HD video playback skipping

[BKeadle]

I recently switched from cable to ATSC (digital OTA) on my Hauppauge HVR-1600s (x2). Only the recorded HD shows have intermittent skipping issues. I've played around with the various SageTV Decoder and Overlay settings with mixed results - but none that fix the stuttering playback. Though, I'll admit I'm very confused about MPEG2 Video decode Filter vs. the H.264 Video decode Filter and which to choose and how to tell what is being used during playback if I chose Default settings and/or try to go through ffdshow.

Is this stuttering playback of HD/H.264 recordings strictly getting the correct mix of the decoder and renderer, config'd correctly, or are there other contributing factors, such as drive fragmentation, CPU power, GPU power, video driver, HDD firmware, Java version, etc.? Too much reading has me overwhelmed with all the potential considerations that I've become lost in the mire.

Everything has been working just dandy with my SageTV server until having switched to digital OTA, and now having digital HD shows, it's only the HD show playback I'm needing to resolve.

[Fuzzy]

ATSC broadcasts are MPEG-2, not H.264, so you need to look there. VMR9 should give the best results on winxp, and the SageTV Decoder should play it back studder free at least, though that is an aging GPU. The files themselves might also be corrupted from bad signal reception, and the decoder is having a hard time recovering with your limited hardware.

[BKeadle]

That is sufficiently definitive, and coming from you, has a lot of merit. Thank you. At least I have a track to go on.

However, watching live HD programming works just fine? What does that tell you? And non-HD programming plays back fine. So if HD and non-HD are both MPEG-2, why does only HD programs stutter in playback?

How does one determine the quality of the signal coming in? If watching live is OK, does that say my signal is fine, and an AMP will not help?

However, sadly, the W.A.F. dropped to zero. She-who-must-be-obeyed has little tolerance or patience for technology "hiccups" and just wants to go back to ... get this ... VHS tapes! I'm inclined to just dismantle it all and see how long it takes to miss all that the HTPC had to offer.
In the mean time, I'll secretly try and get this sorted out, and wait for the day that the tedium of VHS taping will revive the apppreciation for an HTPC, even it's occassional short-comings.

[davenlr]

It plays the HD files on Sage hiccup free when recording, but stutters when playing them back again later? Or it plays them fine live when using another standalone program?

The former would seem to indicate a drive throughput or drive controller issue, the latter would tell me Sage is using different splitters/decoders than the original program.

Just FWIW, Ceton is supposed to have a 6 tuner OTA Media center with extenders coming out this summer. Seemed to mirror a lot of SageTv's features except the satellite and HDPVR tuner ability. Has to be better than VHS tapes

[BKeadle]

Good questions - and on second thought, I don't know that it's hiccup free watching live within SageTV - I think we were actually watching live through the TV. If so, then it goes back to potential config or performance issues on my HTPC - more testing required. I see that I already have my cable going through an amp, then split out 4 ways - 1 to the TV, 1 to a separate DVD/VHS player/recorder, and 2 to each of my HVR-1600 cards. Should this splitting be a concern? Worked fine when I was on Comcast cable (non-digital), but I realize Digital OTA is a different beast.

I did find that my recording drive was *HIGHLY* fragmented - which might cause the "drive throughput" condition you suggested. I have backed up the drive, re-formatted, and am restoring now - which should have everything contiguous. We'll see if that makes a difference - I certainly hope so, that'll be an easy and inexpensive fix!

Presuming that disk I/O is the culprit, would it be worth considering installing an SSD as my recording drive, then have some schedule process that moves recordings x-days old from SSD to a SATA or IDE disk storage for later playback?

Finally, if HD and non-HD recordings are in the same MPEG-2 format, how are they different - what distinguishes an HD recording vs. a non-HD recording?

[Fuzzy]

Any HEALTHY conventional harddrive will be fine for your recording purposes. However, drives that are failing quite often present as poor performance long before any data is truly lost, as they end up having to reread a section of the drive multiple times to get a successful read.

[davenlr]

Originally Posted by BKeadle

Finally, if HD and non-HD recordings are in the same MPEG-2 format, how are they different - what distinguishes an HD recording vs. a non-HD recording?

I would not use an SSD for recording. It has a finite number of sector writes, and a program that continuously buffers to hard drive would use those up pretty quick.

As far as the difference between SD and HD on mpeg2 files, its pretty much just a flag, some differences in the video signal (SD is MP@ML, HD is MP@HL), and the bitrate being much much higher. If you can understand all the tech jargon, here is a page that explains it: http://en.wikipedia.org/wiki/H.262/MPEG-2_Part_2

Basically though, it takes much less effort to decode SD than HD, due to the much smaller amount of data per second.
SD uses 10,368,000, samples per second, HD uses 62,668,800, samples per second. You can see that it would take the decoder much longer to decode the HD signal.

[panteragstk]

One thing no one has mentioned is the video card being used for playback. I see a geforce 660 in your sig, and that is a very old card and was made at the beginning of the days of hardware decoding. I'm willing to bet most decoders will have issues with it. My 8800gt has similar issues with certain decoders, and I wasn't ever successful getting good playback with all formats.

If that isn't the card you are using let us know which one so I can recommend a compatible decoder. Unfortunately I've used almost all of them in combination of a few different video cards.

[gplasky]

Originally Posted by panteragstk

One thing no one has mentioned is the video card being used for playback. I see a geforce 660 in your sig, and that is a very old card and was made at the beginning of the days of hardware decoding. I'm willing to bet most decoders will have issues with it. My 8800gt has similar issues with certain decoders, and I wasn't ever successful getting good playback with all formats.

If that isn't the card you are using let us know which one so I can recommend a compatible decoder. Unfortunately I've used almost all of them in combination of a few different video cards.

Unless he is talking about the GTX 660-a relatively new card.

Gerry

[darcilicious]

Doesn't look like the GTX is even out yet? http://www.tomshardware.com/news/GeF...GPU,15506.html

Plus, I doubt you can get it with only 256MB of memory...

[panteragstk]

Originally Posted by gplasky

Unless he is talking about the GTX 660-a relatively new card.

Gerry

Pretty sure those don't exist yet...I think he actually means a 6600, could be wrong though.