- [Statement] Course learning address: https://ke.qq.com/course/468797
table of Contents
The main parameters
- -i set input stream
- -f set output format (format)
- -ss start time
- -t time length
ffmpeg -i test.mp4 -codec copy -ss 10 -t 10 -f flv out.mp4
- The output is actually in flv format.
- If the suffix prevails, you need to remove -f flv.
[Query the full name of MP3 format]
ffmpeg -encoders | findstr mp3
Audio parameters
- -aframes sets the number of audio frames to be output
- -b:a audio bit rate
- -ar set sampling rate
- -ac sets the number of sound channels
- -acodec sets the sound codec, if copy is used to indicate that the original codec data must be copied.
- -an does not process audio
- -af audio filter
fmpeg -i test.mp4 -b:a 192k -ar 48000 -ac 2 -acodec libmp3lame -aframes 200 out.mp3
Video parameters
- -vframes sets the number of video frames to be output
- -b set video bit rate
- -b:v video bit rate
- -r set frame rate
- -s set the width and height of the screen
- -vn does not process video
- -aspect aspect set the aspect ratio 4:3, 16:9 or 1.3333 1.7777
- -vcodec sets the video codec, if copy is used to indicate that the original codec data must be copied.
- -vf video filter
fmpeg -i test.mp4 -vframes 300 -b:v 300k -r 30 -s 640x480 -aspect 16:9 -vcodec libx265
ffmpeg command to extract audio and video data
Keep package format
ffmpeg -i test.mp4 -acodec copy -vn audio.mp4 ffmpeg -i test.mp4 -vcodec copy -an video.mp4
Extract video
- Keep encoding format:
ffmpeg -i test.mp4 -vcodec copy -an test_copy.h264
- Mandatory format:
ffmpeg -i test.mp4 -vcodec libx264 -an test.h264
Extract audio
- Keep encoding format:
fmpeg -i test.mp4 -acodec copy -vn test.aac
- Mandatory format:
fmpeg -i test.mp4 -acodec libmp3lame -vn test.mp3
- More reference: http://www.ffmpeg.org/ffplay.html