encoded audio to reduce the bit rate and make it stereo, thus reducing the size.

-ac 2-strict an aac-strict-2-BRV a 128k6, compressed audio file

Just like compressing video files, to save some disk space, you can also use the-ab flag to compress audio files.

For example, you have an audio file with a bit rate of 320 kbps. You want to compress it by changing the bit rate to any lower value, like below.

$ffmpeg-I input.mp3-ab 128 output.mp3

A list of various available audio bit rates is:

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96kbps

112kbps

128kbps

160kbps

192kbps

256kbps

320kbps

7. Remove the audio stream from a video file

If you don't want audio in a video file, use the-an flag.

$ffmpeg-I input.mp4-an output.mp4

Here,-an means there is no audio recording.

The above command undoes all audio-related flags because we don't want audio from input.mp4.

8. Remove a video stream from a media file

Similarly, if you don't want a video stream, you can simply remove it from the media file using the-vn flag. -vn represents no video recording. In other words, this command converts a given media file to an audio file.

The following command removes the video from the given media file.

$ffmpeg-I input.mp4-vn output.mp3

You can also use the-ab flag to indicate the bit rate of the output file, as shown in the following example.

$ffmpeg-I input.mp4-vn-ab 320 output.mp39, extract images from video

Another useful feature of FFmpeg is that we can easily extract images from a video file. This can be very useful if you want to create a photo album from a video file.

To extract an image from a video file, use the following command:

$ffmpeg-I input.mp4-r 1-f image2 image-%2d.png

Here,

-r-sets the frame speed. That is, the number of frames to the image is extracted per second. The default value is 25.

-f-represents the output format, that is, an image in our example.

Image-%2d.png-shows how we want to name the extracted image. In this example, the naming should start like image-01.png, image-02.png, image-03.png, and so on. If you use% 3D, then image naming like image-001.png, image-002.png, and so on starts.

10. Cropping video

FFMpeg allows you to tailor a given media file to any range we choose.

The syntax for cropping a video file is given as follows:

Ffmpeg-I input.mp4-filter:v "crop=w:h:x:y" output.mp4

Here,

Input.mp4-Source video file.

-filter:v-represents a video filter.

Crop-represents the crop filter.

W-the width of the rectangle we want to cut from the source video.

H-the height of the rectangle.

X-the x coordinate of the rectangle we want to cut from the source video.

Y-the y coordinate of the rectangle.

For example, if you want a video from a location (200150) with a width of 640 pixels and a height of 480 pixels, the command should be:

$ffmpeg-I input.mp4-filter:v "crop=640:480:200:150" output.mp4

Please note that cutting the video will affect the quality. Do not cut unless necessary.

11. Convert the specific part of a video

Sometimes, you may want to convert only a specific part of the video file to a different format. As an example, the following command converts the first 10 seconds of a given video input.mp4 file to the video .avi format.

$ffmpeg-I input.mp4-t 10 output.avi

Here, we specify the time in seconds. In addition, it is possible to specify the time in hh.mm.ss format.

12. Set the aspect ratio of the video screen

You can use the-aspect flag to set the screen aspect ratio of a video file, like below.

$ffmpeg-I input.mp4-aspect 16:9 output.mp4

The commonly used aspect ratio is:

16:9

4:3

16:10

5:4

2:21:1

2:35:1

2:39:1

13. Add poster images to audio files

You can add poster images to your file so that the images will be displayed when the audio file is played. This is useful for audio files hosted on video hosting hosts or shared websites.

$ffmpeg-loop 1-I inputimage.jpg-I inputaudio.mp3-v libx264-CMV an aac-strict experimental-BRV 19k-shortest output.mp414, cut out a piece of media file using start and stop times

You can use start and stop times to cut a video into small clips, and we can use the following command.

$ffmpeg-I input.mp4-ss 00:00:50-codec copy-t 50 output.mp4

Here,

-ss-indicates the start time of the video clip. In our example, the start time is the 50th second.

-t-represents the total duration.

It is very useful when you want to use start and end times to cut parts from an audio or video file.

Similarly, we can cut the audio like below.

$ffmpeg-I audio.mp3-ss 00:01:54-to 00:06:53-c copy output.mp315, split the video file into multiple parts

Some sites will only allow you to upload videos of a specified size. In this case, you can split the large video file into several smaller parts, like below.

$ffmpeg-I input.mp4-t 00:00:30-c copy part1.mp4-ss 00:00:30-codec copy part2.mp4

Here,

-t 00:00:30 means that a portion of the video is created from the beginning of the video to the 30th second of the video.

-ss 00:00:30 displays the start timestamp for the next part of the video. It means that part 2 will start in the 30th second and continue to the end of the original video file.

16. Join or merge multiple video parts into one

FFmpeg can also join multiple video parts and create a single video file.

Create a join.txt that contains the exact path to the file you want to join. All files should be in the same format (the same encoding format). The paths to all files should be listed one by one, like below.

File / home/sk/myvideos/part1.mp4file / home/sk/myvideos/part2.mp4file / home/sk/myvideos/part3.mp4file / home/sk/myvideos/part4.mp4

Now, join all the files and use the command:

$ffmpeg-f concat-I join.txt-c copy output.mp4

If you get some mistakes like the following

[concat @ 0x555fed174cc0] Unsafe file name'/ path/to/mp4'join.txt: Operation not permitted

Add-safe 0:

$ffmpeg-f concat-safe 0-I join.txt-c copy output.mp4

The above command joins the part1.mp4, part2.mp4, part3.mp4, and part4.mp4 files into a single file called output.mp4.

17. Add subtitles to a video file

We can use FFmpeg to add subtitles to the video file. Download the correct subtitle for your video and add it to your video as shown below.

$fmpeg-I input.mp4-I subtitle.srt-map 0-map 1-c copy-CMV libx264-crf 23-preset veryfast output.mp418, preview or test a video or audio file

You may want to use the preview to verify or test whether the output file has been transcoded properly. To complete the preview, you can play it from your terminal, using the command:

$ffplay video.mp4

Similarly, you can test the audio file, as shown below.

$ffplay audio.mp319, increase / decrease video playback speed

FFmpeg allows you to adjust the speed of video playback.

To increase the video playback speed, run:

$ffmpeg-I input.mp4-vf "setpts=0.5*PTS" output.mp4

This command will double the speed of the video.

To slow down your video speed, you need to use a multiple greater than 1. To reduce the playback speed, run:

$ffmpeg-I input.mp4-vf "setpts=4.0*PTS" output.mp420, GIF for creating animation

We use GIF images on almost all social and professional networks for a variety of purposes. With FFmpeg, we can easily and quickly create animated video files. The following guide illustrates how to use FFmpeg and ImageMagick to create an animated GIF file in a Unix-like system.

How to create animated GIF in Linux

21. Create video from PDF file

I have collected a lot of PDF files over the years, mostly Linux tutorials, and saved them on my tablet. Sometimes I don't bother to read them from my tablet. So I decided to create a video from a PDF file and watch them on a large-screen device like a TV or a computer. If you want to know how to make a movie from a batch of PDF files, the following guide will help you.

How to create a video from a PDF file in Linux

22. Get help

In this guide, I have covered most of the frequently used FFmpeg commands. It has many different options to do a variety of advanced functions. To learn more about usage, please refer to the manual page.

The above $man ffmpeg is all the contents of this article entitled "how to use FFmpeg commands in linux". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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