diff --git a/mythtv/libs/libmythtv/avformatdecoder.cpp b/mythtv/libs/libmythtv/avformatdecoder.cpp
index 3d5b807c7f0..b65b28d270a 100644
--- a/mythtv/libs/libmythtv/avformatdecoder.cpp
+++ b/mythtv/libs/libmythtv/avformatdecoder.cpp
@@ -1768,14 +1768,14 @@ int AvFormatDecoder::ScanStreams(bool novideo)
 
                 codec_is_mpeg = CODEC_IS_FFMPEG_MPEG(enc->codec_id);
 
+                // ffmpeg does not return a bitrate for several codecs and
+                // formats. Forcing it to 500000 ensures the ringbuffer does not
+                // use optimisations for low bitrate (audio and data) streams.
                 if (enc->bit_rate == 0)
-                    unknownbitrate = true;
-
-                // HACK -- begin
-                // ffmpeg is unable to compute H.264 bitrates in mpegts?
-                if (CODEC_IS_H264(enc->codec_id) && enc->bit_rate == 0)
+                {
                     enc->bit_rate = 500000;
-                // HACK -- end
+                    unknownbitrate = true;
+                }
 
                 StreamInfo si(i, 0, 0, 0, 0);
                 tracks[kTrackTypeVideo].push_back(si);
diff --git a/mythtv/libs/libmythtv/ringbuffer.cpp b/mythtv/libs/libmythtv/ringbuffer.cpp
index 96115b2b55c..e9171171a98 100644
--- a/mythtv/libs/libmythtv/ringbuffer.cpp
+++ b/mythtv/libs/libmythtv/ringbuffer.cpp
@@ -352,7 +352,6 @@ void RingBuffer::CalcReadAheadThresh(void)
     const uint KB2   =   2*1024;
     const uint KB4   =   4*1024;
     const uint KB8   =   8*1024;
-    const uint KB16  =  16*1024;
     const uint KB32  =  32*1024;
     const uint KB64  =  64*1024;
     const uint KB128 = 128*1024;
@@ -366,8 +365,7 @@ void RingBuffer::CalcReadAheadThresh(void)
                      (estbitrate >  9000) ? KB256 :
                      (estbitrate >  5000) ? KB128 :
                      (estbitrate >  2500) ? KB64  :
-                     (estbitrate >  1000) ? KB32  :
-                     (estbitrate >   500) ? KB16  :
+                     (estbitrate >=  500) ? KB32  :
                      (estbitrate >   250) ? KB8   :
                      (estbitrate >   125) ? KB4   : KB2;
     if (rbs < CHUNK)