Many of you saw surround sound test type video on YouTube. It declares to test your surround sound system. However, you can also see troll commons of people making fun of it and say it doesn't work at all. In fact, if you play it. All you can hear is stereo Left and Right audio only. So why is that ? This created a lot of debates online. People are arguing if YouTube can deliver the surround sound or not? Some people say it works on their system, which we can not confirm. We set up our own test use Chrome and Firefox. Video below is a 10 channels ProTools monitoring session to monitor all possible audio output from YouTube. Please watch the test video below. After the test we can confirm that YouTube surround video only send two channels of analogue audio output.
So they lie?
To better answer this question. We need to take you back to the previous blog. It explains the surround sound format is a codecs that assign audio signals to different speakers. For example: If you have 5 speakers sound system. To make it surround sound each speaker has to know what to play. As you can see from video above YouTube only sending audio to two speakers. This is why all the other speakers don't have sound. The idea of the surround sound codec is to combine 6 audio channels and send to receiver devices. This means the receiver device need to be able decode the original codec in order to restore the signals to speakers correctly. YouTube so far doesn't decode those codecs. Why not? In fact, almost all our personal devices comes with two channels audio output only. The extra decoded audio channels has nowhere to go. This makes no need to add the decode function for the surround sound channels. Here is the help from YouTube if you type in the search. It is confirmed YouTube does not support sound sound playback.
Whats the YouTube support 5.1 , 7.1 surround sound mean?
It means they support surround sound format upload instead playback. when you upload the 5.1 or 7.1 channels audio. They fold the extra channels into left or right channel. YouTube simply take extra audio channels and render them into the left and right channels. This allow users to upload 5.1 or 7.1 audio film and YouTube will automatically convert it to stereo. The YouTube encoder will take all audio channels and rearrange them into stereo so you don't lose the surround sound information.