Hi, looking at the MIPI Alliance Specification for Camera Serial Interface 2 (I'll call it MIPI-CSI2 from now on, the document I am referring to is mentioned at [1] and available at [2]), I see there is an YUV420 8 bit format (MIPI Data Type 0x18) specified with interleaved components in the form of: YYYY... (odd lines) UYVYUYVY... (even lines) With even lines twice the size of odd lines. Such format is also supported by some sensors, for instance ov5640, and by MIPI-CSI2 receivers like OMAP4 ISS. The doubt I have is: how should I represent those formats as media bus formats? I've seen that some drivers (sensors and SoC, for instance[3]) tend to identify the MIPI-CSI2 format above (0x18) with media bus formats like V4L2_MBUS_FMT_UYVY8_1_5X8 (actually the code above uses V4L2_MBUS_FMT_YUYV8_1_5X8 is this OK?), but from the v4l2 documentation [4] I understand that this format is supposed to have data in this configuration: UUUU... YYYY... YYYY... VVVV... YYYY... YYYY... That is with interleaved lines, but NOT interleaved components. Should new media bus formats be added for YYYY.../UYVYUYVY...? Another doubt I have is: how is the YYYY.../UYVYUYVY... data supposed to be processed in userspace? Is the MIPI Receiver (i.e, the SoC) expected to be able to convert it to a more usable format like YUV420P or NV12/NV21? Or are there applications capable of handling this data directly, or efficiently convert them to planar or semi-planar YUV420 formats? In particular I am curios if the OMAP4 ISS can do the conversion to NV12, I understand that the formats with interleaved _lines_ can be produced by the resizer and handled by the OMAP ISP DMA-Engine by setting buffers offsets to Y and UV in order to send NV12 data to userspace, but I couldn't find info about how to handle the YUV420 MIPI-CSI2 formats (interleaved components) without the resizer in the Developer Manual [5]; having NV12 data directly from the hardware without using the OMAP4 ISS/ISP Resizer can be valuable in some use cases (e.g. dual camera setups). Thanks, Antonio [1] http://www.mipi.org/specifications/camera-interface#CSI2 [2] http://ishare.sina.cn/dintro.php?id=20498632 [3] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/media/platform/soc_camera/sh_mobile_csi2.c;h=a17aba9a0104c41cbc4e5e5d277010ecac577600;hb=HEAD#l108 [4] http://kernel.org/doc/htmldocs/media/subdev.html#v4l2-mbus-pixelcode-yuv8 [5] http://www.ti.com/lit/ug/swpu235w/swpu235w.pdf -- Antonio Ospite http://ao2.it A: Because it messes up the order in which people normally read text. See http://en.wikipedia.org/wiki/Posting_style Q: Why is top-posting such a bad thing? -- 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
