srt: add stream ID option

This patch allows the use of the streamid option when using the SRT
protocol.  For example, we can query the URL
srt://localhost:9710?streamid=demo if a stream server is listening on
localhost:9710 that supports multiple streams on the same server. Like
the others already implemented, this parameter can be overwritten in the
settings of the transport.

In a future patch, it may be good to support the full options.  The
complete list can be found here:
https://github.com/Haivision/srt/blob/master/docs/APISocketOptions.md#list-of-options
A human-friendly version of this list can be found in the ffmpeg
documentation: https://ffmpeg.org/ffmpeg-all.html#srt

Signed-off-by: Thomas Guillem <thomas@gllm.fr>
(cherry picked from commit a55c95a9cc)

Signed-off-by: Steve Lhomme <robux4@ycbcr.xyz>

modules/access/srt.c

@@ -97,6 +97,8 @@ static bool srt_schedule_reconnect(stream_t *p_stream)
     int stat;
     char *psz_passphrase = var_InheritString( p_stream, SRT_PARAM_PASSPHRASE );
     bool passphrase_needs_free = true;
+    char *psz_streamid = var_InheritString( p_stream, SRT_PARAM_STREAMID );
+    bool streamid_needs_free = true;
     char *url = NULL;
     srt_params_t params;
     struct addrinfo hints = {
@@ -145,6 +147,11 @@ static bool srt_schedule_reconnect(stream_t *p_stream)
                 passphrase_needs_free = false;
                 psz_passphrase = (char *) params.passphrase;
             }
+	    if (params.streamid != NULL ) {
+		free( psz_streamid );
+		streamid_needs_free = false;
+		psz_streamid = (char *) params.streamid;
+	    }
         }
     }
 
@@ -177,6 +184,12 @@ static bool srt_schedule_reconnect(stream_t *p_stream)
                 SRTO_PASSPHRASE, psz_passphrase, strlen(psz_passphrase) );
     }
 
+    /* set stream id */
+    if (psz_streamid != NULL && psz_streamid[0] != '\0') {
+        srt_set_socket_option( strm_obj, SRT_PARAM_STREAMID, p_sys->sock,
+                SRTO_STREAMID, psz_streamid, strlen(psz_streamid) );
+    }
+
     /* set maximum payload size */
     srt_set_socket_option( strm_obj, SRT_PARAM_PAYLOAD_SIZE, p_sys->sock,
             SRTO_PAYLOADSIZE, &i_payload_size, sizeof(i_payload_size) );
@@ -211,6 +224,8 @@ out:
 
     if (passphrase_needs_free)
         free( psz_passphrase );
+    if (streamid_needs_free)
+	free( psz_streamid );
     freeaddrinfo( res );
     free( url );
 
@@ -436,6 +451,9 @@ vlc_module_begin ()
     add_integer( SRT_PARAM_KEY_LENGTH, SRT_DEFAULT_KEY_LENGTH,
             SRT_KEY_LENGTH_TEXT, SRT_KEY_LENGTH_TEXT, false )
     change_integer_list( srt_key_lengths, srt_key_length_names )
+    add_string(SRT_PARAM_STREAMID, "",
+            N_(" SRT Stream ID"), NULL, false)
+    change_safe()
 
     set_capability("access", 0)
     add_shortcut("srt")

modules/access/srt_common.c

@@ -107,6 +107,7 @@ bool srt_parse_url(char* url, srt_params_t* params)
     params->key_length = -1;
     params->payload_size = -1;
     params->bandwidth_overhead_limit = -1;
+    params->streamid = NULL;
 
     /* Parse URL parameters */
     query = find( url, '?' );
@@ -127,6 +128,9 @@ bool srt_parse_url(char* url, srt_params_t* params)
                 } else if (strcmp( local_params[i].key, SRT_PARAM_PASSPHRASE )
                         == 0) {
                     params->passphrase = val;
+                } else if (strcmp( local_params[i].key, SRT_PARAM_STREAMID )
+                        == 0) {
+                    params->streamid = val;
                 } else if (strcmp( local_params[i].key, SRT_PARAM_PAYLOAD_SIZE )
                         == 0) {
                     int temp = atoi( val );

modules/access/srt_common.h

@@ -39,6 +39,7 @@
 #define SRT_PARAM_CHUNK_SIZE                  "chunk-size"
 #define SRT_PARAM_POLL_TIMEOUT                "poll-timeout"
 #define SRT_PARAM_KEY_LENGTH                  "key-length"
+#define SRT_PARAM_STREAMID                    "streamid"
 
 
 #define SRT_DEFAULT_BANDWIDTH_OVERHEAD_LIMIT 25
@@ -68,6 +69,7 @@ typedef struct srt_params {
     int key_length;
     int payload_size;
     int bandwidth_overhead_limit;
+    const char* streamid;
 } srt_params_t;
 
 bool srt_parse_url(char* url, srt_params_t* params);

modules/access_output/srt.c

@@ -68,6 +68,8 @@ static bool srt_schedule_reconnect(sout_access_out_t *p_access)
     int i_payload_size = var_InheritInteger( p_access, SRT_PARAM_PAYLOAD_SIZE );
     char *psz_passphrase = var_InheritString( p_access, SRT_PARAM_PASSPHRASE );
     bool passphrase_needs_free = true;
+    char *psz_streamid = var_InheritString( p_access, SRT_PARAM_STREAMID );
+    bool streamid_needs_free = true;
     int i_max_bandwidth_limit =
     var_InheritInteger( p_access, SRT_PARAM_BANDWIDTH_OVERHEAD_LIMIT );
     char *url = NULL;
@@ -136,6 +138,11 @@ static bool srt_schedule_reconnect(sout_access_out_t *p_access)
                 passphrase_needs_free = false;
                 psz_passphrase = (char *) params.passphrase;
             }
+	    if (params.streamid != NULL) {
+                free( psz_streamid );
+                streamid_needs_free = false;
+                psz_streamid = (char *) params.streamid;
+            }
         }
     }
 
@@ -168,6 +175,12 @@ static bool srt_schedule_reconnect(sout_access_out_t *p_access)
                 SRTO_PASSPHRASE, psz_passphrase, strlen(psz_passphrase) );
     }
 
+    /* set streamid */
+    if (psz_streamid != NULL && psz_streamid[0] != '\0') {
+        srt_set_socket_option( access_obj, SRT_PARAM_STREAMID, p_sys->sock,
+                SRTO_STREAMID, psz_streamid, strlen(psz_streamid) );
+    }
+
     /* set maximumu payload size */
     srt_set_socket_option( access_obj, SRT_PARAM_PAYLOAD_SIZE, p_sys->sock,
             SRTO_PAYLOADSIZE, &i_payload_size, sizeof(i_payload_size) );
@@ -204,6 +217,8 @@ out:
 
     if (passphrase_needs_free)
         free( psz_passphrase );
+    if (streamid_needs_free)
+        free( psz_streamid );
     free( psz_dst_addr );
     free( url );
     freeaddrinfo( res );
@@ -448,6 +463,9 @@ vlc_module_begin()
     add_integer( SRT_PARAM_KEY_LENGTH, SRT_DEFAULT_KEY_LENGTH, SRT_KEY_LENGTH_TEXT,
             SRT_KEY_LENGTH_TEXT, false )
     change_integer_list( srt_key_lengths, srt_key_length_names )
+    add_string(SRT_PARAM_STREAMID, "",
+            N_(" SRT Stream ID"), NULL, false)
+    change_safe()
 
     set_capability( "sout access", 0 )
     add_shortcut( "srt" )