// Copyright (c) 2012-2017 VideoStitch SAS
// Copyright (c) 2018 stitchEm
/**
* Simplest Librtmp Send 264
*
* �����裬����
* leixiaohua1020@126.com
* zhanghuicuc@gmail.com
* �й���ý��ѧ/���ֵ��Ӽ���
* Communication University of China / Digital TV Technology
* http://blog.csdn.net/leixiaohua1020
*
* ���������ڽ��ڴ��е�H.264����������RTMP��ý���������
*
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <math.h>
typedef unsigned int UINT;
typedef unsigned char BYTE;
typedef unsigned long DWORD;
UINT Ue(BYTE *pBuff, UINT nLen, UINT &nStartBit) {
//����0bit�ĸ���
UINT nZeroNum = 0;
while (nStartBit < nLen * 8) {
if (pBuff[nStartBit / 8] & (0x80 >> (nStartBit % 8))) //&:��λ�룬%ȡ��
{
break;
}
nZeroNum++;
nStartBit++;
}
nStartBit++;
//������
DWORD dwRet = 0;
for (UINT i = 0; i < nZeroNum; i++) {
dwRet <<= 1;
if (pBuff[nStartBit / 8] & (0x80 >> (nStartBit % 8))) {
dwRet += 1;
}
nStartBit++;
}
return (1 << nZeroNum) - 1 + dwRet;
}
int Se(BYTE *pBuff, UINT nLen, UINT &nStartBit) {
int UeVal = Ue(pBuff, nLen, nStartBit);
double k = UeVal;
int nValue = ceil(k / 2); // ceil������ceil��������������С�ڸ���ʵ������С������ceil(2)=ceil(1.2)=cei(1.5)=2.00
if (UeVal % 2 == 0) nValue = -nValue;
return nValue;
}
DWORD u(UINT BitCount, BYTE *buf, UINT &nStartBit) {
DWORD dwRet = 0;
for (UINT i = 0; i < BitCount; i++) {
dwRet <<= 1;
if (buf[nStartBit / 8] & (0x80 >> (nStartBit % 8))) {
dwRet += 1;
}
nStartBit++;
}
return dwRet;
}
/**
* H264��NAL��ʼ�����������
*
* @param buf SPS��������
*
* @����ֵ
*/
void de_emulation_prevention(BYTE *buf, unsigned int *buf_size) {
unsigned int i = 0, j = 0;
BYTE *tmp_ptr = NULL;
unsigned int tmp_buf_size = 0;
int val = 0;
tmp_ptr = buf;
tmp_buf_size = *buf_size;
for (i = 0; i < (tmp_buf_size - 2); i++) {
// check for 0x000003
val = (tmp_ptr[i] ^ 0x00) + (tmp_ptr[i + 1] ^ 0x00) + (tmp_ptr[i + 2] ^ 0x03);
if (val == 0) {
// kick out 0x03
for (j = i + 2; j < tmp_buf_size - 1; j++) tmp_ptr[j] = tmp_ptr[j + 1];
// and so we should devrease bufsize
(*buf_size)--;
}
}
return;
}
/**
* ����SPS,��ȡ��Ƶͼ���������Ϣ
*
* @param buf SPS��������
* @param nLen SPS���ݵij���
* @param width ͼ�����
* @param height ͼ��߶�
* @�ɹ���1 , ʧ����0
*/
int h264_decode_sps(BYTE *buf, unsigned int nLen, int &width, int &height, int &fps) {
UINT StartBit = 0;
fps = 0;
de_emulation_prevention(buf, &nLen);
int forbidden_zero_bit = u(1, buf, StartBit);
int nal_ref_idc = u(2, buf, StartBit);
int nal_unit_type = u(5, buf, StartBit);
if (nal_unit_type == 7) {
int profile_idc = u(8, buf, StartBit);
int constraint_set0_flag = u(1, buf, StartBit); //(buf[1] & 0x80)>>7;
int constraint_set1_flag = u(1, buf, StartBit); //(buf[1] & 0x40)>>6;
int constraint_set2_flag = u(1, buf, StartBit); //(buf[1] & 0x20)>>5;
int constraint_set3_flag = u(1, buf, StartBit); //(buf[1] & 0x10)>>4;
int reserved_zero_4bits = u(4, buf, StartBit);
int level_idc = u(8, buf, StartBit);
int seq_parameter_set_id = Ue(buf, nLen, StartBit);
if (profile_idc == 100 || profile_idc == 110 || profile_idc == 122 || profile_idc == 144) {
int chroma_format_idc = Ue(buf, nLen, StartBit);
if (chroma_format_idc == 3) int residual_colour_transform_flag = u(1, buf, StartBit);
int bit_depth_luma_minus8 = Ue(buf, nLen, StartBit);
int bit_depth_chroma_minus8 = Ue(buf, nLen, StartBit);
int qpprime_y_zero_transform_bypass_flag = u(1, buf, StartBit);
int seq_scaling_matrix_present_flag = u(1, buf, StartBit);
int seq_scaling_list_present_flag[8];
if (seq_scaling_matrix_present_flag) {
for (int i = 0; i < 8; i++) {
seq_scaling_list_present_flag[i] = u(1, buf, StartBit);
}
}
}
int log2_max_frame_num_minus4 = Ue(buf, nLen, StartBit);
int pic_order_cnt_type = Ue(buf, nLen, StartBit);
if (pic_order_cnt_type == 0)
int log2_max_pic_order_cnt_lsb_minus4 = Ue(buf, nLen, StartBit);
else if (pic_order_cnt_type == 1) {
int delta_pic_order_always_zero_flag = u(1, buf, StartBit);
int offset_for_non_ref_pic = Se(buf, nLen, StartBit);
int offset_for_top_to_bottom_field = Se(buf, nLen, StartBit);
int num_ref_frames_in_pic_order_cnt_cycle = Ue(buf, nLen, StartBit);
int *offset_for_ref_frame = new int[num_ref_frames_in_pic_order_cnt_cycle];
for (int i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++) offset_for_ref_frame[i] = Se(buf, nLen, StartBit);
delete[] offset_for_ref_frame;
}
int num_ref_frames = Ue(buf, nLen, StartBit);
int gaps_in_frame_num_value_allowed_flag = u(1, buf, StartBit);
int pic_width_in_mbs_minus1 = Ue(buf, nLen, StartBit);
int pic_height_in_map_units_minus1 = Ue(buf, nLen, StartBit);
width = (pic_width_in_mbs_minus1 + 1) * 16;
height = (pic_height_in_map_units_minus1 + 1) * 16;
int frame_mbs_only_flag = u(1, buf, StartBit);
if (!frame_mbs_only_flag) int mb_adaptive_frame_field_flag = u(1, buf, StartBit);
int direct_8x8_inference_flag = u(1, buf, StartBit);
int frame_cropping_flag = u(1, buf, StartBit);
if (frame_cropping_flag) {
int frame_crop_left_offset = Ue(buf, nLen, StartBit);
int frame_crop_right_offset = Ue(buf, nLen, StartBit);
int frame_crop_top_offset = Ue(buf, nLen, StartBit);
int frame_crop_bottom_offset = Ue(buf, nLen, StartBit);
}
int vui_parameter_present_flag = u(1, buf, StartBit);
if (vui_parameter_present_flag) {
int aspect_ratio_info_present_flag = u(1, buf, StartBit);
if (aspect_ratio_info_present_flag) {
int aspect_ratio_idc = u(8, buf, StartBit);
if (aspect_ratio_idc == 255) {
int sar_width = u(16, buf, StartBit);
int sar_height = u(16, buf, StartBit);
}
}
int overscan_info_present_flag = u(1, buf, StartBit);
if (overscan_info_present_flag) int overscan_appropriate_flagu = u(1, buf, StartBit);
int video_signal_type_present_flag = u(1, buf, StartBit);
if (video_signal_type_present_flag) {
int video_format = u(3, buf, StartBit);
int video_full_range_flag = u(1, buf, StartBit);
int colour_description_present_flag = u(1, buf, StartBit);
if (colour_description_present_flag) {
int colour_primaries = u(8, buf, StartBit);
int transfer_characteristics = u(8, buf, StartBit);
int matrix_coefficients = u(8, buf, StartBit);
}
}
int chroma_loc_info_present_flag = u(1, buf, StartBit);
if (chroma_loc_info_present_flag) {
int chroma_sample_loc_type_top_field = Ue(buf, nLen, StartBit);
int chroma_sample_loc_type_bottom_field = Ue(buf, nLen, StartBit);
}
int timing_info_present_flag = u(1, buf, StartBit);
if (timing_info_present_flag) {
int num_units_in_tick = u(32, buf, StartBit);
int time_scale = u(32, buf, StartBit);
fps = time_scale / (2 * num_units_in_tick);
}
}
return true;
} else
return false;
}