[Rich A]

Hi all,


I've been searching trying to find an unrelated post where there was some discussion about how they wished RPTV would give them a higher quality than the present 6 Mb/s High recording. But I can't find it, so thought I'd add a new thread on the subject.


There have been a few people wondering why not 8 or 9 Mb/s (more in line with normal DVD bit rates) I have this to offer. Perhaps it's "not" any kind of limitation due to the encoder firmware itself. Remember, these boxes are designed to both play back a pre-recorded video AND capture a new video at the "same" time. That's a LOT of disc access, doing both record and playback simultaneously. I'd suggest that the current 6 Mb/s high recording limit might be as far as they can go without compromising the video playback or record during simultaneous record/view sessions. Just a thought.

 

[Todd H]

That's almost certainly true, given the stuttering that some have seen during simultaneous recording/playback in Medium or Hihg quality.


FYI: The majority of DVDs run around 5-6Mbps. Only the Superbits, and a few titles, push up against the 10Mbps limit.

 

[TomCat]

Most folks would judge the PQ of PVRs as pretty darn good. That's not to say that some of us wouldn't welcome improvement, but the real achilles heel of PVRs is their capacity right now, and this would greatly aggravate that situation.


My broadcast facility just installed a RAID with 1110 hours of 12 MB/s capacity, and it took 70 181 GB drives to accomplish this. Some of my superiors don't find it amusing that a half-dozen hacked Tivos have this much capacity (albeit at a lower bit rate).

 

[proehm]

Quote:

Originally posted by TomCat Most folks would judge the PQ of PVRs as pretty darn good. That's not to say that some of us wouldn't welcome improvement, but the real achilles heel of PVRs is their capacity right now, and this would greatly aggravate that situation. My broadcast facility just installed a RAID with 1110 hours of 12 MB/s capacity, and it took 70 181 GB drives to accomplish this. Some of my superiors don't find it amusing that a half-dozen hacked Tivos have this much capacity (albeit at a lower bit rate).

I have 4 Tek Profile XP's with 360gb chassis attached. Most of our recording on the syndicated stuff and spots is at 6mb/s. I don't normally see enough artifacting at that data rate to worry with. You never get rid of all of it. The WB Aletia is pretty clean on the LA feeds at 26000 spread over 3 sets of PIDS, with the NY feed being basically the same at 13000/2. The Paramount Wegner seem to show a little more on transitions, but it doesn't really affect the Judge shows that we are taking from it. I see it more at home watching UPN. I have recorded news feeds at 4mb/s and with the Profile, you really can begin to see it there. I am judging this from the records of WNT and GMA, the Conus, CNN, regional feeds generally are improved by not encoding some of the noise.


p:

 

[Lee Thompson]

There's a misconception here. The Replay's bitrates are not constant.


It's a 6Mbps *average* bitrate; it actually peaks at around 9MBps (and goes as low as around 2Mbps; granted that's not very often ).



However, any real-time MPEG compression is NOT going to be as nice as a DVD for several reasons:


1. Source material (TV/Satellite/Cable vs HiDef transfer)

2. Grainy images havoc with MPEG

3. No time to do a good 2 pass VBR