iMX95: Two video inputs.

[danielsan-77]

Good morning!

This thread continues the thread https://community.nxp.com/t5/i-MX-Processors/iMX95-Two-video-inputs-and-two-video-outputs/m-p/232998....

We have a project where we want to use the iMX95, but we need two video inputs and two video outputs. For the inputs, we want to use the two MIPI-CSI inputs. As for the video outputs, we want to use the two LVDS outputs, since with two MIPI-CSI inputs we cannot use the MIPI-DSI output (due to the MIPI-DSI/CSI combination).

We want to use the two MIPI-CSI inputs of the iMX95 independently (each with a different video format). We want to connect the first MIPI-CSI input to the TC358743 chip and the second to the TC358748 chip. We want the two MIPI-CSI inputs to support the following formats: 720p50/59/60, 1080p50/59/60, PAL, NTSC and 1080i50/59/60.

This configuration of the two MIPI-CSI inputs raises the following questions:

1. Is it possible to do what we've described for the inputs? That is, one MIPI-CSI input from the TC358743 and the other from the TC358748, both supporting different video formats.

2. Are there any compatible drivers for these two chips (TC358743 and TC358748)?

3. Do the MIPI-CSI inputs also support the interlaced formats PAL, NTSC, and 1080i50/59/60? If so, how would we manage interlacing? Perhaps with so-called "virtual channels"? The documentation seems to support interlacing in the MIPI-CSI inputs ("CSI Pixel Formatter (CSI_PIXEL_FORMATTING)" => "Compatible with interlaced mode for YUV/RGB data types"), but we want to make sure it accepts such interlaced formats (PAL, NTSC and 1080i50/59/60).

4. We cannot use YUV422 with the TC358743 chip's MIPI-CSI interface due to the chip's limitations with interlaced data. We were thinking of using the YUV444 format on this MIPI-CSI interface, but sending it through the MIPI-CSI interface as if it were RGB, which would likely require software modifications. Is this possible? Would the software (driver, etc.) be ready-made, or would we have to develop it ourselves?

5. We want to route the input from one of the two MIPI-CSI interfaces to an H264/HEVC video encoder, but this encoder requires YUV420, while the MIPI-CSI interface is YUV422 (or YUV444). According to the documentation, it seems possible to use the "8-bit YUV422/YUV444/RGB hardware CSC" module. Is this CSC the one from the ISI module, or is it something else? Can this conversion (YUV422/YUV444 to YUV420) be performed via "hardware" using the aforementioned CSC, or would it have to be done via "software"?

6. Following on from the previous question, and considering sending the video decoder output to the LVDS interface, which would require a YUV420 (decoder) to RGB (LVDS) conversion, would it be possible to perform this conversion (YUV420 to RGB) using a "hardware module" (perhaps with the Blit controller for the display controller), or would it have to be done via "software"?

7. Speaking of color conversions, we also have a question about the compatibility and use of BT601 and BT709. Are they supported in "hardware" conversions, or do they depend on a specific coefficient configuration, or are they not supported at all?

8. Due to working with various video formats and chip limitations, we need the number of lanes on the MIPI-CSI interface to be dynamically configurable. Is this possible? If so, is the "software" (driver, etc) already prepared for this, or would we have to add it ourselves?

Thanks, Daniel.

[joanxie]

1)you can connect different device to the different mipi csi

2)you can refer to the driver as below

https://github.com/nxp-imx/linux-imx/blob/lf-6.12.y/drivers/media/i2c/tc358743.c

3)yes, can support interlacing video, but I don't have sample yet for imx95, only for imx8mp

4) mipi csi doesn't support yuv444, if you must use this format, maybe you can convert by your own SW

5)6) I think GPU can do this job, more detailed information, you can refer to the gpu guide

7)you can refer to the chapter 7.3.18 Video conversion of enclosed file

8)couldn't modify data lane dynamically

[danielsan-77]

Thank you for answering all the questions!

Regarding question/answer number 8, could the drivers for the chips used in the MIPI-CSI inputs be modified to allow dynamic changes to the number of lanes?

Thanks, Daniel.

[joanxie]

couldn't dynamic change the data lane