[book club issue 13] packaging format of audio and video files

Some knowledge and concepts of audio and video

• Bit rate
• Duration
• Package format
• Coding protocol

video ：

• The resolution of the
• Frame rate
• Picture quality
• Pixels

Audio ：

• Sampling rate
• Track number
• Channel layout
• Tone quality
• Number of samples
• Number of sampling bits
• Frame length

Common video packaging formats ：

1. MP4、TS、MKV、FLV

MP4 The composition of ： By many Box and FullBox form

FullBox： yes Box Development of , Again iieader Added in 8 position verison Information and 24 Bit flags Information

Box：Header and Data Two parts

Header： It contains the whole Box The length of the size of and type

Data： Contains actual data or Pure data or Son Box（ Son Box Also known as container ）

ftype Box： File start location --- data ： type 、 edition 、 Compatible protocols, etc

moov Containers ： Media data information , There are two sub containers inside

1. mvhd： File header information

2. trak（ orbital ）： In the media file track Information

mdat Box： Store the actual data content of the media file

Common audio packaging formats ：

1. MP3、WMA、AAC、RTMP、RTSP、HLS