1. Overview

 ffmpeg is an open sourcefreecrossplatform

The video and audio stream scheme ofbelongs to free software. It provides a complete solution for recording, conversion, and fluidized sound videos. It contains very advanced audio/video decoding library libavcodec.ffmpeg has very powerful features including video collection function,Video format conversion, video grasping, add watermark to video, etc. For details, please refer to the official website: http://ffmpeg.org/, or my blog: http://blog.csdn.net/gameloft9/article/details/44807439.

Since FFMPEG has an command line tool ffmpeg.exe, it can be convenient to use it in its own project through call batch command commands. Although this is not the best solution for project integration, small projects can indeed save a lot of time. So it is necessary to study its commands and parameters. As for the source code analysis and secondary development, there will be time to study again in the future.

2, grammar format

ffmpeg [global_options] {[input_file_options] -i input_file} … {[output_file_options] output_file} …

3. Introduction to FFMPEG Tools

ffmpeg is a very fast audio and video conversion tool. In addition, it can capture data in the audio and video source, and it can also be convertedsampling rate, you can also quickly change the video size through high -quality multi -phase filters. FFMPEG reads data from multiple sources. It can be conventional files, pipelines, network streaming media, grab device, etc. This is recognized by the -i parameter in the command line. FFMPEG can also
output to
Different goals, specify the accurate file name, note that any non -parameter character in the command line will be considered a file name of the output file.
Each input and output file will contain multiple different types of streams in principle, such as video flow, audio stream, subtitles, accessories, data. The quantity and type of allowed stream are limited by the container format. choose
Which input source, which target output is automatically completed, can also be specified through -MAP parameters.

If you want to use the available input source, they must quote their serial number (starting from 0). For example, the first input file is 0, the second is 1, and so on. Similar, the flow in the file is referenced by their serial number. For example: 2: 3 indicates the fourth stream of the third input file.Pulmon parameters play a role in the next file, so the order is important. You can repeat the same parameter in the command line. Every time the parameter appears, it will work on the next input and output file that follows the following.but global parameters, for example: Verbosity level, such parameters need to be specified first.Do not confuse the input and output file. The first specified is input files, and then all output files. Do not confuse parameters of different files. All parameters are only valid for files followed.

A few simple examples:
1. Set the bit rate of the output video to 64 kbit/s:
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi

2. Set the frame rate of the output file to 24 FPS:
ffmpeg -i input.avi -r 24 output.avi

3. Establish the frame rate of the input file (valid for the RAW format) to 1 FPS, and set the frame rate of the output file to 24 FPS:
ffmpeg -r 1 -i input.m2v -r 24 output.avi
The input file in RAW format may require format parameters.