QAM - Tuning and changing channels - Slow video (HVR-1600)

[ak1i]

Hi,

I've started using PVRX2 (1.1.5 and also just switched to 1.2.9 now) with HVR-1600 to view QAM channels. I am using Windows XP SP2 on a Core Duo 2.8GHz 2GB RAM with latest Hauppauge driver (Jan 2008). I am seeing a problem when changing channel--there will be super-slow-motion video when switching to a channel.

Occasionally, I would see the "No signal detected ..." dialog with signal Quality @ 100% and Strength 0% (it would sometimes switch between 100% Quality/0% Strength and 0% Quality/100% strength), and I would see no video/freezed video/slow-motion video.

This seems to always occur to certain channels.

This problem never occurs when using WinTV 6 from Hauppauge for those same QAM channels. I can always change to those same channels with no problems and video would play fine in WinTV 6.

Using Hauppauge's signal montior, I can see the signal strength to be about SNR 31.2-32 during the time I see the problem w/ PVRX2 with that channel, depending on the channel/condition of the time. I assume this should be good enough signal strength as WinTV 6 has no problems displaying video when chaning to the same channel.


I tried several workaround's:

- if I switch to another channel and switch back to this channel in PVRX2 once or twice, the problem goes away and video plays normally again.

- if I quit PVRX2, relaunch, and then select Live TV from the main menu, I can always successfully view this channel w/o the no video/freezed/slow-motion video issue (so far).

However, the "No signal detected" dialog would sometimes come up despite video plays fine when viewing this channel right after relaunch. You can actually see the dialog over the video which is playing behind. This seems to occur the most if I go to Live TV to that channel right after launching PVRX2. I have to switch to main menu and switch back to Live TV to dismiss this dialog.


I tried setting 'BDADisableStatusChecks' to 'true' but that only dismisses the dialog and does not clear up the slow motion video issue during channel change.

This occurs with both GBPVR and PVRX2 and both in 1.1.5 and in current 1.2.9 and is happening for certain channels everyday.

Also, I notice the QAM physical channel numbers found by Config for quite many QAM channels are not the same as the numbers found by SageTV--they seem to be a bit off (for example, 107.7 instead of 107.9). I think the channel numbers from SageTV is correct as I also tried another tuner and found the channel numbers for same channels to match SageTV's.


thx

[pcostanza]

You seem to have gotten on better than I have with the 1600. I'm using Vista but in WinTV, it picks up a number of QAM channels but only 1 actually seems to work. In GBPVR, it also picks up a number of them but none get me a picture. It may be my ISP (Cox) and I plan on calling them soon to ask questions.
For the meantime, I'm having great luck with OTA channels in GBPVR. In the states it's still early and I also hope to see updated drivers for the 1600 soon.

[Anthony]

> I also hope to see updated drivers for the 1600 soon.

I haven't had the chance to try them, but I believe Hauppauge has new beta drivers for the HVR-1600 on their web site.

Anthony

[pcostanza]

> I also hope to see updated drivers for the 1600 soon.

I haven't had the chance to try them, but I believe Hauppauge has new beta drivers for the HVR-1600 on their web site.

Anthony

Thanks. I do see some listed under the beta section but it's not dated. I also now remember seeing Vista tell me there was an update available for my Hauppauge tuner which I let it do this past weekend. I'm not sure Vista would update with a beta driver but I will say Vista has had no problems with any of my Hauppauge cards.

[whurlston]

ak1i, have you tried a different video and audio decoder?

[carpeVideo]

I have had this happen as well. If I change channels it may go away.

I think the issue is with video format/bit rate changing mid stream, perhaps the splitter or decoder has issues handling that. I think I have had some recordings where the broadcast switched mid-stream that causes odd artifacts or crashes in playback.

[ak1i]

I must be lucky--I am using Comcast and I have about 50 QAM clear channels.

SageTV 6.35 /BTV 4.61 both change QAM channels ok.

I'm using CyberLink video and audio decoder and 'VMR9 Custom' Video Renderer (The PC has 8400GS 128MB).

I just tried changing to Nero/HCW /ATI/InterVideo NonCSS video decoders and there is no change in behavior in all cases. I relaunched PVRX2 after changing videodecoder and saving in Config--that should be good enough to pick up the new decoder? Actually ATI decoder gives me stuttering videos even when channel change is ok using the workaround.

Should I try changing the demultiplexer also (it's the default MS demux right now)?


I found a somewhat simpler workaround:

if I am stuck w/ freezed/no/slow video when changing to that channel in Live TV, I switch to main menu and immediately switch back to Live TV (somewhat similar to relaunch/main menu/Live TV, but no need to relaunch), then video would always display ok. This seems to be the best workaround right now.

Perhaps something can be done while changing channels so it'd be similar to going from main menu to LiveTV so video displays ok?

[ak1i]

BTW, I am using Hauppauge HVR-1600 driver version 1.62.26028.0 (1/28/2008) if anyone is interested.

ftp://wtv:Support07!@www.hauppauge.com/S...igned).zip

[ak1i]

I have one more piece of information:

if the channel video in Live TV is appearing in slow-motion (when changing channel), and I hit the 'Home' key, the video continues on the left (in slow motion) and the main menu's items appear on the right. Now if I press up/down arrows to scroll thru' the menu items, it'd stutter thru' the items in the list slowly.

So this does not only affect the TV video, but also the menu items on the right after I hit the 'Home' key.

[ak1i]

If after I hit the 'Home' key, and I hit Live TV again, the TV video displays normally again.

So these are the 3 workarounds:

- works sometimes: change channel and back again (sometimes still won't help)
- always works:
- go to Main Menu and back to Live TV
- hit 'Home' key and then back to Live TV