Go back to processing TxNumSpeechSamples every TX cycle.

src/pipeline/TxRxThread.cpp

@@ -582,7 +582,7 @@ void TxRxThread::txProcessing_()
                       codec2_fifo_used(cbData->outfifo1), codec2_fifo_free(cbData->outfifo1), nsam_one_modem_frame);
     	}
 
-        int nsam_in_48 = FRAME_DURATION * inputSampleRate_;
+        int nsam_in_48 = freedvInterface.getTxNumSpeechSamples() * ((float)inputSampleRate_ / (float)freedvInterface.getTxSpeechSampleRate());
         assert(nsam_in_48 > 0);
 
         int             nout;