1 ;// 2 ;// Copyright (C) 2007-2008 ARM Limited 3 ;// 4 ;// Licensed under the Apache License, Version 2.0 (the "License"); 5 ;// you may not use this file except in compliance with the License. 6 ;// You may obtain a copy of the License at 7 ;// 8 ;// http://www.apache.org/licenses/LICENSE-2.0 9 ;// 10 ;// Unless required by applicable law or agreed to in writing, software 11 ;// distributed under the License is distributed on an "AS IS" BASIS, 12 ;// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 ;// See the License for the specific language governing permissions and 14 ;// limitations under the License. 15 ;// 16 ;/** 17 ; * 18 ; * File Name: armVCM4P2_DecodeVLCZigzag_AC_unsafe_s.s 19 ; * OpenMAX DL: v1.0.2 20 ; * Revision: 12290 21 ; * Date: Wednesday, April 9, 2008 22 ; * 23 ; * 24 ; * 25 ; * 26 ; * Description: 27 ; * Contains modules for zigzag scanning and VLC decoding 28 ; * for inter, intra block. 29 ; * 30 ; * 31 ; * 32 ; * Function: omxVCM4P2_DecodeVLCZigzag_AC_unsafe 33 ; * 34 ; * Description: 35 ; * Performs VLC decoding and inverse zigzag scan 36 ; * 37 ; * 38 ; * 39 ; * 40 ; */ 41 42 43 INCLUDE omxtypes_s.h 44 INCLUDE armCOMM_s.h 45 INCLUDE armCOMM_BitDec_s.h 46 47 48 M_VARIANTS ARM1136JS 49 50 51 52 53 54 IF ARM1136JS 55 56 57 58 59 60 ;//Input Arguments 61 62 ppBitStream RN 0 63 pBitOffset RN 1 64 pDst RN 2 65 shortVideoHeader RN 3 66 67 68 ;//Local Variables 69 70 Return RN 0 71 72 pVlcTableL0L1 RN 4 73 pLMAXTableL0L1 RN 4 74 pRMAXTableL0L1 RN 4 75 pZigzagTable RN 4 76 77 ftype RN 0 78 temp3 RN 4 79 temp RN 5 80 Count RN 6 81 Escape RN 5 82 83 ;// armVCM4P2_FillVLDBuffer 84 zigzag RN 0 85 storeLevel RN 1 86 temp2 RN 4 87 temp1 RN 5 88 sign RN 5 89 Last RN 7 90 storeRun RN 14 91 92 93 packRetIndex RN 5 94 95 96 markerbit RN 5 97 98 ;// Scratch Registers 99 100 RBitStream RN 8 101 RBitBuffer RN 9 102 RBitCount RN 10 103 104 T1 RN 11 105 T2 RN 12 106 LR RN 14 107 108 109 110 M_ALLOC4 pppBitStream,4 111 M_ALLOC4 ppOffset,4 112 M_ALLOC4 pLinkRegister,4 113 114 M_START armVCM4P2_DecodeVLCZigzag_AC_unsafe 115 116 ;// get the table addresses from stack 117 M_ARG ppVlcTableL0L1,4 118 M_ARG ppLMAXTableL0L1,4 119 M_ARG ppRMAXTableL0L1,4 120 M_ARG ppZigzagTable,4 121 122 ;// Store ALL zeros at pDst 123 124 MOV temp1,#0 ;// Initialize Count to zero 125 MOV Last,#0 126 M_STR LR,pLinkRegister ;// Store Link Register on Stack 127 MOV temp2,#0 128 MOV LR,#0 129 130 ;// Initialize the Macro and Store all zeros to pDst 131 132 STM pDst!,{temp2,temp1,Last,LR} 133 M_BD_INIT0 ppBitStream, pBitOffset, RBitStream, RBitBuffer, RBitCount 134 STM pDst!,{temp2,temp1,Last,LR} 135 M_BD_INIT1 T1, T2, T2 136 STM pDst!,{temp2,temp1,Last,LR} 137 M_BD_INIT2 T1, T2, T2 138 STM pDst!,{temp2,temp1,Last,LR} 139 M_STR ppBitStream,pppBitStream ;// Store ppBitstream on stack 140 STM pDst!,{temp2,temp1,Last,LR} 141 M_STR pBitOffset,ppOffset ;// Store pBitOffset on stack 142 STM pDst!,{temp2,temp1,Last,LR} 143 144 STM pDst!,{temp2,temp1,Last,LR} 145 STM pDst!,{temp2,temp1,Last,LR} 146 147 148 SUB pDst,pDst,#128 ;// Restore pDst 149 150 ;// The armVCM4P2_GetVLCBits begins 151 152 getVLCbits 153 154 M_BD_LOOK8 Escape,7 ;// Load Escape Value 155 LSR Escape,Escape,#25 156 CMP Escape,#3 ;// check for escape mode 157 MOVNE ftype,#0 158 BNE notEscapemode ;// Branch if not in Escape mode 3 159 160 M_BD_VSKIP8 #7,T1 161 CMP shortVideoHeader,#0 ;// Check shortVideoHeader flag to know the type of Escape mode 162 BEQ endFillVLD 163 164 ;// Escape Mode 4 165 166 M_BD_READ8 Last,1,T1 167 M_BD_READ8 storeRun,6,T1 168 M_BD_READ8 storeLevel,8,T1 169 170 171 ;// Check whether the Reserved values for Level are used and Exit with an Error Message if it is so 172 173 TEQ storeLevel,#0 174 TEQNE storeLevel,#128 175 BEQ ExitError 176 177 ADD temp2,storeRun,Count 178 CMP temp2,#64 179 BGE ExitError ;// error if Count+storeRun >= 64 180 181 182 ;// Load address of zigzagTable 183 184 M_LDR pZigzagTable,ppZigzagTable ;// Loading the Address of Zigzag table 185 186 187 ;// armVCM4P2_FillVLDBuffer 188 189 SXTB storeLevel,storeLevel ;// Sign Extend storeLevel to 32 bits 190 191 192 ;// To Reflect Runlength 193 194 ADD Count,Count,storeRun 195 LDRB zigzag,[pZigzagTable,Count] 196 ADD Count,Count,#1 197 STRH storeLevel,[pDst,zigzag] ;// store Level 198 199 B ExitOk 200 201 202 203 endFillVLD 204 205 206 ;// Load Ftype( Escape Mode) value based on the two successive bits in the bitstream 207 208 M_BD_READ8 temp1,1,T1 209 CMP temp1,#0 210 MOVEQ ftype,#1 211 BEQ notEscapemode 212 M_BD_READ8 temp1,1,T1 213 CMP temp1,#1 214 MOVEQ ftype,#3 215 MOVNE ftype,#2 216 217 218 notEscapemode 219 220 ;// Load optimized packed VLC table with last=0 and Last=1 221 222 M_LDR pVlcTableL0L1,ppVlcTableL0L1 ;// Load Combined VLC Table 223 224 225 CMP ftype,#3 ;// If ftype >=3 get perform Fixed Length Decoding (Escape Mode 3) 226 BGE EscapeMode3 ;// Else continue normal VLC Decoding 227 228 ;// Variable lengh decoding, "armUnPackVLC32" 229 230 231 M_BD_VLD packRetIndex,T1,T2,pVlcTableL0L1,4,2 232 233 234 LDR temp3,=0xFFF 235 236 CMP packRetIndex,temp3 ;// Check for invalid symbol 237 BEQ ExitError ;// if invalid symbol occurs exit with an error message 238 239 AND Last,packRetIndex,#2 ;// Get Last from packed Index 240 241 242 243 244 LSR storeRun,packRetIndex,#7 ;// Get Run Value from Packed index 245 AND storeLevel,packRetIndex,#0x7c ;// storeLevel=packRetIndex[2-6],storeLevel[0-1]=0 246 247 248 M_LDR pLMAXTableL0L1,ppLMAXTableL0L1 ;// Load LMAX table 249 250 251 LSR storeLevel,storeLevel,#2 ;// Level value 252 253 CMP ftype,#1 254 BNE ftype2 255 256 ;// ftype==1; Escape mode =1 257 258 259 ADD temp1, pLMAXTableL0L1, Last, LSL#4 ;// If the Last=1 add 32 to table address 260 LDRB temp1,[temp1,storeRun] 261 262 263 ADD storeLevel,temp1,storeLevel 264 265 ftype2 266 267 ;// ftype =2; Escape mode =2 268 269 M_LDR pRMAXTableL0L1,ppRMAXTableL0L1 ;// Load RMAX Table 270 271 CMP ftype,#2 272 BNE FillVLDL1 273 274 ADD temp1, pRMAXTableL0L1, Last, LSL#4 ;// If Last=1 add 32 to table address 275 SUB temp2,storeLevel,#1 276 LDRB temp1,[temp1,temp2] 277 278 279 ADD storeRun,storeRun,#1 280 ADD storeRun,temp1 281 282 FillVLDL1 283 284 285 ;// armVCM4P2_FillVLDBuffer 286 287 M_LDR pZigzagTable,ppZigzagTable ;// Load address of zigzagTable 288 289 M_BD_READ8 sign,1,T1 290 291 CMP sign,#1 292 RSBEQ storeLevel,storeLevel,#0 293 294 ADD temp1,storeRun,Count ;// Exit with an error message if Run + Count exceeds 63 295 CMP temp1,#64 296 BGE ExitError 297 298 299 300 301 302 303 ;// To Reflect Runlenght 304 305 ADD Count,Count,storeRun 306 307 storeLevelL1 308 309 LDRB zigzag,[pZigzagTable,Count] 310 CMP Last,#2 ;// Check if the Level val is Last non zero val 311 ADD Count,Count,#1 312 LSR Last,Last,#1 313 STRH storeLevel,[pDst,zigzag] 314 315 BNE end 316 317 B ExitOk 318 319 320 321 ;// Fixed Lengh Decoding Escape Mode 3 322 323 EscapeMode3 324 325 M_BD_READ8 Last,1,T1 326 M_BD_READ8 storeRun,6,T1 327 328 ADD temp2,storeRun,Count ;// Exit with an error message if Run + Count exceeds 63 329 CMP temp2,#64 330 BGE ExitError 331 332 M_BD_READ8 markerbit,1,T1 333 TEQ markerbit,#0 ;// Exit with an error message if marker bit is zero 334 BEQ ExitError 335 336 M_BD_READ16 storeLevel,12,T1 337 338 TST storeLevel,#0x800 ;// test if the level is negative 339 SUBNE storeLevel,storeLevel,#4096 340 CMP storeLevel,#0 341 CMPNE storeLevel,#-2048 342 BEQ ExitError ;// Exit with an error message if Level==0 or -2048 343 344 M_LDR pZigzagTable,ppZigzagTable ;// Load address of zigzagTable 345 346 M_BD_READ8 markerbit,1,T1 347 348 349 ;// armVCM4P2_FillVLDBuffer ( Sign not used as storeLevel is preprocessed) 350 351 352 353 ;// To Reflect Run Length 354 355 ADD Count,Count,storeRun 356 357 358 359 storeLevelLast 360 361 LDRB zigzag,[pZigzagTable,Count] 362 CMP Last,#1 363 ADD Count,Count,#1 364 STRH storeLevel,[pDst,zigzag] 365 366 BNE end 367 368 B ExitOk 369 370 end 371 372 CMP Count,#64 ;//Run the Loop untill Count reaches 64 373 374 BLT getVLCbits 375 376 377 ExitOk 378 ;// Exit When VLC Decoding is done Successfully 379 380 ;// Loading ppBitStream and pBitOffset from stack 381 382 CMP Last,#1 383 M_LDR ppBitStream,pppBitStream 384 M_LDR pBitOffset,ppOffset 385 386 ;//Ending the macro 387 388 M_BD_FINI ppBitStream,pBitOffset 389 390 MOVEQ Return,#OMX_Sts_NoErr 391 MOVNE Return,#OMX_Sts_Err 392 M_LDR LR,pLinkRegister ;// Load the Link Register Back 393 B exit2 394 395 ExitError 396 ;// Exit When an Error occurs 397 398 M_LDR ppBitStream,pppBitStream 399 M_LDR pBitOffset,ppOffset 400 ;//Ending the macro 401 402 M_BD_FINI ppBitStream,pBitOffset 403 M_LDR LR,pLinkRegister 404 MOV Return,#OMX_Sts_Err 405 406 exit2 407 408 409 M_END 410 ENDIF 411 412 END 413
