10 ‘Avconv’ Commands to Record, Convert and Extract Videos & Audios from Linux Terminal

Are you a Linux user who frequently works with video and audio files? If so, you'll want to learn about the versatile avconv tool. Avconv is a command-line utility that can record, convert, and extract videos and audios from Linux terminals. In this article, we'll explore 10 essential avconv commands that you can use to accomplish a variety of multimedia tasks.

Record a Video

The first avconv command we'll look at is how to record a video. This is useful when you need to capture a video of your screen or webcam. Here's the command

avconv -f x11grab -s 1280x720 -i :0.0+0,0 -vcodec libx264 output.mp4

In this command, we use x11grab format to capture the X11 display server's output. The -s option sets the video size to 1280x720 pixels. The -i option specifies the input source, which is the screen at position 0,0. Finally, we use the libx264 video codec and save the output to a file called output.mp4.

Convert a Video

Avconv can also be used to convert a video from one format to another. For example, you might need to convert a video to a format that is compatible with a specific device. Here's the command to convert a video

avconv -i input.avi -codec:v libx264 -codec:a copy output.mp4

In this command, we use the -i option to specify the input file (input.avi). We then use the libx264 video codec and copy the audio stream with the -codec:a copy option. Finally, we save the output file as output.mp4.

Extract Audio From a Video

If you have a video with a great soundtrack that you want to listen to on its own, you can extract the audio using avconv. Here's how to do it

avconv -i input.mp4 -vn -codec:a copy output.mp3

In this command, we use the -vn option to disable video processing. The -codec:a copy option copies the audio stream without re-encoding it. Finally, we save the output file as output.mp3.

Extract a Specific Section of a Video

Sometimes, you may only need a specific section of a video. Avconv can extract a section of a video by specifying the start time and duration. Here's the command

avconv -i input.mp4 -ss 00:01:30 -t 00:00:30 -codec copy output.mp4

In this command, we use the -ss option to specify the start time (00:01:30) and the -t option to specify the duration (00:00:30). We also use the -codec copy option to copy the video and audio streams without re-encoding them.

Merge Multiple Videos

If you have multiple videos that you want to combine into one, you can use avconv to merge them. Here's how

avconv -i "concat:input1.mp4|input2.mp4|input3.mp4" -codec copy output.mp4

In this command, we use the concat protocol to specify the input files (input1.mp4, input2.mp4, and input3.mp4). We then use the -codec copy option to copy the video and audio streams without re-encoding them. Finally, we save the output file as output.mp4.

Resize a Video

Avconv can also be used to resize a video. This is useful when you need to reduce the file size of a video or make it compatible with a specific device. Here's the command

avconv -i input.mp4 -vf scale=640:360 output.mp4

In this command, we use the -vf option to specify a video filter. The scale filter resizes the video to 640x360 pixels. Finally, we save the output file as output.mp4.

Extract Frames From a Video

If you need to extract individual frames from a video, avconv can help. Here's the command

avconv -i input.mp4 -r 1 -f image2 %d.png

In this command, we use the -r option to specify the frame rate (1 frame per second). The -f option specifies the output format (image2). Finally, we use %d.png to specify the output file name format (frame number.png).

Convert a Video to a GIF

GIFs are a popular format for sharing short animations on social media. You can convert a video to a GIF using avconv. Here's the command

avconv -i input.mp4 -vf scale=320:-1 -t 10 -r 10 output.gif

In this command, we use the scale filter to resize the video to a width of 320 pixels while maintaining the aspect ratio. The -t option specifies the duration of the GIF (10 seconds). The -r option specifies the frame rate (10 frames per second). Finally, we save the output as output.gif.

Add Subtitles to a Video

If you have a video that needs subtitles, avconv can help. Here's how to add subtitles

avconv -i input.mp4 -vf subtitles=subs.srt output.mp4

In this command, we use the subtitles filter to add subtitles from a file called subs.srt. The subtitles file must be in SRT format. Finally, we save the output as output.mp4.

Remove Audio From a Video

Sometimes, you may want to remove audio from a video. Here's the command to do it

avconv -i input.mp4 -an -codec copy output.mp4

In this command, we use the -an option to disable audio processing. The -codec copy option copies the video stream without re-encoding it. Finally, we save the output as output.mp4.

Advanced Format Conversion

Sometimes, you may need to convert a video to a specific format that is compatible with a certain device or software. Avconv can help with fine-tuned encoding parameters. Here's the command

avconv -i input.mp4 -c:v libx264 -preset fast -crf 22 -c:a aac -b:a 128k output.mkv

In this command, we use the -c:v option to specify the video codec (libx264). The -preset option specifies encoding speed and quality (fast). The -crf option sets the video quality (22). The -c:a option specifies the audio codec (aac), and the -b:a option sets the audio bitrate (128k). Finally, we save the output as output.mkv.

Audio Processing Commands

Join Multiple Audio Files

If you have multiple audio files that you want to join together, avconv can help. Here's the command

avconv -i "concat:input1.mp3|input2.mp3|input3.mp3" -acodec copy output.mp3

Convert Audio Format

Avconv can also convert an audio file from one format to another

avconv -i input.wav -vn -codec:a libmp3lame -qscale:a 2 output.mp3

Adjust Audio Volume

If you have an audio file that is too quiet or too loud, you can adjust the volume

avconv -i input.mp3 -filter:a "volume=2" output.mp3

Extract Audio Section

Extract a specific section of an audio file using time parameters

avconv -i input.mp3 -ss 00:01:30 -t 00:00:30 -codec copy output.mp3

Conclusion

Avconv is a powerful command-line tool that simplifies multimedia processing on Linux systems. These commands cover essential tasks from screen recording and format conversion to audio extraction and video manipulation. With practice, avconv becomes an indispensable tool for efficient multimedia workflow automation in terminal environments.