Hi Sergio On Sat, 7 Apr 2012, Aguirre, Sergio wrote: > Hi everyone, > > I'll like to request for your advice on adding NV12 support for my omap4iss > camera driver, which is done after the resizer block in the OMAP4 ISS ISP > (Imaging SubSystem Image Signal Processor). > > So, the problem with that, is that I don't see a match for V4L2_PIX_FMT_NV12 > pixel format in "enum v4l2_mbus_pixelcode". > > Now, I wonder what's the best way to describe the format... Is this correct? > > V4L2_MBUS_FMT_NV12_1X12 > > Because every pixel is comprised of a 8-bit Y element, and it's UV components > are grouped in pairs with the next horizontal pixel, whcih in combination > are represented in 8 bits... So it's like that UV component per-pixel is 4-bits. > Not exactly, but it's the best representation I could think of to > simplify things. Do I understand it right, that your resizer is sending the data to the DMA engine interleaved, not Y and UV planes separately, and it's only the DMA engine, that is separating the planes, when writing to buffers? In such a case I'd use a suitable YUV420 V4L2_MBUS_FMT_* format for that and have the DMA engine convert it to NV12, similar to what sh_mobile_ceu_camera does. Thanks Guennadi > I mean, the HW itself writes in memory to 2 contiguous buffers, so there's 2 > separate DMA writes. I have to program 2 starting addresses, which, in an > internal non-v4l2-subdev implementation, I have been programming like this: > > paddr = start of 32-byte aligned physical address to store buffer > x = width > y = height > > Ysize = (x * y) > UVsize = (x / 2) * y > Total size = Ysize + UVsize > > Ystart = paddr > UVstart = (paddr + Ysize) > > But, in the media controller framework, i have a single DMA output pad, that > creates a v4l2 capture device node, and i'll be queueing a single buffer. > > Any advice on how to address this properly? Does anyone has/had a similar need? > > Regards, > Sergio > -- > 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 > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- 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
