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| author | Michael Niedermayer <michaelni@gmx.at> | 2003-05-11 10:19:05 +0000 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2003-05-11 10:19:05 +0000 |
| commit | 05493021889a6d226791aa2eb412de7becad2ace (patch) | |
| tree | 62df89e81220b59bd6fefafd0ac3b102a4b3f7f4 | |
| parent | 96a7e73b2468051505c68f6db7be2d322bee5793 (diff) | |
| download | ffmpeg-05493021889a6d226791aa2eb412de7becad2ace.tar.gz | |
more idct_permute docs
Originally committed as revision 1852 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavcodec/dsputil.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/libavcodec/dsputil.h b/libavcodec/dsputil.h index 8643e9ac9a..138e6f42c8 100644 --- a/libavcodec/dsputil.h +++ b/libavcodec/dsputil.h @@ -240,6 +240,10 @@ typedef struct DSPContext { /** * idct input permutation. + * several optimized IDCTs need a permutated input (relative to the normal order of the reference + * IDCT) + * this permutation must be performed before the idct_put/add, note, normally this can be merged + * with the zigzag/alternate scan<br> * an example to avoid confusion: * - (->decode coeffs -> zigzag reorder -> dequant -> reference idct ->...) * - (x -> referece dct -> reference idct -> x) |