[MPlayer-dev-eng] [PATCH] shmem - filter, doc
oattila at chello.hu
Thu Sep 13 20:57:50 CEST 2007
2007. szeptember 13. 14.41 dátummal Jason Tackaberry ezt írta:
Hi Jason Tackaberry!
> Hi Attila,
> On Wed, 2007-09-12 at 00:47 +0200, Ötvös Attila wrote:
> > Export filter can modify format of video frame, scale and osd render
> > (similar expand filter).
> Just curious, what are the use cases for this?
> I've done something similar, which we use for Freevo, where the primary
> use case is to be able to manipulate the video from mplayer onto a
> canvas controlled by another application.
> But your patch doesn't appear to implement any locking with the buffer.
> Consequently an application reading the frame from shared memory may end
> up reading at a point where the frame is currently being overwritten,
> resulting in a corrupt frame.
This patch uses the semaphores for buffer lock (stream_sharedmem.c).
> So I suppose the patch might be useful for, say, a GUI wrapper for
> mencoder that wants to output visual progress of the encode. I'm
> curious if there are other use cases you had in mind.
I made this shared memory stream for CCTV:
I needed to record more closed circuit TVs simultaneous with showing this on
> > Import filter implement insert video frames from shared memory stream
> > similar bmovl filter. Import filter can modify size and set insert
> > positions.
> Does shmemin do any alpha blending like bmovl?
Now, the import filter can't use alpha blending.
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