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在工程中，我们常常需要知道视频流的宽高，虽然可以借助一些开源库，但是仅为了获取宽高，却需要调用几十或是几百K的开源库，不太划算。因此，本文从开源库中移植了解析264码流宽高的代码，具体如下：
1 代码源自ffmpeg
1.1 新建get_bits.h文件
#ifndef AVCODEC_GET_BITS_H
#define AVCODEC_GET_BITS_H
#include <stdint.h>
#ifdef WIN
#define inline __inline
#else
#define inline
#endif
typedef struct GetBitContext {
const uint8_t *buffer, *buffer_end;
int index;
int size_in_bits;
int size_in_bits_plus8;
} GetBitContext;
#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
#define FFMAX3(a,b,c) FFMAX(FFMAX(a,b),c)
#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
#define FFMIN3(a,b,c) FFMIN(FFMIN(a,b),c)
#ifndef AV_RB32
# define AV_RB32(x) \
(((uint32_t)((const uint8_t*)(x))[0] << 24) | \
(((const uint8_t*)(x))[1] << 16) | \
(((const uint8_t*)(x))[2] << 8) | \
((const uint8_t*)(x))[3])
#endif
#define OPEN_READER_NOSIZE(name, gb) \
unsigned int name ## _index = (gb)->index; \
unsigned int /*av_unused*/ name ## _cache
#define OPEN_READER(name, gb) \
OPEN_READER_NOSIZE(name, gb); \
unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8
#define CLOSE_READER(name, gb) (gb)->index = name ## _index
# define UPDATE_CACHE_BE(name, gb) name ## _cache = \
AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7)
# define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb)
# define SKIP_COUNTER(name, gb, num) \
name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num))
#define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
#define GET_CACHE(name, gb) ((uint32_t) name ## _cache)
# define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
#define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num)
# define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num)
const static uint8_t ff_log2_tab[256]={
0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};
const static uint8_t ff_golomb_vlc_len[512] = {
19, 17, 15, 15, 13, 13, 13, 13, 11, 11, 11, 11, 11, 11, 11, 11, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
};
const static uint8_t ff_ue_golomb_vlc_code[512] = {
32, 32, 32, 32, 32, 32, 32, 32, 31, 32, 32, 32, 32, 32, 32, 32, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
const static int8_t ff_se_golomb_vlc_code[512] = {
17, 17, 17, 17, 17, 17, 17, 17, 16, 17, 17, 17, 17, 17, 17, 17, 8, -8, 9, -9, 10, -10, 11, -11, 12, -12, 13, -13, 14, -14, 15, -15,
4, 4, 4, 4, -4, -4, -4, -4, 5, 5, 5, 5, -5, -5, -5, -5, 6, 6, 6, 6, -6, -6, -6, -6, 7, 7, 7, 7, -7, -7, -7, -7,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
};
#ifndef ff_log2
#define ff_log2 ff_log2_c
static /*av_always_inline av_const*/ int ff_log2_c(unsigned int v)
{
int n = 0;
if (v & 0xffff0000) {
v >>= 16;
n += 16;
}
if (v & 0xff00) {
v >>= 8;
n += 8;
}
n += ff_log2_tab[v];
return n;
}
#endif
#define av_log2 ff_log2
/**
* Read 1-25 bits.
*/
static inline unsigned int get_bits(GetBitContext *s, int n)
{
register int tmp;
OPEN_READER(re, s);
//av_assert2(n>0 && n <= 25);
UPDATE_CACHE(re, s);
tmp = SHOW_UBITS(re, s, n);
LAST_SKIP_BITS(re, s, n);
CLOSE_READER(re, s);
return tmp;
}
static inline unsigned int get_bits1(GetBitContext *s)
{
unsigned int index = s->index;
uint8_t result = s->buffer[index >> 3];
#ifdef BITSTREAM_READER_LE
result >>= index & 7;
result &= 1;
#else
result <<= index & 7;
result >>= 8 - 1;
#endif
#if 1//!UNCHECKED_BITSTREAM_READER
if (s->index < s->size_in_bits_plus8)
#endif
index++;
s->index = index;
return result;
}
static inline void skip_bits(GetBitContext *s, int n)
{
OPEN_READER(re, s);
LAST_SKIP_BITS(re, s, n);
CLOSE_READER(re, s);
}
/**
* read unsigned exp golomb code, constraint to a max of 31.
* the return value is undefined if the stored value exceeds 31.
*/
static inline int get_ue_golomb_31(GetBitContext *gb)
{
unsigned int buf;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf = GET_CACHE(re, gb);
buf >>= 32 - 9;
LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_ue_golomb_vlc_code[buf];
}
/**
* Read an unsigned Exp-Golomb code in the range 0 to 8190.
*/
static inline int get_ue_golomb(GetBitContext *gb)
{
unsigned int buf;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf = GET_CACHE(re, gb);
if (buf >= (1 << 27)) {
buf >>= 32 - 9;
LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_ue_golomb_vlc_code[buf];
}
else {
int log = 2 * av_log2(buf) - 31;
LAST_SKIP_BITS(re, gb, 32 - log);
CLOSE_READER(re, gb);
if (log < 7) {
//av_log(NULL, AV_LOG_ERROR, "Invalid UE golomb code\n");
return -1;//AVERROR_INVALIDDATA;
}
buf >>= log;
buf--;
return buf;
}
}
/**
* read signed exp golomb code.
*/
static inline int get_se_golomb(GetBitContext *gb)
{
unsigned int buf;
OPEN_READER(re, gb);
UPDATE_CACHE(re, gb);
buf = GET_CACHE(re, gb);
if (buf >= (1 << 27)) {
buf >>= 32 - 9;
LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
CLOSE_READER(re, gb);
return ff_se_golomb_vlc_code[buf];
}
else {
int log = av_log2(buf), sign;
LAST_SKIP_BITS(re, gb, 31 - log);
UPDATE_CACHE(re, gb);
buf = GET_CACHE(re, gb);
buf >>= log;
LAST_SKIP_BITS(re, gb, 32 - log);
CLOSE_READER(re, gb);
sign = -(buf & 1);
buf = ((buf >> 1) ^ sign) - sign;
return buf;
}
}
#endif1.2 新建parser_sps.h文件
#ifndef _H264_PARSER_SPS
#define _H264_PARSER_SPS
#include <stdint.h>
#include "get_bits.h"
#ifdef WIN
#define inline __inline
#else
#define inline
#endif
#define MAX_SPS_COUNT 32
#define MAX_LOG2_MAX_FRAME_NUM (12 + 4)
#define MIN_LOG2_MAX_FRAME_NUM 4
#define MAX_DELAYED_PIC_COUNT 16
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
/**
* Rational number (pair of numerator and denominator).
*/
typedef struct AVRational{
int num; ///< Numerator
int den; ///< Denominator
} AVRational;
/**
* H264Context
*/
typedef struct H264Context {
GetBitContext gb;
// =============================================================
// Things below are not used in the MB or more inner code
int nal_ref_idc;
int nal_unit_type;
uint8_t *rbsp_buffer[2];
unsigned int rbsp_buffer_size[2];
int is_avc; ///< this flag is != 0 if codec is avc1
int nal_length_size; ///< Number of bytes used for nal length (1, 2 or 4)
} H264Context;
/* NAL unit types */
enum {
NAL_SLICE = 1,
NAL_DPA = 2,
NAL_DPB = 3,
NAL_DPC = 4,
NAL_IDR_SLICE = 5,
NAL_SEI = 6,
NAL_SPS = 7,
NAL_PPS = 8,
NAL_AUD = 9,
NAL_END_SEQUENCE = 10,
NAL_END_STREAM = 11,
NAL_FILLER_DATA = 12,
NAL_SPS_EXT = 13,
NAL_AUXILIARY_SLICE = 19,
NAL_FF_IGNORE = 0xff0f001,
};
/**
* Chromaticity coordinates of the source primaries.
*/
enum AVColorPrimaries {
AVCOL_PRI_RESERVED0 = 0,
AVCOL_PRI_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
AVCOL_PRI_UNSPECIFIED = 2,
AVCOL_PRI_RESERVED = 3,
AVCOL_PRI_BT470M = 4, ///< also FCC Title 47 Code of Federal Regulations 73.682 (a)(20)
AVCOL_PRI_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
AVCOL_PRI_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
AVCOL_PRI_SMPTE240M = 7, ///< functionally identical to above
AVCOL_PRI_FILM = 8, ///< colour filters using Illuminant C
AVCOL_PRI_BT2020 = 9, ///< ITU-R BT2020
AVCOL_PRI_SMPTEST428_1 = 10, ///< SMPTE ST 428-1 (CIE 1931 XYZ)
AVCOL_PRI_SMPTE431 = 11, ///< SMPTE ST 431-2 (2011)
AVCOL_PRI_SMPTE432 = 12, ///< SMPTE ST 432-1 D65 (2010)
AVCOL_PRI_NB ///< Not part of ABI
};
/**
* Color Transfer Characteristic.
*/
enum AVColorTransferCharacteristic {
AVCOL_TRC_RESERVED0 = 0,
AVCOL_TRC_BT709 = 1, ///< also ITU-R BT1361
AVCOL_TRC_UNSPECIFIED = 2,
AVCOL_TRC_RESERVED = 3,
AVCOL_TRC_GAMMA22 = 4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
AVCOL_TRC_GAMMA28 = 5, ///< also ITU-R BT470BG
AVCOL_TRC_SMPTE170M = 6, ///< also ITU-R BT601-6 525 or 625 / ITU-R BT1358 525 or 625 / ITU-R BT1700 NTSC
AVCOL_TRC_SMPTE240M = 7,
AVCOL_TRC_LINEAR = 8, ///< "Linear transfer characteristics"
AVCOL_TRC_LOG = 9, ///< "Logarithmic transfer characteristic (100:1 range)"
AVCOL_TRC_LOG_SQRT = 10, ///< "Logarithmic transfer characteristic (100 * Sqrt(10) : 1 range)"
AVCOL_TRC_IEC61966_2_4 = 11, ///< IEC 61966-2-4
AVCOL_TRC_BT1361_ECG = 12, ///< ITU-R BT1361 Extended Colour Gamut
AVCOL_TRC_IEC61966_2_1 = 13, ///< IEC 61966-2-1 (sRGB or sYCC)
AVCOL_TRC_BT2020_10 = 14, ///< ITU-R BT2020 for 10-bit system
AVCOL_TRC_BT2020_12 = 15, ///< ITU-R BT2020 for 12-bit system
AVCOL_TRC_SMPTEST2084 = 16, ///< SMPTE ST 2084 for 10-, 12-, 14- and 16-bit systems
AVCOL_TRC_SMPTEST428_1 = 17, ///< SMPTE ST 428-1
AVCOL_TRC_ARIB_STD_B67 = 18, ///< ARIB STD-B67, known as "Hybrid log-gamma"
AVCOL_TRC_NB ///< Not part of ABI
};
/**
* YUV colorspace type.
*/
enum AVColorSpace {
AVCOL_SPC_RGB = 0, ///< order of coefficients is actually GBR, also IEC 61966-2-1 (sRGB)
AVCOL_SPC_BT709 = 1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
AVCOL_SPC_UNSPECIFIED = 2,
AVCOL_SPC_RESERVED = 3,
AVCOL_SPC_FCC = 4, ///< FCC Title 47 Code of Federal Regulations 73.682 (a)(20)
AVCOL_SPC_BT470BG = 5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
AVCOL_SPC_SMPTE170M = 6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
AVCOL_SPC_SMPTE240M = 7, ///< functionally identical to above
AVCOL_SPC_YCOCG = 8, ///< Used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
AVCOL_SPC_BT2020_NCL = 9, ///< ITU-R BT2020 non-constant luminance system
AVCOL_SPC_BT2020_CL = 10, ///< ITU-R BT2020 constant luminance system
AVCOL_SPC_SMPTE2085 = 11, ///< SMPTE 2085, Y'D'zD'x
AVCOL_SPC_NB ///< Not part of ABI
};
/**
* Sequence parameter set
*/
typedef struct SPS {
unsigned int sps_id;
int profile_idc;
int level_idc;
int chroma_format_idc;
int transform_bypass; ///< qpprime_y_zero_transform_bypass_flag
int log2_max_frame_num; ///< log2_max_frame_num_minus4 + 4
int poc_type; ///< pic_order_cnt_type
int log2_max_poc_lsb; ///< log2_max_pic_order_cnt_lsb_minus4
int delta_pic_order_always_zero_flag;
int offset_for_non_ref_pic;
int offset_for_top_to_bottom_field;
int poc_cycle_length; ///< num_ref_frames_in_pic_order_cnt_cycle
int ref_frame_count; ///< num_ref_frames
int gaps_in_frame_num_allowed_flag;
int mb_width; ///< pic_width_in_mbs_minus1 + 1
int mb_height; ///< pic_height_in_map_units_minus1 + 1
int frame_mbs_only_flag;
int mb_aff; ///< mb_adaptive_frame_field_flag
int direct_8x8_inference_flag;
int crop; ///< frame_cropping_flag
int width, height;
/* those 4 are already in luma samples */
unsigned int crop_left; ///< frame_cropping_rect_left_offset
unsigned int crop_right; ///< frame_cropping_rect_right_offset
unsigned int crop_top; ///< frame_cropping_rect_top_offset
unsigned int crop_bottom; ///< frame_cropping_rect_bottom_offset
int vui_parameters_present_flag;
AVRational sar;
int video_signal_type_present_flag;
int full_range;
int colour_description_present_flag;
enum AVColorPrimaries color_primaries;
enum AVColorTransferCharacteristic color_trc;
enum AVColorSpace colorspace;
int timing_info_present_flag;
uint32_t num_units_in_tick;
uint32_t time_scale;
int fixed_frame_rate_flag;
short offset_for_ref_frame[256]; // FIXME dyn aloc?
int bitstream_restriction_flag;
int num_reorder_frames;
int scaling_matrix_present;
uint8_t scaling_matrix4[6][16];
uint8_t scaling_matrix8[6][64];
int nal_hrd_parameters_present_flag;
int vcl_hrd_parameters_present_flag;
int pic_struct_present_flag;
int time_offset_length;
int cpb_cnt; ///< See H.264 E.1.2
int initial_cpb_removal_delay_length; ///< initial_cpb_removal_delay_length_minus1 + 1
int cpb_removal_delay_length; ///< cpb_removal_delay_length_minus1 + 1
int dpb_output_delay_length; ///< dpb_output_delay_length_minus1 + 1
int bit_depth_luma; ///< bit_depth_luma_minus8 + 8
int bit_depth_chroma; ///< bit_depth_chroma_minus8 + 8
int residual_color_transform_flag; ///< residual_colour_transform_flag
int constraint_set_flags; ///< constraint_set[0-3]_flag
uint8_t data[4096];
size_t data_size;
} SPS;
void *h264Ps_Open();
int h264Ps_Parser(H264Context *h, const uint8_t * const buf, int buf_size, H264SPS *sps);
void h264Ps_Close(void *handle);
#endif1.3 新建parser_sps.c文件
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "get_bits.h"
#include "parser_sps.h"
static const uint8_t default_scaling4[2][16] = {
{ 6, 13, 20, 28, 13, 20, 28, 32,
20, 28, 32, 37, 28, 32, 37, 42 },
{ 10, 14, 20, 24, 14, 20, 24, 27,
20, 24, 27, 30, 24, 27, 30, 34 }
};
static const uint8_t default_scaling8[2][64] = {
{ 6, 10, 13, 16, 18, 23, 25, 27,
10, 11, 16, 18, 23, 25, 27, 29,
13, 16, 18, 23, 25, 27, 29, 31,
16, 18, 23, 25, 27, 29, 31, 33,
18, 23, 25, 27, 29, 31, 33, 36,
23, 25, 27, 29, 31, 33, 36, 38,
25, 27, 29, 31, 33, 36, 38, 40,
27, 29, 31, 33, 36, 38, 40, 42 },
{ 9, 13, 15, 17, 19, 21, 22, 24,
13, 13, 17, 19, 21, 22, 24, 25,
15, 17, 19, 21, 22, 24, 25, 27,
17, 19, 21, 22, 24, 25, 27, 28,
19, 21, 22, 24, 25, 27, 28, 30,
21, 22, 24, 25, 27, 28, 30, 32,
22, 24, 25, 27, 28, 30, 32, 33,
24, 25, 27, 28, 30, 32, 33, 35 }
};
static const uint8_t ff_zigzag_direct[64] = {
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63
};
static const uint8_t ff_zigzag_scan[16+1] = {
0 + 0 * 4, 1 + 0 * 4, 0 + 1 * 4, 0 + 2 * 4,
1 + 1 * 4, 2 + 0 * 4, 3 + 0 * 4, 2 + 1 * 4,
1 + 2 * 4, 0 + 3 * 4, 1 + 3 * 4, 2 + 2 * 4,
3 + 1 * 4, 3 + 2 * 4, 2 + 3 * 4, 3 + 3 * 4,
};
static int decode_scaling_list(GetBitContext *gb, uint8_t *factors, int size,
const uint8_t *jvt_list,
const uint8_t *fallback_list)
{
int i, last = 8, next = 8;
const uint8_t *scan = size == 16 ? ff_zigzag_scan : ff_zigzag_direct;
if (!get_bits1(gb)) /* matrix not written, we use the predicted one */
memcpy(factors, fallback_list, size * sizeof(uint8_t));
else
for (i = 0; i < size; i++) {
if (next) {
int v = get_se_golomb(gb);
if (v < -128 || v > 127) {
return -1;
}
next = (last + v) & 0xff;
}
if (!i && !next) { /* matrix not written, we use the preset one */
memcpy(factors, jvt_list, size * sizeof(uint8_t));
break;
}
last = factors[scan[i]] = next ? next : last;
}
return 0;
}
/* returns non zero if the provided SPS scaling matrix has been filled */
static int decode_scaling_matrices(GetBitContext *gb, const SPS *sps,
void *pps, int is_sps,
uint8_t(*scaling_matrix4)[16],
uint8_t(*scaling_matrix8)[64])
{
int transform_8x8_mode = 0;
int fallback_sps = !is_sps && sps->scaling_matrix_present;
const uint8_t *fallback[4] = {
fallback_sps ? sps->scaling_matrix4[0] : default_scaling4[0],
fallback_sps ? sps->scaling_matrix4[3] : default_scaling4[1],
fallback_sps ? sps->scaling_matrix8[0] : default_scaling8[0],
fallback_sps ? sps->scaling_matrix8[3] : default_scaling8[1]
};
int ret = 0;
if (get_bits1(gb)) {
ret |= decode_scaling_list(gb, scaling_matrix4[0], 16, default_scaling4[0], fallback[0]); // Intra, Y
ret |= decode_scaling_list(gb, scaling_matrix4[1], 16, default_scaling4[0], scaling_matrix4[0]); // Intra, Cr
ret |= decode_scaling_list(gb, scaling_matrix4[2], 16, default_scaling4[0], scaling_matrix4[1]); // Intra, Cb
ret |= decode_scaling_list(gb, scaling_matrix4[3], 16, default_scaling4[1], fallback[1]); // Inter, Y
ret |= decode_scaling_list(gb, scaling_matrix4[4], 16, default_scaling4[1], scaling_matrix4[3]); // Inter, Cr
ret |= decode_scaling_list(gb, scaling_matrix4[5], 16, default_scaling4[1], scaling_matrix4[4]); // Inter, Cb
if (is_sps || transform_8x8_mode) {
ret |= decode_scaling_list(gb, scaling_matrix8[0], 64, default_scaling8[0], fallback[2]); // Intra, Y
ret |= decode_scaling_list(gb, scaling_matrix8[3], 64, default_scaling8[1], fallback[3]); // Inter, Y
if (sps->chroma_format_idc == 3) {
ret |= decode_scaling_list(gb, scaling_matrix8[1], 64, default_scaling8[0], scaling_matrix8[0]); // Intra, Cr
ret |= decode_scaling_list(gb, scaling_matrix8[4], 64, default_scaling8[1], scaling_matrix8[3]); // Inter, Cr
ret |= decode_scaling_list(gb, scaling_matrix8[2], 64, default_scaling8[0], scaling_matrix8[1]); // Intra, Cb
ret |= decode_scaling_list(gb, scaling_matrix8[5], 64, default_scaling8[1], scaling_matrix8[4]); // Inter, Cb
}
}
if (!ret)
ret = is_sps;
}
return ret;
}
int ff_h264_decode_seq_parameter_set(GetBitContext *gb, SPS* sps)
{
int profile_idc, level_idc, constraint_set_flags = 0, reserved_zero_2bits;
unsigned int sps_id;
int i, log2_max_frame_num_minus4;
profile_idc = get_bits(gb, 8);
constraint_set_flags |= get_bits1(gb) << 0; // constraint_set0_flag
constraint_set_flags |= get_bits1(gb) << 1; // constraint_set1_flag
constraint_set_flags |= get_bits1(gb) << 2; // constraint_set2_flag
constraint_set_flags |= get_bits1(gb) << 3; // constraint_set3_flag
constraint_set_flags |= get_bits1(gb) << 4; // constraint_set4_flag
constraint_set_flags |= get_bits1(gb) << 5; // constraint_set5_flag
//reserved_zero_2bits = h264_bs_read_u(gb,2);
skip_bits(gb, 2); // reserved_zero_2bits
level_idc = get_bits(gb, 8);
sps_id = get_ue_golomb_31(gb);
if (sps_id >= MAX_SPS_COUNT) {
goto fail;
}
sps->sps_id = sps_id;
sps->time_offset_length = 24;
sps->profile_idc = profile_idc;
sps->constraint_set_flags = constraint_set_flags;
sps->level_idc = level_idc;
sps->full_range = -1;
memset(sps->scaling_matrix4, 16, sizeof(sps->scaling_matrix4));
memset(sps->scaling_matrix8, 16, sizeof(sps->scaling_matrix8));
sps->scaling_matrix_present = 0;
sps->colorspace = 2; //AVCOL_SPC_UNSPECIFIED
if (sps->profile_idc == 100 || // High profile
sps->profile_idc == 110 || // High10 profile
sps->profile_idc == 122 || // High422 profile
sps->profile_idc == 244 || // High444 Predictive profile
sps->profile_idc == 44 || // Cavlc444 profile
sps->profile_idc == 83 || // Scalable Constrained High profile (SVC)
sps->profile_idc == 86 || // Scalable High Intra profile (SVC)
sps->profile_idc == 118 || // Stereo High profile (MVC)
sps->profile_idc == 128 || // Multiview High profile (MVC)
sps->profile_idc == 138 || // Multiview Depth High profile (MVCD)
sps->profile_idc == 144) { // old High444 profile
sps->chroma_format_idc = get_ue_golomb_31(gb);
if (sps->chroma_format_idc > 3U) {
goto fail;
} else if (sps->chroma_format_idc == 3) {
sps->residual_color_transform_flag = get_bits1(gb);
if (sps->residual_color_transform_flag) {
goto fail;
}
}
sps->bit_depth_luma = get_ue_golomb(gb) + 8;
sps->bit_depth_chroma = get_ue_golomb(gb) + 8;
if (sps->bit_depth_chroma != sps->bit_depth_luma) {
goto fail;
}
if (sps->bit_depth_luma < 8 || sps->bit_depth_luma > 14 ||
sps->bit_depth_chroma < 8 || sps->bit_depth_chroma > 14) {
goto fail;
}
sps->transform_bypass = get_bits1(gb);
sps->scaling_matrix_present |= decode_scaling_matrices(gb, sps, NULL, 1,
sps->scaling_matrix4, sps->scaling_matrix8);
} else {
sps->chroma_format_idc = 1;
sps->bit_depth_luma = 8;
sps->bit_depth_chroma = 8;
}
log2_max_frame_num_minus4 = get_ue_golomb(gb);
if (log2_max_frame_num_minus4 < MIN_LOG2_MAX_FRAME_NUM - 4 ||
log2_max_frame_num_minus4 > MAX_LOG2_MAX_FRAME_NUM - 4) {
goto fail;
}
sps->log2_max_frame_num = log2_max_frame_num_minus4 + 4;
sps->poc_type = get_ue_golomb_31(gb);
if (sps->poc_type == 0) { // FIXME #define
unsigned t = get_ue_golomb(gb);
if (t>12) {
goto fail;
}
sps->log2_max_poc_lsb = t + 4;
} else if (sps->poc_type == 1) { // FIXME #define
sps->delta_pic_order_always_zero_flag = get_bits1(gb);
sps->offset_for_non_ref_pic = get_se_golomb(gb);
sps->offset_for_top_to_bottom_field = get_se_golomb(gb);
sps->poc_cycle_length = get_ue_golomb(gb);
if ((unsigned)sps->poc_cycle_length >=
FF_ARRAY_ELEMS(sps->offset_for_ref_frame)) {
goto fail;
}
for (i = 0; i < sps->poc_cycle_length; i++)
sps->offset_for_ref_frame[i] = get_se_golomb(gb);
} else if (sps->poc_type != 2) {
goto fail;
}
sps->ref_frame_count = get_ue_golomb_31(gb);
if (sps->ref_frame_count > MAX_DELAYED_PIC_COUNT) {
goto fail;
}
sps->gaps_in_frame_num_allowed_flag = get_bits1(gb);
sps->mb_width = get_ue_golomb(gb) + 1;
sps->mb_height = get_ue_golomb(gb) + 1;
sps->frame_mbs_only_flag = get_bits1(gb);
sps->mb_height *= 2 - sps->frame_mbs_only_flag;
if (!sps->frame_mbs_only_flag)
sps->mb_aff = get_bits1(gb);
else
sps->mb_aff = 0;
if ((unsigned)sps->mb_width >= INT_MAX / 16 ||
(unsigned)sps->mb_height >= INT_MAX / (16 * (2 - sps->frame_mbs_only_flag)) ) {
goto fail;
}
sps->direct_8x8_inference_flag = get_bits1(gb);
sps->crop = get_bits1(gb);
sps->width = 16 * sps->mb_width;
sps->height = 16 * sps->mb_height;
if (sps->crop) {
unsigned int crop_left = get_ue_golomb(gb);
unsigned int crop_right = get_ue_golomb(gb);
unsigned int crop_top = get_ue_golomb(gb);
unsigned int crop_bottom = get_ue_golomb(gb);
int width = 16 * sps->mb_width;
int height = 16 * sps->mb_height * (2 - sps->frame_mbs_only_flag);
sps->width = width;
sps->height = height;
if (0) {
sps->crop_left =
sps->crop_right =
sps->crop_top =
sps->crop_bottom = 0;
} else {
int vsub = (sps->chroma_format_idc == 1) ? 1 : 0;
int hsub = (sps->chroma_format_idc == 1 ||
sps->chroma_format_idc == 2) ? 1 : 0;
int step_x = 1 << hsub;
int step_y = (2 - sps->frame_mbs_only_flag) << vsub;
if (crop_left & (0x1F >> (sps->bit_depth_luma > 8))) {
crop_left &= ~(0x1F >> (sps->bit_depth_luma > 8));
}
if (crop_left > (unsigned)INT_MAX / 4 / step_x ||
crop_right > (unsigned)INT_MAX / 4 / step_x ||
crop_top > (unsigned)INT_MAX / 4 / step_y ||
crop_bottom> (unsigned)INT_MAX / 4 / step_y ||
(crop_left + crop_right ) * step_x >= width ||
(crop_top + crop_bottom) * step_y >= height
) {
goto fail;
}
sps->crop_left = crop_left * step_x;
sps->crop_right = crop_right * step_x;
sps->crop_top = crop_top * step_y;
sps->crop_bottom = crop_bottom * step_y;
}
} else {
sps->crop_left =
sps->crop_right =
sps->crop_top =
sps->crop_bottom =
sps->crop = 0;
}
sps->vui_parameters_present_flag = get_bits1(gb);
if (sps->vui_parameters_present_flag) {
int ret = 0;//decode_vui_parameters(gb, avctx, sps);
if (ret < 0)
goto fail;
}
return 0;
fail:
return -1;
}
/**
* Initialize GetBitContext.
* @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes
* larger than the actual read bits because some optimized bitstream
* readers read 32 or 64 bit at once and could read over the end
* @param bit_size the size of the buffer in bits
* @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
*/
static /*inline*/ int init_get_bits(GetBitContext *s, const uint8_t *buffer,
int bit_size)
{
int buffer_size;
int ret = 0;
if (bit_size >= INT_MAX - 7 || bit_size < 0 || !buffer) {
bit_size = 0;
buffer = NULL;
ret = -1;//AVERROR_INVALIDDATA;
}
buffer_size = (bit_size + 7) >> 3;
s->buffer = buffer;
s->size_in_bits = bit_size;
s->size_in_bits_plus8 = bit_size + 8;
s->buffer_end = buffer + buffer_size;
s->index = 0;
return ret;
}
static inline int get_avc_nalsize(H264Context *h, const uint8_t *buf,
int buf_size, int *buf_index)
{
int i, nalsize = 0;
if (*buf_index >= buf_size - h->nal_length_size)
return -1;
for (i = 0; i < h->nal_length_size; i++)
nalsize = ((unsigned)nalsize << 8) | buf[(*buf_index)++];
if (nalsize <= 0 || nalsize > buf_size - *buf_index) {
/*av_log(h->avctx, AV_LOG_ERROR,
"AVC: nal size %d\n", nalsize);*/
return -1;
}
return nalsize;
}
const uint8_t *avpriv_find_start_code(const uint8_t */*av_restrict*/ p,
const uint8_t *end,
uint32_t */*av_restrict*/ state)
{
int i;
//av_assert0(p <= end);
if (p >= end)
return end;
for (i = 0; i < 3; i++) {
uint32_t tmp = *state << 8;
*state = tmp + *(p++);
if (tmp == 0x100 || p == end)
return p;
}
while (p < end) {
if (p[-1] > 1 ) p += 3;
else if (p[-2] ) p += 2;
else if (p[-3]|(p[-1]-1)) p++;
else {
p++;
break;
}
}
p = FFMIN(p, end) - 4;
*state = AV_RB32(p);
return p + 4;
}
static inline int find_start_code(const uint8_t *buf, int buf_size,
int buf_index, int next_avc)
{
uint32_t state = -1;
buf_index = avpriv_find_start_code(buf + buf_index, buf + next_avc + 1, &state) - buf - 1;
return FFMIN(buf_index, buf_size);
}
#define FF_INPUT_BUFFER_PADDING_SIZE 32
#define MAX_MBPAIR_SIZE (256*1024) // a tighter bound could be calculated if someone cares about a few bytes
static size_t max_alloc_size= INT_MAX;
void *av_malloc(size_t size)
{
void *ptr = NULL;
#if CONFIG_MEMALIGN_HACK
long diff;
#endif
/* let's disallow possibly ambiguous cases */
if (size > (max_alloc_size - 32))
return NULL;
#if CONFIG_MEMALIGN_HACK
ptr = malloc(size + ALIGN);
if (!ptr)
return ptr;
diff = ((~(long)ptr)&(ALIGN - 1)) + 1;
ptr = (char *)ptr + diff;
((char *)ptr)[-1] = diff;
#elif HAVE_POSIX_MEMALIGN
if (size) //OS X on SDK 10.6 has a broken posix_memalign implementation
if (posix_memalign(&ptr, ALIGN, size))
ptr = NULL;
#elif HAVE_ALIGNED_MALLOC
ptr = _aligned_malloc(size, ALIGN);
#elif HAVE_MEMALIGN
#ifndef __DJGPP__
ptr = memalign(ALIGN, size);
#else
ptr = memalign(size, ALIGN);
#endif
/* Why 64?
* Indeed, we should align it:
* on 4 for 386
* on 16 for 486
* on 32 for 586, PPro - K6-III
* on 64 for K7 (maybe for P3 too).
* Because L1 and L2 caches are aligned on those values.
* But I don't want to code such logic here!
*/
/* Why 32?
* For AVX ASM. SSE / NEON needs only 16.
* Why not larger? Because I did not see a difference in benchmarks ...
*/
/* benchmarks with P3
* memalign(64) + 1 3071, 3051, 3032
* memalign(64) + 2 3051, 3032, 3041
* memalign(64) + 4 2911, 2896, 2915
* memalign(64) + 8 2545, 2554, 2550
* memalign(64) + 16 2543, 2572, 2563
* memalign(64) + 32 2546, 2545, 2571
* memalign(64) + 64 2570, 2533, 2558
*
* BTW, malloc seems to do 8-byte alignment by default here.
*/
#else
ptr = malloc(size);
#endif
if(!ptr && !size) {
size = 1;
ptr= av_malloc(1);
}
#if CONFIG_MEMORY_POISONING
if (ptr)
memset(ptr, FF_MEMORY_POISON, size);
#endif
return ptr;
}
void *av_mallocz(size_t size)
{
void *ptr = av_malloc(size);
if (ptr)
memset(ptr, 0, size);
return ptr;
}
void av_free(void *ptr)
{
#if CONFIG_MEMALIGN_HACK
if (ptr) {
int v= ((char *)ptr)[-1];
av_assert0(v>0 && v<=ALIGN);
free((char *)ptr - v);
}
#elif HAVE_ALIGNED_MALLOC
_aligned_free(ptr);
#else
free(ptr);
#endif
}
void av_freep(void *arg)
{
void **ptr = (void **)arg;
av_free(*ptr);
*ptr = NULL;
}
static inline int ff_fast_malloc(void *ptr, unsigned int *size, size_t min_size, int zero_realloc)
{
void **p = ptr;
if (min_size <= *size && *p)
return 0;
min_size = FFMAX(17 * min_size / 16 + 32, min_size);
av_free(*p);
*p = zero_realloc ? av_mallocz(min_size) : av_malloc(min_size);
if (!*p)
min_size = 0;
*size = min_size;
return 1;
}
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
{
uint8_t **p = ptr;
if (min_size > SIZE_MAX - FF_INPUT_BUFFER_PADDING_SIZE) {
av_freep(p);
*size = 0;
return;
}
if (!ff_fast_malloc(p, size, min_size + FF_INPUT_BUFFER_PADDING_SIZE, 1))
memset(*p + min_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
}
const uint8_t *ff_h264_decode_nal(H264Context *h, const uint8_t *src,
int *dst_length, int *consumed, int length)
{
int i, si, di;
uint8_t *dst;
int bufidx;
// src[0]&0x80; // forbidden bit
h->nal_ref_idc = src[0] >> 5;
h->nal_unit_type = src[0] & 0x1F;
src++;
length--;
#define STARTCODE_TEST \
if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) { \
if (src[i + 2] != 3 && src[i + 2] != 0) { \
/* startcode, so we must be past the end */ \
length = i; \
} \
break; \
}
#if HAVE_FAST_UNALIGNED
#define FIND_FIRST_ZERO \
if (i > 0 && !src[i]) \
i--; \
while (src[i]) \
i++
#if HAVE_FAST_64BIT
for (i = 0; i + 1 < length; i += 9) {
if (!((~AV_RN64A(src + i) &
(AV_RN64A(src + i) - 0x0100010001000101ULL)) &
0x8000800080008080ULL))
continue;
FIND_FIRST_ZERO;
STARTCODE_TEST;
i -= 7;
}
#else
for (i = 0; i + 1 < length; i += 5) {
if (!((~AV_RN32A(src + i) &
(AV_RN32A(src + i) - 0x01000101U)) &
0x80008080U))
continue;
FIND_FIRST_ZERO;
STARTCODE_TEST;
i -= 3;
}
#endif
#else
for (i = 0; i + 1 < length; i += 2) {
if (src[i])
continue;
if (i > 0 && src[i - 1] == 0)
i--;
STARTCODE_TEST;
}
#endif
// use second escape buffer for inter data
bufidx = h->nal_unit_type == NAL_DPC ? 1 : 0;
av_fast_padded_malloc(&h->rbsp_buffer[bufidx], &h->rbsp_buffer_size[bufidx], length+MAX_MBPAIR_SIZE);
dst = h->rbsp_buffer[bufidx];
if (!dst)
return NULL;
if(i>=length-1){ //no escaped 0
*dst_length= length;
*consumed= length+1; //+1 for the header
if(1/*h->avctx->flags2 & CODEC_FLAG2_FAST*/){
return src;
}else{
memcpy(dst, src, length);
return dst;
}
}
memcpy(dst, src, i);
si = di = i;
while (si + 2 < length) {
// remove escapes (very rare 1:2^22)
if (src[si + 2] > 3) {
dst[di++] = src[si++];
dst[di++] = src[si++];
} else if (src[si] == 0 && src[si + 1] == 0 && src[si + 2] != 0) {
if (src[si + 2] == 3) { // escape
dst[di++] = 0;
dst[di++] = 0;
si += 3;
continue;
} else // next start code
goto nsc;
}
dst[di++] = src[si++];
}
while (si < length)
dst[di++] = src[si++];
nsc:
memset(dst + di, 0, FF_INPUT_BUFFER_PADDING_SIZE);
*dst_length = di;
*consumed = si + 1; // +1 for the header
/* FIXME store exact number of bits in the getbitcontext
* (it is needed for decoding) */
return dst;
}
int h264Ps_Parser(H264Context *h, const uint8_t * const buf, int buf_size, H264SPS *sps)
{
//H264Context *h = s->priv_data;
int buf_index, next_avc;
unsigned int pps_id;
unsigned int slice_type;
int state = -1, got_reset = 0;
const uint8_t *ptr;
//int q264 = buf_size >=4 && !memcmp("Q264", buf, 4);
int field_poc[2];
/* set some sane default values */
//s->pict_type = AV_PICTURE_TYPE_I;
//s->key_frame = 0;
//s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
//h->avctx = avctx;
//ff_h264_reset_sei(h);
//h->sei_fpa.frame_packing_arrangement_cancel_flag = -1;
if (!buf_size)
return 0;
buf_index = 0;
next_avc = h->is_avc ? 0 : buf_size;
for (;;) {
int src_length, dst_length, consumed, nalsize = 0;
if (buf_index >= next_avc) {
nalsize = get_avc_nalsize(h, buf, buf_size, &buf_index);
if (nalsize < 0)
break;
next_avc = buf_index + nalsize;
} else {
buf_index = find_start_code(buf, buf_size, buf_index, next_avc);
if (buf_index >= buf_size)
break;
if (buf_index >= next_avc)
continue;
}
src_length = next_avc - buf_index;
state = buf[buf_index];
switch (state & 0x1f) {
case NAL_SLICE:
case NAL_IDR_SLICE:
// Do not walk the whole buffer just to decode slice header
if ((state & 0x1f) == NAL_IDR_SLICE || ((state >> 5) & 0x3) == 0) {
/* IDR or disposable slice
* No need to decode many bytes because MMCOs shall not be present. */
if (src_length > 60)
src_length = 60;
} else {
/* To decode up to MMCOs */
if (src_length > 1000)
src_length = 1000;
}
break;
}
ptr = ff_h264_decode_nal(h, buf + buf_index, &dst_length,
&consumed, src_length);
if (!ptr || dst_length < 0)
break;
buf_index += consumed;
init_get_bits(&h->gb, ptr, 8 * dst_length);
switch (h->nal_unit_type) {
case NAL_SPS:
ff_h264_decode_seq_parameter_set(h, sps);
break;
}
}
//if (q264)
// return 0;
/* didn't find a picture! */
//av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit with size %d\n", buf_size);
return -1;
}
void *h264Ps_Open()
{
H264Context *h;
h = (H264Context *)malloc(sizeof(*h));
if(h == NULL){
return NULL;
}
memset(h, 0, sizeof(*h));
return h;
}
void h264Ps_Close(void *handle)
{
H264Context *h = (H264Context*)handle;
if(h){
av_freep(&h->rbsp_buffer[1]);
av_freep(&h->rbsp_buffer[0]);
h->rbsp_buffer_size[0] = 0;
h->rbsp_buffer_size[1] = 0;
free(h);
}
}1.4 新建parser_demo.c文件
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "parser_sps.h"
void ParserH264Resolution(char *cpFileName, int *ipWidth, int *ipHeight)
{
FILE *fp;
long len;
unsigned char *buf;
H264Context *h;
H264SPS sps;
fp = fopen(cpFileName,"rb");
fseek(fp,0,SEEK_END);
len = ftell(fp);
fseek(fp,0,SEEK_SET);
buf = (unsigned char*) malloc (len+1);
fread(buf,1,len,fp);
fclose(fp);
h = h264Ps_Open();
if(h == NULL){
printf("[h264Ps can't malloc memory!\n]");
}
h264Ps_Parser(h, buf, len, &sps);
h264Ps_Close(h);
free(buf);
return;
}
int main(int argc, char *argv[])
{
int iHeight=0, iWidth=0;
char *cpFileName = argv[1];
ParserH264Resolution(cpFileName, &iWidth, &iHeight);
return 0;
}