ref: bb4b01a1f96ee6576fb0ccc8237cf635e89a01ec
dir: h264bsd/src/h264bsd_util.c
/*
* Copyright (C) 2009 The Android Open Source Project
* Modified for use by h264bsd standalone library
*
* 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
h264bsdCountLeadingZeros
h264bsdRbspTrailingBits
h264bsdMoreRbspData
h264bsdNextMbAddress
h264bsdSetCurrImageMbPointers
------------------------------------------------------------------------------*/
/*------------------------------------------------------------------------------
1. Include headers
------------------------------------------------------------------------------*/
#include "h264bsd_util.h"
/*------------------------------------------------------------------------------
2. External compiler flags
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
3. Module defines
------------------------------------------------------------------------------*/
/* look-up table for expected values of stuffing bits */
static const u32 stuffingTable[8] = {0x1,0x2,0x4,0x8,0x10,0x20,0x40,0x80};
/* look-up table for chroma quantization parameter as a function of luma QP */
const u32 h264bsdQpC[52] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,
20,21,22,23,24,25,26,27,28,29,29,30,31,32,32,33,34,34,35,35,36,36,37,37,37,
38,38,38,39,39,39,39};
/*------------------------------------------------------------------------------
4. Local function prototypes
------------------------------------------------------------------------------*/
/*------------------------------------------------------------------------------
5.1 Function: h264bsdCountLeadingZeros
Functional description:
Count leading zeros in a code word. Code word is assumed to be
right-aligned, last bit of the code word in the lsb of the value.
Inputs:
value code word
length number of bits in the code word
Outputs:
none
Returns:
number of leading zeros in the code word
------------------------------------------------------------------------------*/
#ifndef H264DEC_NEON
u32 h264bsdCountLeadingZeros(u32 value, u32 length)
{
/* Variables */
u32 zeros = 0;
u32 mask = 1 << (length - 1);
/* Code */
ASSERT(length <= 32);
while (mask && !(value & mask))
{
zeros++;
mask >>= 1;
}
return(zeros);
}
#endif
/*------------------------------------------------------------------------------
5.2 Function: h264bsdRbspTrailingBits
Functional description:
Check Raw Byte Stream Payload (RBSP) trailing bits, i.e. stuffing.
Rest of the current byte (whole byte if allready byte aligned)
in the stream buffer shall contain a '1' bit followed by zero or
more '0' bits.
Inputs:
pStrmData pointer to stream data structure
Outputs:
none
Returns:
HANTRO_OK RBSP trailing bits found
HANTRO_NOK otherwise
------------------------------------------------------------------------------*/
u32 h264bsdRbspTrailingBits(strmData_t *pStrmData)
{
/* Variables */
u32 stuffing;
u32 stuffingLength;
/* Code */
ASSERT(pStrmData);
ASSERT(pStrmData->bitPosInWord < 8);
stuffingLength = 8 - pStrmData->bitPosInWord;
stuffing = h264bsdGetBits(pStrmData, stuffingLength);
if (stuffing == END_OF_STREAM)
return(HANTRO_NOK);
if (stuffing != stuffingTable[stuffingLength - 1])
return(HANTRO_NOK);
else
return(HANTRO_OK);
}
/*------------------------------------------------------------------------------
5.3 Function: h264bsdMoreRbspData
Functional description:
Check if there is more data in the current RBSP. The standard
defines this function so that there is more data if
-more than 8 bits left or
-last bits are not RBSP trailing bits
Inputs:
pStrmData pointer to stream data structure
Outputs:
none
Returns:
HANTRO_TRUE there is more data
HANTRO_FALSE no more data
------------------------------------------------------------------------------*/
u32 h264bsdMoreRbspData(strmData_t *pStrmData)
{
/* Variables */
u32 bits;
/* Code */
ASSERT(pStrmData);
ASSERT(pStrmData->strmBuffReadBits <= 8 * pStrmData->strmBuffSize);
bits = pStrmData->strmBuffSize * 8 - pStrmData->strmBuffReadBits;
if (bits == 0)
return(HANTRO_FALSE);
if ( (bits > 8) ||
((h264bsdShowBits32(pStrmData)>>(32-bits)) != (1 << (bits-1))) )
return(HANTRO_TRUE);
else
return(HANTRO_FALSE);
}
/*------------------------------------------------------------------------------
5.4 Function: h264bsdNextMbAddress
Functional description:
Get address of the next macroblock in the current slice group.
Inputs:
pSliceGroupMap slice group for each macroblock
picSizeInMbs size of the picture
currMbAddr where to start
Outputs:
none
Returns:
address of the next macroblock
0 if none of the following macroblocks belong to same slice
group as currMbAddr
------------------------------------------------------------------------------*/
u32 h264bsdNextMbAddress(u32 *pSliceGroupMap, u32 picSizeInMbs, u32 currMbAddr)
{
/* Variables */
u32 i, sliceGroup, tmp;
/* Code */
ASSERT(pSliceGroupMap);
ASSERT(picSizeInMbs);
ASSERT(currMbAddr < picSizeInMbs);
sliceGroup = pSliceGroupMap[currMbAddr];
i = currMbAddr + 1;
tmp = pSliceGroupMap[i];
while ((i < picSizeInMbs) && (tmp != sliceGroup))
{
i++;
tmp = pSliceGroupMap[i];
}
if (i == picSizeInMbs)
i = 0;
return(i);
}
/*------------------------------------------------------------------------------
5.5 Function: h264bsdSetCurrImageMbPointers
Functional description:
Set luma and chroma pointers in image_t for current MB
Inputs:
image Current image
mbNum number of current MB
Outputs:
none
Returns:
none
------------------------------------------------------------------------------*/
void h264bsdSetCurrImageMbPointers(image_t *image, u32 mbNum)
{
u32 width, height;
u32 picSize;
u32 row, col;
u32 tmp;
width = image->width;
height = image->height;
row = mbNum / width;
col = mbNum % width;
tmp = row * width;
picSize = width * height;
image->luma = (u8*)(image->data + col * 16 + tmp * 256);
image->cb = (u8*)(image->data + picSize * 256 + tmp * 64 + col * 8);
image->cr = (u8*)(image->cb + picSize * 64);
}