5.1 Surround Sound Video File Audio Streams Help needed

melliott1963 wrote on 5/13/2021, 6:01 AM

I've been editing loads of old home videos and have now got the the point when I must have purchased a new camcorder. The files I'm now editing are recorded in 5.1 surround sound, whereas previously everything has been stereo.

I notice that these video files have 2 audio streams. If I set the project audio to stereo and insert a video track, Stream 1 gets inserted into the audio track. However, if I set the project preferences to 5.1 surround sound and insert the video track, I then get 4 audio tracks, all of which are Stream 2, but with different channels.

I'm assuming from this, therefore, that Stream 1 is the standard stereo stream, whereas stream 2 is the surround sound stream?

I was going to render my surround sound video to MP4, but from what I've read, this isn't a straight forward process. At the end of the day I'm not too bothered about having surround sound (they're only home videos), so am happy to stick with stereo if needed

So, do I just set my project to stereo and use Stream 1, or would I get a better sound quality by editing in surround sound, but rendering to stereo? Or alternatively, is there a quick and easy way of setting the render template to render in surround sound?

Thanks in advance for all your help.

Comments

Dexcon wrote on 5/13/2021, 6:48 AM

This is only a partial response, but the 2 rear surround sound tracks can most probably be ignored as they were very likely created within the camera by audio signal processing to simulate rear audio. Going back quite a few years on this forum re a similar 5.1 sound issue with domestic 'handicams', one forum member wrote that he'd disassembled an old5.1 handicamp and found only 3 microphones (FL, FR and C)in the camera. A few years ago, I found on the internet an article by Panasonic or Sony which described how their proprietary audio processing worked to create the rear channels from the 3 microphone setup.

Therefore, the only you likely only have LF, LR and C as original audio tracks. The question then becomes whether or not the C channel is going to carry any audio information that is significantly different to the audio captured by the L and R microphones? In a domestic handicam, I'll take a wild guess and say that the answer is probably 'no'.

melliott1963 wrote on 5/13/2021, 7:44 AM

I think you could well be right.

Since posting, I decided to do a test comparing a stereo video using just Stream 1, against a stereo rendered video using all 4 tracks from Stream 2. Listened through headphones and honestly could not tell the difference. I would say, though, that listening to the surround sound video in Vegas before rendering, the sound was a lot fuller.

So unless there’s an easy way to render surround sound in Vegas Pro, I’m happy to ignore the surround sound stream and just stick to the stereo stream 1.