for #133, decode the h264 NALU from rtp.

@@ -33,19 +33,24 @@ using namespace std;
 #include <srs_kernel_log.hpp>
 #include <srs_app_utility.hpp>
 #include <srs_core_autofree.hpp>
+#include <srs_kernel_stream.hpp>
+#include <srs_kernel_buffer.hpp>
 
 #ifdef SRS_AUTO_STREAM_CASTER
 
-SrsRtpConn::SrsRtpConn(SrsRtspConn* r, int p)
+SrsRtpConn::SrsRtpConn(SrsRtspConn* r, int p, int sid)
 {
     rtsp = r;
     _port = p;
+    stream_id = sid;
     listener = new SrsUdpListener(this, p);
+    cache = new SrsRtpPacket();
 }
 
 SrsRtpConn::~SrsRtpConn()
 {
     srs_freep(listener);
+    srs_freep(cache);
 }
 
 int SrsRtpConn::port()
@@ -61,6 +66,53 @@ int SrsRtpConn::listen()
 int SrsRtpConn::on_udp_packet(sockaddr_in* from, char* buf, int nb_buf)
 {
     int ret = ERROR_SUCCESS;
+
+    if (true) {
+        SrsStream stream;
+
+        if ((ret = stream.initialize(buf, nb_buf)) != ERROR_SUCCESS) {
+            return ret;
+        }
+    
+        SrsRtpPacket pkt;
+        if ((ret = pkt.decode(&stream)) != ERROR_SUCCESS) {
+            srs_error("rtsp: decode rtp packet failed. ret=%d", ret);
+            return ret;
+        }
+
+        if (pkt.chunked) {
+            if (!cache) {
+                cache = new SrsRtpPacket();
+            }
+            cache->copy(&pkt);
+            cache->payload->append(pkt.payload->bytes(), pkt.payload->length());
+            if (!cache->completed) {
+                srs_trace("rtsp: rtp chunked %dB, vt=%d/%u, sts=%u/%#x/%#x, paylod=%dB", 
+                    nb_buf, cache->version, cache->payload_type, cache->sequence_number, cache->timestamp, cache->ssrc, 
+                    cache->payload->length()
+                );
+                return ret;
+            }
+        } else {
+            srs_freep(cache);
+            cache = new SrsRtpPacket();
+            cache->reap(&pkt);
+        }
+    }
+
+    srs_trace("rtsp: rtp %dB, vt=%d/%u, sts=%u/%#x/%#x, paylod=%dB, chunked=%d", 
+        nb_buf, cache->version, cache->payload_type, cache->sequence_number, cache->timestamp, cache->ssrc, 
+        cache->payload->length(), cache->chunked
+    );
+
+    // always free it.
+    SrsAutoFree(SrsRtpPacket, cache);
+    
+    if ((ret = rtsp->on_rtp_packet(cache)) != ERROR_SUCCESS) {
+        srs_error("rtsp: process rtp packet failed. ret=%d", ret);
+        return ret;
+    }
+
     return ret;
 }
 
@@ -162,10 +214,10 @@ int SrsRtspConn::do_cycle()
             SrsRtpConn* rtp = NULL;
             if (req->stream_id == video_id) {
                 srs_freep(video_rtp);
-                rtp = video_rtp = new SrsRtpConn(this, lpm);
+                rtp = video_rtp = new SrsRtpConn(this, lpm, video_id);
             } else {
                 srs_freep(audio_rtp);
-                rtp = audio_rtp = new SrsRtpConn(this, lpm);
+                rtp = audio_rtp = new SrsRtpConn(this, lpm, audio_id);
             }
             if ((ret = rtp->listen()) != ERROR_SUCCESS) {
                 srs_error("rtsp: rtp listen at port=%d failed. ret=%d", lpm, ret);
@@ -210,6 +262,12 @@ int SrsRtspConn::do_cycle()
     return ret;
 }
 
+int SrsRtspConn::on_rtp_packet(SrsRtpPacket* pkt)
+{
+    int ret = ERROR_SUCCESS;
+    return ret;
+}
+
 int SrsRtspConn::cycle()
 {
     // serve the rtsp client.

@@ -45,6 +45,7 @@ class SrsRtspConn;
 class SrsRtspStack;
 class SrsRtspCaster;
 class SrsConfDirective;
+class SrsRtpPacket;
 
 /**
 * a rtp connection which transport a stream.
@@ -54,9 +55,11 @@ class SrsRtpConn: public ISrsUdpHandler
 private:
     SrsUdpListener* listener;
     SrsRtspConn* rtsp;
+    SrsRtpPacket* cache;
+    int stream_id;
     int _port;
 public:
-    SrsRtpConn(SrsRtspConn* r, int p);
+    SrsRtpConn(SrsRtspConn* r, int p, int sid);
     virtual ~SrsRtpConn();
 public:
     virtual int port();
@@ -103,6 +106,9 @@ public:
     virtual int serve();
 private:
     virtual int do_cycle();
+// internal methods
+public:
+    virtual int on_rtp_packet(SrsRtpPacket* pkt);
 // interface ISrsThreadHandler
 public:
     virtual int cycle();

@@ -144,6 +144,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_RTMP_MIC_CACHE_OVERFLOW       2041
 #define ERROR_RTSP_TOKEN_NOT_NORMAL         2042
 #define ERROR_RTSP_REQUEST_HEADER_EOF       2043
+#define ERROR_RTP_HEADER_CORRUPT            2044
 //                                           
 // system control message, 
 // not an error, but special control logic.

@@ -34,6 +34,7 @@ using namespace std;
 #include <srs_kernel_consts.hpp>
 #include <srs_core_autofree.hpp>
 #include <srs_kernel_utility.hpp>
+#include <srs_kernel_stream.hpp>
 
 #ifdef SRS_AUTO_STREAM_CASTER
 
@@ -118,6 +119,121 @@ std::string srs_generate_rtsp_method_str(SrsRtspMethod method)
     }
 }
 
+SrsRtpPacket::SrsRtpPacket()
+{
+    version = 2;
+    padding = 0;
+    extension = 0;
+    csrc_count = 0;
+    marker = 1;
+
+    payload_type = 0;
+    sequence_number = 0;
+    timestamp = 0;
+    ssrc = 0;
+
+    payload = new SrsSimpleBuffer();
+    chunked = false;
+    completed = false;
+}
+
+SrsRtpPacket::~SrsRtpPacket()
+{
+    srs_freep(payload);
+}
+
+void SrsRtpPacket::copy(SrsRtpPacket* src)
+{
+    version = src->version;
+    padding = src->padding;
+    extension = src->extension;
+    csrc_count = src->csrc_count;
+    marker = src->marker;
+    payload_type = src->payload_type;
+    sequence_number = src->sequence_number;
+    timestamp = src->timestamp;
+    ssrc = src->ssrc;
+
+    chunked = src->chunked;
+    completed = src->completed;
+}
+
+void SrsRtpPacket::reap(SrsRtpPacket* src)
+{
+    copy(src);
+
+    payload = src->payload;
+    src->payload = NULL;
+}
+
+int SrsRtpPacket::decode(SrsStream* stream)
+{
+    int ret = ERROR_SUCCESS;
+
+    // 12bytes header, atleast 2bytes content.
+    if (!stream->require(14)) {
+        ret = ERROR_RTP_HEADER_CORRUPT;
+        srs_error("rtsp: rtp header corrupt. ret=%d", ret);
+        return ret;
+    }
+
+    int8_t vv = stream->read_1bytes();
+    version = (vv >> 6) & 0x03;
+    padding = (vv >> 5) & 0x01;
+    extension = (vv >> 4) & 0x01;
+    csrc_count = vv & 0x0f;
+
+    int8_t mv = stream->read_1bytes();
+    marker = (mv >> 7) & 0x01;
+    payload_type = mv & 0x7f;
+
+    sequence_number = stream->read_2bytes();
+    timestamp = stream->read_4bytes();
+    ssrc = stream->read_4bytes();
+
+    // frame type
+    // 0... .... reserverd
+    // .11. .... NALU[0]&0x60
+    // ...1 11.. FU indicator
+    // .... ..00 reserverd
+    int8_t ftv = stream->read_1bytes();
+    int8_t nalu_0x60 = ftv & 0x60;
+    int8_t fu_indicator = ftv & 0x1c;
+
+    // nri, whatever
+    // 10.. .... first chunk.
+    // 00.. .... continous chunk.
+    // 01.. .... last chunk.
+    // ...1 1111 NALU[0]&0x1f
+    int8_t nriv = stream->read_1bytes();
+    bool first_chunk = (nriv & 0xC0) == 0x80;
+    bool last_chunk = (nriv & 0xC0) == 0x40;
+    bool contious_chunk = (nriv & 0xC0) == 0x00;
+    int8_t nalu_0x1f = nriv & 0x1f;
+
+    // chunked, generate the first byte NALU.
+    if (fu_indicator == 0x1c && (first_chunk || last_chunk || contious_chunk)) {
+        chunked = true;
+        completed = last_chunk;
+
+        // generate and append the first byte NALU.
+        if (first_chunk) {
+            int8_t nalu_byte0 = nalu_0x60 | nalu_0x1f;
+            payload->append((char*)&nalu_byte0, 1);
+        }
+        
+        payload->append(stream->data() + stream->pos(), stream->size() - stream->pos());
+        return ret;
+    }
+
+    // no chunked, append to payload.
+    stream->skip(-2);
+    payload->append(stream->data() + stream->pos(), stream->size() - stream->pos());
+    completed = true;
+
+    return ret;
+}
+
 SrsRtspSdp::SrsRtspSdp()
 {
     state = SrsRtspSdpStateOthers;

@@ -37,6 +37,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #ifdef SRS_AUTO_STREAM_CASTER
 
+class SrsStream;
 class SrsSimpleBuffer;
 class ISrsProtocolReaderWriter;
 
@@ -147,6 +148,169 @@ enum SrsRtspTokenState
 };
 
 /**
+* the rtp packet.
+* 5. RTP Data Transfer Protocol, @see rtp-rfc3550-2003.pdf, page 12
+*/
+class SrsRtpPacket
+{
+public:
+    /**
+    * version (V): 2 bits
+    * This eld identies the version of RTP. The version dened by this specication is two (2).
+    * (The value 1 is used by the rst draft version of RTP and the value 0 is used by the protocol
+    * initially implemented in the \vat" audio tool.)
+    */
+    int8_t version; //2bits
+    /**
+    * padding (P): 1 bit
+    * If the padding bit is set, the packet contains one or more additional padding octets at the
+    * end which are not part of the payload. The last octet of the padding contains a count of
+    * how many padding octets should be ignored, including itself. Padding may be needed by
+    * some encryption algorithms with xed block sizes or for carrying several RTP packets in a
+    * lower-layer protocol data unit.
+    */
+    int8_t padding; //1bit
+    /**
+    * extension (X): 1 bit
+    * If the extension bit is set, the xed header must be followed by exactly one header extension,
+    * with a format dened in Section 5.3.1.
+    */
+    int8_t extension; //1bit
+    /**
+    * CSRC count (CC): 4 bits
+    * The CSRC count contains the number of CSRC identiers that follow the xed header.
+    */
+    int8_t csrc_count; //4bits
+    /**
+    * marker (M): 1 bit
+    * The interpretation of the marker is dened by a prole. It is intended to allow signicant
+    * events such as frame boundaries to be marked in the packet stream. A prole may dene
+    * additional marker bits or specify that there is no marker bit by changing the number of bits
+    * in the payload type eld (see Section 5.3).
+    */
+    int8_t marker; //1bit
+    /**
+    * payload type (PT): 7 bits
+    * This eld identies the format of the RTP payload and determines its interpretation by the
+    * application. A prole may specify a default static mapping of payload type codes to payload
+    * formats. Additional payload type codes may be dened dynamically through non-RTP means
+    * (see Section 3). A set of default mappings for audio and video is specied in the companion
+    * RFC 3551 [1]. An RTP source may change the payload type during a session, but this eld
+    * should not be used for multiplexing separate media streams (see Section 5.2).
+    * A receiver must ignore packets with payload types that it does not understand.
+    */
+    int8_t payload_type; //7bits
+    /**
+    * sequence number: 16 bits
+    * The sequence number increments by one for each RTP data packet sent, and may be used
+    * by the receiver to detect packet loss and to restore packet sequence. The initial value of the
+    * sequence number should be random (unpredictable) to make known-plaintext attacks on
+    * encryption more dicult, even if the source itself does not encrypt according to the method
+    * in Section 9.1, because the packets may flow through a translator that does. Techniques for
+    * choosing unpredictable numbers are discussed in [17].
+    */
+    u_int16_t sequence_number; //16bits
+    /**
+    * timestamp: 32 bits
+    * The timestamp reflects the sampling instant of the rst octet in the RTP data packet. The
+    * sampling instant must be derived from a clock that increments monotonically and linearly
+    * in time to allow synchronization and jitter calculations (see Section 6.4.1). The resolution
+    * of the clock must be sucient for the desired synchronization accuracy and for measuring
+    * packet arrival jitter (one tick per video frame is typically not sucient). The clock frequency
+    * is dependent on the format of data carried as payload and is specied statically in the prole
+    * or payload format specication that denes the format, or may be specied dynamically for
+    * payload formats dened through non-RTP means. If RTP packets are generated periodically,
+    * the nominal sampling instant as determined from the sampling clock is to be used, not a
+    * reading of the system clock. As an example, for xed-rate audio the timestamp clock would
+    * likely increment by one for each sampling period. If an audio application reads blocks covering
+    * 160 sampling periods from the input device, the timestamp would be increased by 160 for
+    * each such block, regardless of whether the block is transmitted in a packet or dropped as
+    * silent.
+    *
+    * The initial value of the timestamp should be random, as for the sequence number. Several
+    * consecutive RTP packets will have equal timestamps if they are (logically) generated at once,
+    * e.g., belong to the same video frame. Consecutive RTP packets may contain timestamps that
+    * are not monotonic if the data is not transmitted in the order it was sampled, as in the case
+    * of MPEG interpolated video frames. (The sequence numbers of the packets as transmitted
+    * will still be monotonic.)
+    * 
+    * RTP timestamps from dierent media streams may advance at dierent rates and usually
+    * have independent, random osets. Therefore, although these timestamps are sucient to
+    * reconstruct the timing of a single stream, directly comparing RTP timestamps from dierent
+    * media is not eective for synchronization. Instead, for each medium the RTP timestamp
+    * is related to the sampling instant by pairing it with a timestamp from a reference clock
+    * (wallclock) that represents the time when the data corresponding to the RTP timestamp was
+    * sampled. The reference clock is shared by all media to be synchronized. The timestamp
+    * pairs are not transmitted in every data packet, but at a lower rate in RTCP SR packets as
+    * described in Section 6.4.
+    * 
+    * The sampling instant is chosen as the point of reference for the RTP timestamp because it is
+    * known to the transmitting endpoint and has a common denition for all media, independent
+    * of encoding delays or other processing. The purpose is to allow synchronized presentation of
+    * all media sampled at the same time.
+    * 
+    * Applications transmitting stored data rather than data sampled in real time typically use a
+    * virtual presentation timeline derived from wallclock time to determine when the next frame
+    * or other unit of each medium in the stored data should be presented. In this case, the RTP
+    * timestamp would reflect the presentation time for each unit. That is, the RTP timestamp for
+    * each unit would be related to the wallclock time at which the unit becomes current on the
+    * virtual presentation timeline. Actual presentation occurs some time later as determined by
+    * the receiver.
+    * 
+    * An example describing live audio narration of prerecorded video illustrates the signicance
+    * of choosing the sampling instant as the reference point. In this scenario, the video would
+    * be presented locally for the narrator to view and would be simultaneously transmitted using
+    * RTP. The \sampling instant" of a video frame transmitted in RTP would be established by
+    * referencing its timestamp to the wallclock time when that video frame was presented to the
+    * narrator. The sampling instant for the audio RTP packets containing the narrator's speech
+    * would be established by referencing the same wallclock time when the audio was sampled.
+    * The audio and video may even be transmitted by dierent hosts if the reference clocks on
+    * the two hosts are synchronized by some means such as NTP. A receiver can then synchronize
+    * presentation of the audio and video packets by relating their RTP timestamps using the
+    * timestamp pairs in RTCP SR packets.
+    */
+    u_int32_t timestamp; //32bits
+    /**
+    * SSRC: 32 bits
+    * The SSRC eld identies the synchronization source. This identier should be chosen
+    * randomly, with the intent that no two synchronization sources within the same RTP session
+    * will have the same SSRC identier. An example algorithm for generating a random identier
+    * is presented in Appendix A.6. Although the probability of multiple sources choosing the same
+    * identier is low, all RTP implementations must be prepared to detect and resolve collisions.
+    * Section 8 describes the probability of collision along with a mechanism for resolving collisions
+    * and detecting RTP-level forwarding loops based on the uniqueness of the SSRC identier. If
+    * a source changes its source transport address, it must also choose a new SSRC identier to
+    * avoid being interpreted as a looped source (see Section 8.2).
+    */
+    u_int32_t ssrc; //32bits
+
+    // the payload.
+    SrsSimpleBuffer* payload;
+    // whether transport in chunked payload.
+    bool chunked;
+    // whether message is completed.
+    // normal message always completed.
+    // while chunked completed when the last chunk arriaved.
+    bool completed;
+public:
+    SrsRtpPacket();
+    virtual ~SrsRtpPacket();
+public:
+    /**
+    * copy the header from src.
+    */
+    virtual void copy(SrsRtpPacket* src);
+    /**
+    * reap the src to this packet, reap the payload.
+    */
+    virtual void reap(SrsRtpPacket* src);
+    /**
+    * decode rtp packet from stream.
+    */
+    virtual int decode(SrsStream* stream);
+};
+
+/**
 * the sdp in announce, @see rtsp-rfc2326-1998.pdf, page 159
 * Appendix C: Use of SDP for RTSP Session Descriptions
 * The Session Description Protocol (SDP, RFC 2327 [6]) may be used to