[FFmpeg-devel] [PATCH] up VOFW in swscale?
Wed Apr 1 23:59:46 CEST 2009
Michael Niedermayer wrote:
> On Wed, Apr 01, 2009 at 09:28:46PM +0200, Andreas ?man wrote:
>> I use the scaler to rescale photos (>2048 pixels wide) in my
>> With the old scaler this was not a problem but nowadays it
>> no longer works since the maximum width is limited to 2048 pix.
>> Therefore I propose we up this to 4096.
> can post some benchmarks with a CPU with small cache and a low resolution
Interesting exercise. Seems that increasing it to 4096 causes more
cache aliasing. However, increasing it to 5120 makes it faster than
the original code.
model name : AMD Sempron(tm) Processor 2800+
cpu MHz : 1600.074
cache size : 256 KB
Input #0, avi, from
Duration: 00:41:40.75, start: 0.000000, bitrate: 1176 kb/s
Stream #0.0: Video: mpeg4, yuv420p, 624x352 [PAR 1:1 DAR 39:22],
23.98 tbr, 23.98 tbn, 23.98 tbc
Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s
Output #0, null, to '/dev/null':
Stream #0.0: Video: rawvideo, yuv420p, 256x128 [PAR 39:44 DAR
39:22], q=2-31, 200 kb/s, 90k tbn, 23.98 tbc
VOFW = 2048
VOFW = 4096
VOFW = 5120
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