[FFmpeg-user] Command line to show channel label/position

[Huspnet]

> On Jan 28, 2025, at 4:14 PM, MrNice <wxcvbn2006 at iol.ie> wrote:
> 
> On 28/01/2025 18:26, Carl Zwanzig wrote:
>> On 1/28/2025 8:18 AM, MrNice wrote:
>>> have an audio file, with MediaInfo I get
>>> Audio
>>> Channel layout                           : L R Ls Rs
>> 
>>>  > ffmpeg -v error -layouts | awk '/quad /{print $2}'
>>> FL+FR+BL+BR
>> 
>>> What is the correct answer?
>> 
>> Both.
>> Left, assumed to be front (L) = Front Left (FL)
>> Left surround/side (Ls) = Back Left (BL)
>> etc
>> 
>> (that's part way down the AudioChannelManipulation page, even farther down is a list of the channel names and standard layouts, also in the -layouts output)
>> 
>> z!
>> 
>> _______________________________________________
> 
> Are you sure for good Carl?
> 
> AFAIK, LS is surround and BL is back/Rear
> 
> Please look here
> 
> https://mediaarea.net/AudioChannelLayout
> 
> They say, depending of standardization;
> Left Surround = Ls = CL = SL = Ls (MediaInfo name)
> Right Surround = Rs = CR = SR = Rs (MediaInfo name)
> Left Rear Surround = Lrs = BL = Lsr = SL = Lb (MediaInfo name)
> Right Rear Surround = Rrs = BR = Rsr = Rb (MediaInfo name)
> 

I'm not sure I understand the question, but I believe that "back" channels are only involved if there are more than 5 distinct audio signals plus one low frequency signal. By way of explanation, I believe that 5 distinct audio signals plus one low frequency signal is the configuration commonly referred to as "5.1" audio (front left, front right, center, side left, side right, and low frequency). I don't believe that the term "5.1" when used to describe an audio standard (summarized as the description of speaker locations listed in my previous sentence) specifies any "back' audio signals at all. If you wish to convert 5.1 audio to an audio format having more distinct signals or sends, then I think it is up to you to determine how you would like to distribute the audio signals to make use of the additional available channels. Did I say anything useful, or have I just confused the issue?

LL