我有点新，还在学习socket和RTP的东西。基本上，我想编写一个程序，可以使用UDP协议通过RTP发送jpeg（最终将是mjpeg）。
我有UDP程序，能够使用openCV发送文件或流到本地地址（127.0.0.1）。好。所以这不是问题。
然而，当我尝试从openCV传递通过VideoCapture捕获的帧时，它不会工作。或者更确切地说，我不知道如何做到这一点。
所以现在，我想打破这个问题并决定只在RTP端进行测试。
因为你可以在我的主函数中看到，我试图测试函数，但它看起来不像它的工作原理。
有人能指出我如何正确测试这些功能的正确方向，特别是sendFrame吗？ 此代码主要只是从RFC2435文档中复制和粘贴。
由于
`/*
* Table K.1 from JPEG spec.
*/
static const int jpeg_luma_quantizer[64] = {
16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77,
24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101,
72, 92, 95, 98, 112, 100, 103, 99
};
`
/*
* Table K.2 from JPEG spec.
*/
static const int jpeg_chroma_quantizer[64] = {
17, 18, 24, 47, 99, 99, 99, 99,
18, 21, 26, 66, 99, 99, 99, 99,
24, 26, 56, 99, 99, 99, 99, 99,
47, 66, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
};
int main(int argc, char * argv[]) {
//setup openCV
cvNamedWindow("UDP Video Sender", CV_WINDOW_AUTOSIZE);
CvCapture* capture = cvCreateCameraCapture(0);
if(!capture){
std::cout<<"No camera found."<< std::endl;
goto DONE;
}
IplImage *frame;
frame = cvQueryFrame(capture);
IplImage *small = cvCreateImage(cvSize(frame->width / 2, frame->height / 2),
frame->depth, 3);
while(1){
//capture frame and resize
frame = cvQueryFrame(capture);
cvResize(frame, small, CV_INTER_LINEAR);
cvShowImage("UDP Video Sender", small);
//MakeHeaders(filename,0,5,5,0,128,0);
//MakeTables(128,frame,0);
//MakeDRIHeader();
// MakeHuffmanHeader();
MakeHuffmanHeader(128,1024,1024,uchar *lum_ac_symbols[],1024,1,1 );
//MakeQuantHeader();
DONE:
cout<<"Press any key to continue."<<endl;
}
}
/*
* Call MakeTables with the Q factor and two u_char[64] return arrays
*/
void
MakeTables(int q, u_char *lqt, u_char *cqt)
{
int i;
int factor = q;
if (q < 1) factor = 1;
if (q > 99) factor = 99;
if (q < 50)
q = 5000 / factor;
else
q = 200 - factor*2;
for (i=0; i < 64; i++) {
int lq = (jpeg_luma_quantizer[i] * q + 50) / 100;
int cq = (jpeg_chroma_quantizer[i] * q + 50) / 100;
/* Limit the quantizers to 1 <= q <= 255 */
if (lq < 1) lq = 1;
else if (lq > 255) lq = 255;
lqt[i] = lq;
if (cq < 1) cq = 1;
else if (cq > 255) cq = 255;
cqt[i] = cq;
}
}
/**The following routines can be used to create the JPEG marker segments
corresponding to the table-specification data that is absent from the
RTP/JPEG body.
*/
u_char lum_dc_codelens[] = {
0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
};
u_char lum_dc_symbols[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
};
u_char lum_ac_codelens[] = {
0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d,
};
u_char lum_ac_symbols[] = {
0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa,
};
u_char chm_dc_codelens[] = {
0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
};
u_char chm_dc_symbols[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
};
u_char chm_ac_codelens[] = {
0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77,
};
u_char chm_ac_symbols[] = {
0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa,
};
u_char *
MakeQuantHeader(u_char *p, u_char *qt, int tableNo)
{
*p++ = 0xff;
*p++ = 0xdb; /* DQT */
*p++ = 0; /* length msb */
*p++ = 67; /* length lsb */
*p++ = tableNo;
memcpy(p, qt, 64);
return (p + 64);
}
u_char *
MakeHuffmanHeader(u_char *p, u_char *codelens, int ncodes,
u_char *symbols, int nsymbols, int tableNo,
int tableClass)
{
*p++ = 0xff;
*p++ = 0xc4; /* DHT */
*p++ = 0; /* length msb */
*p++ = 3 + ncodes + nsymbols; /* length lsb */
*p++ = (tableClass << 4) | tableNo;
memcpy(p, codelens, ncodes);
p += ncodes;
memcpy(p, symbols, nsymbols);
p += nsymbols;
return (p);
}
u_char *
MakeDRIHeader(u_char *p, u_short dri) {
*p++ = 0xff;
*p++ = 0xdd; /* DRI */
*p++ = 0x0; /* length msb */
*p++ = 4; /* length lsb */
*p++ = dri >> 8; /* dri msb */
*p++ = dri & 0xff; /* dri lsb */
return (p);
}
/*
* Arguments:
* type, width, height: as supplied in RTP/JPEG header
* lqt, cqt: quantization tables as either derived from
* the Q field using MakeTables() or as specified
* in section 4.2.
* dri: restart interval in MCUs, or 0 if no restarts.
*
* p: pointer to return area
*
* Return value:
* The length of the generated headers.
*
* Generate a frame and scan headers that can be prepended to the
* RTP/JPEG data payload to produce a JPEG compressed image in
* interchange format (except for possible trailing garbage and
* absence of an EOI marker to terminate the scan).
*/
int MakeHeaders(u_char *p, int type, int w, int h, u_char *lqt,
u_char *cqt, u_short dri)
{
u_char *start = p;
/* convert from blocks to pixels */
w <<= 3;
h <<= 3;
*p++ = 0xff;
*p++ = 0xd8; /* SOI */
p = MakeQuantHeader(p, lqt, 0);
p = MakeQuantHeader(p, cqt, 1);
if (dri != 0)
p = MakeDRIHeader(p, dri);
*p++ = 0xff;
*p++ = 0xc0; /* SOF */
*p++ = 0; /* length msb */
*p++ = 17; /* length lsb */
*p++ = 8; /* 8-bit precision */
*p++ = h >> 8; /* height msb */
*p++ = h; /* height lsb */
*p++ = w >> 8; /* width msb */
*p++ = w; /* wudth lsb */
*p++ = 3; /* number of components */
*p++ = 0; /* comp 0 */
if (type == 0)
*p++ = 0x21; /* hsamp = 2, vsamp = 1 */
else
*p++ = 0x22; /* hsamp = 2, vsamp = 2 */
*p++ = 0; /* quant table 0 */
*p++ = 1; /* comp 1 */
*p++ = 0x11; /* hsamp = 1, vsamp = 1 */
*p++ = 1; /* quant table 1 */
*p++ = 2; /* comp 2 */
*p++ = 0x11; /* hsamp = 1, vsamp = 1 */
*p++ = 1; /* quant table 1 */
p = MakeHuffmanHeader(p, lum_dc_codelens,
sizeof(lum_dc_codelens),
lum_dc_symbols,
sizeof(lum_dc_symbols), 0, 0);
p = MakeHuffmanHeader(p, lum_ac_codelens,
sizeof(lum_ac_codelens),
lum_ac_symbols,
sizeof(lum_ac_symbols), 0, 1);
p = MakeHuffmanHeader(p, chm_dc_codelens,
sizeof(chm_dc_codelens),
chm_dc_symbols,
sizeof(chm_dc_symbols), 1, 0);
p = MakeHuffmanHeader(p, chm_ac_codelens,
sizeof(chm_ac_codelens),
chm_ac_symbols,
sizeof(chm_ac_symbols), 1, 1);
*p++ = 0xff;
*p++ = 0xda; /* SOS */
*p++ = 0; /* length msb */
*p++ = 12; /* length lsb */
*p++ = 3; /* 3 components */
*p++ = 0; /* comp 0 */
*p++ = 0; /* huffman table 0 */
*p++ = 1; /* comp 1 */
*p++ = 0x11; /* huffman table 1 */
*p++ = 2; /* comp 2 */
*p++ = 0x11; /* huffman table 1 */
*p++ = 0; /* first DCT coeff */
*p++ = 63; /* last DCT coeff */
*p++ = 0; /* sucessive approx. */
return (p - start);
};
/*
* RTP data header from RFC1889
*/
typedef struct {
unsigned int version:2; /* protocol version */
unsigned int p:1; /* padding flag */
unsigned int x:1; /* header extension flag */
unsigned int cc:4; /* CSRC count */
unsigned int m:1; /* marker bit */
unsigned int pt:7; /* payload type */
u_int16_t seq; /* sequence number */
u_int32_t ts; /* timestamp */
u_int32_t ssrc; /* synchronization source */
u_int32_t csrc[1]; /* optional CSRC list */
} rtp_hdr_t;
#define RTP_HDR_SZ 12
/* The following definition is from RFC1890 */
#define RTP_PT_JPEG 26
struct jpeghdr {
unsigned int tspec:8; /* type-specific field */
unsigned int off:24; /* fragment byte offset */
u_int8_t type; /* id of jpeg decoder params */
u_int8_t q; /* quantization factor (or table id) */
u_int8_t width; /* frame width in 8 pixel blocks */
u_int8_t height; /* frame height in 8 pixel blocks */
};
struct jpeghdr_rst {
u_int16_t dri;
unsigned int f:1;
unsigned int l:1;
unsigned int count:14;
};
struct jpeghdr_qtable {
u_int8_t mbz;
u_int8_t precision;
u_int16_t length;
};
#define RTP_JPEG_RESTART 0x40
/* Procedure SendFrame:
*
* Arguments:
* start_seq: The sequence number for the first packet of the current
* frame.
* ts: RTP timestamp for the current frame
* ssrc: RTP SSRC value
* jpeg_data: Huffman encoded JPEG scan data
* len: Length of the JPEG scan data
* type: The value the RTP/JPEG type field should be set to
* typespec: The value the RTP/JPEG type-specific field should be set
* to
* width: The width in pixels of the JPEG image
* height: The height in pixels of the JPEG image
* dri: The number of MCUs between restart markers (or 0 if there
* are no restart markers in the data
* q: The Q factor of the data, to be specified using the Independent
* JPEG group's algorithm if 1 <= q <= 99, specified explicitly
* with lqt and cqt if q >= 128, or undefined otherwise.
* lqt: The quantization table for the luminance channel if q >= 128
* cqt: The quantization table for the chrominance channels if
* q >= 128
*
* Return value:
* the sequence number to be sent for the first packet of the next
* frame.
*
* The following are assumed to be defined:
*
* PACKET_SIZE - The size of the outgoing packet
* send_packet(u_int8_t *data, int len) - Sends the packet to the network
*/
#define PACKET_SIZE 512
u_int16_t SendFrame(u_int16_t start_seq, u_int32_t ts, u_int32_t ssrc,
u_int8_t *jpeg_data, int len, u_int8_t type,
u_int8_t typespec, int width, int height, int dri,
u_int8_t q, u_int8_t *lqt, u_int8_t *cqt) {
rtp_hdr_t rtphdr;
struct jpeghdr jpghdr;
struct jpeghdr_rst rsthdr;
struct jpeghdr_qtable qtblhdr;
u_int8_t packet_buf[PACKET_SIZE];
u_int8_t *ptr;
int bytes_left = len;
int seq = start_seq;
int pkt_len, data_len;
/* Initialize RTP header
*/
rtphdr.version = 2;
rtphdr.p = 0;
rtphdr.x = 0;
rtphdr.cc = 0;
rtphdr.m = 0;
rtphdr.pt = RTP_PT_JPEG;
rtphdr.seq = start_seq;
rtphdr.ts = ts;
rtphdr.ssrc = ssrc;
/* Initialize JPEG header
*/
jpghdr.tspec = typespec;
jpghdr.off = 0;
jpghdr.type = type | ((dri != 0) ? RTP_JPEG_RESTART : 0);
jpghdr.q = q;
jpghdr.width = width / 8;
jpghdr.height = height / 8;
/* Initialize DRI header
*/
if (dri != 0) {
rsthdr.dri = dri;
rsthdr.f = 1; /* This code does not align RIs */
rsthdr.l = 1;
rsthdr.count = 0x3fff;
}
/* Initialize quantization table header
*/
if (q >= 128) {
qtblhdr.mbz = 0;
qtblhdr.precision = 0; /* This code uses 8 bit tables only */
qtblhdr.length = 128; /* 2 64-byte tables */
}
while (bytes_left > 0) {
ptr = packet_buf + RTP_HDR_SZ;
jpghdr.off = htonl(jpghdr.off);
/*convert offset in hdr to network order, copy to packet*/
memcpy(ptr, &jpghdr, sizeof(jpghdr));
jpghdr.off = ntohl(jpghdr.off);
ptr += sizeof(jpghdr);
data_len = PACKET_SIZE - (ptr - packet_buf);
if (data_len >= bytes_left) {
data_len = bytes_left;
rtphdr.m = 1;
}
rtphdr.seq = htons(rtphdr.seq);
memcpy(packet_buf, &rtphdr, RTP_HDR_SZ);
memcpy(ptr, jpeg_data + jpghdr.off, data_len);
if(((ptr-packet_buf)+data_len) &&
send(sock[0], packet_buf, (ptr - packet_buf) + data_len, 0)<0)
perror("hre");
jpghdr.off += data_len;
bytes_left -= data_len;
rtphdr.seq = ntohs(rtphdr.seq);
rtphdr.seq++;
}
free(packet_buf);
return rtphdr.seq;
}