Tasmota/lib/libesp32/rtsp/CStreamer.cpp

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#include "CStreamer.h"
#include <stdio.h>
//#define STREAM_DEBUG
CStreamer::CStreamer(SOCKET aClient, u_short width, u_short height) : m_Client(aClient)
{
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// printf("Creating TSP streamer\n");
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m_RtpServerPort = 0;
m_RtcpServerPort = 0;
m_RtpClientPort = 0;
m_RtcpClientPort = 0;
m_SequenceNumber = 0;
m_Timestamp = 0;
m_SendIdx = 0;
m_TCPTransport = false;
m_RtpSocket = NULLSOCKET;
m_RtcpSocket = NULLSOCKET;
m_width = width;
m_height = height;
m_prevMsec = 0;
};
CStreamer::~CStreamer()
{
udpsocketclose(m_RtpSocket);
udpsocketclose(m_RtcpSocket);
};
int CStreamer::SendRtpPacket(unsigned const char * jpeg, int jpegLen, int fragmentOffset, BufPtr quant0tbl, BufPtr quant1tbl)
{
#define KRtpHeaderSize 12 // size of the RTP header
#define KJpegHeaderSize 8 // size of the special JPEG payload header
#define MAX_FRAGMENT_SIZE 1100 // FIXME, pick more carefully
int fragmentLen = MAX_FRAGMENT_SIZE;
if(fragmentLen + fragmentOffset > jpegLen) // Shrink last fragment if needed
fragmentLen = jpegLen - fragmentOffset;
bool isLastFragment = (fragmentOffset + fragmentLen) == jpegLen;
// Do we have custom quant tables? If so include them per RFC
bool includeQuantTbl = quant0tbl && quant1tbl && fragmentOffset == 0;
uint8_t q = includeQuantTbl ? 128 : 0x5e;
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//static char RtpBuf[2048]; // Note: we assume single threaded, this large buf we keep off of the tiny stack
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int RtpPacketSize = fragmentLen + KRtpHeaderSize + KJpegHeaderSize + (includeQuantTbl ? (4 + 64 * 2) : 0);
memset(RtpBuf,0x00,sizeof(RtpBuf));
// Prepare the first 4 byte of the packet. This is the Rtp over Rtsp header in case of TCP based transport
RtpBuf[0] = '$'; // magic number
RtpBuf[1] = 0; // number of multiplexed subchannel on RTPS connection - here the RTP channel
RtpBuf[2] = (RtpPacketSize & 0x0000FF00) >> 8;
RtpBuf[3] = (RtpPacketSize & 0x000000FF);
// Prepare the 12 byte RTP header
RtpBuf[4] = 0x80; // RTP version
RtpBuf[5] = 0x1a | (isLastFragment ? 0x80 : 0x00); // JPEG payload (26) and marker bit
RtpBuf[7] = m_SequenceNumber & 0x0FF; // each packet is counted with a sequence counter
RtpBuf[6] = m_SequenceNumber >> 8;
RtpBuf[8] = (m_Timestamp & 0xFF000000) >> 24; // each image gets a timestamp
RtpBuf[9] = (m_Timestamp & 0x00FF0000) >> 16;
RtpBuf[10] = (m_Timestamp & 0x0000FF00) >> 8;
RtpBuf[11] = (m_Timestamp & 0x000000FF);
RtpBuf[12] = 0x13; // 4 byte SSRC (sychronization source identifier)
RtpBuf[13] = 0xf9; // we just an arbitrary number here to keep it simple
RtpBuf[14] = 0x7e;
RtpBuf[15] = 0x67;
// Prepare the 8 byte payload JPEG header
RtpBuf[16] = 0x00; // type specific
RtpBuf[17] = (fragmentOffset & 0x00FF0000) >> 16; // 3 byte fragmentation offset for fragmented images
RtpBuf[18] = (fragmentOffset & 0x0000FF00) >> 8;
RtpBuf[19] = (fragmentOffset & 0x000000FF);
/* These sampling factors indicate that the chrominance components of
type 0 video is downsampled horizontally by 2 (often called 4:2:2)
while the chrominance components of type 1 video are downsampled both
horizontally and vertically by 2 (often called 4:2:0). */
RtpBuf[20] = 0x00; // type (fixme might be wrong for camera data) https://tools.ietf.org/html/rfc2435
RtpBuf[21] = q; // quality scale factor was 0x5e
RtpBuf[22] = m_width / 8; // width / 8
RtpBuf[23] = m_height / 8; // height / 8
int headerLen = 24; // Inlcuding jpeg header but not qant table header
if(includeQuantTbl) { // we need a quant header - but only in first packet of the frame
//printf("inserting quanttbl\n");
RtpBuf[24] = 0; // MBZ
RtpBuf[25] = 0; // 8 bit precision
RtpBuf[26] = 0; // MSB of lentgh
int numQantBytes = 64; // Two 64 byte tables
RtpBuf[27] = 2 * numQantBytes; // LSB of length
headerLen += 4;
memcpy(RtpBuf + headerLen, quant0tbl, numQantBytes);
headerLen += numQantBytes;
memcpy(RtpBuf + headerLen, quant1tbl, numQantBytes);
headerLen += numQantBytes;
}
// printf("Sending timestamp %d, seq %d, fragoff %d, fraglen %d, jpegLen %d\n", m_Timestamp, m_SequenceNumber, fragmentOffset, fragmentLen, jpegLen);
// append the JPEG scan data to the RTP buffer
memcpy(RtpBuf + headerLen,jpeg + fragmentOffset, fragmentLen);
fragmentOffset += fragmentLen;
m_SequenceNumber++; // prepare the packet counter for the next packet
IPADDRESS otherip;
IPPORT otherport;
socketpeeraddr(m_Client, &otherip, &otherport);
// RTP marker bit must be set on last fragment
if (m_TCPTransport) // RTP over RTSP - we send the buffer + 4 byte additional header
socketsend(m_Client,RtpBuf,RtpPacketSize + 4);
else // UDP - we send just the buffer by skipping the 4 byte RTP over RTSP header
udpsocketsend(m_RtpSocket,&RtpBuf[4],RtpPacketSize, otherip, m_RtpClientPort);
return isLastFragment ? 0 : fragmentOffset;
};
void CStreamer::InitTransport(u_short aRtpPort, u_short aRtcpPort, bool TCP)
{
m_RtpClientPort = aRtpPort;
m_RtcpClientPort = aRtcpPort;
m_TCPTransport = TCP;
if (!m_TCPTransport)
{ // allocate port pairs for RTP/RTCP ports in UDP transport mode
for (u_short P = 6970; P < 0xFFFE; P += 2)
{
m_RtpSocket = udpsocketcreate(P);
if (m_RtpSocket)
{ // Rtp socket was bound successfully. Lets try to bind the consecutive Rtsp socket
m_RtcpSocket = udpsocketcreate(P + 1);
if (m_RtcpSocket)
{
m_RtpServerPort = P;
m_RtcpServerPort = P+1;
break;
}
else
{
udpsocketclose(m_RtpSocket);
udpsocketclose(m_RtcpSocket);
};
}
};
};
};
u_short CStreamer::GetRtpServerPort()
{
return m_RtpServerPort;
};
u_short CStreamer::GetRtcpServerPort()
{
return m_RtcpServerPort;
};
void CStreamer::streamFrame(unsigned const char *data, uint32_t dataLen, uint32_t curMsec)
{
if(m_prevMsec == 0) // first frame init our timestamp
m_prevMsec = curMsec;
// compute deltat (being careful to handle clock rollover with a little lie)
uint32_t deltams = (curMsec >= m_prevMsec) ? curMsec - m_prevMsec : 100;
m_prevMsec = curMsec;
// locate quant tables if possible
BufPtr qtable0, qtable1;
if (!decodeJPEGfile(&data, &dataLen, &qtable0, &qtable1)) {
#ifdef STREAM_DEBUG
printf("can't decode jpeg data\n");
#endif
return;
}
int offset = 0;
do {
offset = SendRtpPacket(data, dataLen, offset, qtable0, qtable1);
} while(offset != 0);
// Increment ONLY after a full frame
uint32_t units = 90000; // Hz per RFC 2435
m_Timestamp += (units * deltams / 1000); // fixed timestamp increment for a frame rate of 25fps
m_SendIdx++;
if (m_SendIdx > 1) m_SendIdx = 0;
#ifdef STREAM_DEBUG
printf("frame sent\n");
#endif
};
#include <assert.h>
// search for a particular JPEG marker, moves *start to just after that marker
// This function fixes up the provided start ptr to point to the
// actual JPEG stream data and returns the number of bytes skipped
// APP0 e0
// DQT db
// DQT db
// DHT c4
// DHT c4
// DHT c4
// DHT c4
// SOF0 c0 baseline (not progressive) 3 color 0x01 Y, 0x21 2h1v, 0x00 tbl0
// - 0x02 Cb, 0x11 1h1v, 0x01 tbl1 - 0x03 Cr, 0x11 1h1v, 0x01 tbl1
// therefore 4:2:2, with two separate quant tables (0 and 1)
// SOS da
// EOI d9 (no need to strip data after this RFC says client will discard)
bool findJPEGheader(BufPtr *start, uint32_t *len, uint8_t marker) {
// per https://en.wikipedia.org/wiki/JPEG_File_Interchange_Format
unsigned const char *bytes = *start;
// kinda skanky, will break if unlucky and the headers inxlucde 0xffda
// might fall off array if jpeg is invalid
// FIXME - return false instead
while(bytes - *start < *len) {
uint8_t framing = *bytes++; // better be 0xff
if(framing != 0xff) {
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// printf("malformed jpeg, framing=%x\n", framing);
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return false;
}
uint8_t typecode = *bytes++;
if(typecode == marker) {
unsigned skipped = bytes - *start;
//printf("found marker 0x%x, skipped %d\n", marker, skipped);
*start = bytes;
// shrink len for the bytes we just skipped
*len -= skipped;
return true;
}
else {
// not the section we were looking for, skip the entire section
switch(typecode) {
case 0xd8: // start of image
{
break; // no data to skip
}
case 0xe0: // app0
case 0xdb: // dqt
case 0xc4: // dht
case 0xc0: // sof0
case 0xda: // sos
{
// standard format section with 2 bytes for len. skip that many bytes
uint32_t len = bytes[0] * 256 + bytes[1];
//printf("skipping section 0x%x, %d bytes\n", typecode, len);
bytes += len;
break;
}
default:
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// printf("unexpected jpeg typecode 0x%x\n", typecode);
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break;
}
}
}
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// printf("failed to find jpeg marker 0x%x", marker);
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return false;
}
// the scan data uses byte stuffing to guarantee anything that starts with 0xff
// followed by something not zero, is a new section. Look for that marker and return the ptr
// pointing there
void skipScanBytes(BufPtr *start) {
BufPtr bytes = *start;
while(true) { // FIXME, check against length
while(*bytes++ != 0xff);
if(*bytes++ != 0) {
*start = bytes - 2; // back up to the 0xff marker we just found
return;
}
}
}
void nextJpegBlock(BufPtr *bytes) {
uint32_t len = (*bytes)[0] * 256 + (*bytes)[1];
//printf("going to next jpeg block %d bytes\n", len);
*bytes += len;
}
// When JPEG is stored as a file it is wrapped in a container
// This function fixes up the provided start ptr to point to the
// actual JPEG stream data and returns the number of bytes skipped
bool decodeJPEGfile(BufPtr *start, uint32_t *len, BufPtr *qtable0, BufPtr *qtable1) {
// per https://en.wikipedia.org/wiki/JPEG_File_Interchange_Format
unsigned const char *bytes = *start;
if(!findJPEGheader(&bytes, len, 0xd8)) // better at least look like a jpeg file
return false; // FAILED!
// Look for quant tables if they are present
*qtable0 = NULL;
*qtable1 = NULL;
BufPtr quantstart = *start;
uint32_t quantlen = *len;
if(!findJPEGheader(&quantstart, &quantlen, 0xdb)) {
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// printf("error can't find quant table 0\n");
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}
else {
// printf("found quant table %x\n", quantstart[2]);
*qtable0 = quantstart + 3; // 3 bytes of header skipped
nextJpegBlock(&quantstart);
if(!findJPEGheader(&quantstart, &quantlen, 0xdb)) {
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// printf("error can't find quant table 1\n");
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}
else {
// printf("found quant table %x\n", quantstart[2]);
}
*qtable1 = quantstart + 3;
nextJpegBlock(&quantstart);
}
if(!findJPEGheader(start, len, 0xda))
return false; // FAILED!
// Skip the header bytes of the SOS marker FIXME why doesn't this work?
uint32_t soslen = (*start)[0] * 256 + (*start)[1];
*start += soslen;
*len -= soslen;
// start scanning the data portion of the scan to find the end marker
BufPtr endmarkerptr = *start;
uint32_t endlen = *len;
skipScanBytes(&endmarkerptr);
if(!findJPEGheader(&endmarkerptr, &endlen, 0xd9))
return false; // FAILED!
// endlen must now be the # of bytes between the start of our scan and
// the end marker, tell the caller to ignore bytes afterwards
*len = endmarkerptr - *start;
return true;
}