decode message header

trunk/src/core/srs_core_error.hpp

@@ -50,5 +50,6 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SOCKET_WRITE				209
 
 #define ERROR_RTMP_PLAIN_REQUIRED		300
+#define ERROR_RTMP_CHUNK_START			301
 
 #endif

trunk/src/core/srs_core_protocol.cpp

@@ -28,6 +28,71 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_core_socket.hpp>
 #include <srs_core_buffer.hpp>
 
+/**
+* 6.1.2. Chunk Message Header
+* There are four different formats for the chunk message header,
+* selected by the "fmt" field in the chunk basic header.
+*/
+// 6.1.2.1. Type 0
+// Chunks of Type 0 are 11 bytes long. This type MUST be used at the
+// start of a chunk stream, and whenever the stream timestamp goes
+// backward (e.g., because of a backward seek).
+#define RTMP_FMT_TYPE0 0
+// 6.1.2.2. Type 1
+// Chunks of Type 1 are 7 bytes long. The message stream ID is not
+// included; this chunk takes the same stream ID as the preceding chunk.
+// Streams with variable-sized messages (for example, many video
+// formats) SHOULD use this format for the first chunk of each new
+// message after the first.
+#define RTMP_FMT_TYPE1 1
+// 6.1.2.3. Type 2
+// Chunks of Type 2 are 3 bytes long. Neither the stream ID nor the
+// message length is included; this chunk has the same stream ID and
+// message length as the preceding chunk. Streams with constant-sized
+// messages (for example, some audio and data formats) SHOULD use this
+// format for the first chunk of each message after the first.
+#define RTMP_FMT_TYPE2 2
+// 6.1.2.4. Type 3
+// Chunks of Type 3 have no header. Stream ID, message length and
+// timestamp delta are not present; chunks of this type take values from
+// the preceding chunk. When a single message is split into chunks, all
+// chunks of a message except the first one, SHOULD use this type. Refer
+// to example 2 in section 6.2.2. Stream consisting of messages of
+// exactly the same size, stream ID and spacing in time SHOULD use this
+// type for all chunks after chunk of Type 2. Refer to example 1 in
+// section 6.2.1. If the delta between the first message and the second
+// message is same as the time stamp of first message, then chunk of
+// type 3 would immediately follow the chunk of type 0 as there is no
+// need for a chunk of type 2 to register the delta. If Type 3 chunk
+// follows a Type 0 chunk, then timestamp delta for this Type 3 chunk is
+// the same as the timestamp of Type 0 chunk.
+#define RTMP_FMT_TYPE3 3
+
+/**
+* 6. Chunking
+* The chunk size is configurable. It can be set using a control
+* message(Set Chunk Size) as described in section 7.1. The maximum
+* chunk size can be 65536 bytes and minimum 128 bytes. Larger values
+* reduce CPU usage, but also commit to larger writes that can delay
+* other content on lower bandwidth connections. Smaller chunks are not
+* good for high-bit rate streaming. Chunk size is maintained
+* independently for each direction.
+*/
+#define RTMP_DEFAULT_CHUNK_SIZE 128
+
+/**
+* 6.1. Chunk Format
+* Extended timestamp: 0 or 4 bytes
+* This field MUST be sent when the normal timsestamp is set to
+* 0xffffff, it MUST NOT be sent if the normal timestamp is set to
+* anything else. So for values less than 0xffffff the normal
+* timestamp field SHOULD be used in which case the extended timestamp
+* MUST NOT be present. For values greater than or equal to 0xffffff
+* the normal timestamp field MUST NOT be used and MUST be set to
+* 0xffffff and the extended timestamp MUST be sent.
+*/
+#define RTMP_EXTENDED_TIMESTAMP 0xFFFFFF
+
 SrsProtocol::SrsProtocol(st_netfd_t client_stfd)
 {
 	stfd = client_stfd;
@@ -68,12 +133,12 @@ int SrsProtocol::recv_message(SrsMessage** pmsg)
 		// chunk stream basic header.
 		char fmt = 0;
 		int cid = 0;
-		int size = 0;
-		if ((ret = read_basic_header(fmt, cid, size)) != ERROR_SUCCESS) {
+		int bh_size = 0;
+		if ((ret = read_basic_header(fmt, cid, bh_size)) != ERROR_SUCCESS) {
 			srs_error("read basic header failed. ret=%d", ret);
 			return ret;
 		}
-		srs_info("read basic header success. fmt=%d, cid=%d, size=%d", fmt, cid, size);
+		srs_info("read basic header success. fmt=%d, cid=%d, bh_size=%d", fmt, cid, bh_size);
 		
 		// get the cached chunk stream.
 		SrsChunkStream* chunk = NULL;
@@ -89,11 +154,24 @@ int SrsProtocol::recv_message(SrsMessage** pmsg)
 		}
 
 		// chunk stream message header
-		SrsMessage* msg = NULL;
-		if ((ret = read_message_header(chunk, fmt, &msg)) != ERROR_SUCCESS) {
+		int mh_size = 0;
+		if ((ret = read_message_header(chunk, fmt, bh_size, mh_size)) != ERROR_SUCCESS) {
 			srs_error("read message header failed. ret=%d", ret);
 			return ret;
 		}
+		srs_info("read message header success. "
+				"fmt=%d, mh_size=%d, ext_time=%d, message(type=%d, size=%d, time=%d, sid=%d)", 
+				fmt, mh_size, chunk->extended_timestamp, chunk->header.message_type, 
+				chunk->header.payload_length, chunk->header.timestamp, chunk->header.stream_id);
+		
+		// read msg payload from chunk stream.
+		SrsMessage* msg = NULL;
+		/*int payload_size = 0;
+		if ((ret = read_message_payload(chunk, bh_size, mh_size, payload_size, &msg)) != ERROR_SUCCESS) {
+			srs_error("read message payload failed. ret=%d", ret);
+			return ret;
+		}
+		srs_info("read message payload success. payload_size=%d", payload_size);*/
 		
 		// not got an entire RTMP message, try next chunk.
 		if (!msg) {
@@ -111,6 +189,7 @@ int SrsProtocol::read_basic_header(char& fmt, int& cid, int& size)
 	int ret = ERROR_SUCCESS;
 	
 	if ((ret = buffer->ensure_buffer_bytes(skt, 1)) != ERROR_SUCCESS) {
+		srs_error("read 1bytes basic header failed. ret=%d", ret);
 		return ret;
 	}
 	
@@ -121,19 +200,23 @@ int SrsProtocol::read_basic_header(char& fmt, int& cid, int& size)
     size = 1;
     
     if (cid > 1) {
+		srs_verbose("%dbytes basic header parsed. fmt=%d, cid=%d", size, fmt, cid);
         return ret;
     }
 
 	if (cid == 0) {
 		if ((ret = buffer->ensure_buffer_bytes(skt, 2)) != ERROR_SUCCESS) {
+			srs_error("read 2bytes basic header failed. ret=%d", ret);
 			return ret;
 		}
 		
 		cid = 64;
 		cid += *(++p);
     	size = 2;
+		srs_verbose("%dbytes basic header parsed. fmt=%d, cid=%d", size, fmt, cid);
 	} else if (cid == 1) {
 		if ((ret = buffer->ensure_buffer_bytes(skt, 3)) != ERROR_SUCCESS) {
+			srs_error("read 3bytes basic header failed. ret=%d", ret);
 			return ret;
 		}
 		
@@ -141,6 +224,7 @@ int SrsProtocol::read_basic_header(char& fmt, int& cid, int& size)
 		cid += *(++p);
 		cid += *(++p) * 256;
     	size = 3;
+		srs_verbose("%dbytes basic header parsed. fmt=%d, cid=%d", size, fmt, cid);
 	} else {
 		srs_error("invalid path, impossible basic header.");
 		srs_assert(false);
@@ -149,9 +233,105 @@ int SrsProtocol::read_basic_header(char& fmt, int& cid, int& size)
 	return ret;
 }
 
-int SrsProtocol::read_message_header(SrsChunkStream* chunk, char fmt, SrsMessage** pmsg)
+int SrsProtocol::read_message_header(SrsChunkStream* chunk, char fmt, int bh_size, int& mh_size)
 {
 	int ret = ERROR_SUCCESS;
+	
+	// when not exists cached msg, means get an new message,
+	// the fmt must be type0 which means new message.
+	if (!chunk->msg && fmt != RTMP_FMT_TYPE0) {
+		ret = ERROR_RTMP_CHUNK_START;
+		srs_error("chunk stream start, "
+			"fmt must be %d, actual is %d. ret=%d", RTMP_FMT_TYPE0, fmt, ret);
+		return ret;
+	}
+
+	// when exists cache msg, means got an partial message,
+	// the fmt must not be type0 which means new message.
+	if (chunk->msg && fmt == RTMP_FMT_TYPE0) {
+		ret = ERROR_RTMP_CHUNK_START;
+		srs_error("chunk stream exists, "
+			"fmt must not be %d, actual is %d. ret=%d", RTMP_FMT_TYPE0, fmt, ret);
+		return ret;
+	}
+	
+	// create msg when new chunk stream start
+	if (!chunk->msg) {
+		srs_assert(fmt == RTMP_FMT_TYPE0);
+		chunk->msg = new SrsMessage();
+		srs_verbose("create message for new chunk, fmt=%d, cid=%d", fmt, chunk->cid);
+	}
+
+	// read message header from socket to buffer.
+	static char mh_sizes[] = {11, 7, 1, 0};
+	mh_size = mh_sizes[(int)fmt];
+	srs_verbose("calc chunk message header size. fmt=%d, mh_size=%d", fmt, mh_size);
+	
+	if ((ret = buffer->ensure_buffer_bytes(skt, bh_size + mh_size)) != ERROR_SUCCESS) {
+		srs_error("read %dbytes message header failed. ret=%d", mh_size, ret);
+		return ret;
+	}
+	char* p = buffer->bytes() + bh_size;
+	
+	// parse the message header.
+	// see also: ngx_rtmp_recv
+	if (fmt <= 2) {
+        char* pp = (char*)&chunk->header.timestamp;
+        pp[2] = *p++;
+        pp[1] = *p++;
+        pp[0] = *p++;
+        pp[3] = 0;
+        
+        chunk->extended_timestamp = (chunk->header.timestamp == RTMP_EXTENDED_TIMESTAMP);
+        
+        if (fmt <= 1) {
+            pp = (char*)&chunk->header.payload_length;
+            pp[2] = *p++;
+            pp[1] = *p++;
+            pp[0] = *p++;
+            pp[3] = 0;
+            
+            chunk->header.message_type = *p++;
+            
+            if (fmt == 0) {
+                pp = (char*)&chunk->header.stream_id;
+                pp[0] = *p++;
+                pp[1] = *p++;
+                pp[2] = *p++;
+                pp[3] = *p++;
+				srs_verbose("header read completed. fmt=%d, mh_size=%d, ext_time=%d, time=%d, payload=%d, type=%d, sid=%d", 
+					fmt, mh_size, chunk->extended_timestamp, chunk->header.timestamp, chunk->header.payload_length, 
+					chunk->header.message_type, chunk->header.stream_id);
+			} else {
+				srs_verbose("header read completed. fmt=%d, mh_size=%d, ext_time=%d, time=%d, payload=%d, type=%d", 
+					fmt, mh_size, chunk->extended_timestamp, chunk->header.timestamp, chunk->header.payload_length, 
+					chunk->header.message_type);
+			}
+		} else {
+			srs_verbose("header read completed. fmt=%d, mh_size=%d, ext_time=%d, time=%d", 
+				fmt, mh_size, chunk->extended_timestamp, chunk->header.timestamp);
+		}
+	} else {
+		srs_verbose("header read completed. fmt=%d, size=%d, ext_time=%d", 
+			fmt, mh_size, chunk->extended_timestamp);
+	}
+	
+	if (chunk->extended_timestamp) {
+		mh_size += 4;
+		srs_verbose("read header ext time. fmt=%d, ext_time=%d, mh_size=%d", fmt, chunk->extended_timestamp, mh_size);
+		if ((ret = buffer->ensure_buffer_bytes(skt, bh_size + mh_size)) != ERROR_SUCCESS) {
+			srs_error("read %dbytes message header failed. ret=%d", mh_size, ret);
+			return ret;
+		}
+
+        char* pp = (char*)&chunk->header.timestamp;
+        pp[3] = *p++;
+        pp[2] = *p++;
+        pp[1] = *p++;
+        pp[0] = *p++;
+		srs_verbose("header read ext_time completed. time=%d", chunk->header.timestamp);
+	}
+	
 	return ret;
 }
 
@@ -171,6 +351,7 @@ SrsChunkStream::SrsChunkStream(int _cid)
 {
 	fmt = 0;
 	cid = _cid;
+	extended_timestamp = false;
 	msg = NULL;
 }
 

trunk/src/core/srs_core_protocol.hpp

@@ -58,7 +58,7 @@ public:
 	virtual int recv_message(SrsMessage** pmsg);
 private:
 	virtual int read_basic_header(char& fmt, int& cid, int& size);
-	virtual int read_message_header(SrsChunkStream* chunk, char fmt, SrsMessage** pmsg);
+	virtual int read_message_header(SrsChunkStream* chunk, char fmt, int bh_size, int& mh_size);
 };
 
 /**
@@ -113,6 +113,10 @@ public:
 	*/
 	SrsMessageHeader header;
 	/**
+	* whether the chunk message header has extended timestamp.
+	*/
+	bool extended_timestamp;
+	/**
 	* partially read message.
 	*/
 	SrsMessage* msg;