13306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong/* ------------------------------------------------------------------ 23306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * Copyright (C) 1998-2009 PacketVideo 33306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * 43306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * Licensed under the Apache License, Version 2.0 (the "License"); 53306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * you may not use this file except in compliance with the License. 63306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * You may obtain a copy of the License at 73306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * 83306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * http://www.apache.org/licenses/LICENSE-2.0 93306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * 103306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * Unless required by applicable law or agreed to in writing, software 113306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * distributed under the License is distributed on an "AS IS" BASIS, 123306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 133306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * express or implied. 143306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * See the License for the specific language governing permissions 153306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * and limitations under the License. 163306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong * ------------------------------------------------------------------- 173306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong */ 183306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong#include "mp4dec_lib.h" 193306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong#include "vlc_decode.h" 203306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong#include "bitstream.h" 213306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong#include "zigzag.h" 223306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 233306cfee3bf38ab207a0504e49c2d492bb73ffbfJames DongPV_STATUS PV_DecodePredictedIntraDC( 243306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong int compnum, 253306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong BitstreamDecVideo *stream, 263306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong int16 *INTRADC_delta) 273306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong{ 283306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 293306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong /*---------------------------------------------------------------------------- 303306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong ; Define all local variables 313306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong ----------------------------------------------------------------------------*/ 323306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong PV_STATUS status = PV_SUCCESS; 333306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong uint DC_size; 343306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong uint code; 353306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong int first_bit; 363306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 373306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong /*---------------------------------------------------------------------------- 383306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong ; Function body here 393306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong ----------------------------------------------------------------------------*/ 403306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong /* read DC size 2 - 8 bits */ 413306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong status = PV_VlcDecIntraDCPredSize(stream, compnum, &DC_size); 423306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 433306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong if (status == PV_SUCCESS) 443306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong { 453306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong if (DC_size == 0) 463306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong { 473306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong *INTRADC_delta = 0; 483306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong } 493306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong else 503306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong { 513306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong /* read delta DC 0 - 8 bits */ 523306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong code = (int) BitstreamReadBits16_INLINE(stream, DC_size); 533306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 543306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong first_bit = code >> (DC_size - 1); 553306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 563306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong if (first_bit == 0) 573306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong { 583306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong /* negative delta INTRA DC */ 593306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong *INTRADC_delta = code ^((1 << DC_size) - 1); 603306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong *INTRADC_delta = -(*INTRADC_delta); 613306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong } 623306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong else 633306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong { /* positive delta INTRA DC */ 643306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong *INTRADC_delta = code; 653306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong } 663306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong if (DC_size > 8) BitstreamRead1Bits_INLINE(stream); 673306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong } 683306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong } 693306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 703306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong /*---------------------------------------------------------------------------- 713306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong ; Return nothing or data or data pointer 723306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong ----------------------------------------------------------------------------*/ 733306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong return status; 743306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong} 753306cfee3bf38ab207a0504e49c2d492bb73ffbfJames Dong 76