live tv 'glitchy' until I pause and then play

[Takenover83]

Friendly bump, as this fell back to the 2nd page, where it might get overlooked.

[johnsonx42]

I am having the same problem. I can sometimes fire up Pvrx2, click live tv, and hear the audio for a second, and then it cuts out. I then hit the pause button, and wait for the controls to pop back up, and click pause again, to unpause, and everything plays fine. I have to do this every time I change the channel. I tried the patch, and tried setting the delay to 4000, but the problem persist. My source is QAM.

I just want to check that you do not have Live Preview on? And you are using the TS Mux?

[johnsonx42]

final followup on this thread:

I've finally given up on watching TV in time-shift mode by default. Even the maximum 4000ms pre-delay did not always eliminate the glitching (or the tendency to dump back to the menu), and made channel changes agonizingly slow.

I've decided to go with Preview mode, and make it a matter of user training to switch into time-shift mode if there's any inkling that you'll want it. Coming from a TiVo (which always time-shifts both tuners, even when you're not watching), this will be odd at first but for now is far preferrable to the horribly unreliable behaviour when time-shifting all the time.

In the end I decided this just wasn't the hill I wanted to die on.

[mmatheny]

Sub - I applied this patch, as I also have the same issue, and it corrects it the same way, pressing the LiveTV button, or a quick rewind. However, it did not work, and livetv delay is 500.

This only happens with HD QAM. However, I'm not sure if it's because I hear it, but it only seems to be audio - I will look (hear) more closely and get back.

[mmatheny]

OK - changed it to 1000, and seems to be OK now! Thanx on this one!

[khanu]

I just got an HD Homerun and after a few hours of forum scrubbing and knocking my head on the wall, I figured it out (stupid ffdshow not having an mpeg2 codec setup by default). Once i got it rolling though i started seeing the exact same problems that are being described here (audio/video is intermittent and unwatchable). I'll try the fixed mentioned here and report back.

Thanks Sub and community for such great support!

[khanu]

Quick couple of questions.

What is preview mode vs livetv? Where are settings?

Where are TS Mux settings.

I want to make sure I know know the exact steps I should take.

Thanks,
K

[sub]

Live TV can be run in two ways:

'live preview mode' where video/audio is sent straight from the capture device to the screen/speakers. It has faster channel changes than 'timeshift mode'. Live preview mode is enabled by default, but can be disabled by unchecking the live preview setting on the misc tab of the config app.

'timeshift mode' is where data coming from the capture device is recorded to disk and played from there. It has a slower channel changes than live preview mode, but is able to be paused/rewind etc. Mux filters are used when recording to disk (ie timeshift mode, or doing recordings) - the 'ts mux' mux option is available in the 'misc2' tab of the config app.

[khanu]

Ok, I updated my NativeUtilities with the patch above. I turned off live preview, made sure I had TS MUX selected in misc2. I am still having the intermittent problems.

I'm thinking it might be my video codecs. When I use MPV Decoder Filter the video stops every couple seconds but the audio is fine. When I use ffdshow (libmpeg2), both audio and video cutout, same with DScaler.

I continue to try different decoder combinations with live preview and timeshift mode and the same things occur.

I have the hd homerun and viewing the channels through VLC works just fine.

Are there better decoders I should be using, or any other settings i can change to get gb-pvr to display my video better?

Thanks,
k

[johnsonx42]

Just to be clear, the NativeUtilities.dll patch from this thread pertains ONLY to time-shift mode. Without the patch, the playback process does not respect the Live TV Pre-delay setting. This delay allows the recording file to grow a bit more before the playback process starts reading the file; it seems if the playback process reads too close to the live stream being recorded, it sort of trips and glitches the playback. Any similar problem in Preview mode is caused by something else.

To see your problem is related to the problem described in this thread, do the following:

When in time-shift mode with the 'glitch' occurring, press Pause and then press Play again after a second - if the playback is now smooth, then yes, you have the same problem and increasing the Live TV Pre-Delay (on the playback tab in config) *may* help. If pausing for a second doesn't help, then your trouble lies elsewhere.

As I posted above though, ultimately I could not make Timeshift-Always mode (ie, non-Live Preview mode) work reliably with or without the patch, even with the pre-delay set to 4000ms, so I gave up. Timeshifting itself works perfectly for me, but only when initiated from Preview Mode.

@sub - I think there's more to this problem than just the pre-delay. I can set the delay to zero (or run without the patched dll), and then manually pause the playback for just a moment and then resume, which makes the playback perfectly smooth. In turn however, if I set the pre-delay to 4000ms, which is far longer than the amount of time I need to pause when fixing it manually, the playback often still won't be smooth (and depending on the decoder in use, it will tend to exit back to the menu within a few seconds).

The delay itself does seem to work, as setting it to 4000ms makes channel changes take several seconds longer than with the delay set to zero, but it doesn't accomplish what pausing for the slightest moment does. It should I know, but it just doesn't seem to. What's even stranger is that the patch *does* reduce the problem, so clearly it's related, but it doesn't fix it completely. I don't know what that all adds up to.