[FFmpeg-devel] [PATCH] vorbis_enc.c: avoid div zero that causes noise

Ronald S. Bultje rsbultje
Tue Jun 1 20:35:41 CEST 2010


Hi,

On Tue, Jun 1, 2010 at 2:28 PM, Frank Barchard <fbarchard at google.com> wrote:
> Improves quality for ff vorbis encoding of silence.
>
> Some audio files had clicking, typically at the beginning or end. ?It was
> tracked down to a divide by zero.
> Two samples that improve in quality with the patch are:
> pitivi - http://jeff.ecchi.ca/public/test-html5.html
> red -
> http://movies.apple.com/movies/us/hd_gallery/gl1800/1080p/artbeats_red_m1080p.mov
[..]
> +        if (average) {
> +            average *= pow(tot_average / average, 0.5) * pow(1.25, position/200.); // MAGIC!
> +        } else {
> +            average = 0;
> +        }

The last 3 lines seem unnecessary?

Ronald



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