# Automatic Buffer Overlap - 1 Tuner per channel



## SomeRandomIdiot (Jan 7, 2016)

DirecTV automatically gives a 1 minute overlap buffer (beginning AND end) on Programming where the tuner is not needed on another channel. When you select a recorded program and hit play it ignores this buffered time, but is there if the beginning is cut off. 

A number of the 30 minute comedies have the last segment payoff line clipped as the TiVo stops that recording.

Furthermore, and more importantly, DirecTV allocates 1 tuner to a channel and if, say 60 Minutes and Madam Secretary are being recorded on CBS Sunday Night, 60 Minutes has a 60 second buffer at the end and Madam Secretary has a buffer at the beginning....BOTH FED FROM THE SAME TUNER, not 2 different tuners.

One can manually assign a 60 second buffer, but 2 tuners are needed, effectively cutting the number of tuners in a TiVo in half. So a Roamio Basic/Bolt has 2 effective tuners and 3 on a Plus/Pro.

Even when the programming is subsequent on 2 different programs on a TiVo, as it was between Chicago Fire and Chicago Med (and NCIS/NCIS New Orleans) this week, when Tivo stops one recording and starts another, there is a 1-2 second gap, where in this case, key programming was lost. This was not an issue for DirecTV DVR owners (or the non-TiVo DirecTV DVR owners).

So the overlap buffering and ability to record 2 programs from the same tuner on the same channel seems like a no brainer.


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## jrtroo (Feb 4, 2008)

Its not a no brainer, as they did this for a short period of time and had to pull the code due to issues. Someday it will hopefully come back.


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## bradleys (Oct 31, 2007)

It was a cool feature. Hopefully it will return.


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## SomeRandomIdiot (Jan 7, 2016)

jrtroo said:


> Its not a no brainer, as they did this for a short period of time and had to pull the code due to issues. Someday it will hopefully come back.


So is TiVo admitting that DirecTV can do better DVRs than they can


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## Dan203 (Apr 17, 2000)

They had a way to share a tuner for overlapping recordings when the Roamio first came out. The main issue was that it would cause a brief audio/video glitch where the two recordings overlapped. (i.e. end of one, start of the other) It generated a LOT of complaints here on the forum, so I imagine they got a lot of calls too. The second upgrade after the Roamio was released removed the feature and it has not returned.


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## GoodSpike (Dec 17, 2001)

jrtroo said:


> Its not a no brainer, as they did this for a short period of time and had to pull the code due to issues. Someday it will hopefully come back.


Code problems? It would seem to be fairly simple--even WMC could do that!


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## Dan203 (Apr 17, 2000)

Could be related to the way they record. TiVo has a patent on a special way if recording video that requires less hardware power then the way WMC does it. Maybe they don't have a way to easily find the safe splice points. MPEG-2/H.264 video can't just be cut/spliced anywhere. In fact we've seen a lot of H.264 files that don't have a structure safe for cutting/splicing anywhere. (we use a special technique that works, but TiVo couldn't duplicate it on their hardware) I've seen broadcast H.264 streams with out any IDR frames at all and all open GOPs, which means no matter where you jump into them you will get pixelation for a few seconds. Apparently the broadcasters think that is acceptable.


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## trip1eX (Apr 2, 2005)

SEems like they could just (internally) record 2 or more shows appearing back to back on the same channel as one big long show. And then just mark where the 2nd show starts and the 3rd show and so on. The user would see nothing different on their end. Business as usual. The 2nd show would just point towards the 2nd show starting pt in that (internally) long recording. 

IF the user deletes the 1st program. It would splice it ( to free up space) before the 2nd show starts. Any pixelation wouldn't affect the 2nd show. If the user deleted the 2nd program first, it would splice after the 1st ended and before the 3rd started if there was a 3rd.

Seems strange they can't do that except I have a feeling much of the underpinnings of Tivo are pre-2000.

And I suppose the longer recordings could present a problem the more there are (if a long recording has to be recorded in an unbroken amt of storage space.)


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## SomeRandomIdiot (Jan 7, 2016)

Dan203 said:


> Could be related to the way they record. TiVo has a patent on a special way if recording video that requires less hardware power then the way WMC does it. Maybe they don't have a way to easily find the safe splice points. MPEG-2/H.264 video can't just be cut/spliced anywhere. In fact we've seen a lot of H.264 files that don't have a structure safe for cutting/splicing anywhere. (we use a special technique that works, but TiVo couldn't duplicate it on their hardware) I've seen broadcast H.264 streams with out any IDR frames at all and all open GOPs, which means no matter where you jump into them you will get pixelation for a few seconds. Apparently the broadcasters think that is acceptable.


If it starts 1 minute early and ends 1 minute late, does not matter if there is a few seconds of pixelation at points where you most often would view 98%+ of the time.

If they cannot overlap, then the start time should be able to go negative, with options for 1 sec, 2 sec, 3 sec etc late start (see other suggestion thread...but did not go down to this level).
http://www.tivocommunity.com/tivo-vb/showthread.php?t=535946

As the programming is uplinked at :00 and takes a roundtrip to space and back, then is transcoded or re-encoded at the MVPD (and if Dish or DirecTV, you get ANOTHER round trip up and back), the actual start time can be up to 9 seconds off, which is probably why DirecTV made this happen.

Regardless, even the ABC/NBC/CBS/Fox Affiliates are usually off by a few seconds, as the uplink, downlink, transfer to baseband, re-encode, send out to transmitter or Cable Head End etc.

Simply adjusting the Season Passes start time by a few seconds for the shows on a particular channel could solve the issue (and the time would be easy to figure out after 1 showing).


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## spamymaps (Jan 7, 2016)

GoodSpike said:


> Code problems? It would seem to be fairly simple--even WMC could do that!


WMC never supported tuner sharing like this. What WMC did instead was that overlaps were set to "when possible". In the case where you would have clipping on TiVo, WMC would just not do any overlap and instead stop the first recording on time and start the second on time giving neither show an overlap at that point.

Tuner sharing has been probably the most discussed request on the green button for the last 7 years.


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## GoodSpike (Dec 17, 2001)

spamymaps said:


> WMC never supported tuner sharing like this. What WMC did instead was that overlaps were set to "when possible". In the case where you would have clipping on TiVo, WMC would just not do any overlap and instead stop the first recording on time and start the second on time giving neither show an overlap at that point.
> 
> Tuner sharing has been probably the most discussed request on the green button for the last 7 years.


I'm not so sure, but I don't recall. Yes WMC had the "when possible." But I do remember the same material being recorded as part of the same show. What I don't know is whether that was done using the same tuner (using HDHR, which also might impact the answer).


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## Dan203 (Apr 17, 2000)

SomeRandomIdiot said:


> If it starts 1 minute early and ends 1 minute late, does not matter if there is a few seconds of pixelation at points where you most often would view 98%+ of the time.


It did though. People complained about it incessantly. The worst part was the skip in the audio. If the audio was fluid and there was just a minor pixelation at the start I think people would have been more accepting of the feature.


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## spamymaps (Jan 7, 2016)

GoodSpike said:


> I'm not so sure, but I don't recall. Yes WMC had the "when possible." But I do remember the same material being recorded as part of the same show. What I don't know is whether that was done using the same tuner (using HDHR, which also might impact the answer).


HDHR is the same, it would allocate 2 tuners. You can test this easily by setting up back to back on 3 different channels at the same time (assuming you have 4 tuners). This would result in in 2 channels resulting in no overlap while the 3rd channel would get overlap recorded.


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## aaronwt (Jan 31, 2002)

SomeRandomIdiot said:


> DirecTV automatically gives a 1 minute overlap buffer (beginning AND end) on Programming where the tuner is not needed on another channel. When you select a recorded program and hit play it ignores this buffered time, but is there if the beginning is cut off.
> 
> A number of the 30 minute comedies have the last segment payoff line clipped as the TiVo stops that recording.
> 
> ...


This is also a cable company problem if their time is off or programming delayed by seconds. I'm on FiOS and it's rare that programs get cut off. I get every second of those comedies without having to pad the recording. While at my parents house on Comcast, all their programming is delayed by 20 seconds or so. When at their house, I can be streaming a show, from a TiVo at home, on my cell phone and still be ahead of the so called "live" Broadcast on their Comcast system.


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## SomeRandomIdiot (Jan 7, 2016)

aaronwt said:


> This is also a cable company problem if their time is off or programming delayed by seconds. I'm on FiOS and it's rare that programs get cut off. I get every second of those comedies without having to pad the recording. While at my parents house on Comcast, all their programming is delayed by 20 seconds or so. When at their house, I can be streaming a show, from a TiVo at home, on my cell phone and still be ahead of the so called "live" Broadcast on their Comcast system.


The biggest issue I see is the delay in the multiple satellite bounces 22k miles up as well as MPEG2/MPEG4 Encoder delays of up to 9 seconds.

The problem with a 20 second delay is the beginning of every show would be clipped.


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## CoxInPHX (Jan 14, 2011)

Here are a few Topics of when TiVo enabled the Back-to-Back overlapping recordings.

Here is the main discussion of Back-to-Back overlapping recordings
http://www.tivocommunity.com/tivo-vb/showthread.php?t=512449

Here is just one discussion, but there were many more.
http://www.tivocommunity.com/tivo-vb/showthread.php?t=508756

Duplicate Recordings, when Modifying padding from the To Do List was also another issue.
http://www.tivocommunity.com/tivo-vb/showthread.php?p=9885345#post9885345


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## SomeRandomIdiot (Jan 7, 2016)

CoxInPHX said:


> Here are a few Topics of when TiVo enabled the Back-to-Back overlapping recordings.
> 
> Here is the main discussion of Back-to-Back overlapping recordings
> http://www.tivocommunity.com/tivo-vb/showthread.php?t=512449
> ...


Sure, you can default every recording to have a 1 minute early and 1 minute later buffer, but then your 6 tuner TiVo becomes a 3 tuner Tivo


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## aaronwt (Jan 31, 2002)

CoxInPHX said:


> Here are a few Topics of when TiVo enabled the Back-to-Back overlapping recordings.
> 
> Here is the main discussion of Back-to-Back overlapping recordings
> http://www.tivocommunity.com/tivo-vb/showthread.php?t=512449
> ...


And they still never put it back to the way it was before. Things worked great before this was implemented. But when they removed this, the process changed and isn't like it used to be. Like my TiVos used to always use the same tuner for back to back recordings before this was implemented. Then after it was implemented and removed, the TiVos tend to use a different tuner now.


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