DVR Live Buffer

[jlong27]

I really hate that when a channel, like TNT, that is recording and you are watching that channel about 30 min behind live tv, like during the last 8 laps of the Daytona 500 and the end of the recording time is reached and you are sling-shotted to live TV. I by default have extended nascar races by 1 hour 30 minutes but tonight that was not enough!

UGH, why is the live buffer dumped for the channel you are recording? I have a 622 btw.

 

[DishSubLA]

Well, TiVo works in a similar way, except that even in NON-recording situations when one is watching delayed live TV, if one switches between tuners, one is ALWAYS dumped back to live TV, not delayed, unlike Dish DVR's that will stay delayed when switching between tuners. TiVo's solution is for the user to PAUSE the buffered tuner, then switch between tuners.

In other words, every DVR (or device, for that matter) has its own little limitations or peculiar design for what could be a number of reasons, including instability or fear of patent violations. In this case, and TiVo's, it isn't anything that significantly diminishes either product.

 

[jlong27]

I have these types of situations every once in a while and it sounds like there is no solution to the problem except recording the next 2 shows after an event like nascar that is susceptible to extremely long delays. Hell maybe even the next 3 shows, I'll just have to evaluate it on a case by case basis.

I wish more attention was given to the live buffer.

 

[Mr Tony]

How far can you extend it out by?

I know on Directv you an go 3 hours out which as soon as I heard there was rain I set it to go +3 hours. Normally I set it for +1 hour or on the longer ones +1.5 hours

 

[jlong27]

It looks like 90 min is the max on a 622. Extending by 3 hours would be nice. I have it set to 1 hour but I have missed the end of races before. I extended yesterdays race to 90 min but didn't think about recording the show currently running live, too many beers I guess! I just need to start recording the shows that are on 90 min after the race.

 

[articos]

Well, TiVo works in a similar way, except that even in NON-recording situations when one is watching delayed live TV, if one switches between tuners, one is ALWAYS dumped back to live TV, not delayed, unlike Dish DVR's that will stay delayed when switching between tuners. TiVo's solution is for the user to PAUSE the buffered tuner, then switch between tuners.

In other words, every DVR (or device, for that matter) has its own little limitations or peculiar design for what could be a number of reasons, including instability or fear of patent violations. In this case, and TiVo's, it isn't anything that significantly diminishes either product.

Agreed that each DVR has its own peculiarities and I know Tivo has some weird issues like pausing the buffered tuner to make it stick, but at least that's a workaround to get what you want accomplished. In what the OP's talking about, you can't get what you want, and there is no workaround - it just doesn't buffer. Don't know about the current gen Tivos, but I remember the original DirecTivo's buffer you didn't have to pause to hold what was in it when going from recording to live on the same tuner. It kept the live buffer from where it ended recording, no matter when you actually went back to live tv - either right after recording, 5 mins after or 20 mins after - you could at least rewind back and not miss anything. That's different from the 622's functionality of only picking up from wherever it is when it goes to live tv at that moment. It's an annoyance of mine, too, coming from the other way. To me, a live buffer should just automatically be buffering the stream, no matter what else is going on, so as soon as it stops recording, it should go back immediately to holding what ever's coming down from the bird. I understand why it doesn't, but I wish it did.

 

[jlong27]

I can't think of a technical reason it doesn't.

 

[articos]

On one hand, there shouldn't be a technical reason it doesn't. On the other hand, I'd be very, very afraid of Dish diving into the code on this product to make a change like that, considering how many things break anytime they add or fix something tiny.

 

[DishSubLA]

Agreed that each DVR has its own peculiarities and I know Tivo has some weird issues like pausing the buffered tuner to make it stick, but at least that's a workaround to get what you want accomplished. In what the OP's talking about, you can't get what you want, and there is no workaround - it just doesn't buffer. Don't know about the current gen Tivos, but I remember the original DirecTivo's buffer you didn't have to pause to hold what was in it when going from recording to live on the same tuner. It kept the live buffer from where it ended recording, no matter when you actually went back to live tv - either right after recording, 5 mins after or 20 mins after - you could at least rewind back and not miss anything. That's different from the 622's functionality of only picking up from wherever it is when it goes to live tv at that moment. It's an annoyance of mine, too, coming from the other way. To me, a live buffer should just automatically be buffering the stream, no matter what else is going on, so as soon as it stops recording, it should go back immediately to holding what ever's coming down from the bird. I understand why it doesn't, but I wish it did.

Oh. I misunderstood. Yeah, still a problem. I would say to add even more padding than what Dish may provide to be certain. TiVo also, provides an automatic pad, but one should extend that, as well. Then, no tears.

As for why Dish dumps the buffer, when viewing recordings in the FOREGROUND tuner: probably because NOT to do this would have the same functionality as TiVo, and TiVo would likely sue, as Dish probably couldn't provide the same TiVo functionality without fear patent infringement. So, this takes us back to each device has it own little advantages and disadvantages.

 

[Pepper]

As for why Dish dumps the buffer, when viewing recordings in the FOREGROUND tuner: probably because NOT to do this would have the same functionality as TiVo, and TiVo would likely sue, as Dish probably couldn't provide the same TiVo functionality without fear patent infringement. So, this takes us back to each device has it own little advantages and disadvantages.

I wonder if this is the same reason for absolutely destroying the usefulness of the skip back button. Changing it from 7 to 10 seconds was an annoyance; what it does now is an abomination. Quite often, I'll find myself all the way back at the beginning of a recording I have already watched 1.5 hours of, with only 3 or 4 presses of the button.

I agree, live should always be buffered on both tuners, even while a recording is being watched so if it was just recording but you paused it, you could seamlessly continue on with delayed "live" tv after the recording was over. This is a major deficiency in my opinion.

 

[articos]

I've always wondered if the answer to both of the above is legal or just bad/overlooked software. Don't know. Regarding the skip-back functionality, it just seems really buggy to me...half the time, it skips you 10 seconds, half the time it takes you who-knows-where. That's sort of an unfun game - where is it going to put you this time?

I've heard Tivo uses/used a hardware buffer that is less taxing on their box, and allows it to just continually buffer everything. I believe Dish's solution is to buffer via software, which I'm guessing(?) is one of the ways they differentiate and thereby use a different solution to stay clear of Tivo's lawyers. Using software supposedly runs the buffer through the processor, though, meaning it's not able to do everything as efficiently - or, in the case of older processors, do everything at all. It may be that's why they dump the buffer in this case, or it may just be sloppy legacy coding...don't know. I had a lot of discussions about the buffer when the 622 first came out - they fixed a lot of things, but I really wish they'd fix this, too.

Hopefully that all made sense.

 

[KKlare]

My experience is that it will jump back 2 or 3 minutes and 4 or 6 skips get it right. But this usually happens only after mixing skips with FF/rewind operations and may require a pause. This is most annoying when trying to zero in on a short stretch of recording where you pause and use the 1-sec backup or frame forward and try to mix in some play and 10-sec backs and 30-sec forwards to get to the spot. And you end up no closer to the shot you want.
-Ken

 

[Jim5506]

Digital pictures are not put together like movie film, one frame after another, they are assembled with information from current, following and previous frames.

The problem is with the I, P and B frames that make up a digital moving picture. I (intra-coded) frames are essentially a complete frame, P (predicted) frames use relative static data from previous frames adding only that part of the picture that changes, and B (bi-predictive) frames use data from previous and following frames to build the frame.

All this "guessing" makes assembling FFW and REW pictures VERY CPU intensive and very difficult to assemble a smooth FFWD or REW and thusly also much more difficult to hit a specific spot in the frame chain, because there is no frame chain, just a few links here and there interspersed with pieces of a link.

MPEG4 makes it more difficult because it has fewer I frames and more P and B frames than MPEG2.

I have not watched FFW and REW on DirecTV DVR's but my guess is they have similar problems assembling a smoothe FFW and REW and smoothe, accurate jumps, also.

 

[articos]

Digital pictures are not put together like movie film, one frame after another, they are assembled with information from current, following and previous frames.

The problem is with the I, P and B frames that make up a digital moving picture. I (intra-coded) frames are essentially a complete frame, P (predicted) frames use relative static data from previous frames adding only that part of the picture that changes, and B (bi-predictive) frames use data from previous and following frames to build the frame.

All this "guessing" makes assembling FFW and REW pictures VERY CPU intensive and very difficult to assemble a smooth FFWD or REW and thusly also much more difficult to hit a specific spot in the frame chain, because there is no frame chain, just a few links here and there interspersed with pieces of a link.

MPEG4 makes it more difficult because it has fewer I frames and more P and B frames than MPEG2.

I have not watched FFW and REW on DirecTV DVR's but my guess is they have similar problems assembling a smoothe FFW and REW and smoothe, accurate jumps, also.

Good points Jim. Thanks. I do remember Tivo and DirecTV's boxes had issues with Rwd/FF at times, although not to the extent Dish's boxes jump around.

 

[KKlare]

I don't think the lack of full frames explains it all. You can back up multiple times from pause at 2 sec each and then play and it may or may not play correctly although it obviously has a valid full frame. The problem shows up mostly when you mix FF/Rew with skips. This is likely a engineer's coding error.
-Ken