[MPlayer-users] video scaling doesn't work

Grant emailgrant at gmail.com
Sat Feb 15 16:19:58 CET 2014

>>>>>> so I can either prescale with mencoder/ffmpeg or try to get mplayer to
>>>>>> scale on the fly.  This works nicely except the video only appears in
>>>>>> the top 35% of the screen:
>>>>>> mplayer -vf scale=1360:-1 -fs file.mp4
>>>>> You'll want something like "-vf scale=1360:-2,expand=aspect=16/9"
>>>>> but the saying about lipstick and pig applies...
>>>> That scales it perfectly although performance isn't up to snuff as expected.
>>>>> Also I don't know what code you are using, but since this code in the
>>>>> comment right on top:
>>>>> http://cgit.openembedded.org/openembedded/plain/recipes/mplayer/files/vo_omapfb.c
>>>>> explicitly says that _downscaling_ doesn't work that should
>>>>> mean that upscaling certainly should work.
>>>>> (Note: there is some ancient code there, so that link is not meant as
>>>>> endorsement...)
>>>> I've been using the xf86-video-omapfb driver but I haven't tried -vo
>>>> omapfb.
>>> It would have saved some confusion if you had said that the first time I asked.
>> I apologize.
>>>> How can I get mplayer to consider that omapfb C file at
>>>> compile time?  Does it just need to be in a certain folder in the
>>>> source?
>>> There's also a diff that needs to be applied, and even then I have some doubts it will work.
>>> The code misses about 5 years of updates to libvo functionality..
>> I doubt the diff would even apply.  The only other thing I can think
>> of would be using mencoder to prescale every video I watch up to
>> 1360x768.  Is there a simple command for highest quality there?
> Hm, at that resolution the risk is decoding itself will be too slow. For highest quality without getting too large and causing bottlenecks elsewhere, using H.264 would be best, but it is also slowest.

I'm using the following.  Could it be improved?

ffmpeg -i input.mp4 -filter:v scale=1360:-1 -sws_flags spline -c:a
copy output.mkv

I can play that back in sync with -lavdopts fast:skiploopfilter=all:threads=3.

> I also looked into it again, installing Ubuntu 14.04. What is the result? Well, omapfb no longer exists, instead you have to use "omap" xorg driver, which does not support XVideo at all.

The omap driver supports XV and scaling if you also load the pvr-omap4
kernel module and binary libraries, but then you have to use a
branched version of the 3.4 kernel along with an old version of
xorg-server, mesa, and cairo.  3D should also work at that point but I
couldn't get it working.

> So once more my conclusion is that the best thing to do with a beagleboard (and pandaboard is only marginally better) really is throwing it onto the trash.

This I have no argument for.  Still, the thing is doing about 99% of
what I need it to do so I'd like to finish it if possible.

- Grant

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