GPMF_bitstream.h File Reference

GPMF Parser library include. More...

#include <stdint.h>

Include dependency graph for GPMF_bitstream.h:

Go to the source code of this file.

Classes
struct	bitstream
struct	rlv
struct	RLVTABLE

Macros
#define	_BITMASK(n)   ((((BITSTREAM_WORD_TYPE )1 << (n))) - 1)
#define	BITMASK(n)   _bitmask[n]
#define	BITSTREAM_ERROR_OVERFLOW   1
#define	BITSTREAM_WORD_SIZE   16
#define	BITSTREAM_WORD_TYPE   uint16_t
#define	HUFF_END_CODE_ENTRY   1
#define	HUFF_ESC_CODE_ENTRY   0

Typedefs
typedef struct bitstream	BITSTREAM
typedef struct rlv	RLV

Variables
static const BITSTREAM_WORD_TYPE	_bitmask []
static RLVTABLE	enccontrolcodestable
static RLVTABLE	enchuftable
static RLVTABLE	enczerorunstable

Detailed Description

GPMF Parser library include.

Some GPMF streams may contain compressed data, this is useful for high frequency sensor data that is highly correlated like IMU data. The compression is Huffman coding of the delta between samples, with addition codewords for runs of zeros, and optional quantization. The compression scheme is similar to the Huffman coding in JPEG. As it intended for lossless compression (with quantize set to 1) it can only compress/decompress integer based streams.

Version

1.2.0

(C) Copyright 2017 GoPro Inc (http://gopro.com/).

Licensed under either:

• Apache License, Version 2.0, http://www.apache.org/licenses/LICENSE-2.0
• MIT license, http://opensource.org/licenses/MIT at your option.

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.

Definition in file GPMF_bitstream.h.

Macro Definition Documentation

_BITMASK

#define _BITMASK

(

n

)

((((BITSTREAM_WORD_TYPE )1 << (n))) - 1)

Definition at line 58 of file GPMF_bitstream.h.

BITMASK

#define BITMASK

(

n

)

_bitmask[n]

Definition at line 57 of file GPMF_bitstream.h.

BITSTREAM_ERROR_OVERFLOW

#define BITSTREAM_ERROR_OVERFLOW   1

Definition at line 55 of file GPMF_bitstream.h.

BITSTREAM_WORD_SIZE

#define BITSTREAM_WORD_SIZE   16

Definition at line 54 of file GPMF_bitstream.h.

BITSTREAM_WORD_TYPE

#define BITSTREAM_WORD_TYPE   uint16_t

Definition at line 53 of file GPMF_bitstream.h.

HUFF_END_CODE_ENTRY

#define HUFF_END_CODE_ENTRY   1

Definition at line 141 of file GPMF_bitstream.h.

HUFF_ESC_CODE_ENTRY

#define HUFF_ESC_CODE_ENTRY   0

Definition at line 140 of file GPMF_bitstream.h.

Typedef Documentation

BITSTREAM

typedef struct bitstream BITSTREAM

RLV

typedef struct rlv RLV

Variable Documentation

_bitmask

const BITSTREAM_WORD_TYPE _bitmask[]

static

Initial value:

=
{
        _BITMASK(0),  _BITMASK(1),  _BITMASK(2),  _BITMASK(3),
        _BITMASK(4),  _BITMASK(5),  _BITMASK(6),  _BITMASK(7),
        _BITMASK(8),  _BITMASK(9),  _BITMASK(10), _BITMASK(11),
        _BITMASK(12), _BITMASK(13), _BITMASK(14), _BITMASK(15),
        0xFFFF
}

Definition at line 60 of file GPMF_bitstream.h.

enccontrolcodestable

RLVTABLE enccontrolcodestable

static

Initial value:

= {
        2,
        {
                { 16, 0b1110001111000100, 0, 0 },       
                { 16, 0b1110001111000101, 0, 0 },       
        }
}

Definition at line 142 of file GPMF_bitstream.h.

enchuftable

RLVTABLE enchuftable

static

Definition at line 83 of file GPMF_bitstream.h.

enczerorunstable

RLVTABLE enczerorunstable

static

Initial value:

= {
        4,
        {
                { 7, 0b1111110,  16,  0 },              
                { 8, 0b11111110,  32,  0 },             
                { 9, 0b111111111,  64,  0 },    
                { 10,0b1111111101, 128,  0 },   
        }
}

Definition at line 130 of file GPMF_bitstream.h.