rtp: set the payload type as stream id

Support multiple video/audio streams with different format in the
same session.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavformat/avformat.h

@@ -1684,6 +1684,9 @@ int av_filename_number_test(const char *filename);
 /**
  * Generate an SDP for an RTP session.
  *
+ * Note, this overwrites the id values of AVStreams in the muxer contexts
+ * for getting unique dynamic payload types.
+ *
  * @param ac array of AVFormatContexts describing the RTP streams. If the
  *           array is composed by only one context, such context can contain
  *           multiple AVStreams (one AVStream per RTP stream). Otherwise,

libavformat/internal.h

@@ -124,7 +124,8 @@ int ff_url_join(char *str, int size, const char *proto,
  *
  * @param buff the buffer to append the SDP fragment to
  * @param size the size of the buff buffer
- * @param c the AVCodecContext of the media to describe
+ * @param st the AVStream of the media to describe
+ * @param idx the global stream index
  * @param dest_addr the destination address of the media stream, may be NULL
  * @param dest_type the destination address type, may be NULL
  * @param port the destination port of the media stream, 0 if unknown
@@ -132,7 +133,7 @@ int ff_url_join(char *str, int size, const char *proto,
  * @param fmt the AVFormatContext, which might contain options modifying
  *            the generated SDP
  */
-void ff_sdp_write_media(char *buff, int size, AVCodecContext *c,
+void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
                         const char *dest_addr, const char *dest_type,
                         int port, int ttl, AVFormatContext *fmt);
 

libavformat/movenc.c

@@ -1536,13 +1536,16 @@ static int mov_write_uuid_tag_psp(AVIOContext *pb, MOVTrack *mov)
     return 0x34;
 }
 
-static int mov_write_udta_sdp(AVIOContext *pb, AVFormatContext *ctx, int index)
+static int mov_write_udta_sdp(AVIOContext *pb, MOVTrack *track)
 {
+
+    AVFormatContext *ctx = track->rtp_ctx;
     char buf[1000] = "";
     int len;
 
-    ff_sdp_write_media(buf, sizeof(buf), ctx->streams[0]->codec, NULL, NULL, 0, 0, ctx);
-    av_strlcatf(buf, sizeof(buf), "a=control:streamid=%d\r\n", index);
+    ff_sdp_write_media(buf, sizeof(buf), ctx->streams[0], track->src_track,
+                       NULL, NULL, 0, 0, ctx);
+    av_strlcatf(buf, sizeof(buf), "a=control:streamid=%d\r\n", track->track_id);
     len = strlen(buf);
 
     avio_wb32(pb, len + 24);
@@ -1573,7 +1576,7 @@ static int mov_write_trak_tag(AVIOContext *pb, MOVMuxContext *mov,
     if (track->mode == MODE_PSP)
         mov_write_uuid_tag_psp(pb,track);  // PSP Movies require this uuid box
     if (track->tag == MKTAG('r','t','p',' '))
-        mov_write_udta_sdp(pb, track->rtp_ctx, track->track_id);
+        mov_write_udta_sdp(pb, track);
     if (track->enc->codec_type == AVMEDIA_TYPE_VIDEO && track->mode == MODE_MOV) {
         double sample_aspect_ratio = av_q2d(st->sample_aspect_ratio);
         if (0.0 != sample_aspect_ratio && 1.0 != sample_aspect_ratio)

libavformat/movenchint.c

@@ -44,7 +44,7 @@ int ff_mov_init_hinting(AVFormatContext *s, int index, int src_index)
     track->enc->codec_tag  = track->tag;
 
     ret = ff_rtp_chain_mux_open(&track->rtp_ctx, s, src_st, NULL,
-                                RTP_MAX_PACKET_SIZE);
+                                RTP_MAX_PACKET_SIZE, src_index);
     if (ret < 0)
         goto fail;
 

libavformat/rtp.c

@@ -90,7 +90,8 @@ int ff_rtp_get_codec_info(AVCodecContext *codec, int payload_type)
     return -1;
 }
 
-int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecContext *codec)
+int ff_rtp_get_payload_type(AVFormatContext *fmt,
+                            AVCodecContext *codec, int idx)
 {
     int i;
     AVOutputFormat *ofmt = fmt ? fmt->oformat : NULL;
@@ -124,8 +125,11 @@ int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecContext *codec)
             return AVRtpPayloadTypes[i].pt;
         }
 
+    if (idx < 0)
+        idx = codec->codec_type == AVMEDIA_TYPE_AUDIO;
+
     /* dynamic payload type */
-    return RTP_PT_PRIVATE + (codec->codec_type == AVMEDIA_TYPE_AUDIO);
+    return RTP_PT_PRIVATE + idx;
 }
 
 const char *ff_rtp_enc_name(int payload_type)

libavformat/rtp.h

@@ -25,13 +25,18 @@
 #include "libavcodec/avcodec.h"
 
 /**
- * Return the payload type for a given codec used in the given format context.
+ * Return the payload type for a given stream used in the given format context.
+ * Static payload types are derived from the codec.
+ * Dynamic payload type are derived from the id field in AVStream.
+ * The format context private option payload_type overrides both.
  *
  * @param fmt   The context of the format
  * @param codec The context of the codec
+ * @param idx   The stream index
  * @return The payload type (the 'PT' field in the RTP header).
  */
-int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecContext *codec);
+int ff_rtp_get_payload_type(AVFormatContext *fmt, AVCodecContext *codec,
+                            int idx);
 
 /**
  * Initialize a codec context based on the payload type.

libavformat/rtpenc.c

@@ -101,8 +101,17 @@ static int rtp_write_header(AVFormatContext *s1)
         return -1;
     }
 
-    if (s->payload_type < 0)
-        s->payload_type = ff_rtp_get_payload_type(s1, st->codec);
+    if (s->payload_type < 0) {
+        /* Re-validate non-dynamic payload types */
+        if (st->id < RTP_PT_PRIVATE)
+            st->id = ff_rtp_get_payload_type(s1, st->codec, -1);
+
+        s->payload_type = st->id;
+    } else {
+        /* private option takes priority */
+        st->id = s->payload_type;
+    }
+
     s->base_timestamp = av_get_random_seed();
     s->timestamp = s->base_timestamp;
     s->cur_timestamp = 0;

libavformat/rtpenc_chain.c

@@ -23,13 +23,15 @@
 #include "avio_internal.h"
 #include "rtpenc_chain.h"
 #include "avio_internal.h"
+#include "rtp.h"
 #include "libavutil/opt.h"
 
 int ff_rtp_chain_mux_open(AVFormatContext **out, AVFormatContext *s,
-                          AVStream *st, URLContext *handle, int packet_size)
+                          AVStream *st, URLContext *handle, int packet_size,
+                          int idx)
 {
     AVFormatContext *rtpctx = NULL;
-    int ret;
+    int ret, pt;
     AVOutputFormat *rtp_format = av_guess_format("rtp", NULL, NULL);
     uint8_t *rtpflags;
     AVDictionary *opts = NULL;
@@ -57,6 +59,12 @@ int ff_rtp_chain_mux_open(AVFormatContext **out, AVFormatContext *s,
     rtpctx->max_delay = s->max_delay;
     /* Copy other stream parameters. */
     rtpctx->streams[0]->sample_aspect_ratio = st->sample_aspect_ratio;
+    /* Get the payload type from the codec */
+    if (st->id < RTP_PT_PRIVATE)
+        rtpctx->streams[0]->id =
+            ff_rtp_get_payload_type(rtpctx, st->codec, idx);
+    else
+        rtpctx->streams[0]->id = st->id;
 
     if (av_opt_get(s, "rtpflags", AV_OPT_SEARCH_CHILDREN, &rtpflags) >= 0)
         av_dict_set(&opts, "rtpflags", rtpflags, AV_DICT_DONT_STRDUP_VAL);

libavformat/rtpenc_chain.h

@@ -26,6 +26,7 @@
 #include "url.h"
 
 int ff_rtp_chain_mux_open(AVFormatContext **out, AVFormatContext *s,
-                          AVStream *st, URLContext *handle, int packet_size);
+                          AVStream *st, URLContext *handle, int packet_size,
+                          int id);
 
 #endif /* AVFORMAT_RTPENC_CHAIN_H */

libavformat/rtsp.c

@@ -630,7 +630,8 @@ int ff_rtsp_open_transport_ctx(AVFormatContext *s, RTSPStream *rtsp_st)
     if (s->oformat && CONFIG_RTSP_MUXER) {
         int ret = ff_rtp_chain_mux_open(&rtsp_st->transport_priv, s, st,
                                         rtsp_st->rtp_handle,
-                                        RTSP_TCP_MAX_PACKET_SIZE);
+                                        RTSP_TCP_MAX_PACKET_SIZE,
+                                        rtsp_st->stream_index);
         /* Ownership of rtp_handle is passed to the rtp mux context */
         rtsp_st->rtp_handle = NULL;
         if (ret < 0)

libavformat/sapenc.c

@@ -151,7 +151,7 @@ static int sap_write_header(AVFormatContext *s)
             ret = AVERROR(EIO);
             goto fail;
         }
-        ret = ff_rtp_chain_mux_open(&contexts[i], s, s->streams[i], fd, 0);
+        ret = ff_rtp_chain_mux_open(&contexts[i], s, s->streams[i], fd, 0, i);
         if (ret < 0)
             goto fail;
         s->streams[i]->priv_data = contexts[i];

libavformat/sdp.c

@@ -590,12 +590,15 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,
     return buff;
 }
 
-void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, const char *dest_type, int port, int ttl, AVFormatContext *fmt)
+void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
+                        const char *dest_addr, const char *dest_type,
+                        int port, int ttl, AVFormatContext *fmt)
 {
+    AVCodecContext *c = st->codec;
     const char *type;
     int payload_type;
 
-    payload_type = ff_rtp_get_payload_type(fmt, c);
+    payload_type = ff_rtp_get_payload_type(fmt, c, idx);
 
     switch (c->codec_type) {
         case AVMEDIA_TYPE_VIDEO   : type = "video"      ; break;
@@ -617,7 +620,7 @@ int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
 {
     AVDictionaryEntry *title = av_dict_get(ac[0]->metadata, "title", NULL, 0);
     struct sdp_session_level s = { 0 };
-    int i, j, port, ttl, is_multicast;
+    int i, j, port, ttl, is_multicast, index = 0;
     char dst[32], dst_type[5];
 
     memset(buf, 0, size);
@@ -656,10 +659,10 @@ int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
                 ttl = 0;
         }
         for (j = 0; j < ac[i]->nb_streams; j++) {
-            ff_sdp_write_media(buf, size,
-                                  ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
-                                  dst_type, (port > 0) ? port + j * 2 : 0, ttl,
-                                  ac[i]);
+            ff_sdp_write_media(buf, size, ac[i]->streams[j], index++,
+                               dst[0] ? dst : NULL, dst_type,
+                               (port > 0) ? port + j * 2 : 0,
+                               ttl, ac[i]);
             if (port <= 0) {
                 av_strlcatf(buf, size,
                                    "a=control:streamid=%d\r\n", i + j);
@@ -675,7 +678,9 @@ int av_sdp_create(AVFormatContext *ac[], int n_files, char *buf, int size)
     return AVERROR(ENOSYS);
 }
 
-void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, const char *dest_type, int port, int ttl, AVFormatContext *fmt)
+void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
+                        const char *dest_addr, const char *dest_type,
+                        int port, int ttl, AVFormatContext *fmt)
 {
 }
 #endif