Reclock and live TV (1 Viewer)

[tourettes]

Are you really positive that your system never drops a frame, or could it be possible that you are one of the fortunate who doesn't see this? If you watch a news ticker for a minute, does it go completely smooth all the time? I just don't undestand how perfect playback would be possible without using Reclock.

Unfortunately I'm not one of those lucky ones that don't see the judder. Perfect playback is possible if audio and video clocks run at the same speed. So it depends on the luck what HW you have.

btw. Have you noticed that there is ugly stuttering when some news clips are converted from NTSC to PAL?

For example in my setup, MediaPortal always claims zero dropped frames, but during pans, news tickers or scrolling credits there is a very brief "jump" once in three to five seconds.

News tickers are smooth always (unless there is dropped data in the signal).

 

[Spragleknas]

Short and simple answer.. Hmm.. Anyone interested in a Sony 40D3000 then? Guess I have to buy myself a new TV.

Are you certain that you can't force the TV to do 50 Hz?
I made my Tatung do 50 Hz @ 1920x1080, although EDID only wanted 60 (and other "useless" rr).

 

[kenwonders]

If you're in EU then Sony 40D3000 will support 50hz. It might not in pixel resolution over VGA, but pixel resolution < refresh rate in my book.

 

[Owlsroost]

Are you really positive that your system never drops a frame, or could it be possible that you are one of the fortunate who doesn't see this? If you watch a news ticker for a minute, does it go completely smooth all the time? I just don't undestand how perfect playback would be possible without using Reclock.

For example in my setup, MediaPortal always claims zero dropped frames, but during pans, news tickers or scrolling credits there is a very brief "jump" once in three to five seconds.

How often the frame drops/repeats happen is down to the differences in video & audio clock rates between the broadcaster and the PC - basically because the standard PC architecture uses unrelated video & sound clocks the A/V synchonisation model is fundamentally broken. If you are lucky and have have close to perfect frequency video and audio clocks the frame drops/repeats will be rare (and I think Vista+EVR handles the sync problems quite well).

ReClock attempts to fix the video-audio sync problem when playing files by accurately measuring the video card refresh (frame) rate, pretending to the system that the frame rate of the source file is the same (or a multiple/division of it) so that it is rendered out at exactly the correct rate to match the display, and then re-sampling the audio to match it to the refresh rate.

With live TV, the data is pushed to the PC by the broadcast so ReClock can't fix the problem.....except that (as a workaround) if you skip back in the timeshift buffer a little, MP is then doing the equivalent of playing from a file - so ReClock can work in this situation.

(Hardware STBs have video/audio clock generators which are automatically synchronised to the broadcast MPEG clock, so they don't suffer from the problems)

Tony

 

[tourettes]

With live TV, the data is pushed to the PC by the broadcast so ReClock can't fix the problem.....except that (as a workaround) if you skip back in the timeshift buffer a little, MP is then doing the equivalent of playing from a file - so ReClock can work in this situation.

Actually you wont even have to jump backwards. If the stream clock (PCR) is running as fast or faster than the PC video clock then the playback is same as with the file. TsReader wont ever play the stream as it is, but it will have a small delay between the live point and the current playback position (just to prevent the possible buffer underruns).

ReClock is just most likely not behaving well when it comes to zapping. I.e. it confuses it's internal sync logic when the playback freezes for a moment and then its causing havoc after that

Maybe James on Slysoft forum could comment what happens actually on the Reclock side when the zapping is done (as he has access to the Reclock source code, I can only guess how the code behaves in such situation )

Of cource the optimal situation could be received when we could "patch" the video cards crystal to match perfectly with the broadcast PCR, but as TsReader is always running a little bit behind the current stream point there will always be small breathing room for situation where the GPU clock is a little bit too fast. ...and GPU clocks are pretty accurate.

 

[lordarcane]

I can confirm that reclock messes with live tv. Before I uninstalled it completely it caused audio/video sync problems when changing the channel. So, i dont recommend it at all when watching tv. I did not matter how I tried to configure it. No difference.

And, when Irun the Tv at 50hz and watching live tv in sweden I get no stutter at all.

 

[Owlsroost]

I can confirm that reclock messes with live tv. Before I uninstalled it completely it caused audio/video sync problems when changing the channel. So, i dont recommend it at all when watching tv. I did not matter how I tried to configure it. No difference.

And, when Irun the Tv at 50hz and watching live tv in sweden I get no stutter at all.

Which version of ReClock are were you using ?

I use ReClock 1.8.3.9 for video and DVD playback - but not TV, and I haven't noticed any effect on live TV when it's not selected as the renderer.

Tony