[FFmpeg-devel] [PATCH] Remove swscale_internal.h:fmt_depth()

[Stefano Sabatini]

On date Sunday 2010-01-17 23:36:26 +0100, Stefano Sabatini encoded:
> On date Sunday 2010-01-17 22:04:47 +0100, Michael Niedermayer encoded:
> > On Sun, Jan 17, 2010 at 06:46:40PM +0100, Stefano Sabatini wrote:
> > > On date Saturday 2010-01-16 17:08:48 -0200, Ramiro Polla encoded:
> > > > Hi,
> > > > 
> > > > On Sat, Jan 16, 2010 at 4:59 PM, Stefano Sabatini
> > > > <stefano.sabatini-lala at poste.it> wrote:
> > > > > Hi, I'm aware this patch introduces a slow-down, an idea would be to
> > > > > initialize a ff_bits_per_pixel array during the init phase, and then
> > > > > use a function of the kind:
> > > > >
> > > > > static inline int fmt_depth(int fmt)
> > > > > {
> > > > > ? ?return ff_bits_per_pixel[fmt];
> > > > > }
> > > > >
> > > > > Would be that acceptable?
> > > > > In this case can you suggest where to initialize stuff?
> > > > 
> > > > I think all code that uses fmt_depth currently should eventually be
> > > > moved to some init code that's only run once, and so a small slow-down
> > > > wouldn't be a problem.
> > > 
> > > Check the attached: smaller, more extensible, faster, the price is a
> > > little more bloat in the context.
> > > 
> > 
> > > Regression test passed.
> > 
> > if(regression == swscale_example) patch ok
> > else not ok
> 
> I had to hack swscale-example since the recent change in pixfmt.h
> broke it (BTW does it ever worked with big-endian system?), anyway
> what should I test with swscale-example?
> 
> I tried to run swscale-example first and before the patch, and then
> many times with the same binary, each time I got some small differences
> in the outputs, for example (two runs with the same binary):
> 
> stefano at geppetto ~/s/f/libswscale> diff -u swscale-example2.out swscale-example3.out 
> --- swscale-example2.out	2010-01-17 23:23:35.000000000 +0100
> +++ swscale-example3.out	2010-01-17 23:29:15.000000000 +0100
> @@ -50514,12 +50514,12 @@
>   argb 96x96 -> rgba   96x  64 flags= 8 SSD=    6,    0,    0,    1
>   argb 96x96 -> rgba   96x  64 flags=16 SSD=   12,    0,    0,   16
>   argb 96x96 -> rgba   96x  64 flags=32 SSD=    9,    1,    2,    1
> - argb 96x96 -> rgba   96x  96 flags= 1 SSD= 1729, 1202,  729, 4513
> - argb 96x96 -> rgba   96x  96 flags= 2 SSD= 1729, 1180,  720, 4513
> - argb 96x96 -> rgba   96x  96 flags= 4 SSD= 1729, 1202,  730, 4513
> - argb 96x96 -> rgba   96x  96 flags= 8 SSD= 1729, 1190,  724, 4513
> - argb 96x96 -> rgba   96x  96 flags=16 SSD= 1729, 1234,  755, 4513
> - argb 96x96 -> rgba   96x  96 flags=32 SSD= 1729, 1202,  729, 4513
> + argb 96x96 -> rgba   96x  96 flags= 1 SSD= 1728, 1202,  729, 4513
> + argb 96x96 -> rgba   96x  96 flags= 2 SSD= 1728, 1180,  720, 4513
> + argb 96x96 -> rgba   96x  96 flags= 4 SSD= 1728, 1202,  729, 4513
> + argb 96x96 -> rgba   96x  96 flags= 8 SSD= 1728, 1189,  724, 4513
> + argb 96x96 -> rgba   96x  96 flags=16 SSD= 1728, 1234,  755, 4513
> + argb 96x96 -> rgba   96x  96 flags=32 SSD= 1728, 1202,  729, 4513
>   argb 96x96 -> rgba   96x 128 flags= 1 SSD=    8,    1,    2,    0
>   argb 96x96 -> rgba   96x 128 flags= 2 SSD=    8,    1,    1,    0
>   argb 96x96 -> rgba   96x 128 flags= 4 SSD=    5,    0,    0,    0
> @@ -55282,12 +55282,12 @@
>   abgr 96x96 -> bgra   96x  64 flags= 8 SSD=    6,    0,    0,    1
>   abgr 96x96 -> bgra   96x  64 flags=16 SSD=   12,    0,    0,   16
>   abgr 96x96 -> bgra   96x  64 flags=32 SSD=    9,    1,    2,    1
> - abgr 96x96 -> bgra   96x  96 flags= 1 SSD= 1729, 1196,  724, 4513
> - abgr 96x96 -> bgra   96x  96 flags= 2 SSD= 1729, 1174,  716, 4513
> - abgr 96x96 -> bgra   96x  96 flags= 4 SSD= 1729, 1197,  725, 4513
> - abgr 96x96 -> bgra   96x  96 flags= 8 SSD= 1729, 1183,  719, 4513
> - abgr 96x96 -> bgra   96x  96 flags=16 SSD= 1729, 1229,  751, 4513
> - abgr 96x96 -> bgra   96x  96 flags=32 SSD= 1729, 1196,  724, 4513
> + abgr 96x96 -> bgra   96x  96 flags= 1 SSD= 1728, 1196,  724, 4513
> + abgr 96x96 -> bgra   96x  96 flags= 2 SSD= 1728, 1174,  716, 4513
> + abgr 96x96 -> bgra   96x  96 flags= 4 SSD= 1728, 1197,  725, 4513
> + abgr 96x96 -> bgra   96x  96 flags= 8 SSD= 1728, 1183,  719, 4513
> + abgr 96x96 -> bgra   96x  96 flags=16 SSD= 1728, 1229,  751, 4513
> + abgr 96x96 -> bgra   96x  96 flags=32 SSD= 1728, 1196,  724, 4513
>   abgr 96x96 -> bgra   96x 128 flags= 1 SSD=    8,    1,    2,    0
>   abgr 96x96 -> bgra   96x 128 flags= 2 SSD=    8,    1,    1,    0
>   abgr 96x96 -> bgra   96x 128 flags= 4 SSD=    5,    0,    0,    0
> 
> which I found very strange and still cannot explain (where is the
> random source, lfg in swscale-example.c uses always the same seed).

argb -> bgra
abgr -> bgra

both are not supported, so the scaler doesn't write nothing in output
and this explains the high SSD value and the randomicity of the
output.

Time to fix rgb2rgbWrapper!
-- 
FFmpeg = Faithless and Faboulous Merciless Powerful Eretic Geisha