[FFmpeg-cvslog] r14956 - trunk/libavformat/matroskadec.c

[Robert Swain]

2008/8/26 Aurelien Jacobs <aurel at gnuage.org>:
> Robert Swain wrote:
>
>> 2008/8/26 Mike Melanson <mike at multimedia.cx>:
>> > Michael Niedermayer wrote:
>> >> On Mon, Aug 25, 2008 at 11:51:52PM +0200, Aurelien Jacobs wrote:
>> >>> Mike Melanson wrote:
>> >>>
>> >>>> aurel wrote:
>> >>>>> Author: aurel
>> >>>>> Date: Mon Aug 25 01:57:29 2008
>> >>>>> New Revision: 14956
>> >>>>>
>> >>>>> Log:
>> >>>>> matroskadec: don't try to seek to negative timestamp
>> >>>>> matroska timestamps are unsigned
>> >>>>>
>> >>>>>
>> >>>>> Modified:
>> >>>>>    trunk/libavformat/matroskadec.c
>> >>>> Either 14955 or 14956 (both from you) broke the seek regressions.
>> >>>> Representative breakage:
>> >>> Grmlll... I was pretty sure those commit would change the seek
>> >>> regressions. But when I wanted to test this, I just couldn't
>> >>> run the test due to the wma regression (floating-point issue IIRC,
>> >>> running on amd64).
>> >>
>> >> Which commit did cause this wma regression test failure?
>
> I thought it was due to r14698 as this was already discussed, and I
> got the same md5. But In fact it's not.
>
>> > One of the 3 revisions following 14755 broke WMA. According to an
>> > earlier email, it was 14758, specifically.
>
> Almost. It's in fact r14757 which broke reg tests for me.

Before r14757:

/* init MDCT windows : simple sinus window */
for(i = 0; i < s->nb_block_sizes; i++) {
    int n, j;
    float alpha;
    n = 1 << (s->frame_len_bits - i);
    window = av_malloc(sizeof(float) * n);
    alpha = M_PI / (2.0 * n);
    for(j=0;j<n;j++) {
        window[j] = sin((j + 0.5) * alpha);
    }
    s->windows[i] = window;
}

Now:

// Generate a sine window.
void ff_sine_window_init(float *window, int n) {
    int i;
    for(i = 0; i < n; i++)
        window[i] = sin((i + 0.5) / (2 * n) * M_PI);
}

and

/* init MDCT windows : simple sinus window */
for(i = 0; i < s->nb_block_sizes; i++) {
    int n;
    n = 1 << (s->frame_len_bits - i);
    ff_sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
    s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
}

Why does this work fine with some compilers and not with others? Why
does it not work fine on some archs and not others with the same
compiler?

Rob