Changeset 3974 for vic/branches/mpeg4/codec/decoder-h264.cpp

Timestamp:

03/23/07 18:11:29 (6 years ago)

Author:

piers

Message:

RTP Payload format for H.264 (RFC 3984)

Most of this work below has been done by Socrates. Tidy up and bug fixes by Piers.

General comments:

1. Implemented the H.264 RTP framing according to RFC 3984. The implementation covers the "Single NAL Unit" (Single NALU packet type) and "Non-Interleaved" modes (STAP-A, FU-A packet types). The interleaved mode (STAP-B, MTAP16, MTAP24, FU-B) has not been implemented at this stage. [I don't know of another tool, closed source or open, that has implemented this mode to date to be able to test with (the current QuickTime? Player 7.1.3 does not implement it either, as far as I know).]

2. The decoder has been tested with the MPEG4IP's mp4live server 1.5.0.1. An example SDP file is provided to set up VIC to decode mp4live streams. Please edit the file default_mpeg4ip.sdp with your details, or better generate your own SDP files using mp4live, and place the edited SDP file in your home directory. The filename should be "default.sdp"

3. The H264 depayloader implementation is currently based libavformat (part of ffpmeg). The plan to is re-write the H264 depayloader under BSD license in the near future.

4. The H.264 VIC encoder will not aggregate NAL units at the moment (STAP-A). The decoder will properly decode such packets.

5. VIC sends SPS/PPS NAL units in-band at the start of H.264 transmission. One has to check whether this can be done periodically. This way we may avoid SDP and sprep-parameter-set.

6. The SDP may be configured for the decoder which uses either a default embedded SDP or from "$HOME/default.sdp"

7. The SDP file is only used to convey SPS/PPS sprop-parameter-sets. IP addresses, ports, etc. are read from VIC command-line as normal.

Files:

• vic/branches/mpeg4/codec/decoder-h264.cpp (modified) (12 diffs)

vic/branches/mpeg4/codec/decoder-h264.cpp

@@ -4 +4 @@
 #include <assert.h>
 #include <iostream>
+#include <errno.h>
 #include "inet.h"
 #include "rtp.h"
@@ -11 +12 @@
 #include "databuffer.h"
 #include "ffmpeg_codec.h"
+#include "rtp_h264_depayloader.h"
+
+
+#define SDP_LINE_LEN 10000
 
 //#define DIRECT_DISPLAY 1
-
-using namespace std;
-
-extern "C" UCHAR * video_frame;
+//using namespace std;
+//extern "C" UCHAR * video_frame;
+
 
 class H264Decoder:public Decoder
@@ -24 +28 @@
     ~H264Decoder();
 
+    void handleSDP();
     virtual void recv(pktbuf *);
     int colorhist(u_int * hist) const;
@@ -31 +36 @@
 
     /* packet statistics */
-    u_int16_t last_seq;         /* sequence number */
+    uint16_t last_seq;          /* sequence number */
 
     UCHAR bitstream[MAX_CODED_SIZE];    /* bitstream data */
 
     /* collecting data for a frame */
-    int idx;
+    uint16_t idx;
     int last_mbit;
     int last_iframe;
@@ -44 +49 @@
     UCHAR xxx_frame[MAX_FRAME_SIZE];
     FFMpegCodec h264;
-    PacketBuffer *stream;
-
+    PacketBuffer *stream; //SV: probably this is going to be substituted by the AVPacket->data when we call decode()...
+    H264Depayloader *h264depayloader;
 
     //For DEBUG
-    FILE *fptr;
+    //FILE *fptr;
+    FILE *sdp_fptr;
 };
 
@@ -68 +74 @@
 
 
-H264Decoder::H264Decoder():Decoder(2)
+H264Decoder::H264Decoder():Decoder(0 /* 0 byte extra header */)
 {                               /* , codec_(0), */
 
+
+    //Barz: =============================================
     decimation_ = 411;
     /*
@@ -79 +87 @@
     inh_ = 0;
 
-     /*XXX*/ resize(inw_, inh_);
+     /*XXX*/ 
+    resize(inw_, inh_);
 
     // libavcodec
@@ -89 +98 @@
     last_iframe = 0;
     last_seq = 0;
+    //===================================================
+
+
+    //SV: ===============================================
+    //Create payloader
+    h264depayloader = new H264Depayloader;
+
+    handleSDP();
+    //make sure all codec params are set up properly before decoding
+
+    //check whether AVPacket struct can be used in stead of Barz's PacketBuffer
+    //===================================================
+
 
     //256 packets, each 1600 byte (default will not exceed 1600 byte)
     //cout << "new PacketBuffer..\n";
-    stream = new PacketBuffer(1024, 1600);
+    stream = new PacketBuffer(1024, 1600); //SV: 1024 = ??? 
     startPkt = false;
+}
+
+void
+H264Decoder::handleSDP()
+{
+    char SdpFilename[SDP_LINE_LEN];
+    char *line, *sdp_string;
+    char *SdpLine=NULL;
+    int n_char;
+    size_t nBytes = 0;
+    ssize_t SdpRead;
+    char defaultSDP[]="a=rtpmap:96 H264/90000\na=fmtp:96 profile-level-id=00000d; packetization-mode=1\n";
+
+    sprintf(SdpFilename, "%s/default.sdp", getenv("HOME"));
 
     //fptr = fopen("out.m4v", "w");
+    if ((sdp_fptr = fopen(SdpFilename, "r")) != NULL ) {
+        //fprintf(stderr, "H264_RTP: Opened SDP file %s for read.\n", SdpFilename);
+
+      //Read SDP file into struct
+      //fprintf(stderr, "H264_RTP: Spitting SDP ================================================\n");
+      while ((SdpRead = getline(&SdpLine, &nBytes, sdp_fptr)) != -1) {
+        //fprintf(stderr, "H264_RTP: Read %d bytes from SDP file.\n", SdpRead);
+        //fprintf(stderr, "%s", SdpLine);
+        //call SDP parse h264 routine
+          h264depayloader->parse_h264_sdp_line(h264.c, h264depayloader->h264_extradata, SdpLine);
+      }
+      if (SdpLine)
+          free(SdpLine);
+        
+    } else {
+        fprintf(stderr, "H264_RTP: Couldn't open SDP file %s to read. Errno = %d\n", SdpFilename, errno);
+        fprintf(stderr, "H264_RTP: Using default SDP: %s \n", defaultSDP);
+
+      line=defaultSDP;
+      do {
+        n_char = strcspn(line, "\n");
+        SdpLine = (char *)malloc(n_char+1);
+        memset(SdpLine, '\0', n_char+1);
+        strncpy(SdpLine, line, n_char);
+        line += n_char + 1;
+          h264depayloader->parse_h264_sdp_line(h264.c, h264depayloader->h264_extradata, SdpLine);
+        free(SdpLine);
+      } while (n_char != 0);
+    //fprintf(stderr, "H264_RTP: Done spitting SDP ===========================================\n");
+    }
 }
 
@@ -101 +167 @@
 {
     delete stream;
+    delete h264depayloader;
     //fclose(fptr);
+    if (sdp_fptr != NULL) fclose(sdp_fptr);
+    //fprintf(stderr, "H264_RTP: Closed SDP file.\n");
 }
 
 int H264Decoder::colorhist(u_int * hist)  const
 {
+    UNUSED(hist);
+
     return (1);
 }
@@ -115 +186 @@
     u_char *bp = pb->dp + hdrsize;
     int cc = pb->len - hdrsize;
-    static int iframe_c = 0, pframe_c = 0;
+    //static int iframe_c = 0, pframe_c = 0;
 
     int mbit = ntohs(rh->rh_flags) >> 7 & 1;
-    int seq = ntohs(rh->rh_seqno);
+    uint16_t seq = ntohs(rh->rh_seqno);
     int ts = ntohl(rh->rh_ts);
 
+
+
+    //Barz: =============================================
     if (!startPkt) {
        stream->clear();
        startPkt = true;
        idx = seq;
-           last_seq = seq - 1;
+       last_seq = seq - 1;
     }
           
@@ -134 +208 @@
 
     if (abs(seq - last_seq) > 5) {
-            debug_msg("h264dec: sequece interrupt!\n");
+            //fprintf(stderr, "H264_RTP: sequece interrupt!\n");
             idx = seq;
             pktIdx = 0;
             stream->clear();
     }else if (last_seq + 1 != seq) {
-            /* oops - missing packet */
-            debug_msg("h264dec: missing packet\n");
-    }
+            // oops - missing packet
+            //fprintf(stderr, "H264_RTP: missing packet\n");
+    }
+
+    //===================================================
+
 
     //copy packet
-    stream->write(pktIdx, cc, (char *) bp);
-    
+    //stream->write(pktIdx, cc, (char *) bp);
+    //fprintf(stderr, "H264_RTP: -------------------------------- seq = %d, m=%d, ts=%d, cc=%d\n", seq, mbit, ts, cc);
+    //fprintf(stderr, "H264_RTP: pktIdx = %d\n", pktIdx);
+    int yo = h264depayloader->h264_handle_packet(h264depayloader->h264_extradata, pktIdx, stream, /*ts,*/ bp, cc);
+    //fprintf(stderr, "H264_RTP: h264_handle_packet = %d\n", yo);
+
+
+    //Barz: =============================================
+
     last_seq = seq;
     int len=0;
-        
     if (mbit) {
             stream->setTotalPkts(pktIdx + 1);
 
-            DataBuffer *f;          
+            DataBuffer *f;
             if (stream->isComplete()) {
-                        f = stream->getStream();
+                    f = stream->getStream();
                     len =  h264.decode((UCHAR *) f->getData(), f->getDataSize(), xxx_frame);
             }
             
             if (len < 0) {
-               debug_msg("h264dec: frame error\n");
+                //fprintf(stderr, "H264_RTP: frame error\n");
             }
            
@@ -170 +253 @@
                         Decoder::redraw(xxx_frame);
             }
-        stream->clear();
+            stream->clear();
             idx = seq+1;
-                     
-    }
+    }
+
+    //===================================================
+
     pb->release();
 }