diff options
Diffstat (limited to 'media/libstagefright/codecs/on2/h264dec/source/h264bsd_pic_order_cnt.c')
| -rwxr-xr-x | media/libstagefright/codecs/on2/h264dec/source/h264bsd_pic_order_cnt.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/on2/h264dec/source/h264bsd_pic_order_cnt.c b/media/libstagefright/codecs/on2/h264dec/source/h264bsd_pic_order_cnt.c new file mode 100755 index 0000000..fb23352 --- /dev/null +++ b/media/libstagefright/codecs/on2/h264dec/source/h264bsd_pic_order_cnt.c @@ -0,0 +1,347 @@ +/* + * Copyright (C) 2009 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/*------------------------------------------------------------------------------ + + Table of contents + + 1. Include headers + 2. External compiler flags + 3. Module defines + 4. Local function prototypes + 5. Functions + h264bsdDecodePicOrderCnt + +------------------------------------------------------------------------------*/ + +/*------------------------------------------------------------------------------ + 1. Include headers +------------------------------------------------------------------------------*/ + +#include "h264bsd_util.h" +#include "h264bsd_pic_order_cnt.h" + +/*------------------------------------------------------------------------------ + 2. External compiler flags +-------------------------------------------------------------------------------- + +-------------------------------------------------------------------------------- + 3. Module defines +------------------------------------------------------------------------------*/ + +/*------------------------------------------------------------------------------ + 4. Local function prototypes +------------------------------------------------------------------------------*/ + +/*------------------------------------------------------------------------------ + + Function: h264bsdDecodePicOrderCnt + + Functional description: + Compute picture order count for a picture. Function implements + computation of all POC types (0, 1 and 2), type is obtained from + sps. See standard for description of the POC types and how POC is + computed for each type. + + Function returns the minimum of top field and bottom field pic + order counts. + + Inputs: + poc pointer to previous results + sps pointer to sequence parameter set + slicHeader pointer to current slice header, frame number and + other params needed for POC computation + pNalUnit pointer to current NAL unit structrue, function needs + to know if this is an IDR picture and also if this is + a reference picture + + Outputs: + poc results stored here for computation of next POC + + Returns: + picture order count + +------------------------------------------------------------------------------*/ + +i32 h264bsdDecodePicOrderCnt(pocStorage_t *poc, seqParamSet_t *sps, + sliceHeader_t *pSliceHeader, nalUnit_t *pNalUnit) +{ + +/* Variables */ + + u32 i; + i32 picOrderCnt; + u32 frameNumOffset, absFrameNum, picOrderCntCycleCnt; + u32 frameNumInPicOrderCntCycle; + i32 expectedDeltaPicOrderCntCycle; + u32 containsMmco5; + +/* Code */ + + ASSERT(poc); + ASSERT(sps); + ASSERT(pSliceHeader); + ASSERT(pNalUnit); + ASSERT(sps->picOrderCntType <= 2); + +#if 0 + /* JanSa: I don't think this is necessary, don't see any reason to + * increment prevFrameNum one by one instead of one big increment. + * However, standard specifies that this should be done -> if someone + * figures out any case when the outcome would be different for step by + * step increment, this part of the code should be enabled */ + + /* if there was a gap in frame numbering and picOrderCntType is 1 or 2 -> + * "compute" pic order counts for non-existing frames. These are not + * actually computed, but process needs to be done to update the + * prevFrameNum and prevFrameNumOffset */ + if ( sps->picOrderCntType > 0 && + pSliceHeader->frameNum != poc->prevFrameNum && + pSliceHeader->frameNum != ((poc->prevFrameNum + 1) % sps->maxFrameNum)) + { + + /* use variable i for unUsedShortTermFrameNum */ + i = (poc->prevFrameNum + 1) % sps->maxFrameNum; + + do + { + if (poc->prevFrameNum > i) + frameNumOffset = poc->prevFrameNumOffset + sps->maxFrameNum; + else + frameNumOffset = poc->prevFrameNumOffset; + + poc->prevFrameNumOffset = frameNumOffset; + poc->prevFrameNum = i; + + i = (i + 1) % sps->maxFrameNum; + + } while (i != pSliceHeader->frameNum); + } +#endif + + /* check if current slice includes mmco equal to 5 */ + containsMmco5 = HANTRO_FALSE; + if (pSliceHeader->decRefPicMarking.adaptiveRefPicMarkingModeFlag) + { + i = 0; + while (pSliceHeader->decRefPicMarking.operation[i]. + memoryManagementControlOperation) + { + if (pSliceHeader->decRefPicMarking.operation[i]. + memoryManagementControlOperation == 5) + { + containsMmco5 = HANTRO_TRUE; + break; + } + i++; + } + } + switch (sps->picOrderCntType) + { + + case 0: + /* set prevPicOrderCnt values for IDR frame */ + if (IS_IDR_NAL_UNIT(pNalUnit)) + { + poc->prevPicOrderCntMsb = 0; + poc->prevPicOrderCntLsb = 0; + } + + /* compute picOrderCntMsb (stored in picOrderCnt variable) */ + if ( (pSliceHeader->picOrderCntLsb < poc->prevPicOrderCntLsb) && + ((poc->prevPicOrderCntLsb - pSliceHeader->picOrderCntLsb) >= + sps->maxPicOrderCntLsb/2) ) + { + picOrderCnt = poc->prevPicOrderCntMsb + + (i32)sps->maxPicOrderCntLsb; + } + else if ((pSliceHeader->picOrderCntLsb > poc->prevPicOrderCntLsb) && + ((pSliceHeader->picOrderCntLsb - poc->prevPicOrderCntLsb) > + sps->maxPicOrderCntLsb/2) ) + { + picOrderCnt = poc->prevPicOrderCntMsb - + (i32)sps->maxPicOrderCntLsb; + } + else + picOrderCnt = poc->prevPicOrderCntMsb; + + /* standard specifies that prevPicOrderCntMsb is from previous + * rererence frame -> replace old value only if current frame is + * rererence frame */ + if (pNalUnit->nalRefIdc) + poc->prevPicOrderCntMsb = picOrderCnt; + + /* compute top field order cnt (stored in picOrderCnt) */ + picOrderCnt += (i32)pSliceHeader->picOrderCntLsb; + + /* if delta for bottom field is negative -> bottom will be the + * minimum pic order count */ + if (pSliceHeader->deltaPicOrderCntBottom < 0) + picOrderCnt += pSliceHeader->deltaPicOrderCntBottom; + + /* standard specifies that prevPicOrderCntLsb is from previous + * rererence frame -> replace old value only if current frame is + * rererence frame */ + if (pNalUnit->nalRefIdc) + { + /* if current frame contains mmco5 -> modify values to be + * stored */ + if (containsMmco5) + { + poc->prevPicOrderCntMsb = 0; + /* prevPicOrderCntLsb should be the top field picOrderCnt + * if previous frame included mmco5. Top field picOrderCnt + * for frames containing mmco5 is obtained by subtracting + * the picOrderCnt from original top field order count -> + * value is zero if top field was the minimum, i.e. delta + * for bottom was positive, otherwise value is + * -deltaPicOrderCntBottom */ + if (pSliceHeader->deltaPicOrderCntBottom < 0) + poc->prevPicOrderCntLsb = + (u32)(-pSliceHeader->deltaPicOrderCntBottom); + else + poc->prevPicOrderCntLsb = 0; + picOrderCnt = 0; + } + else + { + poc->prevPicOrderCntLsb = pSliceHeader->picOrderCntLsb; + } + } + + break; + + case 1: + + /* step 1 (in the description in the standard) */ + if (IS_IDR_NAL_UNIT(pNalUnit)) + frameNumOffset = 0; + else if (poc->prevFrameNum > pSliceHeader->frameNum) + frameNumOffset = poc->prevFrameNumOffset + sps->maxFrameNum; + else + frameNumOffset = poc->prevFrameNumOffset; + + /* step 2 */ + if (sps->numRefFramesInPicOrderCntCycle) + absFrameNum = frameNumOffset + pSliceHeader->frameNum; + else + absFrameNum = 0; + + if (pNalUnit->nalRefIdc == 0 && absFrameNum > 0) + absFrameNum -= 1; + + /* step 3 */ + if (absFrameNum > 0) + { + picOrderCntCycleCnt = + (absFrameNum - 1)/sps->numRefFramesInPicOrderCntCycle; + frameNumInPicOrderCntCycle = + (absFrameNum - 1)%sps->numRefFramesInPicOrderCntCycle; + } + + /* step 4 */ + expectedDeltaPicOrderCntCycle = 0; + for (i = 0; i < sps->numRefFramesInPicOrderCntCycle; i++) + expectedDeltaPicOrderCntCycle += sps->offsetForRefFrame[i]; + + /* step 5 (picOrderCnt used to store expectedPicOrderCnt) */ + /*lint -esym(644,picOrderCntCycleCnt) always initialized */ + /*lint -esym(644,frameNumInPicOrderCntCycle) always initialized */ + if (absFrameNum > 0) + { + picOrderCnt = + (i32)picOrderCntCycleCnt * expectedDeltaPicOrderCntCycle; + for (i = 0; i <= frameNumInPicOrderCntCycle; i++) + picOrderCnt += sps->offsetForRefFrame[i]; + } + else + picOrderCnt = 0; + + if (pNalUnit->nalRefIdc == 0) + picOrderCnt += sps->offsetForNonRefPic; + + /* step 6 (picOrderCnt is top field order cnt if delta for bottom + * is positive, otherwise it is bottom field order cnt) */ + picOrderCnt += pSliceHeader->deltaPicOrderCnt[0]; + + if ( (sps->offsetForTopToBottomField + + pSliceHeader->deltaPicOrderCnt[1]) < 0 ) + { + picOrderCnt += sps->offsetForTopToBottomField + + pSliceHeader->deltaPicOrderCnt[1]; + } + + /* if current picture contains mmco5 -> set prevFrameNumOffset and + * prevFrameNum to 0 for computation of picOrderCnt of next + * frame, otherwise store frameNum and frameNumOffset to poc + * structure */ + if (!containsMmco5) + { + poc->prevFrameNumOffset = frameNumOffset; + poc->prevFrameNum = pSliceHeader->frameNum; + } + else + { + poc->prevFrameNumOffset = 0; + poc->prevFrameNum = 0; + picOrderCnt = 0; + } + break; + + default: /* case 2 */ + /* derive frameNumOffset */ + if (IS_IDR_NAL_UNIT(pNalUnit)) + frameNumOffset = 0; + else if (poc->prevFrameNum > pSliceHeader->frameNum) + frameNumOffset = poc->prevFrameNumOffset + sps->maxFrameNum; + else + frameNumOffset = poc->prevFrameNumOffset; + + /* derive picOrderCnt (type 2 has same value for top and bottom + * field order cnts) */ + if (IS_IDR_NAL_UNIT(pNalUnit)) + picOrderCnt = 0; + else if (pNalUnit->nalRefIdc == 0) + picOrderCnt = + 2 * (i32)(frameNumOffset + pSliceHeader->frameNum) - 1; + else + picOrderCnt = + 2 * (i32)(frameNumOffset + pSliceHeader->frameNum); + + /* if current picture contains mmco5 -> set prevFrameNumOffset and + * prevFrameNum to 0 for computation of picOrderCnt of next + * frame, otherwise store frameNum and frameNumOffset to poc + * structure */ + if (!containsMmco5) + { + poc->prevFrameNumOffset = frameNumOffset; + poc->prevFrameNum = pSliceHeader->frameNum; + } + else + { + poc->prevFrameNumOffset = 0; + poc->prevFrameNum = 0; + picOrderCnt = 0; + } + break; + + } + + /*lint -esym(644,picOrderCnt) always initialized */ + return(picOrderCnt); + +} + |