On Sat, Dec 19, 2009 at 01:07:44PM +0100, Tobia Conforto wrote: > Hi > I have a couple of questions about a HD movie. I would like to better understand scaling issues. > > The movie clip is WMV3 anamorphic 1440x1080 and my monitor has a 1440x900 resolution with square pixels. I'm using MPlayer OS X Extended rev12 (mplayer r29777) > > The first issue is that ffwmv3 doesn't detect the aspect ratio of the movie clip. I guess that's a bug with FFMpeg. > > So I go ahead and add the -aspect 16:9 option, and this is what happens: > > Movie-Aspect is 1.78:1 - prescaling to correct movie aspect. > SwScaler: reducing / aligning filtersize 5 -> 4 > SwScaler: reducing / aligning filtersize 5 -> 4 > SwScaler: reducing / aligning filtersize 1 -> 1 > SwScaler: reducing / aligning filtersize 5 -> 4 > [swscaler @ 0x100ff60c0]BICUBIC scaler, from yuv420p to rgb24 using MMX2 > [swscaler @ 0x100ff60c0]using 4-tap MMX scaler for horizontal luminance scaling > [swscaler @ 0x100ff60c0]using 4-tap MMX scaler for horizontal chrominance scaling > [swscaler @ 0x100ff60c0]using n-tap MMX scaler for vertical scaling (BGR) > [swscaler @ 0x100ff60c0]1440x1080 -> 1920x1080 > VO: [corevideo] 1440x1080 => 1920x1080 Packed YUY2 [fs] > > Why is it software-scaling the movie horizontally, up to 1920x1080? It isn't. The line > VO: [corevideo] 1440x1080 => 1920x1080 Packed YUY2 [fs] tells the overlay is scaling it. As someone else pointed out the other output is just the screenshot filter preparing to do its job. > Can't it just play the 1440x1080 source in a 1440x810 window, using the hardware overlay? Sure just use -noaspect. Or just don't add -aspect if you don't want it to scale.. > If that's not possible, wouldn't it be more efficient to down-scale vertically to 1440x810? You can tell it to by using either -vf scale or dsize manually.
