从H264的SPS中获取图像长宽

1、从H264的SPS中获取图像长宽作者：李国帅从开源项目mpegip中选取，并封装。1， 调用方法#include "H264Parser.h"h264_decode_t dec;memset(&dec, 0, sizeof(dec);uint8_t * buffer = (uint8_t*)cbSPS;h264_parse_sequence_parameter_set(&dec, buffer,nSPS * 8);outWidth = dec.pic_width;/1920;/outHeight = dec.pic_height;/1080;/2， H264

2、Parser.h代码#pragma once#ifndef _H264_H_#define _H264_H_ 1#include <stdio.h>#include <math.h>#include "stdint.h"#include "bitstream.h" /在mpegip中得到，就不粘贴了。typedef unsigned int uint;#define H264_START_CODE 0x000001#define H264_PREVENT_3_BYTE 0x000003#pragma pack(push)#prag

3、ma pack(1)typedef struct h264_decode_tuint8_t profile;uint8_t level;uint32_t chroma_format_idc;uint8_t residual_colour_transform_flag;uint32_t bit_depth_luma_minus8;uint32_t bit_depth_chroma_minus8;uint8_t qpprime_y_zero_transform_bypass_flag;uint8_t seq_scaling_matrix_present_flag;uint32_t log2_max

4、_frame_num_minus4;uint32_t log2_max_pic_order_cnt_lsb_minus4;uint32_t pic_order_cnt_type;uint8_t frame_mbs_only_flag;uint8_t pic_order_present_flag;uint8_t delta_pic_order_always_zero_flag;int32_t offset_for_non_ref_pic;int32_t offset_for_top_to_bottom_field;uint32_t pic_order_cnt_cycle_length;int16

5、_t offset_for_ref_frame256;uint8_t nal_ref_idc;uint8_t nal_unit_type;uint8_t field_pic_flag;uint8_t bottom_field_flag;uint32_t frame_num;uint32_t idr_pic_id;uint32_t pic_order_cnt_lsb;int32_t delta_pic_order_cnt_bottom;int32_t delta_pic_order_cnt2;uint32_t pic_width, pic_height;uint32_t slice_type;/

6、* POC state */int32_t pic_order_cnt; /* can be < 0 */uint32_t pic_order_cnt_msb;uint32_t pic_order_cnt_msb_prev;uint32_t pic_order_cnt_lsb_prev;uint32_t frame_num_prev;int32_t frame_num_offset;int32_t frame_num_offset_prev;uint8_t NalHrdBpPresentFlag;uint8_t VclHrdBpPresentFlag;uint8_t CpbDpbDela

7、ysPresentFlag;uint8_t pic_struct_present_flag;uint8_t cpb_removal_delay_length_minus1;uint8_t dpb_output_delay_length_minus1;uint8_t time_offset_length;uint32_t cpb_cnt_minus1;uint8_t initial_cpb_removal_delay_length_minus1; h264_decode_t;static uint8_t exp_golomb_bits =8, 7, 6, 6, 5, 5, 5, 5, 4, 4,

8、 4, 4, 4, 4, 4, 4, 3,3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 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, 1, 1, 1, 1,1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

9、 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,

10、 0, 0, 0, 0, 0, 0, 0,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,0;/256static const uint8_t trailing_bits = 0, 0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80 ;/9#ifdef _cplusplusextern "C" #endifuint32_t h264_ue(CBitstream *bs)uint32_t bi

11、ts, read;int bits_left;uint8_t coded;bool done = false;bits = 0;/ we want to read 8 bits at a time - if we don't have 8 bits,/ read what's left, and shift. The exp_golomb_bits calc remains the/ same.while(done = false)bits_left = bs->bits_remain();if(bits_left < 8)read = bs->PeekBit

12、s(bits_left) <<(8 - bits_left);done = true;elseread = bs->PeekBits(8);if(read = 0)bs->GetBits(8);bits += 8;elsedone = true;coded = exp_golomb_bitsread;bs->GetBits(coded);bits += coded;/ printf("ue - bits %dn", bits);return bs->GetBits(bits + 1) - 1;int32_t h264_se(CBitstr

13、eam *bs)uint32_t ret;ret = h264_ue(bs);if(ret & 0x1) = 0)ret >>= 1;int32_t temp = 0 - ret;return temp;return(ret + 1) >> 1;void h264_check_0s(CBitstream *bs, int count)uint32_t val;val = bs->GetBits(count);if(val != 0)/printf("field error - %d bits should be 0 is %xn", c

14、ount, val);void scaling_list(uint32_t ix, uint32_t sizeOfScalingList, CBitstream *bs)uint32_t lastScale = 8, nextScale = 8;uint32_t jx;int deltaScale;for(jx = 0; jx < sizeOfScalingList; jx+)if(nextScale != 0)deltaScale = h264_se(bs);nextScale =(lastScale + deltaScale + 256) % 256;/printf(" d

15、elta: %dn", deltaScale);if(nextScale = 0)lastScale = lastScale;elselastScale = nextScale;/printf(" scaling list%u%u: %un", ix, jx, lastScale);void h264_parse_sequence_parameter_set(h264_decode_t *dec, uint8_t* Buffer,size_t Buffer_Size)CBitstream ourbs;ourbs.init(Buffer, Buffer_Size);

16、CBitstream *bs = &ourbs;uint32_t type = 0;h264_check_0s(bs, 1);/检查首字节dec->nal_ref_idc = bs->GetBits(2);/NAL 的优先级dec->nal_unit_type = type = bs->GetBits(5);/nal类型if(type != 0x7)return;uint32_t temp;dec->profile = bs->GetBits(8);/第个字节/printf(" profile: %un", dec->pro

17、file);temp = bs->GetBits(1);/printf(" constaint_set0_flag: %dn", temp);temp = bs->GetBits(1);/printf(" constaint_set1_flag: %dn", temp);temp = bs->GetBits(1);/printf(" constaint_set2_flag: %dn", temp);temp = bs->GetBits(1);/printf(" constaint_set3_flag:

18、 %dn", temp);h264_check_0s(bs, 4);/第个字节temp = bs->GetBits(8);/第个字节/printf(" level_idc: %un", temp);temp = h264_ue(bs);/printf(" seq parameter set id: %un", temp);if(dec->profile = 100 | dec->profile = 110 | dec->profile = 122 | dec->profile = 144)dec->chrom

19、a_format_idc = h264_ue(bs);if(dec->chroma_format_idc = 3)dec->residual_colour_transform_flag = bs->GetBits(1);dec->bit_depth_luma_minus8 = h264_ue(bs);dec->bit_depth_chroma_minus8 = h264_ue(bs);dec->qpprime_y_zero_transform_bypass_flag = bs->GetBits(1);dec->seq_scaling_matrix

20、_present_flag = bs->GetBits(1);if(dec->seq_scaling_matrix_present_flag)for(uint32_t ix = 0; ix < 8; ix+)temp = bs->GetBits(1);if(temp)scaling_list(ix, ix < 6 ? 16 : 64, bs);dec->log2_max_frame_num_minus4 = h264_ue(bs);dec->pic_order_cnt_type = h264_ue(bs);if(dec->pic_order_cn

21、t_type = 0)dec->log2_max_pic_order_cnt_lsb_minus4 = h264_ue(bs);else if(dec->pic_order_cnt_type = 1)dec->delta_pic_order_always_zero_flag = bs->GetBits(1);temp = h264_se(bs);/printf(" offset_for_non_ref_pic: %dn", temp);temp = h264_se(bs);/printf(" offset_for_top_to_bottom

22、_field: %dn",temp);temp = h264_ue(bs);for(uint32_t ix = 0; ix < temp; ix+)temp = h264_se(bs);/printf(" offset_for_ref_frame%u: %dn", ix, temp);temp = h264_ue(bs);/printf(" num_ref_frames: %un", temp);temp = bs->GetBits(1);/printf(" gaps_in_frame_num_value_allowed_

23、flag: %un", temp);uint32_t PicWidthInMbs = h264_ue(bs) + 1;/printf(" pic_width_in_mbs_minus1: %u(%u)n", PicWidthInMbs - 1, PicWidthInMbs * 16);uint32_t PicHeightInMapUnits = h264_ue(bs) + 1;/printf(" pic_height_in_map_minus1: %un", PicHeightInMapUnits - 1);dec->frame_mbs_

24、only_flag = bs->GetBits(1);if(!dec->frame_mbs_only_flag)temp = bs->GetBits(1);/printf(" mb_adaptive_frame_field_flag: %un", temp);temp = bs->GetBits(1);/printf(" direct_8x8_inference_flag: %un",temp);temp = bs->GetBits(1);if(temp)temp = h264_ue(bs);/printf(" f

25、rame_crop_left_offset: %un", temp);temp = h264_ue(bs);/printf(" frame_crop_right_offset: %un", temp);temp = h264_ue(bs);/printf(" frame_crop_top_offset: %un", temp);temp = h264_ue(bs);/printf(" frame_crop_bottom_offset: %un", temp);/temp = bs->GetBits(1);/if(tem

26、p)/h264_vui_parameters(dec, bs);/海康sps可能没有这个东西/dec->pic_width = PicWidthInMbs * 16;dec->pic_height =( 2 - dec->frame_mbs_only_flag ) * PicHeightInMapUnits * 16;static uint32_t calc_ceil_log2(uint32_t val)uint32_t ix, cval;ix = 0;cval = 1;while(ix < 32)if(cval >= val) return ix;cval &l

27、t;<= 1;ix+;return ix;void h264_parse_pic_parameter_set(h264_decode_t *dec, CBitstream *bs)uint32_t num_slice_groups, temp, iGroup;temp = h264_ue(bs);/printf(" pic_parameter_set_id: %un", temp);temp = h264_ue(bs);/printf(" seq_parameter_set_id: %un", temp);temp = bs->GetBits

28、(1);/printf(" entropy_coding_mode_flag: %un",temp);dec->pic_order_present_flag = bs->GetBits(1);/printf(" pic_order_present_flag: %un", dec->pic_order_present_flag);num_slice_groups = h264_ue(bs);/printf(" num_slice_groups_minus1: %un", num_slice_groups);if(num

29、_slice_groups > 0)temp = h264_ue(bs);/printf(" slice_group_map_type: %un", temp);if(temp = 0)for(iGroup = 0; iGroup <= num_slice_groups; iGroup+)temp = h264_ue(bs);/printf(" run_length_minus1%u: %un", iGroup,temp);else if(temp = 2)for(iGroup = 0; iGroup < num_slice_group

30、s; iGroup+)temp = h264_ue(bs);/printf(" top_left%u: %un", iGroup, temp);temp = h264_ue(bs);/printf(" bottom_right%u: %un", iGroup, temp);else if(temp < 6) / 3, 4, 5temp = bs->GetBits(1);/printf(" slice_group_change_direction_flag: %un", temp);temp = h264_ue(bs);/p

31、rintf(" slice_group_change_rate_minus1: %un", temp);else if(temp = 6)temp = h264_ue(bs);/printf(" pic_size_in_map_units_minus1: %un", temp);uint32_t bits = calc_ceil_log2(num_slice_groups + 1);/printf(" bits - %un", bits);for(iGroup = 0; iGroup <= temp; iGroup+)temp

32、= bs->GetBits(bits);/printf(" slice_group_id%u: %un", iGroup, temp);temp = h264_ue(bs);/printf(" num_ref_idx_l0_active_minus1: %un",temp);temp = h264_ue(bs);/printf(" num_ref_idx_l1_active_minus1: %un",temp);temp = bs->GetBits(1);/printf(" weighted_pred_flag: %un",temp);temp = bs->GetBits(2);/printf(" weighted_bipred_idc: %un",temp);temp = h264_se(bs);/printf(" pic_init_qp_minus26: %dn", temp);temp = h264_se(bs);/printf(" pic_init_qs_minus26: %dn", temp);temp = h264_se(bs