Reusing memory buffers idea

[frankcohen]

I'm writing an entertaining experience using Arduino_GFX, JPEGDEC, NAND/SD, on ESP32-S3 (8 MBytes), and a round TFT display with a GC9A01 controller. Half of the time it streams MJPEG images to the display. The other time it does sprite animation using Arduino_Canvas. I can't do both with the current set-up, I run out of memory.

I'm thinking of creating a branch of Arduino_GFX that lets me do the malloc() buffer creation outside. In this way I could reuse the memory I allocate for Arduino_Canvas for the JPEGDEC decoder when I'm only streaming.

What do you think?

[moononournation]

240x240x2=115.2k memory, how can you used up 8M memory?

[frankcohen]

I like to do EVERYTHING in Strings. :-D no, not really.

ESP32-S3 memory starts as:
Total Size : 238232 B ( 232.6 KB)
Free Bytes : 98480 B ( 96.2 KB)
Allocated Bytes : 132816 B ( 129.7 KB)
Minimum Free Bytes: 98376 B ( 96.1 KB)
Largest Free Block: 86004 B ( 84.0 KB)

My display uses Arduino_GFX for 240 x 240 pixels, 115200 bytes
JPEGDEC uses ( 240 * 240 * 2 ) / 10, 11,520 bytes
Arduino_Canvas, another 115200 bytes

[moononournation]

The image data should use PSRAM,thats why it add a 8M PSRAM besides the MCU.

[frankcohen]

I'm using ESP32-S3-MINI-1-N8. It comes with 8 Mbyte of flash memory and no PSRAM.

[frankcohen]

My code sets up the gfx object, and internally it malloc's 115,200 bytes of heap. _framebuffer is the internal pointer to the heap space allocated.

Arduino_GFX *gfx = new Arduino_GC9A01(bus, Display_SPI_RST, 1 /* rotation */, true /* IPS */);

Then my code sets up an Arduino_Canvas, and it internally mallocs another 115,200 bytes of heap (240x240x8)

Arduino_Canvas *bufferCanvas = new Arduino_Canvas(240, 240, gfx);

buffer.Canvas.flush() uses draw16bitRGBBitmap() to move the bit map data to the _framebuffer. To avoid using Arduino_Canvas and it's memory use for the buffer, could I instead modify draw16bitRGBBitmap to copy to the _framebuffer and wait on a new method I would add, gfx->flush(), to actually draw to the gfx controller?

I'm trying to avoid flicker and save memory.

What do you think?

-Frank

[frankcohen]

I have that wrong. From what I see Arduino_GFX does not allocate memory, Arduino_Canvas does.