JPEG on NIOS II

Hi janhendrik,

Here is an sample result of JPEG decoding on Nios II. No Hardware Acceleration.

I have only Stratix Edition, so -mno-hw-mul option is used to near to Cyclone.

-- Hardware --

Nios Dev Board : Stratix edition

SOPC config : based on standard32

Nios II /f , ic 4k, dc 8k, hw-div enabled

VGA controller added(original)

Frecuency : SOPC core : 90MHz

VGA dot frec : 40MHz

VGA config : 800x600x16

-- Software --

OS : none (HAL)

JPEG Decoder : modified "JPEGLS" library. I got from Japanese WEB site. (You may find "jpegls mona" on Google if you read Japanese...). This library uses Divide operation.# I tryed to use IJG source code before. Compiling was passed but it did not work correctly. I give up. http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/tongue.gif

JPEG Image file : "Sunset.jpeg (800x600)". WindowsXP may include this sample image. JPEG Image is put to ROZIPFS, so this file access might be overhead.

-- Result --

Compile Options : Clocks : Time@90MHz

(1) -O2 -mno-hw-mul : 3,198M : 35[s]

(2) -O2 : 1,280M : 14[s]

(3) -O2 -mhw-div : 327M : 3.6[s]

I think the result of Cyclone may slower than (1). Because Nios II on Cyclone can not have Barrel Shifter. I&#39;m not sure -mno-hw-mul disable Barrel Shift or not.

I hope the info helps.

p.s.

for More faster JPEG decoding, I think I need to do ...

- eliminate divide operation

- SIMD custom instruction

- Hardware DCT/IDCT

- Hardware color conversion (YUV-RGB)