[FFmpeg-soc] rfc: swscale-example weird output
michaelni at gmx.at
Tue Jun 24 19:03:35 CEST 2008
On Tue, Jun 24, 2008 at 04:32:05PM +0200, Keiji Costantini wrote:
> I pulled out getcoeff() from initFilter(), as a step for simplify the code.
> The patch attached is the relevant part.
> This patch changes output of swscale-example
> for example:
> - yuv420p 96x96 -> rgb565 64x 64 flags=32 SSD= 79, 983, 746
> + yuv420p 96x96 -> rgb565 64x 64 flags=32 SSD= 77, 980, 738
> only a (relative) small number of lines are affected, but it's nonetheless
> strange that moving code makes different output.
> Does anyone have any idea about how this can happens?
1. float rounding issues (try if using gcc -O0 for both, maybe that
makes the differences dissapear)
2. uninitialized variables (valgrind should find them, also try disabling
all mmx/sse/... if the other ideas havnt located the issue yet)
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 189 bytes
Desc: Digital signature
More information about the FFmpeg-soc