Add RTP packetization of VP8

Patch by Josh Allmann, joshua dot allmann at gmail

Originally committed as revision 24797 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/Makefile

@@ -219,6 +219,7 @@ OBJS-$(CONFIG_RTP_MUXER)                 += rtp.o         \
                                             rtpenc_mpv.o     \
                                             rtpenc.o      \
                                             rtpenc_h264.o \
+                                            rtpenc_vp8.o  \
                                             rtpenc_xiph.o \
                                             avc.o
 OBJS-$(CONFIG_RTSP_DEMUXER)              += rtsp.o httpauth.o

libavformat/rtpenc.c

@@ -55,6 +55,7 @@ static int is_supported(enum CodecID id)
     case CODEC_ID_AMR_WB:
     case CODEC_ID_VORBIS:
     case CODEC_ID_THEORA:
+    case CODEC_ID_VP8:
         return 1;
     default:
         return 0;
@@ -144,6 +145,9 @@ static int rtp_write_header(AVFormatContext *s1)
         s->max_payload_size -= 6; // ident+frag+tdt/vdt+pkt_num+pkt_length
         s->num_frames = 0;
         goto defaultcase;
+    case CODEC_ID_VP8:
+        av_log(s1, AV_LOG_WARNING, "RTP VP8 payload is still experimental\n");
+        break;
     case CODEC_ID_AMR_NB:
     case CODEC_ID_AMR_WB:
         if (!s->max_frames_per_packet)
@@ -407,6 +411,9 @@ static int rtp_write_packet(AVFormatContext *s1, AVPacket *pkt)
     case CODEC_ID_THEORA:
         ff_rtp_send_xiph(s1, pkt->data, size);
         break;
+    case CODEC_ID_VP8:
+        ff_rtp_send_vp8(s1, pkt->data, size);
+        break;
     default:
         /* better than nothing : send the codec raw data */
         rtp_send_raw(s1, pkt->data, size);

libavformat/rtpenc.h

@@ -68,5 +68,6 @@ void ff_rtp_send_aac(AVFormatContext *s1, const uint8_t *buff, int size);
 void ff_rtp_send_amr(AVFormatContext *s1, const uint8_t *buff, int size);
 void ff_rtp_send_mpegvideo(AVFormatContext *s1, const uint8_t *buf1, int size);
 void ff_rtp_send_xiph(AVFormatContext *s1, const uint8_t *buff, int size);
+void ff_rtp_send_vp8(AVFormatContext *s1, const uint8_t *buff, int size);
 
 #endif /* AVFORMAT_RTPENC_H */

libavformat/rtpenc_vp8.c

@@ -0,0 +1,47 @@
+/*
+ * RTP VP8 Packetizer
+ * Copyright (c) 2010 Josh Allmann
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "rtpenc.h"
+
+/* Based on a draft spec for VP8 RTP.
+ * ( http://www.webmproject.org/code/specs/rtp/ ) */
+void ff_rtp_send_vp8(AVFormatContext *s1, const uint8_t *buf, int size)
+{
+    RTPMuxContext *s = s1->priv_data;
+    int len, max_packet_size;
+
+    s->buf_ptr      = s->buf;
+    s->timestamp    = s->cur_timestamp;
+    max_packet_size = s->max_payload_size - 1; // minus one for header byte
+
+    *s->buf_ptr++ = 1; // 0b1 indicates start of frame
+    while (size > 0) {
+        len = FFMIN(size, max_packet_size);
+
+        memcpy(s->buf_ptr, buf, len);
+        ff_rtp_send_data(s1, s->buf, len+1, size == len); // marker bit is last packet in frame
+
+        size         -= len;
+        buf          += len;
+        s->buf_ptr    = s->buf;
+        *s->buf_ptr++ = 0; // payload descriptor
+    }
+}

libavformat/sdp.c

@@ -412,6 +412,10 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,
                                     c->width, c->height, pix_fmt, config);
             break;
         }
+        case CODEC_ID_VP8:
+            av_strlcatf(buff, size, "a=rtpmap:%d VP8/90000\r\n",
+                                     payload_type);
+            break;
         default:
             /* Nothing special to do here... */
             break;