FS-9601: mod_opus: make adjustable bitrate mutually exclusive with FEC enforcing...

add step calculation for bitrate adjustment, fix bug on context settings

diff --git a/src/mod/codecs/mod_opus/mod_opus.c b/src/mod/codecs/mod_opus/mod_opus.c
index d4b5b81ac34fedcaa3cb27f9da2d77bb9829b55b..8eb3396db9eb3cdcba6f0367e57fb0ec4a0d97b3 100644 (file)
--- a/src/mod/codecs/mod_opus/mod_opus.c
+++ b/src/mod/codecs/mod_opus/mod_opus.c
@@ -496,7 +496,6 @@ static switch_status_t switch_opus_init(switch_codec_t *codec, switch_codec_flag
                codec_fmtp_only_remote.private_info = &opus_codec_settings_remote;
                switch_opus_fmtp_parse(codec->fmtp_in, &codec_fmtp_only_remote);
        }
-       context->codec_settings = opus_codec_settings;
 
        /* If bitrate negotiation is allowed, verify whether remote is asking for a smaller maxaveragebitrate */
        if (opus_prefs.maxaveragebitrate &&
@@ -619,8 +618,8 @@ static switch_status_t switch_opus_init(switch_codec_t *codec, switch_codec_flag
                                        opus_encoder_ctl(context->encoder_object, OPUS_SET_BITRATE(fec_bitrate)); 
                                        /* will override the maxaveragebitrate set in opus.conf.xml  */ 
                                        opus_codec_settings.maxaveragebitrate = fec_bitrate;
-                                       context->control_state.keep_fec = opus_prefs.keep_fec ; 
                                }
+                               context->control_state.keep_fec = opus_prefs.keep_fec;
                        }
                }
 
@@ -669,6 +668,7 @@ static switch_status_t switch_opus_init(switch_codec_t *codec, switch_codec_flag
                }
        }
 
+       context->codec_settings = opus_codec_settings;
        codec->private_info = context;
 
        return SWITCH_STATUS_SUCCESS;
@@ -1164,6 +1164,21 @@ static switch_status_t switch_opus_control(switch_codec_t *codec,
                                                                          context->old_plpct, plpct);
                                }
                        }
+                       if (opus_prefs.adjust_bitrate) {
+                               /* make bitrate adjust the step , but keep it as a  multiple of 400 (see OpusFAQ). 
+                                * usual RTCP interval is 5 seconds  which is long time - the step should be bigger. */
+                               /* step's value should depend on packet loss too, to decrease more abrubtly 
+                                * at high packet loss. */
+                               int base_step = 400; /*bps*/
+                               int range = context->codec_settings.maxaveragebitrate - SWITCH_OPUS_MIN_BITRATE;
+                               float steps = (float)((float)(range / 100) / base_step);
+                               int br_step = (int)(round(steps) * base_step) * plpct; 
+                               if (globals.debug || context->debug) {
+                                       switch_log_printf(SWITCH_CHANNEL_LOG, 
+                                                       SWITCH_LOG_DEBUG, "Opus encoder: bitrate increase/decrease step now is: %d bps, range:%d\n", br_step, range); 
+                               }
+                               context->control_state.increase_step = context->control_state.decrease_step = br_step; 
+                       }
                        context->old_plpct = plpct;
                }
                break;
@@ -1192,8 +1207,10 @@ static switch_status_t switch_opus_control(switch_codec_t *codec,
                                        int br_step = context->control_state.decrease_step?context->control_state.decrease_step:400;
                                        opus_encoder_ctl(context->encoder_object, OPUS_GET_BITRATE(&current_bitrate));
                                        if (current_bitrate > SWITCH_OPUS_MIN_BITRATE) {
-                                               if ((context->control_state.keep_fec) && (current_bitrate < SWITCH_OPUS_MIN_FEC_BITRATE)) {
-                                                       opus_prefs.keep_fec = 0; /* no point to try to keep FEC enabled anymore, we're low on network bandwidth (that's why we ended up here) */
+                                               if (context->control_state.keep_fec) {
+                                                       /* no point to try to keep FEC enabled anymore, 
+                                                        * we're low on network bandwidth (that's why we ended up here) */
+                                                       opus_prefs.keep_fec = 0;
                                                }
                                                opus_encoder_ctl(context->encoder_object, OPUS_SET_BITRATE(current_bitrate-br_step));
                                                if (globals.debug || context->debug) {