H264ParserUtils.h

#pragma once
 
#include <stddef.h>
 
using namespace std;
struct sps_pps_properties {
    sps_pps_properties() {
        width = 640;
        height = 360;
        bitrate = 400000;
        fps = 30;
    }
    int width;
    int height;
    int bitrate;
    int fps;
};
 
// refeferd from https://stackoverflow.com/questions/12018535/get-the-width-height-of-the-video-from-h-264-nalu
class SpsPpsParsser{
public:
    SpsPpsParsser() {}
    void ParseSps(const unsigned char * pStart, unsigned short nLen, sps_pps_properties *output);
    void ParsePps(const unsigned char * pStart, unsigned short nLen, sps_pps_properties *output);
private:
    const unsigned char * m_pStart;
    unsigned short m_nLength;
    int m_nCurrentBit;
private:
    unsigned int ReadBit();
    unsigned int ReadBits(int n);
    unsigned int ReadExponentialGolombCode();
    unsigned int ReadSE();
};
 
class H264ParserUtils {
private:
    H264ParserUtils(void) {}
public:
    static void parse_sps(const char *sps, size_t len, sps_pps_properties *output);
    static void parse_pps(const char *pps, size_t len, sps_pps_properties *output);
};