FS-6992 [mod_opus] global configuration or maxplaybackrate and maxaveragebitrate

from opus.conf.xml

conf/vanilla/autoload_configs/opus.conf.xml

@@ -2,5 +2,18 @@
     <settings>
         <param name="use-vbr" value="1"/>
         <param name="complexity" value="10"/>
+
+        <!--
+           maxaveragebitrate: the maximum average codec bitrate (values: 6000 to 510000 in bps) 0 is not considered
+           maxplaybackrate: the maximum codec internal frequency (values: 8000, 12000, 16000, 24000, 48000 in Hz) 0 is not considered
+           This will set the local encoder and instruct the remote encoder trough specific "fmtp" attibute in the SDP.
+
+           Example: if you receive "maxaveragebitrate=20000" from SDP and you have set "maxaveragebitrate=24000" in this configuration
+                    the lowest will prevail in this case "20000" is set on the encoder and the corresponding fmtp attribute will be set
+                    to instruct the remote encoder to do the same.
+        -->
+        <param name="maxaveragebitrate" value="0"/>
+        <param name="maxplaybackrate" value="0"/>
+
     </settings>
 </configuration>

src/mod/codecs/mod_opus/mod_opus.c

@@ -78,6 +78,8 @@ struct opus_context {
 struct {
     int use_vbr;
     int complexity;
+    int maxaveragebitrate;
+    int maxplaybackrate;
     switch_mutex_t *mutex;
 } opus_prefs;
 
@@ -240,6 +242,15 @@ static switch_status_t switch_opus_init(switch_codec_t *codec, switch_codec_flag
 	memset(&codec_fmtp, '\0', sizeof(struct switch_codec_fmtp));
 	codec_fmtp.private_info = &opus_codec_settings;
 	switch_opus_fmtp_parse(codec->fmtp_in, &codec_fmtp);
+
+	/* Verify if the local or remote configuration are lowering maxaveragebitrate and/or maxplaybackrate */
+	if ( opus_prefs.maxaveragebitrate && (opus_prefs.maxaveragebitrate < opus_codec_settings.maxaveragebitrate || !opus_codec_settings.maxaveragebitrate) ) {
+		opus_codec_settings.maxaveragebitrate = opus_prefs.maxaveragebitrate;
+	}
+	if ( opus_prefs.maxplaybackrate && (opus_prefs.maxplaybackrate < opus_codec_settings.maxplaybackrate || !opus_codec_settings.maxplaybackrate) ) {
+		opus_codec_settings.maxplaybackrate = opus_prefs.maxplaybackrate;
+	}
+
 	codec->fmtp_out = gen_fmtp(&opus_codec_settings, codec->memory_pool);
 
 	if (encoding) {
@@ -260,8 +271,6 @@ static switch_status_t switch_opus_init(switch_codec_t *codec, switch_codec_flag
         }
         
 
-
-
 		/* Setting documented in "RTP Payload Format for Opus Speech and Audio Codec"  draft-spittka-payload-rtp-opus-03 */
 		if( opus_codec_settings.maxaveragebitrate ) { /* Remote codec settings found in SDP "fmtp", we accept to tune the Encoder */
 			opus_encoder_ctl(context->encoder_object, OPUS_SET_BITRATE(opus_codec_settings.maxaveragebitrate));
@@ -430,6 +439,17 @@ static switch_status_t opus_load_config(switch_bool_t reload)
 				opus_prefs.use_vbr = atoi(val);
 			} else if (!strcasecmp(key, "complexity")) {
 				opus_prefs.complexity = atoi(val);
+			} else if (!strcasecmp(key, "maxaveragebitrate")) {
+				opus_prefs.maxaveragebitrate = atoi(val);
+				if ( opus_prefs.maxaveragebitrate < 6000 || opus_prefs.maxaveragebitrate > 510000 ) {
+					opus_prefs.maxaveragebitrate = 0; /* values outside the range between 6000 and 510000 SHOULD be ignored */
+				}
+			} else if (!strcasecmp(key, "maxplaybackrate")) {
+				opus_prefs.maxplaybackrate = atoi(val);
+				if ( opus_prefs.maxplaybackrate != 8000 && opus_prefs.maxplaybackrate != 12000 && opus_prefs.maxplaybackrate != 16000
+							&& opus_prefs.maxplaybackrate != 24000 && opus_prefs.maxplaybackrate != 48000) {
+					opus_prefs.maxplaybackrate = 0; /* value not supported */
+				}
 			}
 		}
 	}