[FFmpeg-devel] [PATCH] AAC encoder: improve SF range utilization

Claudio Freire klaussfreire at gmail.com
Tue Dec 1 07:35:40 CET 2015

On Mon, Nov 30, 2015 at 1:04 PM, Hendrik Leppkes <h.leppkes at gmail.com> wrote:
> On Mon, Nov 30, 2015 at 4:50 PM, Claudio Freire <klaussfreire at gmail.com> wrote:
>> On Mon, Nov 30, 2015 at 12:27 PM, Rostislav Pehlivanov
>> <atomnuker at gmail.com> wrote:
>>> On Sun, 2015-11-29 at 16:54 -0300, Claudio Freire wrote:
>>>> Before pushing this, I'd like some feedback,
>>>> especially about
>>>> the implementation of point 3. I'm not sure the AAC encoder
>>>> setting the cutoff in the encoder context like this is legal or
>>>> desirable.
>>> I think setting the cutoff is necessary. You can't avoid holes and yet
>>> keep a full bandwidth as you decrease bits unless you like the sound of massive quantization errors.
>> My point was more about whether a codec should write into the context
>> struct like that or not. Basically an API technicality that's unclear
>> to me.
> It seems slightly odd to write into that variable, since thats the
> cutoff the user requests.
> Maybe you can use/write into a private variable instead? ac3enc seems
> to use a private variable for similar purposes.

Attached patch does that.

I'm far more comfortable with this implementation, so if all agree, I'll push.

On Mon, Nov 30, 2015 at 2:20 PM, Rostislav Pehlivanov
<atomnuker at gmail.com> wrote:
> On Mon, 2015-11-30 at 12:50 -0300, Claudio Freire wrote:
>> Also I don't see how a static var would help or even be correct here.
>> Perhaps you meant something else?
> static uint8_t cond1 = param1 && param2;
> static uint8_t cond2 = param3 && !param4;
> ...etc
> return cond1 && cond2;

I didn't do that since it would not short circuit some terms that
ought to be short-circuited.

But I did split lines and it does read better. In fact, maybe that was
all that was needed?
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