[FFmpeg-cvslog] r11883 - trunk/libavcodec/vorbis.c

[Loren Merritt]

On Sun, 10 Feb 2008, Balatoni Denes wrote:
> Saturday 09 February 2008 14:53-kor lorenm ezt ?rta:
>> Log:
>> 30% faster ff_vorbis_floor1_render_list, 3% faster overall
>
>>          if (flag[pos]) {
>> -            render_line(lx, ly, list[pos].x, y_list[pos] * multiplier,
>> out, samples); -            lx = list[pos].x;
>> -            ly = y_list[pos] * multiplier;
>> +            int x1 = list[pos].x;
>> +            int y1 = y_list[pos] * multiplier;
>> +            if (lx < samples)
>> +                render_line(lx, ly, FFMIN(x1,samples), y1, out);
>
> However this change seems to be functionally different when x1>samples - the
> steepness of the line in render_line  will be different, no? I haven't
> checked in the spec whether "x1" can be greater than "samples", though
> (probably it can be, as there has always been a check for this kind of
> clipping in render_line and it's predecessors).

In the vorbis spec, samples is not an argument to render_line. Afaict 
x1>samples isn't supposed to happen, the check is there only to prevent 
buffer overrun on invalid bitstreams.

--Loren Merritt