Copyright © 2003 Texas Instruments. All rights reserved. DSP C5000 Chapter 18 Image Compression and Hardware Extensions

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 2 Image Compression  Discrete Cosine Transform (DCT) based compression  Still image: JPEG.  Remove spatial redundancy  Video: H263, MPEG4.  Remove spatial redundancy  Remove temporal redundancy

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 3 JPEG Encoder  Image is split into 8x8 pixel block that are processed.  DCT is applied on input block to obtain the frequency data.  Values are read from low to high frequency thanks to zig-zag addressing.  Data are then quantized according to a quality factor.  This output is then run length and entropy coded.

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 4 JPEG Decoder  Data are entropy decoded.  They are dequantized according to a quality factor.  Zig-zag addressing to re-order the data pixel by pixel.  Inverse DCT to recover spatial data.

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 5 H263 and MPEG4 encoder  Same basic building blocks Hardware accelerator provided by C5509/10

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 6 H263 and MPEG4 Decoder  Same basic building blocks Hardware accelerator provided by C5509/10

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 7 Hardware Extensions  ‘C5509 and ‘C5510 provide H/W extensions for video compression:  DCT, IDCT  Pixel interpolation  Motion estimation  Hardware extensions are embedded co- processors:  Access to ACx, DARAM and SARAM.  Provide video codec with less than half of the processing bandwidth.

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 8 DCT H/W Extension 1 of 5  Allows 4x4 and 8x8 pixels DCT/IDCT computation:  2D DCT  2D IDCT

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 9 DCT H/W Extension 2 of 5  Basic steps to complete a 2D DCT/IDCT:  Input Data: macro block (4x4 or 8x8) is read in (DCT). DCT coefficient matrix is read in (IDCT).  Column DCT/IDCT process: output to temporary registers that will be transposed for Row processing.  Row DCT/IDCT process: data read from temporary register which are processed column by column.

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 10 DCT H/W Extension 3 of 5

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 11 DCT H/W Extension 4 of 5  Instruction set:  Load+computation+transfer to accumulator: ACy=copr(k8,ACx,Xmem,Ymem)  Computation+transfer to accumulator+memory write: ACy=copr(k8,ACx,ACy),Lmem=Acz  Special instructions: ACy=copr(k8,ACx,ACy)  Refer to application note for details and listings of macros realizing complete 8x8 DCT/IDCT. application noteapplication note

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 12 DCT H/W Extension 5 of 5  H/W extensions can be used through C- callable functions provided by IMLIB IMLIB

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 13 Debug To look at the internal register of the hardware extension …To look at the internal register of the hardware extension … DCT and IDCT Hardware accelerator registers

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 14 Tutorial DCT/IDCT with IMLIB  Describe step by step how to use H/W extensions with IMLIB.  Requires installation of IMLIB before continuing. IMLIB  Requires special memory configuration to obtain optimum performance.  CCS allows display of image contained in DSP memory.

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 15 Memory Configuration dct.cmd hwdct.cdb

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 16 Display Input Image 1 of 2  Load hwdct.pjt  Build and load application  Input image is « goldhill » 128x128 which is included by the header file ( #include «imagesample.h» ) at the address goldhill  To have the internal memory initialized use Debug>go to main command.  You are now ready to display the input image using view>Graph>image

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 17 Display Input Image 2 of 2

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 18 In place DCT Computation  

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 19 Actual dct.c Program   

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 20 Output Display and Initialization

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 21 Output Buffer Update

Copyright © 2003 Texas Instruments. All rights reserved. ESIEE, Slide 22 References  JPEG for digital panel (SPRA664) SPRA664  TMS320C55x Hardware extensions for image/video applications - Programmer’s reference (SPRU098) SPRU098  TMS320C55x image/video processing library programmer’s reference (SPRU037) SPRU037