[FFmpeg-devel] [RFC] Channel layouts

[Justin Ruggles]

M?ns Rullg?rd wrote:
> Peter Ross <pross at xvid.org> writes:
> 
>> On Fri, Aug 29, 2008 at 10:21:28PM -0400, Justin Ruggles wrote:
>>> Peter Ross wrote:
>>>> On Fri, Aug 29, 2008 at 04:28:00PM +1000, Peter Ross wrote:
>>>>> Hi.
>>>>>
>>>>> This patch adds the notion of channel layouts to libavcodec.
>>>> [...]
>>> I think your solution works well for now.  I am not 100% clear about how
>>> the encoders/decoders should handle unsupported or undefined layouts.
>>> Firstly, is the channel layout is guessed by default?  If so, that would
>> At this stage, the guess function is used only for display purposes.
>[...] 
>>>> +int64_t avcodec_guess_channel_layout(int nb_channels)
>>>> +{
>>>> +    switch(nb_channels) {
>>>> +    case 1: return CHANNEL_LAYOUT_MONO;
>>>> +    case 2: return CHANNEL_LAYOUT_STEREO;
>>>> +    case 4: return CHANNEL_LAYOUT_QUAD;
>>>> +    case 6: return CHANNEL_LAYOUT_5POINT1;
>>>> +    case 8: return CHANNEL_LAYOUT_7POINT1;
>>>> +    default: return 0;
>>>> +    }
>>>> +}
>>> Why not add 3 and 5 to the list?  My vote would be for left/right/center
>>> and 5.0.
> 
> 2.1 and 4.1 are equally, if not more, likely.  I have such DVDs, but
> none with x.0 where x > 2.

Well, if it's only used for displaying the layout name, why not use
generic names if the layout is unspecified, like "3-channel" and
"5-channel"?

-Justin