代码
flv.cpp
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#pragma pack(1)
#define TAG_TYPE_SCRIPT 18
#define TAG_TYPE_AUDIO 8
#define TAG_TYPE_VIDEO 9
typedef unsigned char byte;
typedef unsigned int uint;
typedef struct {
byte Signature[3]; //F L V
byte Version;
byte Flags; //5表示有音频+视频
uint DataOffset;//头部长度，占4字节
} FLV_HEADER;
typedef struct {
byte TagType;
byte DataSize[3];
byte Timestamp[3];
uint Reserved;
} TAG_HEADER;
//reverse_bytes - turn a BigEndian byte array into a LittleEndian integer
uint reverse_bytes(byte *p, char c) {
int r = 0;
int i;
for (i=0; i<c; i++)
r |= ( *(p+i) << (((c-1)*8)-8*i));
return r;
}
/**
* Analysis FLV file
* @param url Location of input FLV file.
*/
int simplest_flv_parser(char *url){
//whether output audio/video stream
int output_a=1;
int output_v=1;
//-------------
FILE *ifh=NULL,*vfh=NULL, *afh = NULL;
//FILE *myout=fopen("output_log.txt","wb+");
FILE *myout=stdout;
FLV_HEADER flv;
TAG_HEADER tagheader;
uint previoustagsize, previoustagsize_z=0;
uint ts=0, ts_new=0;
ifh = fopen(url, "rb+");
if ( ifh== NULL) {
printf("Failed to open files!");
return -1;
}
//FLV file header
fread((char *)&flv,1,sizeof(FLV_HEADER),ifh); // (存放数据的内存指针， 每次读取字节数，读取次数， 文件流)，sizeof以字节为单位
fprintf(myout,"============== FLV Header ==============\n");
fprintf(myout,"Signature: 0x %c %c %c\n",flv.Signature[0],flv.Signature[1],flv.Signature[2]);
fprintf(myout,"Version: 0x %X\n",flv.Version);
fprintf(myout,"Flags : 0x %X\n",flv.Flags);
fprintf(myout,"HeaderSize: 0x %X\n",reverse_bytes((byte *)&flv.DataOffset, sizeof(flv.DataOffset)));
fprintf(myout,"========================================\n");
//move the file pointer to the end of the header
fseek(ifh, reverse_bytes((byte *)&flv.DataOffset, sizeof(flv.DataOffset)), SEEK_SET); // (文件，偏移量字节，起始点) SEEK_SET为文件开头
//process each tag
do {
//读掉遇到的第一个整数(16进制里的大于0和必定不是"字母"的数），每次循环在FLV文件格式中读掉prev tag size的四个字节
previoustagsize = getw(ifh);
//读tag header
fread((void *)&tagheader,sizeof(TAG_HEADER),1,ifh);
//int temp_datasize1=reverse_bytes((byte *)&tagheader.DataSize, sizeof(tagheader.DataSize));
int tagheader_datasize=tagheader.DataSize[0]*65536+tagheader.DataSize[1]*256+tagheader.DataSize[2]; // ？
int tagheader_timestamp=tagheader.Timestamp[0]*65536+tagheader.Timestamp[1]*256+tagheader.Timestamp[2];
char tagtype_str[10];
switch(tagheader.TagType){
case TAG_TYPE_AUDIO:sprintf(tagtype_str,"AUDIO");break;
case TAG_TYPE_VIDEO:sprintf(tagtype_str,"VIDEO");break;
case TAG_TYPE_SCRIPT:sprintf(tagtype_str,"SCRIPT");break;
default:sprintf(tagtype_str,"UNKNOWN");break;
}
fprintf(myout,"[%6s] %6d %6d |",tagtype_str,tagheader_datasize,tagheader_timestamp);
//if we are not past the end of file, process the tag
if (feof(ifh)) {
break;
}
//process tag by type
switch (tagheader.TagType) {
case TAG_TYPE_AUDIO:{
char audiotag_str[100]={0};
strcat(audiotag_str,"| ");
// tag data部分第一个字节不表示数据
char tagdata_first_byte;
tagdata_first_byte=fgetc(ifh);//读取一个字节后，光标位置后移一个字节
int x=tagdata_first_byte&0xF0; //0xf0：1111 0000
x=x>>4;// tag data部分的第一个字节，取前四位，表示soundformat
switch (x)
{
case 0:strcat(audiotag_str,"Linear PCM, platform endian");break;
case 1:strcat(audiotag_str,"ADPCM");break;
case 2:strcat(audiotag_str,"MP3");break;
case 3:strcat(audiotag_str,"Linear PCM, little endian");break;
case 4:strcat(audiotag_str,"Nellymoser 16-kHz mono");break;
case 5:strcat(audiotag_str,"Nellymoser 8-kHz mono");break;
case 6:strcat(audiotag_str,"Nellymoser");break;
case 7:strcat(audiotag_str,"G.711 A-law logarithmic PCM");break;
case 8:strcat(audiotag_str,"G.711 mu-law logarithmic PCM");break;
case 9:strcat(audiotag_str,"reserved");break;
case 10:strcat(audiotag_str,"AAC");break;
case 11:strcat(audiotag_str,"Speex");break;
case 14:strcat(audiotag_str,"MP3 8-Khz");break;
case 15:strcat(audiotag_str,"Device-specific sound");break;
default:strcat(audiotag_str,"UNKNOWN");break;
}
strcat(audiotag_str,"| ");
x=tagdata_first_byte&0x0C; // 0000 1100 取中间两位
x=x>>2;
switch (x)
{
case 0:strcat(audiotag_str,"5.5-kHz");break;
case 1:strcat(audiotag_str,"1-kHz");break;
case 2:strcat(audiotag_str,"22-kHz");break;
case 3:strcat(audiotag_str,"44-kHz");break;
default:strcat(audiotag_str,"UNKNOWN");break;
}
strcat(audiotag_str,"| ");
x=tagdata_first_byte&0x02; // 0000 0010 取倒数第二位
x=x>>1;
switch (x)
{
case 0:strcat(audiotag_str,"8Bit");break;
case 1:strcat(audiotag_str,"16Bit");break;
default:strcat(audiotag_str,"UNKNOWN");break;
}
strcat(audiotag_str,"| ");
x=tagdata_first_byte&0x01; // 0000 0001 取最后一位
switch (x)
{
case 0:strcat(audiotag_str,"Mono");break;
case 1:strcat(audiotag_str,"Stereo");break;
default:strcat(audiotag_str,"UNKNOWN");break;
}
fprintf(myout,"%s",audiotag_str);
//if the output file hasn't been opened, open it.
if(output_a!=0&&afh == NULL){
afh = fopen("output.mp3", "wb");
}
//TagData - First Byte Data
int data_size=reverse_bytes((byte *)&tagheader.DataSize, sizeof(tagheader.DataSize))-1;//-1是因为tag data第一个字节不是数据
if(output_a!=0){
//TagData+1
for (int i=0; i<data_size; i++)
fputc(fgetc(ifh),afh);//写到output里，ifh afh都往后移
}else{
for (int i=0; i<data_size; i++)
fgetc(ifh);//不需要输出
}
break;
}
case TAG_TYPE_VIDEO:{
char videotag_str[100]={0};
strcat(videotag_str,"| ");
char tagdata_first_byte;
tagdata_first_byte=fgetc(ifh);
int x=tagdata_first_byte&0xF0;//取前四位，帧类型
x=x>>4;
switch (x)
{
case 1:strcat(videotag_str,"key frame ");break;
case 2:strcat(videotag_str,"inter frame");break;
case 3:strcat(videotag_str,"disposable inter frame");break;
case 4:strcat(videotag_str,"generated keyframe");break;
case 5:strcat(videotag_str,"video info/command frame");break;
default:strcat(videotag_str,"UNKNOWN");break;
}
strcat(videotag_str,"| ");
x=tagdata_first_byte&0x0F;//取后四位，编码类型
switch (x)
{
case 1:strcat(videotag_str,"JPEG (currently unused)");break;
case 2:strcat(videotag_str,"Sorenson H.263");break;
case 3:strcat(videotag_str,"Screen video");break;
case 4:strcat(videotag_str,"On2 VP6");break;
case 5:strcat(videotag_str,"On2 VP6 with alpha channel");break;
case 6:strcat(videotag_str,"Screen video version 2");break;
case 7:strcat(videotag_str,"AVC");break;
default:strcat(videotag_str,"UNKNOWN");break;
}
fprintf(myout,"%s",videotag_str);
fseek(ifh, -1, SEEK_CUR); //往前一位
//if the output file hasn't been opened, open it.
if (vfh == NULL&&output_v!=0) {
//write the flv header (reuse the original file's hdr) and first previoustagsize
//分离视频FLV必须有flv header，prevtagsize，tagheader，tagdata，首次打开文件时，这里写好前两个。分离出的音频不需要
vfh = fopen("output.flv", "wb");
fwrite((char *)&flv,1, sizeof(flv),vfh);
fwrite((char *)&previoustagsize_z,1,sizeof(previoustagsize_z),vfh);
}
#if 0
//Change Timestamp
//Get Timestamp
ts = reverse_bytes((byte *)&tagheader.Timestamp, sizeof(tagheader.Timestamp));
ts=ts*2;
//Writeback Timestamp
ts_new = reverse_bytes((byte *)&ts, sizeof(ts));
memcpy(&tagheader.Timestamp, ((char *)&ts_new) + 1, sizeof(tagheader.Timestamp));
#endif
//TagData + Previous Tag Size
//写一个tag，包含：prev tag size(4 byte), tagheader, tagdata
int data_size=reverse_bytes((byte *)&tagheader.DataSize, sizeof(tagheader.DataSize))+4;// tagdata + prevtagsize长度
if(output_v!=0){
//TagHeader
fwrite((char *)&tagheader,1, sizeof(tagheader),vfh);
//TagData
for (int i=0; i<data_size; i++)
fputc(fgetc(ifh),vfh);
}else{
for (int i=0; i<data_size; i++)
fgetc(ifh);
}
//rewind 4 bytes, because we need to read the previoustagsize again for the loop's sake
//每个循环的开始都会读掉pretagsize的4个字节
fseek(ifh, -4, SEEK_CUR);
break;
}
default:
//skip the data of this tag
fseek(ifh, reverse_bytes((byte *)&tagheader.DataSize, sizeof(tagheader.DataSize)), SEEK_CUR);
}
fprintf(myout,"\n");
} while (!feof(ifh));
fcloseall();
return 0;
}
main.cpp
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
/**
* Analysis H.264 Bitstream
* @param url Location of input H.264 bitstream file.
*/
int simplest_h264_parser(char *url);
/**
* Analysis FLV file
* @param url Location of input FLV file.
*/
int simplest_flv_parser(char *url);
/**
* Analysis AAC file
* @param url Location of input AAC file.
*/
int simplest_aac_parser(char *url);
/**
* Analysis RTP stream
* @param url RTP URL
*/
int simplest_udp_parser(int port);
/**
* Generate RGB24 colorbar.
* @param width Width of Output RGB file.
* @param height Height of Output RGB file.
* @param url_out Location of Output RGB file.
*/
int simplest_rgb24_colorbar(int width, int height,char *url_out);
/**
* Convert RGB24 file to BMP file
* @param rgb24path Location of input RGB file.
* @param width Width of input RGB file.
* @param height Height of input RGB file.
* @param url_out Location of Output BMP file.
*/
int simplest_rgb24_to_bmp(const char *rgb24path,int width,int height,const char *bmppath);
/**
* Split R, G, B planes in RGB24 file.
* @param url Location of Input RGB file.
* @param w Width of Input RGB file.
* @param h Height of Input RGB file.
* @param num Number of frames to process.
*
*/
int simplest_rgb24_split(char *url, int w, int h,int num);
/**
* Convert RGB24 file to YUV420P file
* @param url_in Location of Input RGB file.
* @param w Width of Input RGB file.
* @param h Height of Input RGB file.
* @param num Number of frames to process.
* @param url_out Location of Output YUV file.
*/
int simplest_rgb24_to_yuv420(char *url_in, int w, int h,int num,char *url_out);
/**
* Generate YUV420P gray scale bar.
* @param width Width of Output YUV file.
* @param height Height of Output YUV file.
* @param ymin Max value of Y
* @param ymax Min value of Y
* @param barnum Number of bars
* @param url_out Location of Output YUV file.
*/
int simplest_yuv420_graybar(int width, int height,int ymin,int ymax,int barnum,char *url_out);
/**
* Convert YUV420P file to gray picture
* @param url Location of Input YUV file.
* @param w Width of Input YUV file.
* @param h Height of Input YUV file.
* @param num Number of frames to process.
*/
int simplest_yuv420_gray(char *url, int w, int h,int num);
/**
* Split Y, U, V planes in YUV420P file.
* @param url Location of Input YUV file.
* @param w Width of Input YUV file.
* @param h Height of Input YUV file.
* @param num Number of frames to process.
*
*/
int simplest_yuv420_split(char *url, int w, int h,int num);
/**
* Halve Y value of YUV420P file
* @param url Location of Input YUV file.
* @param w Width of Input YUV file.
* @param h Height of Input YUV file.
* @param num Number of frames to process.
*/
int simplest_yuv420_halfy(char *url, int w, int h,int num);
/**
* Add border for YUV420P file
* @param url Location of Input YUV file.
* @param w Width of Input YUV file.
* @param h Height of Input YUV file.
* @param border Width of Border.
* @param num Number of frames to process.
*/
int simplest_yuv420_border(char *url, int w, int h,int border,int num);
/**
* Calculate PSNR between 2 YUV420P file
* @param url1 Location of first Input YUV file.
* @param url2 Location of another Input YUV file.
* @param w Width of Input YUV file.
* @param h Height of Input YUV file.
* @param num Number of frames to process.
*/
int simplest_yuv420_psnr(char *url1,char *url2,int w,int h,int num);
/**
* Split Y, U, V planes in YUV444P file.
* @param url Location of YUV file.
* @param w Width of Input YUV file.
* @param h Height of Input YUV file.
* @param num Number of frames to process.
*
*/
int simplest_yuv444_split(char *url, int w, int h,int num);
/**
* Cut a 16LE PCM single channel file.
* @param url Location of PCM file.
* @param start_num start point
* @param dur_num how much point to cut
*/
int simplest_pcm16le_cut_singlechannel(char *url,int start_num,int dur_num);
/**
* Split Left and Right channel of 16LE PCM file.
* @param url Location of PCM file.
*
*/
int simplest_pcm16le_split(char *url);
/**
* Halve volume of Left channel of 16LE PCM file
* @param url Location of PCM file.
*/
int simplest_pcm16le_halfvolumeleft(char *url);
/**
* Re-sample to double the speed of 16LE PCM file
* @param url Location of PCM file.
*/
int simplest_pcm16le_doublespeed(char *url);
/**
* Convert PCM-16 data to PCM-8 data.
* @param url Location of PCM file.
*/
int simplest_pcm16le_to_pcm8(char *url);
/**
* Convert PCM16LE raw data to WAVE format
* @param pcmpath Input PCM file.
* @param channels Channel number of PCM file.
* @param sample_rate Sample rate of PCM file.
* @param wavepath Output WAVE file.
*/
int simplest_pcm16le_to_wave(const char *pcmpath,int channels,int sample_rate,const char *wavepath);
int main(int argc, char* argv[]){
//Test
// simplest_yuv420_split("lena_256x256_yuv420p.yuv",256,256,1);
// simplest_yuv444_split("lena_256x256_yuv444p.yuv",256,256,1);
// simplest_yuv420_halfy("lena_256x256_yuv420p.yuv",256,256,1);
// simplest_yuv420_gray("lena_256x256_yuv420p.yuv",256,256,1);
// simplest_yuv420_border("lena_256x256_yuv420p.yuv",256,256,20,1);
// simplest_yuv420_graybar(640, 360,0,255,10,"graybar_640x360.yuv");
// simplest_yuv420_psnr("lena_256x256_yuv420p.yuv","lena_distort_256x256_yuv420p.yuv",256,256,1);
// simplest_rgb24_split("cie1931_500x500.rgb", 500, 500,1);
// simplest_rgb24_to_bmp("lena_256x256_rgb24.rgb",256,256,"output_lena.bmp");
// simplest_rgb24_to_yuv420("lena_256x256_rgb24.rgb",256,256,1,"output_lena.yuv");
// simplest_rgb24_colorbar(640, 360,"colorbar_640x360.rgb");
// simplest_pcm16le_split("NocturneNo2inEflat_44.1k_s16le.pcm");
// simplest_pcm16le_halfvolumeleft("NocturneNo2inEflat_44.1k_s16le.pcm");
// simplest_pcm16le_doublespeed("NocturneNo2inEflat_44.1k_s16le.pcm");
// simplest_pcm16le_to_pcm8("NocturneNo2inEflat_44.1k_s16le.pcm");
// simplest_pcm16le_cut_singlechannel("drum.pcm",2360,120);
// simplest_pcm16le_to_wave("NocturneNo2inEflat_44.1k_s16le.pcm",2,44100,"output_nocturne.wav");
// simplest_h264_parser("sintel.h264");
simplest_flv_parser("cuc_ieschool.flv");
// simplest_aac_parser("nocturne.aac");
// simplest_udp_parser(8880);
return 0;
}
编译运行
g++ -c flv.cpp
g++ -c main.cpp
g++ flv.o main.o -o test
./test
