Merge commit '86d9181c'

* commit '86d9181c':
  rtpdec: Support sending RTCP feedback packets

Conflicts:
	libavformat/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/rtpdec.c

@@ -30,6 +30,8 @@
 #include "rtpdec.h"
 #include "rtpdec_formats.h"
 
+#define MIN_FEEDBACK_INTERVAL 200000 /* 200 ms in us */
+
 static RTPDynamicProtocolHandler realmedia_mp3_dynamic_handler = {
     .enc_name   = "X-MP3-draft-00",
     .codec_type = AVMEDIA_TYPE_AUDIO,
@@ -366,6 +368,100 @@ void ff_rtp_send_punch_packets(URLContext *rtp_handle)
     av_free(buf);
 }
 
+static int find_missing_packets(RTPDemuxContext *s, uint16_t *first_missing,
+                                uint16_t *missing_mask)
+{
+    int i;
+    uint16_t next_seq = s->seq + 1;
+    RTPPacket *pkt = s->queue;
+
+    if (!pkt || pkt->seq == next_seq)
+        return 0;
+
+    *missing_mask = 0;
+    for (i = 1; i <= 16; i++) {
+        uint16_t missing_seq = next_seq + i;
+        while (pkt) {
+            int16_t diff = pkt->seq - missing_seq;
+            if (diff >= 0)
+                break;
+            pkt = pkt->next;
+        }
+        if (!pkt)
+            break;
+        if (pkt->seq == missing_seq)
+            continue;
+        *missing_mask |= 1 << (i - 1);
+    }
+
+    *first_missing = next_seq;
+    return 1;
+}
+
+int ff_rtp_send_rtcp_feedback(RTPDemuxContext *s, URLContext *fd,
+                              AVIOContext *avio)
+{
+    int len, need_keyframe, missing_packets;
+    AVIOContext *pb;
+    uint8_t *buf;
+    int64_t now;
+    uint16_t first_missing, missing_mask;
+
+    if (!fd && !avio)
+        return -1;
+
+    need_keyframe = s->handler && s->handler->need_keyframe &&
+                    s->handler->need_keyframe(s->dynamic_protocol_context);
+    missing_packets = find_missing_packets(s, &first_missing, &missing_mask);
+
+    if (!need_keyframe && !missing_packets)
+        return 0;
+
+    /* Send new feedback if enough time has elapsed since the last
+     * feedback packet. */
+
+    now = av_gettime();
+    if (s->last_feedback_time &&
+        (now - s->last_feedback_time) < MIN_FEEDBACK_INTERVAL)
+        return 0;
+    s->last_feedback_time = now;
+
+    if (!fd)
+        pb = avio;
+    else if (avio_open_dyn_buf(&pb) < 0)
+        return -1;
+
+    if (need_keyframe) {
+        avio_w8(pb, (RTP_VERSION << 6) | 1); /* PLI */
+        avio_w8(pb, RTCP_PSFB);
+        avio_wb16(pb, 2); /* length in words - 1 */
+        // our own SSRC: we use the server's SSRC + 1 to avoid conflicts
+        avio_wb32(pb, s->ssrc + 1);
+        avio_wb32(pb, s->ssrc); // server SSRC
+    }
+
+    if (missing_packets) {
+        avio_w8(pb, (RTP_VERSION << 6) | 1); /* NACK */
+        avio_w8(pb, RTCP_RTPFB);
+        avio_wb16(pb, 3); /* length in words - 1 */
+        avio_wb32(pb, s->ssrc + 1);
+        avio_wb32(pb, s->ssrc); // server SSRC
+
+        avio_wb16(pb, first_missing);
+        avio_wb16(pb, missing_mask);
+    }
+
+    avio_flush(pb);
+    if (!fd)
+        return 0;
+    len = avio_close_dyn_buf(pb, &buf);
+    if (len > 0 && buf) {
+        ffurl_write(fd, buf, len);
+        av_free(buf);
+    }
+    return 0;
+}
+
 /**
  * open a new RTP parse context for stream 'st'. 'st' can be NULL for
  * MPEG2-TS streams to indicate that they should be demuxed inside the

libavformat/rtpdec.h

@@ -73,6 +73,8 @@ void ff_rtp_send_punch_packets(URLContext* rtp_handle);
  */
 int ff_rtp_check_and_send_back_rr(RTPDemuxContext *s, URLContext *fd,
                                   AVIOContext *avio, int count);
+int ff_rtp_send_rtcp_feedback(RTPDemuxContext *s, URLContext *fd,
+                              AVIOContext *avio);
 
 // these statistics are used for rtcp receiver reports...
 typedef struct RTPStatistics {
@@ -130,6 +132,7 @@ struct RTPDynamicProtocolHandler {
     void (*free)(PayloadContext *protocol_data);
     /** Parse handler for this dynamic packet */
     DynamicPayloadPacketHandlerProc parse_packet;
+    int (*need_keyframe)(PayloadContext *context);
 
     struct RTPDynamicProtocolHandler *next;
 };
@@ -180,6 +183,8 @@ struct RTPDemuxContext {
     unsigned int packet_count;
     unsigned int octet_count;
     unsigned int last_octet_count;
+    int64_t last_feedback_time;
+
     /* buffer for partially parsed packets */
     uint8_t buf[RTP_MAX_PACKET_LENGTH];
 

libavformat/rtsp.c

@@ -380,6 +380,8 @@ static void sdp_parse_line(AVFormatContext *s, SDPParseState *s1,
         get_word(buf1, sizeof(buf1), &p); /* protocol */
         if (!strcmp(buf1, "udp"))
             rt->transport = RTSP_TRANSPORT_RAW;
+        else if (strstr(buf1, "/AVPF") || strstr(buf1, "/SAVPF"))
+            rtsp_st->feedback = 1;
 
         /* XXX: handle list of formats */
         get_word(buf1, sizeof(buf1), &p); /* format list */
@@ -1932,6 +1934,12 @@ redo:
         ret = ff_rdt_parse_packet(rtsp_st->transport_priv, pkt, &rt->recvbuf, len);
     } else if (rt->transport == RTSP_TRANSPORT_RTP) {
         ret = ff_rtp_parse_packet(rtsp_st->transport_priv, pkt, &rt->recvbuf, len);
+        if (rtsp_st->feedback) {
+            AVIOContext *pb = NULL;
+            if (rt->lower_transport == RTSP_LOWER_TRANSPORT_CUSTOM)
+                pb = s->pb;
+            ff_rtp_send_rtcp_feedback(rtsp_st->transport_priv, rtsp_st->rtp_handle, pb);
+        }
         if (ret < 0) {
             /* Either bad packet, or a RTCP packet. Check if the
              * first_rtcp_ntp_time field was initialized. */

libavformat/rtsp.h

@@ -437,6 +437,9 @@ typedef struct RTSPStream {
     /** private data associated with the dynamic protocol */
     PayloadContext *dynamic_protocol_context;
     //@}
+
+    /** Enable sending RTCP feedback messages according to RFC 4585 */
+    int feedback;
 } RTSPStream;
 
 void ff_rtsp_parse_line(RTSPMessageHeader *reply, const char *buf,

libavformat/version.h

@@ -31,7 +31,7 @@
 
 #define LIBAVFORMAT_VERSION_MAJOR 54
 #define LIBAVFORMAT_VERSION_MINOR 59
-#define LIBAVFORMAT_VERSION_MICRO 106
+#define LIBAVFORMAT_VERSION_MICRO 107
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \