FAQs

EdgeAI SDK vs Processor SDK

It is important to know the differences between EdgeAI SDK and PROCESSOR SDK and on similar lines the differences between TDA4VM-SK and J721E EVM.

While the SoC is common between TDA4VM-SK and J721E EVM, the board design and peripherals are very different. For example both eDP and HDMI port is directly available on TDA4VM-SK where as only eDP port is available on J721E EVM and it requires add-on infotainment card for HDMI. Similarly there are differences related to other available peripherals and board properties starting from power supply. Kindly refer to the respective board user-guide to know the differences better.

The SDKs are not compatible either. The EdgeAI SDK works only on TDA4VM SK and the Processor SDK works only on J721E EVM. There are differences in software driver availability between both the SDK. Even though EdgeAI SDK is built on top of Processor SDK, the build configuration is different. For example peripheral access like GPIO is enabled using Linux on EdgeAI SDK whereas the same is made available from RTOS core in Processor SDK.

The key differences are highlighted here but not limited to below list.

Component

EdgeAI SDK

Processor SDK

TDA4VM-SK

Supported

Not Supported

J721E-EVM

Not Supported

Supported

Capture Driver

Linux Device Driver

RTOS Driver

Display Driver

Linux Device Driver

RTOS Driver

Video Codecs

Linux Device Driver

Linux Device Driver

VPAC Driver

RTOS Driver

RTOS Driver

DMPAC Driver

RTOS Driver

RTOS Driver

ETHFW

Not Supported

Supported

Peripherals

Linux Device Driver

RTOS Driver

The SDK Development flow steps are given mostly for users to developing additional algorithms on C66x/C71x DSP or update existing VPAC/DMPAC hardware accelerator drivers on RTOS or update the memory map or add a new linux device driver and so on.

For best experience, kindly use the EdgeAI SDK only on TDA4VM-SK and Processor SDK on J721E EVM.

Getting Error when trying to capture from multiple USB cameras simultaneously

This is a common issue faced in the industry with many USB cameras. You may get errors like Failed to allocate required memory. when tying to capture simultaneously from more than one usb cameras.

The root cause for this issue is that most of the USB cameras requests for more BW than actually required. If the use case is to capture only from 2 USB cameras , it can be done by connecting one of them to USB type-C port since it is internally connected to a separate instance of USB controller. But if the use case is to capture from more than 2 cameras, you need to modify the UVC driver to override the BW allocation.

The root cause and work around is explained in detail in this blog Multiple UVC cameras on linux

To apply the work around to our SDK, use below steps

  1. Download and install Processor SDK Linux Processor SDK Linux

  2. Get the patch to add bandwidth_cap parameter to uvcvideo kernel module uvcvideo patch

  3. Apply the patch to kernel source in Processor SDK Linux Install path. Please refer to PSDK building kernel

  4. Compile only uvcvideo module using below command

    make ARCH=arm64 CROSS_COMPILE=aarch64-none-linux-gnu- tisdk_j7-evm_defconfig
make ARCH=arm64 CROSS_COMPILE=aarch64-none-linux-gnu- ./drivers/media/usb/uvc/uvcvideo.ko

  5. Copy ./drivers/media/usb/uvc/uvcvideo.ko to sk

  6. Remove uvcvideo module and install modified version using below commands

    rmmmod uvcvideo
insmod uvcvideo.ko

  7. Set the desired BW cap as shown below

    echo 1200 >  /sys/module/uvcvideo/parameters/bandwidth_cap

Note

The unit of BW here is Bytes/125us, you can estimate the approximate BW requirement by multiplying fps with size/frame

PROCESSOR-SDK-RTOS-J721E Developer notes

Kindly refer to this link to know more about PROCESSOR-SDK-RTOS Developer Notes

PROCESSOR-SDK-LINUX-J721E How to Guides

Kindly refer to this link to know more about PROCESSOR-SDK-Linux How to Guides