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spelling/phrasing fixes, mostly by Mans 

Originally committed as revision 4378 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Diego Biurrun 2005-06-11 18:18:13 +00:00
parent 79cc8267f4
commit c5a44f5715
1 changed files with 9 additions and 8 deletions
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17
doc/optimization.txt
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@ -1,7 +1,7 @@
optimization Tips (for libavcodec):
What to optimize:
If you plan to do non-x86 architecture specific optimiztions (SIMD normally)
If you plan to do non-x86 architecture specific optimizations (SIMD normally),
then take a look in the i386/ directory, as most important functions are
already optimized for MMX.
@ -14,10 +14,11 @@ As many functions, like the C ones tend to be a bit unreadable currently
because of optimizations it is difficult to understand them (and write
architecture specific versions, or optimize the C functions further) it is
recommended to look at older CVS versions of the interesting files (just use
ViewCVS at http://www1.mplayerhq.hu/cgi-bin/cvsweb.cgi/ffmpeg/?cvsroot=FFMpeg)
or perhaps look into the other architecture-specific versions in i386/, ppc/,
alpha/, ... Even if you don't understand the instructions exactly it could
help understanding the functions & how they can be optimized.
ViewCVS at http://www1.mplayerhq.hu/cgi-bin/cvsweb.cgi/ffmpeg/?cvsroot=FFMpeg).
Alternatively, look into the other architecture-specific versions in the i386/,
ppc/, alpha/ subdirectories. Even if you don't exactly understand the
instructions, it could help understanding the functions and how they
can be optimized.
NOTE: If you still don't understand some function, ask at our mailing list!!!
(http://www1.mplayerhq.hu/mailman/listinfo/ffmpeg-devel)
@ -33,7 +34,7 @@ put(_no_rnd)_pixels{,_x2,_y2,_xy2}
avg_pixels{,_x2,_y2,_xy2}
Used in motion compensation of B-frames.
These are less important then the put*pixels functions.
These are less important than the put*pixels functions.
avg_no_rnd_pixels*
unused
@ -43,7 +44,7 @@ pix_abs16x16{,_x2,_y2,_xy2}
pix_abs8x8{,_x2,_y2,_xy2}
Used in motion estimation (encoding) with SAD of MPEG-4 4MV only.
These are less important then the pix_abs16x16* functions.
These are less important than the pix_abs16x16* functions.
put_mspel8_mc* / wmv2_mspel8*
Used only in WMV2.
@ -128,7 +129,7 @@ BTW, most of these functions are in dsputil.c/.h, some are in mpegvideo.c/.h.
Alignment:
Some instructions on some architectures have strict alignment restrictions,
for example most SSE/SSE2 inctructios on x86.
for example most SSE/SSE2 instructions on x86.
The minimum guaranteed alignment is written in the .h files, for example:
void (*put_pixels_clamped)(const DCTELEM *block/*align 16*/, UINT8 *pixels/*align 8*/, int line_size);