> -----Original Message----- > From: Marek Szyprowski [mailto:m.szyprowski@xxxxxxxxxxx] > Sent: Tuesday, October 06, 2009 11:53 AM > To: Hiremath, Vaibhav; 'Ivan T. Ivanov'; linux-media@xxxxxxxxxxxxxxx > Cc: kyungmin.park@xxxxxxxxxxx; Tomasz Fujak; Pawel Osciak; Marek > Szyprowski > Subject: RE: Mem2Mem V4L2 devices [RFC] > > Hello, > > On Monday, October 05, 2009 8:27 PM Hiremath, Vaibhav wrote: > > > > > [Hiremath, Vaibhav] IMO, this implementation is not streaming > > > model, we are trying to fit mem-to-mem > > > > forcefully to streaming. > > > > > > Why this does not fit streaming? I see no problems with > streaming > > > over mem2mem device with only one video node. You just queue > input > > > and output buffers (they are distinguished by 'type' parameter) > on > > > the same video node. > > > > > [Hiremath, Vaibhav] Do we create separate queue of buffers based > on type? I think we don't. > > Why not? I really see no problems implementing such driver, > especially if this heavily increases the number of use cases where > such > device can be used. > [Hiremath, Vaibhav] I thought of it and you are correct, it should be possible. I was kind of biased and thinking in only one direction. Now I don't see any reason why we should go for 2 device node approach. Earlier I was thinking of 2 device nodes for 2 queues, if it is possible with one device node then I think we should align to single device node approach. Do you see any issues with it? Thanks, Vaibhav > > App1 App2 App3 ... AppN > > | | | | | > > ----------------------------------------------- > > | > > /dev/video0 > > | > > Resizer Driver > > > > Everyone will be doing streamon, and in normal use case every > application must be getting buffers from > > another module (another driver, codecs, DSP, etc...) in multiple > streams, 0, 1,2,3,4....N <snip> > case in which the operation can be performed in-place. Usually all > other types of operations (like color space conversion or rotation) > require 2 buffers. Please note that having only one video node > would not mean that all operations must be done in-place. As Ivan > stated you can perfectly queue 2 separate input and output buffers > into the one video node and the driver can handle this correctly. > > Best regards > -- > Marek Szyprowski > Samsung Poland R&D Center > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
