New Zealand Channel FOUR Skip Problem with Sandy Bridge

[waldoverkill]

Hi All

I have recently built my second HTPC using the following:

Intel DH67BL MicroATX LGA1155 DDR3-1333 Motherboard

CORE I5 2500 3.30GHZ 6MB LGA1155 CPU
2x hauppauge HVR2200 tuners

The problem I am having only seems to occur on channel FOUR (I am in New Zealand).

When anyone skips forwards using the remote while watching recorded TV it works fine the first time. Subsequent skips nearly always skip to a blank screen, audio playing, time bar moving.

If you wait 10-30 seconds it comes right or if you stop playback then resume it comes right.

Any ideas anyone?

Cheers

[gbwelly]

I see this on my old core2 duo system too with an Nvidia 9400 graphics card, asus tiger and avermedia/pinnacle tuners. I think it's just the way they are encoding most shows. For example some copies of Sesame Street are easily skippable, care bears and top chef masters are laggy. I've just been putting up with it and being easy on the skips through the ads.
That said, given it's your second system, does your first media center have the same problem? If not I'd be interested to know what's different.

[waldoverkill]

Same problem on the first system. I was hoping a rebuild would fix it.

[CyberSimian]

When anyone skips forwards using the remote while watching recorded TV it works fine the first time. Subsequent skips nearly always skip to a blank screen, audio playing, time bar moving.

If you wait 10-30 seconds it comes right or if you stop playback then resume it comes right.

Are your channels digital or analogue? Digital channels work by transmitting a key frame that encodes the entire picture digitally, but subsequent frames consist only of differences from the key frame. This significantly reduces the datastream required. At regular time intervals a new key frame is sent. The interval between key frames affects the bandwidth required for a channel: a short interval between key frames requires a higher bandwidth (i.e. larger datastream), whereas a long interval between key frames requires a lower bandwidth (less datastream). Lower bandwidth is likely to be favoured by poorly-funded channels (who have to pay for bandwidth).

When you use the skip key on the remote control, you might be lucky and skip to the start of a key frame in the recorded file, in which case replay should resume immediately. But in general you will skip to a point between key frames. The previous key frame is no longer relevant, so media center has to read the recorded file until a new key frame in encountered, at which point replay can resume. Until this happens the screen may freeze, or appear blank (depending on what the writers of the replay program thought was best).

In the UK, datastream rates vary between channels, and on those which have the lowest datastream rates I also experience a similar effect to you, but it is a much smaller effect -- perhaps 2-3 seconds of blank screen after a skip forward. 10-30 seconds of blank screen sounds improbably large to be caused by the key-frame effect described above.

-- from CyberSimian in the UK

[spaceboy]

In the UK, datastream rates vary between channels, and on those which have the lowest datastream rates I also experience a similar effect to you, but it is a much smaller effect -- perhaps 2-3 seconds of blank screen after a skip forward. 10-30 seconds of blank screen sounds improbably large to be caused by the key-frame effect described above.

i have never ever seen this and i receive digital channels and have a Sandy Bridge motherboard

[gbwelly]

i have never ever seen this and i receive digital channels and have a Sandy Bridge motherboard

Both UK and NZ use H.264 over DVB-T. Are your digital channels MPEG2?

[waldoverkill]

New Zealand channels are H264. I understand the keyframe idea but 30 seconds sounds too long. I windered whether this channel is interlaced differently to the others in NZ and this was upsetting the Microsoft decoder.

[spaceboy]

Both UK and NZ use H.264 over DVB-T. Are your digital channels MPEG2?

HD channels are h.264 and SD channels are MPEG2. I'm no expert on this but i know i have never seen what you are describing

[spaceboy]

and its DVB-S and DVB-S2 but I don't think that makes a difference?

[waldoverkill]

The channels I am seeign this on are all DVB-T.