Observation on Slip Performance

dukefan · 03-19-07, 11:21 AM

Using FF during the NCAA tournament led to an interesting observation... the frames that the HR20 is selecting during FFx4 are not selected in non-decreasing order, much less linearly.

To wit - you want the recorded to show (more or less) all frames, but at a much faster speed than normal. The HR20 appears to jump forward about 3 minute incrememts when in FFx4 mode. However, during the NCAA tournament on MPG4 CBS, there was a game clock always visible on the screen in the perfect location just below the timebar. What I noticed was that when FFx4, I would see things like (moving forward in a game) the game clock going 10:00..9:31..9:11..9:23..9:00..8:33..8:43..8:22..8 :00..7:57..8:02.. etc.

In other words, it would push forward, but then show a freeze frame of something out of sequence with where it should be. This isn't noticeable when watching just a regular show, but having the timeline of the game clock caused me to pick up on this inconsistency.

I still want the FFx3 and x4 to show ever frame, but much faster... but at least it should show stuff in order.

P.S. I still want multi-slip fixed so that 4 presses = 2 min and 6 presses = 3 min, etc. (had to get in that plug!).

MartyS · 03-19-07, 12:44 PM

That's fascinating. I always suspected that that was what was happening, based on how things came in and out of trick play, but could never confirm it. I believe that that is exactly why the picture is choppy and not smooth, since it keeps going back and forth.

Hopefully D* can verify this and see what can be done!

islesfan · 03-19-07, 01:24 PM

Quote:

Originally Posted by MartyS

That's fascinating. I always suspected that that was what was happening, based on how things came in and out of trick play, but could never confirm it. I believe that that is exactly why the picture is choppy and not smooth, since it keeps going back and forth.

Hopefully D* can verify this and see what can be done!

We've all see this at one point or another. You're skipping foward through commercials, then you hit 6 sec replay, and you see the commercial, then a frame or two of the show, then the rest of the commercial. Trick play is a disaster with this machine, but fortunately, the quality of trick play is far less important than the overall reliability of the box.

Milominderbinder2 · 03-19-07, 02:20 PM

Press and hold the FFW button for FFx5. You will jump 15 minutes (or 30 minutes) every 3 seconds. That is 30x or 60x speed. You will like it.

Also, if you have not yet tried it, Do a keyword search for Test Pattern. You will record it at about 5 am on HDNet. It will give you an accurate time clock as well as a number of test screens.

- Craig

sequoiadean · 03-19-07, 02:57 PM

Quote:

Originally Posted by islesfan

We've all see this at one point or another. You're skipping foward through commercials, then you hit 6 sec replay, and you see the commercial, then a frame or two of the show, then the rest of the commercial. Trick play is a disaster with this machine, but fortunately, the quality of trick play is far less important than the overall reliability of the box.

Well, less important, true, but still very important. It's one thing, IMO, where Tivo works way better than the HR20, and is the only reason at this point why I don't replace my HR10 and SD Tivo with two more HR20s - it's much more difficult to easily fast forward through commercials on the HR20.

garywitt · 03-19-07, 03:24 PM

Just to add my two cents:

It seems like with the last few software updates the reliability and stability of the box have been vastly improved. I feel the poor trickplay performance described above is really the last thing keeping this box from being a DVR I would recommend. I have hope that it continues to be improved, however. Just have a long way to go.

In my own opinion (and I know others would disagree with me), I would put improved trickplay higher in priority than DLB, higher than CID, higher than just about anything else, with the exception of reliable recording and playback.

sequoiadean · 03-19-07, 04:45 PM

Quote:

Originally Posted by garywitt

Just to add my two cents:

In my own opinion (and I know others would disagree with me), I would put improved trickplay higher in priority than DLB, higher than CID, higher than just about anything else, with the exception of reliable recording and playback.

I completely agree with you!

jzoomer · 03-19-07, 10:34 PM

Whole frames are not always transmitted, in fact good compression dictates that you avoid this!

In mep2, this would be your I pictures and early encoding schemes usually had a fixed I frame rate. But with advance encoding techniques you might go for a scheme where you only use an I picture when needed. This could vary depending on the changes in the scene.