Introduction to ffmpeg

1. Basic composition

FFmpeg The basic components of the framework include AVFormat、AVCodec、AVFilter、AVDevice、AVUtil Wait for module library .

2.AVFormat

AVFormat Most media encapsulation formats are implemented in , Including encapsulation and unpacking , Such as MP4、FLV、TS Wait for the file encapsulation format ,RTMP、RTSP、HLS And so on network protocol encapsulation format .

3.AVCodec

AVCodec It realizes most commonly used encoding and decoding formats , Both support coding , It also supports decoding . In addition to supporting MPEG4、AAC、MJPEG And other self-contained media encoding and decoding formats , Third party codecs are also supported , Such as H.264 code 、H.265 code ;MP3 code .

4.AVFilter

AVFilter Provides a general audio 、 video 、 Subtitle and other filter processing frame .

5.swscale

swscale The module provides high-level image conversion API, For example, image scaling and pixel format conversion are allowed . example ： hold 1080P convert to 720P, Or the YUV Convert to RGB data .

6.swresample

swresample The module provides high-level audio resampling API, For example, allow the operation of audio sampling .

7. Tool introduction

When we go to the official website to download the development library , There will be the following exe Program .

7.1FFmpeg Codec tools ffmpeg.exe

example ： Turn to encapsulate , take MP4 The file to avi Format

./ffmpeg.exe -i input.mp4 output.avi

Parameters -i take input.mp4 Input as input source , Then conduct transcoding and repacking , Output to output.avi

The workflow is as follows ：

• decapsulation
• decode
• code
• encapsulation

The following steps are required ：

7.2FFmpeg Player tools ffplay.exe

If you want to use ffplay, The system needs to have SDL To support the foundation .

7.3FFmpeg Multimedia analysis tools ffprobe.exe

You can get the desired media information from the media file , For example, the parameters of audio 、 Video parameters, etc .

Example ： Display file information

./ffprobe.exe -show_streams F:\movie\1.mp4

give the result as follows ：