diff --git a/transcoder/utils/throttler.c b/transcoder/utils/throttler.c
index ca41f764..fbffd868 100644
--- a/transcoder/utils/throttler.c
+++ b/transcoder/utils/throttler.c
@@ -9,12 +9,18 @@
 #include "throttler.h"
 #include "json_parser.h"
 
+// forward declarations
 static void doThrottle(float maxDataRate,
-    bool useStatsDataRate,
     double minThrottleWaitMs,
     samples_stats_t *stats,
     AVRational targetFramerate);
 
+static
+bool getFrameRateFromMediaInfo(
+    const transcode_mediaInfo_t *mediaInfo,
+    AVRational *result);
+
+// api
 int
 throttler_init(samples_stats_t *stats,throttler_t *throttler) {
     json_value_t *config = GetConfig();
@@ -32,15 +38,13 @@ throttler_process(throttler_t *throttler,transcode_session_t *transcode_session)
    if(throttler && throttler->maxDataRate < INFINITY) {
         const transcode_mediaInfo_t *mediaInfo = transcode_session ? transcode_session->currentMediaInfo : NULL;
         if(mediaInfo && mediaInfo->codecParams){
-            const bool isVideo = mediaInfo->codecParams->codec_type == AVMEDIA_TYPE_VIDEO;
-            // TODO: currently only AAC 'fps' is supported, MP3 and opus etc.
-            // may have a different frame allocation schemes
-            const AVRational frameRate = isVideo ? mediaInfo->frameRate :
-                (AVRational){ .num = mediaInfo->codecParams->sample_rate ,
-                  .den = 1024 };
+            AVRational frameRate = {0};
+
+            if(!throttler->useStatsDataRate) {
+                getFrameRateFromMediaInfo(mediaInfo,&frameRate);
+            }
 
             doThrottle(throttler->maxDataRate,
-                throttler->useStatsDataRate,
                 throttler->minThrottleWaitMs,
                 throttler->stats,
                 frameRate);
@@ -48,50 +52,79 @@ throttler_process(throttler_t *throttler,transcode_session_t *transcode_session)
     }
 }
 
+// implementation:
+static
+bool
+getFrameRateFromMediaInfo(
+    const transcode_mediaInfo_t *mediaInfo,
+    AVRational *result) {
+   if(AVMEDIA_TYPE_VIDEO == mediaInfo->codecParams->codec_type){
+       *result = mediaInfo->frameRate;
+       return true;
+   }
+   else if(AV_CODEC_ID_AAC == mediaInfo->codecParams->codec_id){
+        *result = (AVRational){
+            .num = mediaInfo->codecParams->sample_rate ,
+            .den = 960 // 1024
+        };
+        return true;
+   }
+
+   LOGGER(CATEGORY_THROTTLER,
+       AV_LOG_DEBUG,"%s. unsupported (av) codec %d",
+       __FUNCTION__,
+       mediaInfo->codecParams->codec_id);
+
+   return false;
+}
+
+static
+int64_t calculateThrottleWindow(samples_stats_t *stats,AVRational targetFramerate){
+     if(targetFramerate.den == 0) {
+        if(stats->dtsPassed < 90000) {
+            return av_rescale(1000*1000,stats->dtsPassed , 90000);
+        }
+     } else if(stats->totalFrames * targetFramerate.den < targetFramerate.num) {
+         // during startup frame rate is not stable and usually is high
+         // due to system delays related to various factors. therefore.
+         // we must work with high pressures in small intervals of time.
+         // In order to not overshoot we take smaller intervals proportional to
+         // time passed since beginning.
+         return av_rescale_q(1000*1000,
+             (AVRational){stats->totalFrames,1},
+             targetFramerate);
+      }
+      return 1000 * 1000;
+}
+
 static
 void
 doThrottle(float maxDataRate,
-    bool useStatsDataRate,
     double minThrottleWaitMs,
     samples_stats_t *stats,
     AVRational targetFramerate)
 {
+     const double currentDataRate = targetFramerate.den == 0 ? stats->currentRate :
+        stats->currentFrameRate * targetFramerate.den / (float)targetFramerate.num;
 
-    if(targetFramerate.den > 0 && targetFramerate.num > 0) {
-         const double currentDataRate = useStatsDataRate ? stats->currentRate :
-            stats->currentFrameRate * targetFramerate.den / (float)targetFramerate.num;
-
-         samples_stats_log(CATEGORY_RECEIVER,AV_LOG_DEBUG,stats,"Throttle-Stats");
-
-         LOGGER(CATEGORY_THROTTLER,
-            AV_LOG_DEBUG,"%s. data rate current: %.3f max: %.3f",
-            __FUNCTION__,
-            currentDataRate,
-            maxDataRate);
-
-         if(currentDataRate > maxDataRate) {
-             // going to sleep for a period of time gained due to race
-              int throttleWindowUs;
-              if(stats->totalFrames * targetFramerate.den < targetFramerate.num) {
-                 // during startup frame rate is not stable and usually is high
-                 // due to system delays related to various factors. therefore.
-                 // we must work with high pressures in small intervals of time.
-                 // In order to not overshoot we take smaller intervals proportional to
-                 // time passed since beginning.
-                 throttleWindowUs = av_rescale_q(1000*1000,
-                     (AVRational){stats->totalFrames,1},
-                     targetFramerate);
-              } else {
-                 throttleWindowUs = 1000 * 1000;
-              }
-             int throttleWaitUSec = (currentDataRate - maxDataRate) * throttleWindowUs;
-             if(throttleWaitUSec > minThrottleWaitMs * 1000) {
-                 LOGGER(CATEGORY_THROTTLER,AV_LOG_INFO,"%s. throttling %.3f ms",
-                 __FUNCTION__,
-                 throttleWaitUSec / 1000.f);
-                 stats->throttleWait += av_rescale_q(throttleWaitUSec, clockScale, standard_timebase);
-                 av_usleep(throttleWaitUSec);
-             }
+     samples_stats_log(CATEGORY_RECEIVER,AV_LOG_DEBUG,stats,"Throttle-Stats");
+
+     LOGGER(CATEGORY_THROTTLER,
+        AV_LOG_DEBUG,"%s. data rate current: %.3f max: %.3f",
+        __FUNCTION__,
+        currentDataRate,
+        maxDataRate);
+
+     if(currentDataRate > maxDataRate) {
+         // going to sleep for a period of time gained due to race
+         int64_t throttleWindowUs = calculateThrottleWindow(stats,targetFramerate);
+         int throttleWaitUSec = (currentDataRate - maxDataRate) * throttleWindowUs;
+         if(throttleWaitUSec > minThrottleWaitMs * 1000) {
+             LOGGER(CATEGORY_THROTTLER,AV_LOG_INFO,"%s. throttling %.3f ms",
+             __FUNCTION__,
+             throttleWaitUSec / 1000.f);
+             stats->throttleWait += av_rescale_q(throttleWaitUSec, clockScale, standard_timebase);
+             av_usleep(throttleWaitUSec);
          }
-    }
+     }
 }
\ No newline at end of file