[FFmpeg-devel] [PATCH 09/11] aaccoder: add a new perceptual noise substitution implementation

[Claudio Freire]

On Fri, Jun 26, 2015 at 5:16 PM, Rostislav Pehlivanov
<atomnuker at gmail.com> wrote:
> +                if (spread > NOISE_SPREAD_THRESHOLD &&
> +                    ((sce->zeroes[w*16+g] && energy >= threshold) ||
> +                    energy < threshold*(NOISE_LAMBDA_NUMERATOR/lambda))) {
> +                    sce->band_type[w*16+g] = NOISE_BT;
> +                    sce->pns_ener[w*16+g] = energy;
> +                    sce->zeroes[w*16+g] = 0;
> +                }


This should be:
sce->pns_ener[w*16+g] = energy / sce->ics.group_len[w];

Also, "spread > NOISE_SPREAD_THRESHOLD" works beetter as:

spread > (NOISE_SPREAD_THRESHOLD * 120.f / lambda)

And  "energy < threshold*(NOISE_LAMBDA_NUMERATOR/lambda)" as:

energy < threshold*(NOISE_LAMBDA_NUMERATOR*sce->ics.group_len[w]/lambda))

(to account for the transient situation in which the encoder is
switching to and form short windows)