[FFmpeg-devel] SWSCALE: Colorspace conversion for images
fbarchard at google.com
Wed Mar 30 08:56:17 CEST 2011
On Tue, Mar 29, 2011 at 2:40 PM, Michael Niedermayer <michaelni at gmx.at>wrote:
> On Tue, Mar 29, 2011 at 01:58:57PM -0700, Frank Barchard wrote:
> > Bump swscaler width limitation from 5120 to 16384.
> > Advantage: images (ie jpeg) are often larger than 5120 these days.
> > 5120x2880 is about 15 megapixels
> > Disadvantage: slightly slower
> > no scaling
> > timex ffmpeg -y -i tulip2.mp4 tulip2.yuv
> > timex 8866.21ms
> > scaling
> > C:\ffwork>timex ffmpeg -y -i tulip2.mp4 -s 1272x724 tulip2.yuv
> > timex 23633.13ms with VOFW 5120
> > timex 26246.90ms with VOFW 16384
> could you try 21504 instead of 16384 ?
21504 works better. Heres a benchmark
VOFW 5120 VOFW 21504 Note10438.8 10344.2 timex ffmpeg -y
-i tulip2.mp4 tulip2.yuv25611.9 24256.9 timex ffmpeg -y -i
tulip2.mp4 -s 1272x724 tulip2.yuv24485.7 26006.6 "28573.1
24291.3 "24069.1 26995.9 "25684.95 25387.675
This is on a Nehalem i7. Despite being a 500 frame, 720p video, the numbers
fluctuate, so I took an average of 4 runs.
Another reason I'd like this change is youtube accepts videos with higher
resolutions than 5120.
16384 is vp8's maximum resolution, so that should keep us amused for a
I thought 16k would fix into L1 better, but I guess it had collisions.
diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h
index daa6731..fc684f1 100644
@@ -34,7 +34,7 @@
#define MAX_FILTER_SIZE 256
-#define VOFW 5120
+#define VOFW 21502
#define VOFW 2048 // faster on PPC and not tested on others
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