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Diffstat (limited to 'media/libstagefright/codecs/on2/h264dec/source/h264bsd_stream.c')
| -rwxr-xr-x | media/libstagefright/codecs/on2/h264dec/source/h264bsd_stream.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/on2/h264dec/source/h264bsd_stream.c b/media/libstagefright/codecs/on2/h264dec/source/h264bsd_stream.c new file mode 100755 index 0000000..20d1083 --- /dev/null +++ b/media/libstagefright/codecs/on2/h264dec/source/h264bsd_stream.c @@ -0,0 +1,242 @@ +/* + * 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 + h264bsdGetBits + h264bsdShowBits32 + h264bsdFlushBits + h264bsdIsByteAligned + +------------------------------------------------------------------------------*/ + +/*------------------------------------------------------------------------------ + 1. Include headers +------------------------------------------------------------------------------*/ + +#include "h264bsd_util.h" +#include "h264bsd_stream.h" + +/*------------------------------------------------------------------------------ + 2. External compiler flags +-------------------------------------------------------------------------------- + +-------------------------------------------------------------------------------- + 3. Module defines +------------------------------------------------------------------------------*/ + +/*------------------------------------------------------------------------------ + 4. Local function prototypes +------------------------------------------------------------------------------*/ + +/*------------------------------------------------------------------------------ + + Function: h264bsdGetBits + + Functional description: + Read and remove bits from the stream buffer. + + Input: + pStrmData pointer to stream data structure + numBits number of bits to read + + Output: + none + + Returns: + bits read from stream + END_OF_STREAM if not enough bits left + +------------------------------------------------------------------------------*/ + +u32 h264bsdGetBits(strmData_t *pStrmData, u32 numBits) +{ + + u32 out; + + ASSERT(pStrmData); + ASSERT(numBits < 32); + + out = h264bsdShowBits32(pStrmData) >> (32 - numBits); + + if (h264bsdFlushBits(pStrmData, numBits) == HANTRO_OK) + { + return(out); + } + else + { + return(END_OF_STREAM); + } + +} + +/*------------------------------------------------------------------------------ + + Function: h264bsdShowBits32 + + Functional description: + Read 32 bits from the stream buffer. Buffer is left as it is, i.e. + no bits are removed. First bit read from the stream is the MSB of + the return value. If there is not enough bits in the buffer -> + bits beyong the end of the stream are set to '0' in the return + value. + + Input: + pStrmData pointer to stream data structure + + Output: + none + + Returns: + bits read from stream + +------------------------------------------------------------------------------*/ + +u32 h264bsdShowBits32(strmData_t *pStrmData) +{ + + i32 bits, shift; + u32 out; + u8 *pStrm; + + ASSERT(pStrmData); + ASSERT(pStrmData->pStrmCurrPos); + ASSERT(pStrmData->bitPosInWord < 8); + ASSERT(pStrmData->bitPosInWord == + (pStrmData->strmBuffReadBits & 0x7)); + + pStrm = pStrmData->pStrmCurrPos; + + /* number of bits left in the buffer */ + bits = (i32)pStrmData->strmBuffSize*8 - (i32)pStrmData->strmBuffReadBits; + + /* at least 32-bits in the buffer */ + if (bits >= 32) + { + u32 bitPosInWord = pStrmData->bitPosInWord; + out = ((u32)pStrm[0] << 24) | ((u32)pStrm[1] << 16) | + ((u32)pStrm[2] << 8) | ((u32)pStrm[3]); + + if (bitPosInWord) + { + u32 byte = (u32)pStrm[4]; + u32 tmp = (8-bitPosInWord); + out <<= bitPosInWord; + out |= byte>>tmp; + } + return (out); + } + /* at least one bit in the buffer */ + else if (bits > 0) + { + shift = (i32)(24 + pStrmData->bitPosInWord); + out = (u32)(*pStrm++) << shift; + bits -= (i32)(8 - pStrmData->bitPosInWord); + while (bits > 0) + { + shift -= 8; + out |= (u32)(*pStrm++) << shift; + bits -= 8; + } + return (out); + } + else + return (0); + +} + +/*------------------------------------------------------------------------------ + + Function: h264bsdFlushBits + + Functional description: + Remove bits from the stream buffer + + Input: + pStrmData pointer to stream data structure + numBits number of bits to remove + + Output: + none + + Returns: + HANTRO_OK success + END_OF_STREAM not enough bits left + +------------------------------------------------------------------------------*/ +#ifndef H264DEC_NEON +u32 h264bsdFlushBits(strmData_t *pStrmData, u32 numBits) +{ + + ASSERT(pStrmData); + ASSERT(pStrmData->pStrmBuffStart); + ASSERT(pStrmData->pStrmCurrPos); + ASSERT(pStrmData->bitPosInWord < 8); + ASSERT(pStrmData->bitPosInWord == (pStrmData->strmBuffReadBits & 0x7)); + + pStrmData->strmBuffReadBits += numBits; + pStrmData->bitPosInWord = pStrmData->strmBuffReadBits & 0x7; + if ( (pStrmData->strmBuffReadBits ) <= (8*pStrmData->strmBuffSize) ) + { + pStrmData->pStrmCurrPos = pStrmData->pStrmBuffStart + + (pStrmData->strmBuffReadBits >> 3); + return(HANTRO_OK); + } + else + return(END_OF_STREAM); + +} +#endif +/*------------------------------------------------------------------------------ + + Function: h264bsdIsByteAligned + + Functional description: + Check if current stream position is byte aligned. + + Inputs: + pStrmData pointer to stream data structure + + Outputs: + none + + Returns: + TRUE stream is byte aligned + FALSE stream is not byte aligned + +------------------------------------------------------------------------------*/ + +u32 h264bsdIsByteAligned(strmData_t *pStrmData) +{ + +/* Variables */ + +/* Code */ + + if (!pStrmData->bitPosInWord) + return(HANTRO_TRUE); + else + return(HANTRO_FALSE); + +} + |