Channels and audio tracks

Generally, an audio/video file contains 0-N audio tracks. Each audio track contains 1-M audio tracks.

Each audio track is an independent sound unit. The most common application scenarios of multiple audio tracks are the language of the video (Mandarin, English, Cantonese) and the comment audio track of the movie. Will a movie play multiple audio tracks at the same time? Generally, this is not because audio tracks are generally independent from each other and there is no need for simultaneous playback. For example, normal people do not require Mandarin sound and Cantonese sound when playing a movie.

A sound track usually contains multiple channels. The common two channels and six channels (5.1 channels) are used. If one channel is used (or the left and right channels are enabled for two channels ), this sound signal will be sent to two speakers at the same time, and the sound of the speakers will be the same; if there are two channels, the sound of the two channels will enter two speakers separately, then the sound will produce a stereo effect; if it is 6-channel, it is generally the headset or audio of 6 speakers that can play the desired effect. Can the headset of 2 Speakers play 5.1-channel? It is said that there is a technology called Dolby headphones, through the acoustic principle of 6 channels virtualized into two channels, and then sent to the headset. Multiple channels of a single audio track usually need to be played at the same time, but why should the player distinguish between the left and right channels? Because the VCD era does not support multiple audio tracks, there are also many scenarios that do not support multiple audio tracks (such as FLV files). At this time, sound channels Replace the functions of audio tracks, you can use each audio channel to record the voice of a language, and then select the left-right audio channel to be Mandarin Cantonese.