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Common FFmpeg Commands

#水文#视频处理125
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This post is translated from Chinese into English through AI.View Original
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The document introduces FFmpeg, a powerful and free open-source tool for audio and video processing, and provides a guide for beginners on common FFmpeg commands. It includes installation instructions for Windows and Ubuntu, an overview of container formats (like MP4, MKV, WebM), and various encoding options (both licensed and royalty-free). Key commands are outlined for tasks such as format conversion, transcoding, trimming clips, bitrate control, resizing, frame rate adjustment, audio extraction, separating audio and video, merging them, compressing audio, taking screenshots, and adding covers to videos or audio files. The document emphasizes the use of specific parameters for each command and provides examples for clarity. It also references additional resources for further learning.

Preface#

Recently discovered and used FFmpeg and found it to be very powerful, capable of various audio and video operations. Some software also references FFmpeg mainly because it is a free and open-source tool that does not require a license. Here is a simple note on several common FFmpeg commands to help novice readers easily convert their video encoding! Most of the content here is referenced from existing online sources with marked citations.

Let's have some fun together ฅ՞•ﻌ•՞ฅ

Installing FFmpeg#

image

Windows#

Since FFmpeg only provides source code that needs to be compiled, there are experts who have compiled FFmpeg that can be directly used from the repository.

https://github.com/BtbN/FFmpeg-Builds/releases

Ubuntu#

sudo add-apt-repository universe
sudo apt update
sudo apt install ffmpeg

Overview#

Container Formats#

The common video file formats are actually containers that include video tracks, audio tracks, metadata, subtitles, titles, cover images, etc. Common video container formats include:

  • MP4 (MPEG 4)
  • MKV (Matroska)
  • WebM
  • AVI (ASF)
  • MOV (QuickTime)

TOP: WebM is a popular container for AV1, VP9, and VP8, which require specific hardware acceleration for encoding and decoding.

For example, AIN's 2022 new products all support AV1 encoding and decoding hardware acceleration.

Encoding#

Common types of encoding include licensed encoding, royalty-free encoding, and audio encoding formats.

Licensed Encoding

  • H.262
  • H.264
  • H.265

Royalty-Free Encoding

  • VP8
  • VP9
  • AV1

Audio Encoding Formats

  • MP3
  • AAC

Video Encoders

  • libx264: The most popular open-source H.264 encoder
  • NVENC: H.264 encoder based on NVIDIA GPU
  • libx265: Open-source HEVC encoder
  • libvpx: Google's VP8 and VP9 encoders
  • libaom: AV1 encoder

Audio Encoders

  • libfdk-aac
  • aac

View the installed encoders in FFmpeg

ffmpeg -encoders

Usage#

ffmpeg [1] [2] -i [3] [4] [5]

[1] Global parameters

[2] Input file parameters

[3] Input file

[4] Output file parameters

[5] Output file

Parameters#

  • -c: Specify the encoder
  • -c copy: Directly copy without re-encoding, faster
  • -c:v: Specify the video encoder
  • -c:a: Specify the audio encoder
  • -i: Specify the input file
  • -an: Remove the audio stream
  • -vn: Remove the video stream
  • -preset: Video encoding quality ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow
  • -y: Overwrite files without confirmation

More: https://zh.m.wikipedia.org/zh-hans/FFmpeg

File Information#

ffmpeg -i input.mp4

Only display metadata, clean
ffmpeg -i input.mp4 -hide_banner

Format Conversion#

ffmpeg -i input.avi output.mp4

Direct copy is the fastest
ffmpeg -i input.avi -c copy output.mp4

-i Input file

-c copy Direct copy without transcoding is faster

Transcoding#

ffmpeg -i input.mp4 -c:v libx264 output.mp4

Choose H.265 encoder
ffmpeg -i input.mp4 -c:v libx265 output.mp4

-i Input file

-c Convert encoder

Clip#

ffmpeg -ss 00:00:00 -t 00:00:30 -i input.mp4 -vcodec copy -acodec copy output.mp4

-ss Start time

-t End time

-i Input file

Bitrate#

This section is too professional and requires a deeper understanding! Here we only demonstrate the simplest encoding methods, excluding compression configurations.

ABR (VBR) Two-Pass Encoding#

ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -pass 1 -f null /dev/null
ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -pass 2 output.mp4

Of course, you can also do VBR in one pass
ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -pass 1 output.mp4

CBR Constant Bitrate#

Compress to 2M bitrate
ffmpeg -i input.mp4 -b:v 2M output.mp4

Stabilize compression at 2M bitrate
ffmpeg -i input.mp4 -b:v 2M -bufsize 2M output.mp4

Stabilize at 2M bitrate allowing a maximum of 2.5M bitrate
ffmpeg -i input.mp4 -b:v 2M -bufsize 2M -maxrate 2.5M output.mp4

Using libx264 encoder with a minimum bitrate of 1M, maximum bitrate of 2M, stabilized at 1M bitrate
ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -minrate 1M -maxrate 2M -bufsize 1M output.mp4

-i Input file

-b Audio bitrate

-b Video bitrate

-minrate Minimum allowed bitrate

-maxrate Maximum allowed bitrate

-bufsize Bitrate control buffer

Size#

ffmpeg -i input.avi -fs 114M output.mp4

-i Input file

-fs Control file size

Resolution#

ffmpeg -i input.mp4 -vf scale=1920:1080 output.mp4

Maintain aspect ratio with -1
ffmpeg -i input.mp4 -vf scale=1920:-1 output.mp4

-i Input file
[Maintain aspect ratio -1]

FPS#

ffmpeg -i input.avi -r 30 output.mp4

-i Input file

-r Frame rate value

Extract Audio#

ffmpeg -i input.mp4 -aq 0 -f mp3 -vn output.mp3

ffmpeg -i input.mp4 -acodec aac -vn output.mp3

-i Input file

-f Output format

-vn Exclude video

-aq 0 Compression quality

-acodec Set audio codec

Separate Audio and Video#

Separate Video

ffmpeg -i input.mp4 -vcodec copy -an output.mp4

Separate acc Format

ffmpeg -i input.mp4 -acodec copy -vn output.m4a
ffmpeg -i m.m4a m.mp3

Directly Extract Audio

ffmpeg -i mavel4.mp4 m.mp3

Merge Audio and Video#

ffmpeg -i video.mp4 -i audio.mp3 -c:v copy -c:a aac -strict experimental output.mp4

-i Input file

-c Audio encoding method

-c Video encoding method

Compress Audio#

ffmpeg -i input.wav -b:a 64k -acodec mp3 -ar 44100 -ac 1 output.mp3

-i Input file

-b Bitrate

-ar Sample rate

Screenshot#

Screenshot at a specified time

ffmpeg -ss 00:11:45 -i input.mp4 -r 1 output.jpg

Extract frames from the beginning

ffmpeg -i input.mp4 -r 1 -q:v 2 -f image2 output.jpg

-i Input file

-r Frames per second

-q Image quality

-f Output format

Cover#

Video Cover

ffmpeg -i input.mp4 -i input.jpg -map 0 -map 1:0 -c copy -disposition:v:1 output.mp4

Audio Cover

ffmpeg -i input.mp3 -i input.jpg -map 0:0 -map 1:0 -codec copy -id3v2_version 3 \ 
-metadata:s:v title="Album cover" -metadata:s:v comment="Cover (front)" output.mp3

Citations:
FFmpeg Video Processing Beginner's Tutorial

Using ffmpeg to Separate Video and Audio Streams

Common FFmpeg Parameters Explanation and Examples

Bitrate Control (1): Understanding Bitrate Control Modes (x264,x264,vpx)

This article is updated synchronously by Mix Space to xLog. The original link is https://www.miaoer.net/posts/blog/ffmpeg

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