STM32N6 VENC at higher resolutions

[therealnerd2]

Hi,

We have STM32N6570-DK and are testing camera input, video encode and write to SD card

We have not been able to make the "VENC_SDCard_Appli" example work, the SD card just contains zeros.

The "VENC_SDCard_ThreadX" example does work however, resulting in an 800x480 video.

Are there any examples on encoding at 1080p resolution? Changing the encoder parameters and level results in memory allocation failures in EncAsicMemAlloc_V2.

Many thanks

 

[RomainR.]

Hello @therealnerd2 

Can you provide details about the reading of the SD card for the VENC_SDCard_Appli demo? Did you follow all the recommendations in the Readme.html of this project below:

• The configuration of OTP124 fuses VDDIO3_HSLV=1 I/O XSPIM_P2 High speed option enabled.
• Have you signed and programmed the FSBL in external memory at address 0x7000 0000 and the Application at 0x7010 0000 by applying the correct header (STM32_SigningTool_CLI.exe)?
• Are you viewing the image from the OV5640 camera on the LCD screen?
• The re-reading of the SDCard must be done in raw mode as explained in the Readme.html in the section After execution.

Best regards

Romain,

[therealnerd2]

Hi,

We have been testing by running directly from the Cube IDE, and using Run and Debug. 

We have not flashed or programmed the OTP.

We can see the image on the LCD screen.

Command to read SD card attached.

Thanks.

 

[therealnerd2]

If I step through the example, I can see that "encoder_prepare" is actually failing, but the error is not being checked.

The error comes from EWLmalloc, which is not able to allocate any memory.

[therealnerd2]

I see this is https://github.com/STMicroelectronics/STM32CubeN6/issues/1. With that patch, the example now runs and the SDcard is now readable.

[therealnerd2]

Can you please:

1) confirm if the patch in that issue is valid

2) explain how to increase the recording resolution to 1080p

[DanielS]

Hello @therealnerd2 ,

Unfortunately, increasing the resolution to 1080p within VENC_SDCard_ThreadX requires a bit of work. The fact is that 1080p won't fit into the internal memory as in the original application. Camera and encoder buffer allocation requires some rework to be placed in external memory.

Best regards,

Daniel

[therealnerd2]

Hi Daniel,

Thanks for the reply, this makes sense with what we are seeing.

Is such an example using external memory planned? It's a shame for a chip advertised as 1080p capable that we cannot easily prove this working and test power usage.

Many thanks.

[DanielS]

Hi therealnerd2,

I understand your frustration.
We will strive to provide a 'ready-to-use' 1080p example in upcoming releases

Best regards,

Daniel

[therealnerd2]

Great, thank you

[therealnerd2]

Do you have any (estimated or actual) power consumption numbers for the device when doing a 1080p encode? Including the external memory ideally. 

Thanks

[DanielS]

Hello,

We have published power consumption measures here: https://wiki.st.com/stm32mcu/wiki/Introduction_to_Hardware_Video_Encoding_with_STM32#Power_consumption

Regards,

[exarian]

Thank you @DanielS, that is a great reference!

Will this example soon be available in the STM32CubeN6 github?

Alternatively, where can the reference example be found that was used to take the power measurements?

Thank you in Advance.