implementing jpeg with tms320c2xx assembly … jpeg with tms320c2xx assembly language software ......

Application ReportSPRA615 - January 2000

1

Implementing JPEG with TMS320C2xxAssembly Language Software

Vivian Shao Digital Signal Processing Solutions

ABSTRACT

JPEG compression/decompression technique is widely used for still image applications.There are two major ways to implement JPEG algorithm – hardware and software. Thehardware approach is good for speed but it has less flexibility and it costs more. The softwareapproach, on the other hand, is less expensive and more flexible. Implementing JPEG withTMS320C2xx DSP software is a good solution for consumer image products, such as digitalstill camera and color printer. This application report introduces the basic concepts of JPEGand the TMS320C2xx software is attached in the Appendices.

Contents1 Introduction 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 JPEG Algorithm Overview 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 JPEG Encoding 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.1 DCT 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.1 ZIGZAG 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2 Huffman Encoding 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3 Encoding DC coefficients 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.4 Encoding AC Coefficients 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.2 JPEG Decoding 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.1 Huffman Decoding 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.2 Dequantization 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.3 IDCT 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.4 Image Reconstruction 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 Conclusion 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Appendix A JPEG Encoding Software 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix B JPEG Decoding Software 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix C JPEG Tables 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appendix D Huffman AC Coefficient Tables 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

List of Figures

Figure 1. JPEG Encoding Block Diagram 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 2. JPEG Decoding Block Diagram 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 3. Zig-Zag Order 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 4. Difference Magnitude Categories for DC Coding 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 5. Table for Luminance DC Difference 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 6. Table for Chrominance DC Difference 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Figure 7. Categories Assigned to Coefficient Values 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SPRA615

2 Implementing JPEG with TMS320C2xx Assembly Language Software

1 Introduction

This application report includes the following sections: JPEG Algorithm Overview, JPEG Encoding,JPEG Decoding, and Conclusion. In the JPEG compression and JPEG decompression sections, thedetailed algorithms, such as DCT/IDCT, quantization, ZIGZAG, Huffman encode/decode, will beintroduced and some of implementation tricks will be described as well. The TMS320C2xx JPEGsource code is attached in the Appendices.

2 JPEG Algorithm Overview

The JPEG (Joint Photographic Experts Group) technical specification is applicable tocontinuous-tone-grayscale or color digital still image data. It is applicable to a wide range ofapplications that require use of compressed images. This specification:

• Specifies processes for converting source image data to compressed image data

• Specifies processes for converting compressed image data to reconstructed image data

• Gives guidance on how to implement these processes in practice

• Specifies coded representations for compressed image data

Figure 1 shows the main procedure for JPEG encoding process based on the DCT (discretecosine transform). The original image should be grouped into 8x8 blocks first. Each 8x8 block istransferred by forward DCT into a set of 64 values referred to as DCT coefficients. Each of the64 coefficients is then quantized using a quantization table with 64 corresponding values. BeforeHuffman encoding, the entropy encoding, the two-dimensional image data is converted toone-dimensional zigzag sequences.

DCT QUANT. ZIGZAG HUFFMANENCODE

8x8 block

Original ImageCompressed Data

QUANT.TABLE HUFFMAN

TABLE8x8 block

Figure 1. JPEG Encoding Block Diagram

Figure 2 shows the main procedure for JPEG decoding process, which is the reversed processof encoding. The detailed algorithms and implementation techniques will be discussed in thefollowing sections.

IDCTDeQUANT.8x8 blockreconstruction

HUFFMANDECODE

Recovered Image

Compressed Data

DEQUANT.TABLEHUFFMAN

DECODETABLE

Figure 2. JPEG Decoding Block Diagram

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3 JPEG Encoding

3.1 DCT

The first step in JPEG encoding is level shifting of image by 128, i.e., image data minus 128.After which the forward DCT is applied onto the image data to transform the originaltwo-dimensional data into a set of coefficients. One of these values is referred as the DCcoefficient and the other 63 as the AC coefficients. The forward DCT equation is

Fv, u � 14

cu cv �7

x�0

�7y�0

fy, x cos(2x � 1)u�

16cos

(2y � 1)v�16

It can be written in matrix multiplication form as

[Y] � [A] � [X] � [A]T

where

[X] is the 8 x 8 input data matrix

[A] is the 8 x 8 DCT coefficient matrix

[Y] is the result of DCT transformation

The coefficient matrix [A] for forward DCT is

[A] �

��

�

�

12�

cos �

16

cos 2�16

cos 3�16

cos 4�16

cos 5�16

cos 6�16

cos 7�16

12�

cos 3�16

cos 6�16

cos 9�16

cos 12�16

cos 15�16

cos 18�16

cos 21�16

12�

cos 5�16

cos 10�16

cos 15�16

cos 20�16

cos 25�16

cos 30�16

cos 35�16

12�

cos 7�16

cos 14�16

cos 21�16

cos 28�16

cos 35�16

cos 42�16

cos 49�16

12�

� cos 7�16

cos 14�16

� cos 21�16

cos 28�16

� cos 35�16

cos 42�16

� cos 49�16

12�

� cos 5�16

cos 10�16

� cos 15�16

cos 20�16

� cos 25�16

cos 30�16

� cos 35�16

12�

� cos 3�16

cos 6�16

� cos 9�16

cos 12�16

� cos 15�16

cos 18�16

� cos 21�16

12�

� cos �

16

cos 2�16

� cos 3�16

cos 4�16

� cos 5�16

cos 6�16

� cos 7�16

��

DSP supports powerful instruction “MAC” for multiply-and-accumulate operations, which can beused to code DCT very efficiently. The DCT subroutine is shown in Appendix A.

Each of the 64 coefficients is then quantized using one of 64 corresponding values from aquantization table. No default values for quantization tables are specified in the JPEGspecification; applications may specify values which customize picture quality for their particularimage characteristics, display devices, and viewing conditions.

The quantization table is declared in “tables.asm” file, which is attached in Appendix C.

(1)

(2)

(3)

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3.1.1 ZIGZAG

After quantization, the DC coefficient and the 63 AC coefficients are prepared for entropy, which isHuffman encoding. The previous quantized DC coefficient is used to predict the current quantizedDC coefficient, and the difference is encoded. The 63 quantized AC coefficients undergo no suchdifferential encoding, but are converted into a one-dimensional zig-zag sequence, as shown inFigure 3, where the numbers are the zig-zag orders, notified as ZZ(0), ZZ(1),...,ZZ(63).

ÉÉÉÉ

0ÉÉÉÉ

1ÉÉÉÉ

5ÉÉÉÉÉÉ

6ÉÉÉÉ

14ÉÉÉÉ

15ÉÉÉÉÉÉ

27ÉÉÉÉ

28ÉÉÉÉ

2ÉÉÉÉ

4ÉÉÉÉ

7ÉÉÉÉÉÉ

13ÉÉÉÉ

16ÉÉÉÉ

26ÉÉÉÉÉÉ

29ÉÉÉÉ

42ÉÉÉÉ

3ÉÉÉÉ

8ÉÉÉÉ

12ÉÉÉÉÉÉ

17ÉÉÉÉ

25ÉÉÉÉ

30ÉÉÉÉÉÉ

41ÉÉÉÉ

43ÉÉÉÉ

9ÉÉÉÉ

11ÉÉÉÉ

18ÉÉÉÉÉÉ

24ÉÉÉÉ

31ÉÉÉÉ

40ÉÉÉÉÉÉ

44ÉÉÉÉ

53ÉÉÉÉ

10ÉÉÉÉ

19ÉÉÉÉ

23ÉÉÉÉÉÉ

32ÉÉÉÉ

39ÉÉÉÉ

45ÉÉÉÉÉÉ

52ÉÉÉÉ

54ÉÉÉÉ

20ÉÉÉÉ

22ÉÉÉÉ

33ÉÉÉÉÉÉ

38ÉÉÉÉ

46ÉÉÉÉ

51ÉÉÉÉÉÉ

55ÉÉÉÉ

60ÉÉÉÉ

21ÉÉÉÉ

34ÉÉÉÉ

37ÉÉÉÉÉÉ

47ÉÉÉÉ

50ÉÉÉÉ

56ÉÉÉÉÉÉ

59ÉÉÉÉ

61ÉÉÉÉ

35ÉÉÉÉ

36ÉÉÉÉ

48ÉÉÉÉÉÉ

49ÉÉÉÉ

57ÉÉÉÉ

58ÉÉÉÉÉÉ

62ÉÉÉÉ

63

Figure 3. Zig-Zag Order

3.1.2 Huffman Encoding

Two coding procedures are used, one for the DC coefficient ZZ(0) and the other for the ACcoefficients ZZ(1)…ZZ(63). The coefficients are encoded in the order in which they occur in ZZ,starting with the DC coefficient.

3.1.3 Encoding DC coefficients

The DC coefficients are coded differentially, using a one-dimensional predictor, PRED, which is thequantized DC value from the most recently coded 8x8 block from the same component (Y, U, V).The difference, DIFF, is obtained from

DIFF = ZZ(0) – RPED

At the beginning of the scan and at the beginning of each restart interval, the prediction for theDC coefficient prediction is initialized to 0.

The twos-complement difference magnitudes are grouped into 12 categories, SSSS, as shownin Figure 4. A Huffman code is created for each of the 12 difference magnitude categories byHuffman DC tables, as shown in Figure 5 and Figure 6.

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SSSS DIFF Values0 01 –1,12 –3,–2,2,33 –7,...,–4,4,...74 –15...,–8,8,...,155 –31,...,–16,16,...,316 –63,...,–32,32,...,637 –127,...,–64,64,...,1278 –255,...,–128,128,...2559 –511,...,–256,256,...,51110 –1023,...,–512,512,...102311 –2047,...,–1024,1024,...2047

Figure 4. Difference Magnitude Categories for DC Coding

Category Code Length Code Word0 2 001 3 0102 3 0113 3 1004 3 1015 3 1106 4 11107 5 111108 6 1111109 7 111111010 8 1111111011 9 111111110

Figure 5. Table for Luminance DC Difference

Category Code Length Code Word0 2 001 2 012 2 103 3 1104 4 11105 5 111106 6 1111107 7 11111108 8 111111109 9 11111111010 10 111111111011 11 11111111110

Figure 6. Table for Chrominance DC Difference

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For each category, except SSSS=0, and additional bits field is appended to the code word touniquely identify which difference in that category actually occurred. The number of extra bits isgiven by SSSS; the extra bits are appended to the LSB of ther preceding Huffman code, mostsignificant bit first. When DIFF is positive, the SSSS low order bits of DIFF are transmitted. WhenDIFF is negative, the SSSS low order bits of (DIFF-1) are transmitted. Note that the most significantbit of the appended bit sequence is 0 for negative differences and 1 for positive differences.

3.1.4 Encoding AC Coefficients

Since many coefficients are zero, runs of zeros are identified and coded efficiently. In addition, ifthe last part of ZZ is entirely zero, this is coded explicitly as an end-of-block (EOB).

Each nonezero AC coefficient in ZZ is described by a composite 8-bit value, R/S, of the form

R/S = binary ‘RRRR/SSSS’

The four bits, ‘SSSS’, define a category for the amplitude of the next nonzero coefficient in ZZ. The‘SSSS’ is defined by category table, which is shown in Figure 7. The four bits, ‘RRRR’, give theposition of the coefficient in ZZ relative to the previous nonzero coefficient. The Huffman AC codetable consists of one Huffman code (maximum length of 16 bits) for each possible composite value.The Huffman table for luminance AC coefficients and chrominance AC coefficients are shown inAppendix D.

SSSS DIFF Values1 –1,12 –3,–2,2,33 –7,...,–4,4,...74 –15...,–8,8,...,155 –31,...,–16,16,...,316 –63,...,–32,32,...,637 –127,...,–64,64,...,1278 –255,...,–128,128,...2559 –511,...,–256,256,...,51110 –1023,...,–512,512,...102311 –2047,...,–1024,1024,...2047

Figure 7. Categories Assigned to Coefficient Values

Each Huffman code is followed by additional bits, which specify the sign and exact amplitude ofthe coefficient. The format for the additional bits is the same as in the coding of DC coefficients.ZZ(K) is the Kth coefficient in the zig-zag sequence of coefficients being coded. The value ofSSSS gives the number of additional bits required to specify the sign and precise amplitude ofthe coefficient. The additional bits are either the low-order SSSS bits of ZZ(K) when ZZ(K) ispositive or the low-order SSSS bits of ZZ(K)–1 when ZZ(K) is negative.

The JPEG encoding C2xx software, including subroutines of DCT, QUANT, HUFF_ENCODE, isattached on Appendix A. The JPEG encoding related tables, such as DCT coefficients table,quantization table, zig-zag sequence table, Huffman DC and AC coefficients tables are alldefined and implemented in “tables.asm” file, which is attached in Appendix C.

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3.2 JPEG Decoding

3.2.1 Huffman Decoding

The Huffman decoding table is used to recover the compressed data from bit stream format to64 16-bit data. The Huffman decoding procedure is:

1. Get code word from bit stream

2. Get the information of RRRR/SSSS by looking up Huffman decoding table

3. Get the exact value from extra bits of bit stream

4. Reconstruct the 64 16-bit values before Huffman encoding

3.2.2 Dequantization

The values in Dequantization table are the inverse of the values in quantization table. Thedequantization table used here combines the dequantization value and zig-zag sequence, thatis, the data order after dequantization will be in the order of ZZ(0), ZZ(1), ZZ(5), ZZ(6), ZZ(14),ZZ(15),… as shown in Figure 3.

3.2.3 IDCT

The inverse DCT equation is

fy, x � 14�7u�0

�7y�0

cu cv Fv, u cos(2x � 1)u�

16cos

(2y � 1)v�16

Which can be represented as the form of matrix multiplication as described in DCT section. The coefficient matrix of IDCT is

�A� �

��

�

12�

12�

12�

12�

12�

12�

12�

12�

cos �

16

cos 3�16

cos 5�16

cos 7�16

� cos 7�16

� cos 5�16

� cos 3�16

� cos �

16

cos 2�16

cos 6�16

cos 10�16

cos 14�16

cos 14�16

cos 10�16

cos 6�16

cos 2�16

cos 3�16

cos 9�16

cos 15�16

cos 21�16

� cos 21�16

� cos 15�16

� cos 9�16

� cos 3�16

cos 4�16

cos 12�16

cos 20�16

cos 28�16

cos 28�16

cos 20�16

cos 12�16

cos 4�16

cos 5�16

cos 15�16

cos 25�16

cos 35�16

� cos 35�16

� cos 25�16

� cos 15�16

� cos5pi16

cos 6�16

cos 18�16

cos 30�16

cos 42�16

cos 42�16

cos 30�16

cos 18�16

cos 6�16

cos 7�16

cos 21�16

cos 35�16

cos 49�16

� cos 49�16

� cos 35�16

� cos 21�16

� cos 7�16

��

�

(4)

(5)

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3.2.4 Image Reconstruction

After IDCT, the JPEG decoding of 8x8 block is completed. The last procedure is to reconstructthe 8x8 blocks to the original image. It can be done by moving the data to the original imageaddresses.

The JPEG decoding software is attached on Appendix B and the related tables is in “tables.asm”file, which is attached on Appendix C.

4 Conclusion

This application report has described the JPEG specification and explained the implementationsteps. It also provides the JPEG ’C2xx assembly source code for DSP application engineers.Some simple modification may be needed to be adapted to individual systems; however, itprovides the baisc starting for software engineers and save on development time and efforts.Note that this report only describte the encode/decode process of a basic 8x8 block under thecontext of JPEG standard. It does not include the file parsing routine required to extract headerdata information when decoding a JPEG image file that is compliant to for a JPEG file format.

SPRA615

9 Implementing JPEG With TMS320C2xx Assembly Language Software

Appendix A JPEG Encoding Software

JEPGEN.ASM;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Program Name : JPEGEN.ASM

; Discription : This program includes JPEG encoder

; The modules of JPEG includes

; 1. Frame => 8x8 blocks

; 2. JPEG Coefficients Initialization

; 3. Testing Data Initialization

; Editor : Vivian Shao

; Date : 02/20/1997

; Possessor : Texas Instruments

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.def JPEG_EN

.def J_STATUS, J_STACK

.ref PICT

.ref IMAGE_LENGTH, IMAGE_WIDTH, NEXT_LINE, NEXT_SECTION

.ref BLOCK_ENCODE, HUFF_EN

.ref DCT_COEF, Y_QUANTIZE_TABLE, ZIGZAG_TABLE0, RDCHUFF

.ref QUANT_TABLE, ZIGZAG_TABLE, DCHUFF

.ref DCTB1, COMPRESS_DATA, RNDOFF

.ref MASKDATA, MASKSIZE, EOB, LAST_DC, LAST_RESULT

.ref DIFF, DIFF1, RZERO, IN_SIZE, COWORD, USER_BIT, LESS_BIT

.ref ABSDIFF, ABSDIFF1, TRANSDIFF, DC_HEAD, DC_TAIL

.ref SIZE, COWORD_SIZE, V_SIZE, NEG_VSIZE, JUDGE_DATA, F_TAB

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; JPEGEN VARIABLES

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.bss J_STATUS, 2

J_STACK .usect ”.j_stack”, 10h

DCTB1_ADDR .set DCTB1

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; JPEG_EN PROGRAM BEGINS

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.text

JPEG_EN:

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT SAVING ;

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

SST #0, J_STATUS

SST #1, J_STATUS+1

LDP #J_STACK

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SAR AR1, J_STACK+1 ; AR1 is used in DCT, QUANT & HUFF_EN



SAR AR4, J_STACK+4 ; AR4 is used for PICT DISASSEMBLE

SAR AR5, J_STACK+5 ; AR5 is used in QUANT & HUFF_EN

POPD J_STACK+8

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; JPEG_EN MAIN ; AR4 CANNOT BE USED FOR OTHER PURPOSE

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

CALL JPEG_EN_INIT

LAR AR7, #IMAGE_WIDTH–1 ; block # of width

blocken_loop0:

LAR AR6, #IMAGE_LENGTH–1 ; block # of length

blocken_loop:

CALL BLOCK_INIT ; initialize 8x8 block data

CALL BLOCK_ENCODE ; compressed data –> COMPRESS_DATA

MAR *, AR6

BANZ blocken_loop, *–

LAR AR0, #NEXT_SECTION

MAR *, AR4

MAR *0+, AR7

BANZ blocken_loop0, *–

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT RESTORE

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

LDP #J_STACK

PSHD J_STACK+8

LAR AR5, J_STACK+5

LAR AR4, J_STACK+4

LAR AR3, J_STACK+3

LAR AR2, J_STACK+2

LAR AR1, J_STACK+1

LDP #0

LST #1, J_STATUS+1

LST #0, J_STATUS

RET ; retutn from JPEG_EN

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Inintialize Block Data

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

BLOCK_INIT:

LAR AR0, #NEXT_LINE

MAR *, AR4

RPT #7

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BLDD *+, #DCTB1

MAR *0+

RPT #7

BLDD *+, #DCTB1+8

MAR *0+

RPT #7

BLDD *+, #DCTB1+16

MAR *0+

RPT #7

BLDD *+, #DCTB1+24

MAR *0+

RPT #7

BLDD *+, #DCTB1+32

MAR *0+

RPT #7

BLDD *+, #DCTB1+40

MAR *0+

RPT #7

BLDD *+, #DCTB1+48

MAR *0+

RPT #7

BLDD *+, #DCTB1+56


MAR *0–, AR2

LAR AR2, #DCTB1 ; data – 128

LAR AR3, #63

ji_loop:

LACC *

SUB #128

SACL *+, 0, AR3

BANZ ji_loop, *–, AR2

LDP #RNDOFF ; initialize RNDOFF value

SPLK #8000h, RNDOFF

RET ; return from BLOCK_INIT

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

;

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

JPEG_EN_INIT:

dct_init:

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CLRC CNF ; B0 is mapped to data memory

SETC SXM ; SXM=1

SETC OVM ; OVM=1

SPM 0 ; PM=0

MAR *, AR5

LAR AR5, #0200h ; LOAD DCT COEF to B0

RPT #63

BLPD #DCT_COEF, *+

SETC CNF ; B0 is mapped to program memory

quant_init:

MAR *, AR5

LAR AR5, #QUANT_TABLE ; Initialize Quant table

RPT #63

BLPD #Y_QUANTIZE_TABLE, *+

LAR AR5, #ZIGZAG_TABLE ; Initialize ZigZag table

RPT #63

BLPD #ZIGZAG_TABLE0, *+

huffen_init:

LAR AR1, #DCHUFF

MAR *, AR1

RPT #220

BLPD #RDCHUFF, *+

LAR AR1, #COMPRESS_DATA

LACL #0

RPT #255

SACL *+

; RPT #255

; SACL *+

; RPT #255

; SACL *+


LAR AR4, #PICT

LDP #DIFF

; SPLK #0, DIFF

; SPLK #0, DIFF1

; SPLK #0, ABSDIFF

; SPLK #0, ABSDIFF1

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; SPLK #0, TRANSDIFF

; SPLK #0, RZERO

; SPLK #0, IN_SIZE

; SPLK #0, COWORD

SPLK #0FFF0h,MASKDATA

SPLK #0F000h,MASKSIZE

SPLK #0Ah, EOB ; Luminance

; SPLK #00h, EOB ; Chrominance

SPLK #0h, LAST_DC

SPLK #0h, LAST_RESULT

SPLK #010h, USER_BIT

SPLK #0h, LESS_BIT

; LDP #SIZE

; SPLK #0, SIZE

; SPLK #0, COWORD_SIZE

; SPLK #0, V_SIZE

; SPLK #0, NEG_VSIZE

; SPLK #0, JUDGE_DATA

; SPLK #0, F_TAB

RET ; retrun from JPEG_EN_INIT

BLOCKEN.ASM;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Program Name : BLOCKEN.ASM

; Discription : This program includes JPEG 8x8 block encoder

; The modules of BLOCKEN include

; 1. DCT

; 2. QUANT

; 3. HUFF


; Date : 02/20/1997


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.def BLOCK_ENCODE, IDCT, HUFF_EN

.def RNDOFF, BLK2_ADDR, DCTB1, EOB_SIZE

.def QUANT_TABLE, ZIGZAG_TABLE, DCHUFF

.def B_STATUS, B_STACK

.ref DCT_COEF, Y_QUANTIZE_TABLE, ZIGZAG_TABLE0

.ref MAX_VALUE, MIN_VALUE

.def DIFF, DIFF1, ABSDIFF, ABSDIFF1, TRANSDIFF

.def RZERO, IN_SIZE, COWORD, EOB

.def MASKDATA, MASKSIZE, LAST_DC, LAST_RESULT, USER_BIT, LESS_BIT

.def SRC, DST, DC_TAIL, DC_HEAD, DATA

SPRA615


.def ACHUFF, DCHUFF, LMASK

.def DIFFSIZE

.ref RDCHUFF

.ref COMPRESS_DATA

B_STACK .usect ”.b_stack”, 10h

RNDOFF .usect ”.dct_var”, 1

DCTB1 .usect ”.dct_blk”, 64

DCTB2 .usect ”.dct_blk”, 64

QZBI .usect ”.qz_blk”, 64

QZBR .usect ”.qz_blk”, 64

QUANT_TABLE .usect ”.qz_tbl”, 64

ZIGZAG_TABLE .usect ”.qz_tbl”, 64

DIFF .usect ”.huf_var”, 1

DIFF1 .usect ”.huf_var”, 1

ABSDIFF .usect ”.huf_var”, 1

ABSDIFF1 .usect ”.huf_var”, 1

RZERO .usect ”.huf_var”, 1

IN_SIZE .usect ”.huf_var”, 1

COWORD .usect ”.huf_var”, 1

TRANSDIFF .usect ”.huf_var”, 1

MASKDATA .usect ”.huf_var”, 1

MASKSIZE .usect ”.huf_var”, 1

EOB .usect ”.huf_var”, 1

LAST_DC .usect ”.huf_var”, 1

LAST_RESULT .usect ”.huf_var”, 1

USER_BIT .usect ”.huf_var”, 1

LESS_BIT .usect ”.huf_var”, 1

DC_HEAD .usect ”.huf_var”, 1

DC_TAIL .usect ”.huf_var”, 1

BLOCK_NUMBER .usect ”.huf_var”, 1

SRC .usect ”.huf_var”, 1

DST .usect ”.huf_var”, 1

LENGTH .usect ”.huf_var”, 1

DATA .usect ”.huf_var”, 1

SPRA615


DCHUFF .usect ”huftable”, 12

DIFFSIZE .usect ”huftable”, 16

LMASK .usect ”huftable”, 17

ACHUFF .usect ”huftable”,176

.bss B_STATUS, 2

EOB_SIZE .set 4

BLK2_ADDR .set QZBR

.text

BLOCK_ENCODE:

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT SAVING ; AR5 cannot be assigned to other usage!!

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

SST #0, B_STATUS

SST #1, B_STATUS+1

LDP #B_STACK

SAR AR1, B_STACK ; AR1 is used in DCT, QUANT & HUFF_EN

SAR AR2, B_STACK+1 ; AR2 is used in DCT, QUANT & HUFF_EN

SAR AR3, B_STACK+2 ; AR3 is used in DCT, QUANT & HUFF_EN

SAR AR6, B_STACK+3 ; AR6 is used in QUANT & HUFF_EN

POPD B_STACK+4

CALL DCT

CALL QUANT

CALL HUFF_EN

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT RESTORE

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

LDP #B_STACK

PSHD B_STACK+4

LAR AR6, B_STACK+3

LAR AR3, B_STACK+2

LAR AR2, B_STACK+1

LAR AR1, B_STACK

LDP #0

LST #1, B_STATUS+1

LST #0, B_STATUS

RET

SPRA615


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Subroutine : DCT

; Function : A 2D 8x8 Discrete Cosine Transform

; Disciption : This program is based on the matrix

; formulation.

; T T T

; 8X8 DCT = [c] [d] [c] = [c] { [c] [d] } }

;

; Notes: 1. [c] is cosine matrix for DCT

; 2. [d] is 8x8 input data matrix

; 3. T is the symbol for matrix transpose

;

; Input matrix is stored in B1, and the results

; are stored in the input matrix.

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; DCT Main

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

IDCT:

DCT:

; SOVM ; SET OVM=1

CNFP ; set B0 is PROGRAM MEMORY

LAR AR1,#DCTB1

LAR AR2,#DCTB2

CALL DCT1D

LAR AR1,#DCTB2

LAR AR2,#DCTB1

CALL DCT1D

CNFD

RET

;––––––––––––––––––––––––––––––––––––––

; DCT1D

; T

; 8X8 DCT1D = [c] [d]

;––––––––––––––––––––––––––––––––––––––

DCT1D:

LAR AR0, #64 ; BLOCKSIZE

LDP #RNDOFF

SPRA615


;––––––––––––––––––––––––––––––––––––––

; DCT1D Main Program

;––––––––––––––––––––––––––––––––––––––

MAR *, AR1 ; ACTIVE AR1

LAR AR3, #7 ; COUNT FOR 8 1–D DCTs

ROW1 ZAC ; ACC=0

MPY #0 ; Preg=0

RPT #7

MAC 0ff00h,*+ ; ACC = X0*Y0 + X1*Y1 + ... + X6*Y6,

; Preg = X7*Y7

LTA *,AR2 ; ACC+ = X7*Y7, ARP=2

ADDS RNDOFF ; ROUND OFF

SACH *+,AR3 ; dma = ACCH, ARP=3

BANZ ROW1,*–,AR1 ; if AR3!=0 GOTO ROW1,AR3––,ARP=1

MAR *0– ; AR1– = AR0

LAR AR3, #7 ; COUNT FOR 8 1–D DCTs

ROW2 ZAC ; ACC=0 ,Preg=0

MPY #0 ; Preg=0

RPT #7

MAC 0ff08h,*+ ; ACC=X0*Y0+X1*Y1+...+X6*Y6,

; Preg=X7*Y7

LTA *,AR2 ; ACC+=X7*Y7,ARP=2


SACH *+,AR3 ; dma=ACCH,ARP=3


MAR *0– ; AR1–=AR0

LARK AR3, 7 ; COUNT FOR 8 1–D DCTs


MPYK 0 ; Preg=0

RPTK 7


; Preg=X7*Y7





MAR *0– ; AR1–=AR0



MPYK 0 ; Preg=0

RPTK 7


; Preg=X7*Y7

SPRA615






MAR *0– ; AR1–=AR0



MPYK 0 ; Preg=0

RPTK 7


; Preg=X7*Y7





MAR *0– ; AR1–=AR0



MPYK 0 ; Preg=0

RPTK 7


; Preg=X7*Y7





MAR *0– ; AR1–=AR0



MPYK 0 ; Preg=0

RPTK 7


; Preg=X7*Y7





MAR *0– ; AR1–=AR0



MPYK 0 ; Preg=0

RPTK 7

SPRA615



; Preg=X7*Y7




BANZ ROW8,*–,AR1 ; if AR3!=0 GOTO ROW8, AR3––,ARP=1

RET

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Subroutine : QUANT

; Function : QUANTIZATION and ZIGZAG for JPEG Encoding

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

QUANT:

;–––––––––––––––––––––––––––––––––

; QUANT+ZIGZAG Main

;–––––––––––––––––––––––––––––––––

; SPM 2 ; LEFT_SHIFTED 4 PLACES

SPM 1

LAR AR0, #63 ; BLOCKSIZE–1

LAR AR1, #QZBI ; SOURCE ADDRESS

LAR AR2, #ZIGZAG_TABLE ; ZIGZAG TABLE REGISTER

LAR AR6, #QUANT_TABLE ; QUANTIZE TABLE REGISTER

MAR *, AR2 ; ACTIVE AR2

Q_loop: LAR AR3, *+, AR1 ; ASSIGN (DST+ZIGZAG) TO AR3

LT *+, AR6 ; (dma)––>Treg

MPY *+, AR3 ; (Treg)*(Quantize Cofficient)

PAC ; (Preg)––>ACC

ADDS RNDOFF ; ACC+RNDOFF

SACH *, AR0 ; Put the result to DST

BANZ Q_loop, *–, AR2 ; Repeat 64 Times

SPM 0 ; NO SHIFT

RET

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Subroutine : HUFF_EN

; Discription : Huffman Encoding

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

HUFF_EN:

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Huffman Encode Main Program

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

LDP #DIFF ;

ZAC ; ACC=0

SACL DIFF ; DIFF=0

SPRA615


SACL IN_SIZE ; IN_SIZE=0

SACL RZERO ; RZERO(ZERO RUNS)=0

DCENHUFF:

LARP AR1

LAR AR1, #QZBR

LACC * ; JPEGB(COEFF)–>ACC,AR0=>ABSDIFF

SUB LAST_DC ; ACC=COEFF–LAST_DC

CALL GSIZE, *, 2 ; CALL GETSIZE FOR GET REAL SIZE

LARP AR3

LAR AR3, #DCHUFF

LAR AR0, ABSDIFF

MAR *0+

LAC *0–, 12, 5 ;FOR EXAMPLE 0063,006 IS COWARD, 3 IS SIZE

CALL GCOWORD, *, 5

ACENHUFF:

LAR AR1, #QZBR

LARK AR6,3EH ;AR6=BLOCK_SIZE–2

LARP 1

LAC *+

SACL LAST_DC

CHECKZERO:

LAC *+,0,6

BZ CKZERO

CALL GSIZE,*,2

CONCHECK:

LAC RZERO

SUBK 10H

BLZ NEXT1

DMOV ABSDIFF

DMOV DIFF

SACL RZERO

LALK 07F9BH,12

SACL ABSDIFF,4

SACL DIFF,4

CALL GCOWORD

LAC ABSDIFF1

SACL ABSDIFF

LAC DIFF1

SACL DIFF

B CONCHECK

SPRA615


NEXT1:

RSXM

LAC RZERO

ADD ABSDIFF,4

SACL TRANSDIFF

LARP 3

LRLK AR3,ACHUFF

LAR AR0,TRANSDIFF

MAR *0+

BIT *,0H,3

BBZ nouser_16

BIT *,8H,3

BBZ nouser_16

user_16:

ZALH *0–,5

b conte

nouser_16:

LAC *0–,12,5

conte:

CALL GCOWORD,*,5

ZAC

SACL RZERO

LARP 6

BANZ CHECKZERO,*–,1

B INSERT_EOB

CKZERO:

LAC RZERO

ADDK 1H

SACL RZERO

BANZ CHECKZERO,*–,1

INSERT_EOB:

LARP 3

LRLK AR3,ACHUFF

LAC *,12

SACL ABSDIFF,4

SACL DIFF,4 ;EOB–>0A4h

CALL GCOWORD

RET

SPRA615


;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; GET THE REAL SIZE SUBROUTION

; HUFFDCENCODE HUFFACENCODE

; DIFF = DC(I)=DC(I–1) DIFF = COEFF

; THE INICIAL STATE OF THIS SUBROUTINE

; ARP=AR0(ABSDIFF)

; AR2=THE HEADER OF DIFFSIZE TABLE

; THE OUTPUT STATE OF THIS SUBROUTINE

; ARP=AR0(DIFFSIZE)

; DSIZE = REAL SIZE

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

GSIZE:

SACL DIFF ;ACC–>DIFF

BIT DIFF,0H ;CHECK MSB OF DIFF

BBZ POSITIVE ;IF MSB=1 THEN DIFF IS NEGATIVE

NEGATIVE:

ABS

CMPL ;GET COMPLEMENT OF DIFF

SACL DIFF

CMPL ;GET OLD DIFF

POSITIVE:

SACL ABSDIFF ;ABS(COEFF–LAST_DC)–>AR0(DIFF),AR2(DIFFSIZE)

AND MASKDATA ;MASKDATA = 0XFFF0H

; BZ GETSIZE,*,AR2 ;IF ACC&0XFFF0H =0 THEN SIZE <4 BIT

MAR *, AR2

BZ GETSIZE

LAC ABSDIFF,12 ;ELSE SIZE >4 BIT

SACH ABSDIFF ;SHIFT RIGHT 4 BIT

LACL IN_SIZE ;IN_SIZE = IN_SIZE+4

ADDK 04H

SACL IN_SIZE

LACL ABSDIFF

B POSITIVE

GETSIZE:

LARP 2

LRLK AR2,DIFFSIZE

LAR AR0,ABSDIFF

MAR *0+

LAC * ;ARP=AR2+AR0–>ACC

ADD IN_SIZE

SACL ABSDIFF

SACH IN_SIZE

LRLK AR2,LMASK

SPRA615


LAR AR0,ABSDIFF

MAR *0+

LAC *

AND DIFF

SACL DIFF

RET

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; FIND THE COWORD AND COWORD_SIZE

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

GCOWORD:

LARP 5

SACH COWORD ;COWRD=6 , AR5–>RESULT

AND MASKSIZE

BNZ not_16

ADLK 10H,12

not_16

SUB USER_BIT,0CH ;USER_BIT=16 => 10000

NEG ; 3000

SACH USER_BIT,4 ; = 0D =D0000

BGEZ SHIFT_LT

NEWORD1:

LAC USER_BIT

ADDK 10H

SACL USER_BIT

LT USER_BIT

ZALH *

ADDT COWORD

SACH *+

SACL *

B CONDIFF

SHIFT_LT:

LT USER_BIT ;LOAD USER_BIT TO T REGISTER

LAC * ;RESULT–>ACC

ADDT COWORD

SACL *

CONDIFF:

LAC USER_BIT

SUB ABSDIFF

SACL USER_BIT

BGEZ NORMALS

SPRA615


NEWORD2:

ADDK 10H

SACL USER_BIT

LT USER_BIT

ZALH *

ADDT DIFF

SACH *+

SACL *

B ENDSUB

NORMALS:

LT USER_BIT

LAC *

ADDT DIFF

SACL *

ENDSUB:

SSXM

RET

SPRA615


Appendix B JPEG Decoding Software

JPEGDE.ASM;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Program Name : JPEGDE.ASM

; Discription : This program includes JPEG decode


; 1. JPEG Coefficients Initialization

; 2. CALL BLOCK_DECODE

; 3. 8x8 block –> image frame


; Date : 11/26/1997


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.def JPEG_DEC

.ref PICT

.ref IMAGE_LENGTH, IMAGE_WIDTH, NEXT_LINE, NEXT_SECTION

.ref BLOCK_DECODE, DCTB1

.ref J_STATUS, J_STACK

.ref IDCT_COEF, Y_DQUANTIZE_TABLE, ZIGZAG_TABLE1

.ref RD48TAB, RD12TAB, LOWMASK

.ref HDCDECODE_TABLE, DCDETAB ; ADDED on 11/26/97

.ref DQZBR, DQZBI, DQUANT_TABLE, DZIGZAG_TABLE, DETABLE, D12TAB

.ref EMASK, COMPRESS_DATA, DST, DC_TAIL, DATA

.ref MASKDATA, MASKSIZE, EOB, LAST_DC, LAST_RESULT, USER_BIT, LESS_BIT

BLOCK_RESULT .set DCTB1

.text

JPEG_DEC:

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT SAVING ;

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

SST #0, J_STATUS

SST #1, J_STATUS+1

LDP #J_STACK




SAR AR4, J_STACK+4

SAR AR5, J_STACK+5 ; AR5 is used in QUANT & HUFF_EN

SAR AR6, J_STACK+6 ; AR6 is used as counter


POPD J_STACK+8

SPRA615


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; JPEG_DE MAIN ;

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

CALL JPEG_DEC_INIT

LAR AR7, #IMAGE_WIDTH–1 ; block # of width

blockde_loop0:

LAR AR6, #IMAGE_LENGTH–1 ; block # of length

blockde_loop:

CALL BLOCK_DECODE ; decompressed data –> PICT

CALL BLOCK_ASSEMBLE

MAR *, AR6

BANZ blockde_loop, *–


MAR *, AR5

MAR *0+, AR7

; MAR *, AR7

BANZ blockde_loop0, *–

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; OUTPUT DATA TO FILE ”jpegout.dat”

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

JPEGOUT:

MAR *, AR4

LAR AR4, #PICT

LAR AR7, #(160*120/8)–1

JPEGOUT_LOOP:

OUT *+, 0

OUT *+, 0

OUT *+, 0

OUT *+, 0

OUT *+, 0

OUT *+, 0

OUT *+, 0

OUT *+, 0, AR7

BANZ JPEGOUT_LOOP, *–, AR4

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT RESTORE

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

LDP #J_STACK

PSHD J_STACK+8



LAR AR5, J_STACK+5

SPRA615


LAR AR4, J_STACK+4

LAR AR3, J_STACK+3

LAR AR2, J_STACK+2

LAR AR1, J_STACK+1

LDP #0

LST #1, J_STATUS+1

LST #0, J_STATUS

RET

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Assemble Blockes of Data to Image Frame

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

BLOCK_ASSEMBLE:

LAR AR0, #NEXT_LINE

MAR *, AR5

RPT #7

BLDD #BLOCK_RESULT, *+

MAR *0+

RPT #7

BLDD #BLOCK_RESULT+8, *+

MAR *0+

RPT #7


MAR *0+

RPT #7


MAR *0+

RPT #7


MAR *0+

RPT #7


MAR *0+

RPT #7


MAR *0+

RPT #7



MAR *0–

RET ; return from BLOCK_INIT

SPRA615


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

;

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

JPEG_DEC_INIT:

idct_init:

CLRC CNF ; B0 is mapped to data memory

SSXM ; SXM=1

SOVM ; OVM=1

SPM 0 ; PM=0

MAR *, AR5

LAR AR5, #0200h ; LOAD DCT COEF to B0

RPT #63

BLPD #IDCT_COEF, *+

SETC CNF ; B0 is mapped to program memory

dequant_init:

MAR *, AR5

LAR AR5, #DQUANT_TABLE ; Initialize DeQuant table

RPT #63

BLPD #Y_DQUANTIZE_TABLE, *+

LAR AR5, #DZIGZAG_TABLE ; Initialize ZigZag table

RPT #63

BLPD #ZIGZAG_TABLE1, *+

dehuff_init:

;–––––––––––––––––––––––––––––––––––––––––––––––

; Huffman Decode Initialization

;–––––––––––––––––––––––––––––––––––––––––––––––

MAR *, AR4

LAR AR4, #DETABLE

RPT #250

BLPD #RD48TAB, *+

LAR AR4, #D12TAB

RPT #87

BLPD #RD12TAB, *+

RPT #47 ; Added by V.S. 11/26/97

BLPD #HDCDECODE_TABLE, *+ ; Added by V.S. 11/26/97

RPT #16

BLPD #LOWMASK, *+

SPRA615


LDP #MASKDATA

SPLK #0fff0h, MASKDATA

SPLK #0f000h, MASKSIZE

SPLK #0Ah, EOB ; Luminance

; SPLK #00h, EOB ; Chrominance

SPLK #0h, LAST_DC

SPLK #0h, LAST_RESULT

SPLK #10h, USER_BIT

SPLK #0h, LESS_BIT


LACC *+

SAR AR4, DC_TAIL

SACL DATA

LDP #DC_TAIL

LAR AR4, DC_TAIL

LAR AR5, #PICT

SAR AR5, DST

RET

BLOCKDE.ASM

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Program Name : BLOCKDE.ASM

; Discription : This program includes JPEG encoder and decoder


; 1. IDCT

; 2. DEQUANT

; 3. HUFF Decode


; Date : 03/25/1997


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.def BLOCK_DECODE

.def BLK1_ADDR, DQZBI, DQZBR

.def EMASK, DETABLE

.def DQUANT_TABLE, DZIGZAG_TABLE, D12TAB

.def DCDETAB

.def F_TAB, SIZE, COWORD_SIZE, V_SIZE, NEG_VSIZE, JUDGE_DATA

SPRA615


.ref B_STATUS, B_STACK

.ref SRC, LAST_RESULT, LESS_BIT, EOB, DC_TAIL, DATA, LAST_DC

.ref IDCT

.ref IDCT_COEF, Y_DQUANTIZE_TABLE, ZIGZAG_TABLE1

.ref RD48TAB, RD12TAB, LOWMASK

.ref MAX_VALUE, MIN_VALUE

.ref COWORD, DCTB1, USER_BIT, DIFF, RZERO, ABSDIFF, EOB_SIZE, COMPRESS_DATA

DQZBR .usect ”.dq_blk”, 64

DQZBI .usect ”.dq_blk”, 64

DQUANT_TABLE .usect ”.dq_tbl”, 64

DZIGZAG_TABLE .usect ”.dq_tbl”, 64

DETABLE .usect ”dehuftab”,251

D12TAB .usect ”dehuftab”, 88

DCDETAB .usect ”dehuftab”, 48

EMASK .usect ”dehuftab”, 17

F_TAB .usect ”.huf_var”, 1

SIZE .usect ”.huf_var”, 1

COWORD_SIZE .usect ”.huf_var”, 1

V_SIZE .usect ”.huf_var”, 1

NEG_VSIZE .usect ”.huf_var”, 1

JUDGE_DATA .usect ”.huf_var”, 1

CHECK_DC .usect ”.huf_var”, 1

BLK1_ADDR .set DQZBI

.text

BLOCK_DECODE:

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT SAVING ; AR4 cannot be assigned to other usage!!

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

SST #0, B_STATUS

SST #1, B_STATUS+1

LDP #B_STACK

SAR AR1, B_STACK ; AR1 is used in DCT, QUANT & HUFF_DE

SAR AR2, B_STACK+1 ; AR2 is used in DCT, QUANT & HUFF_DE

SAR AR3, B_STACK+2 ; AR3 is used in DCT, QUANT & HUFF_DE

SAR AR6, B_STACK+3 ; AR6 is used in QUANT & HUFF_DE

SPRA615


; SAR AR4, B_STACK+4

; SAR AR5, B_STACK+5

POPD B_STACK+4

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; BLOCK_DECODE MAIN

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

CALL HUFFDECODE

CALL DQUANT

CALL IDCT

CALL JPEG_FINAL

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; CONTEXT RESTORE

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

LDP #B_STACK

PSHD B_STACK+4

; LAR AR5, B_STACK+5

; LAR AR4, B_STACK+4

LAR AR6, B_STACK+3

LAR AR3, B_STACK+2

LAR AR2, B_STACK+1

LAR AR1, B_STACK

LDP #0

LST #1, B_STATUS+1

LST #0, B_STATUS

RET

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Subroutine: JPEG_FINAL

; Functions: 1. Limit the range of data to {MAX_VALUE, MIN_VALUE}

; 2. SUB 128

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

JPEG_FINAL:

LAR AR2, #DCTB1

LAR AR3, #63

LARP AR2

BOUND: LACC *

BCND neg_BOUND, LT

SUB #MAX_VALUE

BCND end_BOUND, LT

LACC #MAX_VALUE

SACL *

B end_BOUND

SPRA615


neg_BOUND:

SUB #MIN_VALUE

BCND end_BOUND, GT

LACC #MIN_VALUE

SACL *

B end_BOUND

end_BOUND

MAR *+, AR0

BANZ BOUND, *–, AR2

ADD_128:

LARP AR2

LAR AR2, #DCTB1

LAR AR3, #63

jf_loop:

LACC * ; +128

ADD #128

SACL *+, 0, AR3

BANZ jf_loop, *–, AR2

RET

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; DEQUANT+ZIGZAG Main

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

DQUANT:

LAR AR0, #63 ; BLOCKSIZE–1

LAR AR2, #DQZBR ; DESTINATION ADDRESS

LAR AR3, #DZIGZAG_TABLE ; ZIGZAG TABLE REGISTER

LAR AR6, #DQUANT_TABLE ; QUANTIZE TABLE REGISTER

LARP AR3 ; ACTIVE AR3

DQ_loop:

LAR AR1, *+, AR1 ; LOAD SOURCE ADDRESS

LT *+, AR6 ; (dma)––>Treg

MPY *+, AR2 ; (dma)*Treg––>Preg

SPL *+, AR0 ; Preg(15..0)––>(dma)

BANZ DQ_loop, *–, AR3 ; REPETS 64 Times

RET

SPRA615


;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Subroutine : HUFFDECODE

; Function : Huffman decode

; Date : 02/14/97

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

;––––––––––––––––––––––––––––––––––––––––––––––––

; Adress point EXPLANATION

;

; AR1 EMASK

; AR2 DETABLE

; AR3 DQZBI

; AR4 COMPRESS_DAT

; AR6 COUNTER

;––––––––––––––––––––––––––––––––––––––––––––––––

HUFFDECODE:

;–––––––––––––––––––––––––––––––––––––––––––––––––

; Huffman Decode Main

;–––––––––––––––––––––––––––––––––––––––––––––––––

RSXM ;SXM=0

;assign 0 to the result

ZAC

LARP 3

LAR AR3, #DQZBI

RPTK 63

SACL *+

DC_DECODE:

LAR AR3, #DQZBI

LARP 4

LDP #LESS_BIT

SPLK #0FFFFh, CHECK_DC ; DC decode flag, 12/9/97

LT LESS_BIT

ZALH DATA

ADDT *

; LDP #JUDGE_DATA

SACH JUDGE_DATA

LAC JUDGE_DATA,4

SACH ABSDIFF

LAC ABSDIFF ;if ABSDIFF<15

SUBK 0FH

BLZ GDCANS ;goto GDCANS

LAC JUDGE_DATA,8

SACH ABSDIFF

LAC ABSDIFF

SPRA615


SUBK 0FFh ;––––––––––––––––––––––––––––

BLZ DCCWLT9B ; added on 11/27/97

LAC JUDGE_DATA,12 ; by Vivian Shao

ANDK 0Fh ;

ADDK 20h ; to check DC codeword > 9 bits

SACL ABSDIFF ;

B GDCANS ;–––––––––––––––––––––––––––––

DCCWLT9B:

LAC ABSDIFF ;else

ANDK 0FH ;ABSDIFF=ABSDIFF mod 16

ADDK 10H ;ABSDIFF+=16

SACL ABSDIFF

GDCANS: ;get DC answer

LARP 2

; LRLK AR2,DETABLE ; marked on 11/26/97

LRLK AR2, DCDETAB ; added on 11/26/97

LAR AR0,ABSDIFF

MAR *0+

LAC *0–,8

ANDK 00FFH,8

SACL F_TAB

CALL GET_VEN

LARP AR3

MAR *–

LAC *

ADD LAST_DC

SACL *+,AR4

SACL LAST_DC

LRLK AR6,63

AC_DECODE:

SPLK #0, CHECK_DC ; DC decode flag, 12/9/97

LRLK AR2, DETABLE ; added on 11/26/97

LT LESS_BIT

ZALH DATA

ADDT *

SACH JUDGE_DATA

LAC JUDGE_DATA,8

SACH ABSDIFF

LAC ABSDIFF ; if JUDGE_DATA <= 0bfffh

SPRA615


;Luminance

SUBK 0BFH

;Chrominance

; SUBK 0AFH

BLEZ NOZERO ; goto NOZERO

;Luminance

SUBK 03BH ; elseif JUDGE_DATA <= 0faffh

;Chrominance

; SUBK 04AH ; elseif JUDGE_DATA <= 0faffh

BLEZ WITHZERO ; goto WITHZERO

LAC JUDGE_DATA

;Luminance

SUBK 0FF81H ; elseif JIDGE_DATA < 0ff81h

;Chrominance

; SUBK 0FF83H ; elseif JIDGE_DATA < 0ff81h

BLZ BIT12 ; goto BIT12

; else goto BIT16

BIT16: ; COWORD= 16 BITS

; Luminance

ADDK 21H

; Chrominance

; ADDK 23H

SACL ABSDIFF

LT LESS_BIT

ZALH DATA

ADDT *+

SACL DATA

SAR 4,DC_TAIL

; LAC DC_TAIL ; Marked by V.S., 11/26/97

; ANDK 11FFH ; WRONG CODE => Need to be deleted

; SACL DC_TAIL ; Marked by V.S., 11/26/97

; LAR 4,DC_TAIL ; Marked by V.S., 11/26/97

CALL JUMPZERO,*,AR2

LAC F_TAB,4

ANDK 0F00H

SACL F_TAB

SPRA615


SPLK #0FFFFh, CHECK_DC ; 12/09/97, not checking EOB

CALL GET_VEN

END_ACDECODE:

BANZ AC_DECODE,*,AR4

LAC COWORD

SUB EOB

BZ END_DECODE

LACK EOB_SIZE ; the last entry is not zero

CALL GET_COWORD

SACH COWORD

END_DECODE:

SSXM ; SSXM=1

RET

BIT12: ; COWORD = 12 bits

LARP 2

LAC JUDGE_DATA,12

SACH ABSDIFF

LAC ABSDIFF

;––––––– Changed on 11/17 –––––––––––––––

; SBLK 0FB0H–(0FAH+1H) ;original

SBLK 0FA0H–(0FAH+1H)

;––––––––––––––––––––––––––––––––––––––––

SACL ABSDIFF

WITHZERO:

CALL JUMPZERO,*,AR2

LAC F_TAB

ANDK 0FFH,8

SACL F_TAB

CALL GET_VEN

B END_ACDECODE

NOZERO:

LARP 2

LRLK AR2,DETABLE

LAR AR0,ABSDIFF

MAR *0+

LAC *0–

ANDK 0FFH,8

SACL F_TAB

CALL GET_VEN

B END_ACDECODE

SPRA615


;

; JUMP RZERO

;

JUMPZERO:

; LARP 2

; LRLK AR2,DETABLE

LAR AR0,ABSDIFF

MAR *0+

LAC *0–

; LDP #F_TAB

SACL F_TAB

ANDK 0FH

; LDP #RZERO

SACL RZERO

LAR AR0,RZERO

LARP 3

MAR *0+,AR6

MAR *0–

RET

;

; GET THE V VALUE

;

GET_VEN:

LAC F_TAB,4

SACH COWORD_SIZE

ANDK 0F000H

SACH V_SIZE,4

LAC COWORD_SIZE

CALL GET_COWORD,*,AR4

SACH COWORD

LACC CHECK_DC ; Distinct EOB(00B) and DC SSSS=0(00B)

BNZ SKIP_EOB_CHECKING ; 12/9/97

LAC COWORD

SUB EOB

MAR *, AR6

BZ FIND_EOB

SKIP_EOB_CHECKING:

LAC V_SIZE

CALL GET_COWORD,*,AR4

SACH DIFF

SPRA615


LACL #16 ; modifid from next 3 original code

SUB V_SIZE

SACL NEG_VSIZE

; LAC V_SIZE ; original code

; NEG ; original code

; SACL NEG_VSIZE ; original code

LAC DIFF

LT NEG_VSIZE

BITT DIFF

BBNZ DPOSITIVE

LARP 1

LRLK AR1,EMASK

LAR AR0,V_SIZE

MAR *0+

LAC *0–

CMPL

OR DIFF

ADDK 1H

;

DPOSITIVE:

LARP 3

SACL *+,AR6

MAR *–

RET

FIND_EOB:

LRLK AR6,0 ; AR6 reseted if EOB met

RET

;

; GET THE COWORD

;

GET_COWORD:

; LARP 4

SACL SIZE

SUB USER_BIT

SACL LESS_BIT

NEG

LT SIZE

BLEZ GET_NEWWORD ; if user_bit < 0 goto GET_NEWWORD

SACL USER_BIT ; else coword shift size bits

LACT DATA

SACL DATA

B END_GCOWORD

SPRA615


GET_NEWWORD: ; get new coword

ADDK 10H ; user_bit += 16

SACL USER_BIT

LACT DATA ; coword shift size bits

LT LESS_BIT ; new coword shift less bits

ADDT *+

SACH DIFF

SACL DATA

SAR 4,DC_TAIL

LAC DC_TAIL

; ANDK 11FFH

SACL DC_TAIL

LAR 4,DC_TAIL

ZALH DIFF

END_GCOWORD:

RET

SPRA615


Appendix C JPEG TablesTABLES.ASM;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Program Name : TABLES.ASM

; Discription : This program includes the tables JPEG encoder/decoder

; needed:

; 1. DCT/IDCT coefficient tables

; 2. QUANT/DEQUANT tables

; 3. HUFFMAN ENCODE/DECODE tables


; Date : 11/27/1997


;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

.def MAX_VALUE, MIN_VALUE

.def DCT_COEF, Y_QUANTIZE_TABLE, ZIGZAG_TABLE0

.def IDCT_COEF, Y_DQUANTIZE_TABLE, ZIGZAG_TABLE1

.def RDCHUFF, RACHUFF

.def RD48TAB, RD12TAB, LOWMASK

.def RDCHUFF

.def HDCDECODE_TABLE

.def MAX_VALUE, MIN_VALUE

.def IMAGE_LENGTH, IMAGE_WIDTH, NEXT_LINE, NEXT_SECTION

.def COMPRESS_DATA

.ref BLK1_ADDR, BLK2_ADDR

.ref PICT

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; DEFINE IMAGE SIZE:

; NEED TO BE MODIFIED FOR REAL CASE !!

; example shown below: 32=pixels/line; 24=lines/frame

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

IMAGE_LENGTH .set 160/8 ; block # of image length

IMAGE_WIDTH .set 120/8 ; block # of image width

NEXT_LINE .set 8*(160/8–1)

;NEXT_SECTION .set 8*7*(120/8)

NEXT_SECTION .set 7*160

COMPRESS_DATA .usect ”.jpgen”, 800h ; size 400h can be changed

;PICT .usect ”.picture”, 8000h ; size 8000h can be changed

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

MAX_VALUE .set 255/2 ; color resolution

MIN_VALUE .set –255/2–1 ; color resolution

.sect ”jpeg_tbl”

SPRA615


;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; DCT cofficients x 65536

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

DCT_COEF:

.word 23170, 23170, 23170, 23170, 23170, 23170, 23170, 23170

.word 32138, 27246, 18205, 6393, –6393,–18205,–27246,–32138

.word 30274, 12540,–12540,–30274,–30274,–12540, 12540, 30274

.word 27246, –6393,–32138,–18205, 18205, 32138, 6393,–27246

.word 23170,–23170,–23170, 23170, 23170,–23170,–23170, 23170

.word 18205,–32138, 6393, 27246,–27246, –6393, 32138,–18205

.word 12540,–30274, 30274,–12540,–12540, 30274,–30274, 12540

.word 6393,–18205, 27246,–32138, 32138,–27246, 18205, –6393

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; Inverse DCT cofficients x 65536

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

IDCT_COEF:

.word 23170, 32138, 30274, 27246, 23170, 18205, 12540, 6393

.word 23170, 27246, 12540, –6393,–23170,–32138,–30274,–18205

.word 23170, 18205,–12540,–32138,–23170, 6393, 30274, 27246

.word 23170, 6393,–30274,–18205, 23170, 27246,–12540,–32138

.word 23170, –6393,–30274, 18205, 23170,–27246,–12540, 32138

.word 23170,–18205,–12540, 32138,–23170, –6393, 30274,–27246

.word 23170,–27246, 12540, 6393,–23170, 32138,–30274, 18205

.word 23170,–32138, 30274,–27246, 23170,–18205, 12540, –6393

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; QUANTIZATION table

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

Y_QUANTIZE_TABLE:

;–––––––––––––––––Quantization table 1–––––––––––––––––––––––––––––

.word 2048, 2979, 3277, 2048, 1365, 819, 643, 537

.word 2731, 2731, 2341, 1725, 1260, 565, 546, 596

.word 2341, 2521, 2048, 1365, 819, 575, 475, 585

.word 2341, 1928, 1489, 1130, 643, 377, 410, 529

.word 1820, 1489, 886, 585, 482, 301, 318, 426

.word 1365, 936, 596, 512, 405, 315, 290, 356

.word 669, 512, 420, 377, 318, 271, 273, 324

.word 455, 356, 345, 334, 293, 328, 318, 331

;;–––––––––––––––––Quantization table 2–––––––––––––––––––––––––––––

; .word 2048*2, 2979*2, 3277*2, 2048*2, 1365*2, 819*2, 643*2, 537*2

; .word 2731*2, 2731*2, 2341*2, 1725*2, 1260*2, 565*2, 546*2, 596*2

; .word 2341*2, 2521*2, 2048*2, 1365*2, 819*2, 575*2, 475*2, 585*2

; .word 2341*2, 1928*2, 1489*2, 1130*2, 643*2, 377*2, 410*2, 529*2

; .word 1820*2, 1489*2, 886*2, 585*2, 482*2, 301*2, 318*2, 426*2

SPRA615


; .word 1365*2, 936*2, 596*2, 512*2, 405*2, 315*2, 290*2, 356*2

; .word 669*2, 512*2, 420*2, 377*2, 318*2, 271*2, 273*2, 324*2

; .word 455*2, 356*2, 345*2, 334*2, 293*2, 328*2, 318*2, 331*2

UV_QUANTIZE_TABLE:

.word 1928, 1820, 1365, 697, 331, 331, 331, 331

.word 1820, 1560, 1260, 496, 331, 331, 331, 331

.word 1365, 1260, 585, 331, 331, 331, 331, 331

.word 697, 496, 331, 331, 331, 331, 331, 331

.word 331, 331, 331, 331, 331, 331, 331, 331

.word 331, 331, 331, 331, 331, 331, 331, 331

.word 331, 331, 331, 331, 331, 331, 331, 331

.word 331, 331, 331, 331, 331, 331, 331, 331

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; QUANTIZATION table

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

Y_DQUANTIZE_TABLE:

;–––––––––––––––––De Quantization table 1–––––––––––––––––––––––––––––

.word 16, 11, 10, 16, 24, 40, 51, 61

.word 12, 12, 14, 19, 26, 58, 60, 55

.word 14, 13, 16, 24, 40, 57, 69, 56

.word 14, 17, 22, 29, 51, 87, 80, 62

.word 18, 22, 37, 56, 68, 109, 103, 77

.word 24, 35, 55, 64, 81, 104, 113, 92

.word 49, 64, 78, 87, 103, 121, 120, 101

.word 72, 92, 95, 98, 112, 100, 103, 99

;;–––––––––––––––––De Quantization table 2–––––––––––––––––––––––––––––

; .word 8, 6, 5, 8,12,20,26,31

; .word 6, 6, 7,10,13,29,30,28

; .word 7, 7, 8,12,20,29,35,28

; .word 7, 9,11,15,26,44,40,31

; .word 9,11,19,28,34,55,52,39

; .word 12,18,28,32,41,52,57,46

; .word 25,32,39,44,52,61,60,51

; .word 36,46,48,49,56,50,52,50

UV_DQUANTIZE_TABLE:

.word 17, 18, 24, 47, 99, 99, 99, 99

.word 18, 21, 26, 66, 99, 99, 99, 99

.word 24, 26, 56, 99, 99, 99, 99, 99

.word 47, 66, 99, 99, 99, 99, 99, 99

.word 99, 99, 99, 99, 99, 99, 99, 99

.word 99, 99, 99, 99, 99, 99, 99, 99

.word 99, 99, 99, 99, 99, 99, 99, 99

.word 99, 99, 99, 99, 99, 99, 99, 99

SPRA615


;–––––––––––––––––––––––––––––––––––––––––––––

; ZIGZAG Cofficient

;–––––––––––––––––––––––––––––––––––––––––––––

ZIGZAG_TABLE0:

.word 0+BLK2_ADDR, 1+BLK2_ADDR, 5+BLK2_ADDR,6+BLK2_ADDR,14+BLK2_ADDR,15+BLK2_ADDR,27+BLK2_ADDR,28+BLK2_ADDR

.word 2+BLK2_ADDR, 4+BLK2_ADDR,7+BLK2_ADDR,13+BLK2_ADDR,16+BLK2_ADDR,26+BLK2_ADDR,29+BLK2_ADDR,42+BLK2_ADDR

.word 3+BLK2_ADDR,8+BLK2_ADDR,12+BLK2_ADDR,17+BLK2_ADDR,25+BLK2_ADDR,30+BLK2_ADDR,41+BLK2_ADDR,43+BLK2_ADDR

.word9+BLK2_ADDR,11+BLK2_ADDR,18+BLK2_ADDR,24+BLK2_ADDR,31+BLK2_ADDR,40+BLK2_ADDR,44+BLK2_ADDR,53+BLK2_ADDR





;–––––––––––––––––––––––––––––––––––––––––––––

; ZIGZAG Cofficient

;–––––––––––––––––––––––––––––––––––––––––––––

ZIGZAG_TABLE1:

.word 0+BLK1_ADDR, 1+BLK1_ADDR, 5+BLK1_ADDR,6+BLK1_ADDR,14+BLK1_ADDR,15+BLK1_ADDR,27+BLK1_ADDR,28+BLK1_ADDR

.word 2+BLK1_ADDR, 4+BLK1_ADDR,7+BLK1_ADDR,13+BLK1_ADDR,16+BLK1_ADDR,26+BLK1_ADDR,29+BLK1_ADDR,42+BLK1_ADDR

.word 3+BLK1_ADDR,8+BLK1_ADDR,12+BLK1_ADDR,17+BLK1_ADDR,25+BLK1_ADDR,30+BLK1_ADDR,41+BLK1_ADDR,43+BLK1_ADDR






;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; DC Huffman Coding Table

; The High byte means code word size

; Low byte means code word

; Bit position 15 14 13 12 11 10 9 8 7 6 4 5 3 2 1 0

; \ \ | | | | | | | | / / \ \ / /

; code word size

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

SPRA615


RDCHUFF: ; Luminance DC table

.word 0002h,0023h,0033h,0043h,0053h,0063h

.word 00e4h,01e5h,03e6h,07e7h,0fe8h,1fe9h

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; From DIFF to Get the real size of Diff

; DIFF 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

; SSSS 0 1 2 2 3 3 3 3 4 4 4 4 4 4 4 4

;––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

DIFFSIZE:

.word 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4

LOWMASK

.word 0000H,0001h,0003h,0007h,000fh,001fh,003fh,007fh

.word 00ffh,01ffh,03ffh,07ffh,0fffh,1fffh,3fffh,7fffh

.word 0ffffh

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; AC Huffman Coding Table

; Bit position 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

; \ | | | . . . . . . ./.. / \ . . /

; Codeword Size

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

RACHUFF: ; Luminance

.word 000a4h,00000h,00000h,00000h,00000h,00000h,00000h,00000h ;0/0

.word 00000h,00000h,00000h,00000h,00000h,00000h,00000h,07f9bh ;8/0

.word 00002h,000c4h,001c5h,003a6h,003b6h,007a7h,007b7h,00fa8h ;0/1

.word 01f89h,01f99h,01fa9h,03f9ah,03faah,07f8bh,0ffebh,0fff5h ;8/1

.word 00012h,001b5h,00f98h,01f79h,03f8ah,07f7bh,0ff6ch,0ff7ch ;0/2

.word 0ff81h,0ffbeh,0ffc7h,0ffd0h,0ffd9h,0ffe2h,0ffech,0fff6h ;8/2

.word 00043h,00797h,03f7ah,0ff5ch,0ff96h,0ff9eh,0ffa6h,0ffaeh ;0/3

.word 0ffb6h,0ffbfh,0ffc8h,0ffd1h,0ffdah,0ffe3h,0ffedh,0fff7h ;8/3

.word 000b4h,01f69h,0ff4ch,0ff8fh,0ff97h,0ff9fh,0ffa7h,0ffafh ;0/4

.word 0ffb7h,0ffc0h,0ffc9h,0ffd2h,0ffdbh,0ffe4h,0ffeeh,0fff8h ;8/4

.word 001a5h,07f6bh,0ff89h,0ff90h,0ff98h,0ffa0h,0ffa8h,0ffb0h ;0/5

.word 0ffb8h,0ffc1h,0ffcah,0ffd3h,0ffdch,0ffe5h,0ffefh,0fff9h ;8/5

.word 00787h,0ff84h,0ff8ah,0ff91h,0ff99h,0ffa1h,0ffa9h,0ffb1h ;0/6

.word 0ffb9h,0ffc2h,0ffcbh,0ffd4h,0ffddh,0ffe6h,0fff0h,0fffah ;8/6

.word 00f88h,0ff85h,0ff8bh,0ff92h,0ff9ah,0ffa2h,0ffaah,0ffb2h ;0/7

.word 0ffbah,0ffc3h,0ffcch,0ffd5h,0ffdeh,0ffe7h,0fff1h,0fffbh ;8/7

.word 03f6ah,0ff86h,0ff8ch,0ff93h,0ff9bh,0ffa3h,0ffabh,0ffb3h ;0/8

.word 0ffbbh,0ffc4h,0ffcdh,0ffd6h,0ffdfh,0ffe8h,0fff2h,0fffch ;8/8

.word 0ff82h,0ff87h,0ff8dh,0ff94h,0ff9ch,0ffa4h,0ffach,0ffb4h ;0/9

.word 0ffbch,0ffc5h,0ffceh,0ffd7h,0ffe0h,0ffe9h,0fff3h,0fffdh ;8/9

.word 0ff83h,0ff88h,0ff8eh,0ff95h,0ff9dh,0ffa5h,0ffadh,0ffb5h ;0/A

.word 0ffbdh,0ffc6h,0ffcfh,0ffd8h,0ffe1h,0ffeah,0fff4h,0fffeh ;8/A

SPRA615


;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; decoder table

; for coword_size < 4 bit | for coword _size = 16 bit

; put in high byte | put in low byte

; number of zeros is always 0 | codeword size is always 16

; bit position

; 15 14 13 12 11 10 09 08 | 07 06 05 04 03 02 01 00

; \ | | / \ | | / \ | | / \ | | /

; codeword size v_len size v_length number of zeros

; byte positon 0 1 2 3 4 5 6 7 8 9 10 1112 13 14 15

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

RD48TAB: ; Luminance

.word02120h,02120h,02120h,02120h,02131h,02131h,02132h,02132h,02133h,02133h,02134h,02134h,02135h,02135h,02146h,02100h

.word02157h,02157h,02157h,02157h,02157h,02157h,02157h,02157h,02168h,02168h,02168h,02168h,02179h,02179h,0218ah,0219bh

.word02128h,02128h,02190h,021a0h,02161h,02171h,02181h,02191h,021a1h,02152h,02162h,02172h,02182h,02192h,021a2h,02143h

.word02153h,02163h,02173h,02183h,02193h,021a3h,02134h,02144h,02154h,02164h,02174h,02184h,02194h,021a4h,02135h,02145h



.word02249h,02259h,02269h,02279h,02289h,02299h,022a9h,0222ah,0223ah,0224ah,0225ah,0226ah,0227ah,0228ah,0229ah,022aah

.word0222bh,0223bh,0224bh,0225bh,0226bh,0227bh,0228bh,0229bh,022abh,0222ch,0223ch,0224ch,0225ch,0226ch,0227ch,0228ch

.word0339ch,033ach,0332dh,0333dh,0334dh,0335dh,0336dh,0337dh,0338dh,0339dh,033adh,0331eh,0332eh,0333eh,0334eh,0335eh

.word0336eh,0337eh,0338eh,0339eh,033aeh,0331fh,0332fh,0333fh,0334fh,0335fh,0336fh,0337fh,0338fh,0339fh,033afh,03300h

;–––––––––––––––––––––––––––––––––––––

; Code Word : 4–8 bits

;–––––––––––––––––––––––––––––––––––––






.word 07600h,07600h,07301h,07301h,07105h,07105h,07106h,07106h,08700h,08202h,08107h

SPRA615


;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

; decoder table

; for 12bit cowrod

; bit position

; 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00

; \ | | / \ | | / \ | / / \ | | /

; coword size v_lengyh don’t care number of zeros

; 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

;–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

RD12TAB ; Luminance




.word0910ah,0910ah,0910ah,0910ah,0910ah,0910ah,0910ah,0910ah,0a800h,0a800h,0a800h,0a800h,0a302h,0a302h,0a302h,0a302h

.word0a204h,0a204h,0a204h,0a204h,0a10bh,0a10bh,0a10bh,0a10bh,0a10ch,0a10ch,0a10ch,0a10ch,0b501h,0b501h,0b205h,0b205h

.word 0b10dh,0b10dh,0b00fh,0b00fh,0c402h,0c303h,0c206h,0c207h

HDCDECODE_TABLE:

.word 0020h,0020h,0020h,0020h,0031h,0031h,0032h,0032h,0033h,0033h,0034h,0034h,0035h,0035h,0046h,0000h

.word 0057h,0057h,0057h,0057h,0057h,0057h,0057h,0057h,0068h,0068h,0068h,0068h,0079h,0079h,008ah,009bh

.word 0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h,0000h

SPRA615


Appendix D Huffman AC Coefficient Tables

Table for Luminance AC Coefficients

RRRR/SSSS Code length Code word0/0(EOB) 4 10100/1 2 000/2 2 010/3 3 1000/4 4 10110/5 5 110100/6 7 11110000/7 8 111110000/8 10 1111110110

Table for Chrominance AC Coefficients

RRRR/SSSS Code length Code word0/0(EOB) 2 000/1 2 010/2 3 1000/3 4 10100/4 5 110000/5 6 11001

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