Frame rate for 1080i transcoding at half speed

[mkanet]

I have no issues with Placeshifter anymore since I upgraded my CPU to 3.2GHz.

However, I have a strange issue with with ONLY 1080i video. Frame rate appears to be at only 15fps (or possibly less) as opposed to 30fps. Even if I turn off post-processing wtih CPU power to spare. I dont have this issue with 720p/480i/480p/analog video

I also noticed that the bitrate doesnt go any higher than ~150kbps for 1080i transcoded video; even if manually set the bitrate to higher. If I choose anything that's not 1080i, everything works correctly.

It doesnt matter which version of the nvidia decoder I use. They all work the same way.

How does 1080i transcoded video look for other people?

[mkanet]

I also noticed that sound also falls behind. I had noticed this symptom before, but couldn't isolate the cause of it... now I know that it's related to high bitrate 1080i (19.2kbps) Whatever it is, it seems to only happen on NBC and CBS.

The weird thing is that it doesnt happen on PBS 1080i or independantly owned local San Francisco KRON 1080i channels. The only thing different with these channels is, they have allocated relatively less bandwidth to their digital sub-channels.

It seems the only difference between CBS/NBC and all other channels is the bitrate of the source is significantly higher.

What can I do to fix this? SageTV support asked to me send log files, but not sure if Logs will provide any useful information for just those two channels.

[ldavis]

I reported the same thing some time ago but I have not gotten any response. I only have about 2.7 GHz of CPU so I was not sure if that was the problem, but you have confirmed this is not CPU releated. 1080i channels seem to encode/stream video slower than the audio. Strange.

[mkanet]

Okay, now I know it's not just me. Before my CPU upgrade, I had a 2.6GHz CPU. It wasn't fast enough for any HD streams. The symptom for me, when there isn't enough CPU power is, the video starts to skip and only show a video/picture slideshow.

However, this seems to be a different issue.. If I had to guess, it's possible that it some strange bug between Nvidia decoders and the video transcoder.

I hope that we can get others at SageTV to reproduce and fix this.