Bad stuttering when client buffer below 2 secs

[Olive]

Hi,

I'm still evaluating the Placeshifter client over a 54G wifi LAN, with Dynamic Streaming System enabled ;-)

I found another issue, this time playing a recording that starts with rather static images then switches to dynamic clips with fast movements. I was expecting the quality to degrade somewhat with the movements (just as I see in the static bitrate output of my hardware encoder tuner), but that the automatic bitrate feature would deal with it and keep the playback smooth.

What I see however is that the playback starts to stutter very badly. There are short pauses (clicks) in the audio, but more importantly the video repeatedly freezes for several seconds then jumps a few seconds forward to the next frozen frame. It looks as if a video frame was dropped then all the following delta-frames had to be dropped as well until the next key-frame.

What's also interesting is that the stuttering repeadtedly starts when the client buffer size decreases below 2 seconds (see stats attached). Which reminds me of a similar issue we've had in a Windows streaming project. What we eventually found is that the default DirectShow Audio Renderer from Microsoft maintains its own internal buffer for re-sampling, about 1.5 to 2 secs. When it can't get enough data to keep its internal buffer full, it then starts to do very strange things with the DirectShow graph reference clock.

The solution was to replace the AR with our own. However for the SageTV Placeshifter, a workaround might be to dynamically adjust the target bitrate in such a way as to avoid having the client buffer size go below 2 secs. Would that be possible?

Cheers,

Olive