memory alignment and/or k4a_set_allocator() needed for modern CPUs, OpenCV, Eigen, and many other libraries

[diablodale]

In your developer transition PDF and at

OrbbecSDK-K4A-Wrapper/src/orbbec/ob_k4a_impl.c

Lines 140 to 145 in 5659cc8

	k4a_result_t k4a_set_allocator(k4a_memory_allocate_cb_t allocate, k4a_memory_destroy_cb_t free)
	{
	k4a_result_t result = K4A_RESULT_FAILED;
	LOG_WARNING("unsupported api [allocate=%d,free=%d]", allocate, free);

I read you have disabled the k4a_set_allocator() API. Unfortunately, this immediately breaks my application and makes adoption of Femto sensors difficult.
Specifically, my application needs 64-byte alignment of image data coming from the sensor.

Many modern (in the last 10 years) solutions require 64-byte alignment for AVX2 and GPU acceleration. When this hardware/library doesn't get 64-byte aligned memory, this can lead to crashes due to memory access violations. 64 is required, not optional for many scenarios.

In 2020 I escalated this issue to Microsoft microsoft#1274. To workaround the lack of memory alignment in the SDK, I analyzed the k4a SDK and wrote my own allocator that handles their 32-byte shift and results in a 64-byte aligned memory being returned. This as worked well for 3 years with zero problems.

Given that...how can I use Femto sensors and have 64-byte aligned frames to be returned to me?

I am 100% happy if you hardcode the 64-byte alignment somewhere and always return that. 👍 Microsoft's approach was always broken and this is a good opportunity for your sdk to get it right.

Alternatively, I need the k4a_set_allocator() to work as it was designed...which allows me to use my custom allocation to correct the alignment. Now having aligned memory is not only about performance, it is also about no crashes.

[zhonghong322]

Thank you for your suggestion. We will consider adding this feature in future versions, as it would require refactoring the internal memory management code in the SDK.

[diablodale]

Please keep this issue open and update it when (or if) you ever do that. Only after you fix your wrapper compatibility, can I write software for and sell your sensors.

[diablodale]

Checking back with you on this bug. A customer has paid for me to purchase two of your Femto sensors, I just ordered today. Is this missing code on your project list?