2 and 6 Channel Audio

[husaskin]

Hi everyone. Sorry if this has been posted already but I got a quick question. Using the below info for an example, is this proper surround sound ? It says 2ch, then says original 6ch, so my question is, was it 6ch originally, then when the video was ripped, it went to 2ch?


Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 1h 52mn
Bit rate mode : Constant
Bit rate : 224 Kbps
Channel(s) : 2 channels
Channel(s)_Original : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 180 MiB (8%)
Language : English
Encoded date : UTC 1904-01-01 00:00:00
Tagged date : UTC 1904-01-01 00:00:00

Thank you

[Bernix]

Media info sourceforge discusion
I think you can get it playing in potplayer and hit tab and see input number channels, or drag drop to audacity and press stop and you can see it graphicaly.
Or simply right click right mouse button on properties and then tab details. It should work too

Bernix

[husaskin]

I've done a right click / properties ... it says 6ch ... but is it 6ch surround sound or does all audio come out of all 6ch at once. Also, it still doesn't answer my questions about what this means

Channel(s) : 2 channels
Channel(s)_Original : 6 channels

[Bernix]

Have you read the link ?

The current core implementation is the correct one (displaying the problem between container and raw stream), and thinking about how to better display such errors is a long term feature.

And if it has 6 channels, it has most probably L C R and L R, LFE channels mapping as mentioned.
You can try MediaTab, if it has a better sollution MediaTab

Bernix

[husaskin]

thanks Bernix ... i read it, it was a very very long winded read ...

[hello_hello]

I've done a right click / properties ... it says 6ch ... but is it 6ch surround sound or does all audio come out of all 6ch at once. Also, it still doesn't answer my questions about what this means
Channel(s) : 2 channels
Channel(s)_Original : 6 channels

If I remember correctly, it's a backwards compatibility thing. The original spec was only for two channels, so for a while some encoders wrote both specifications, the original one being wrong for multi-channel audio. It's nothing to worry about as the audio is still 5.1ch surround and it'll still be decoded that way.

Of the five AAC encoders I have on this PC (FDKAAC, FhGAAC, NeroAAC, QAAC and ffmpeg) only FhGAAC and ffmpeg still write the obsolete 2ch data when encoding multi-channel audio. If you open one of your m4a/mp4 files with MKVToolNixGUI and remux it as an mka/mkv, MediaInfo will no longer display the "2ch" data. The audio will just display correctly as 6ch.

[-Habanero-]

So does his video have 2ch or 6ch audio? Which one?

[hello_hello]

It has 6 channels. It's standard 5.1ch surround.