# Amazon streaming bitrate



## christheman (Feb 21, 2013)

I just thought I'd post this here, as a Tivo qualifies to stream Amazon Instant Video. I am wondering what the typical video bitrates turn out to be, both for HD and SD streaming (as I see both are being used). I am interested in whatever anyone might know about the bitrate of the actual video, as well as the incoming transfer bitrate requirement. Does TWC internet service bandwidth-throttle Amazon like they do Youtube?

Thanks
Chris


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## Dan203 (Apr 17, 2000)

Best info I can find is that Amazon is only using 720p with a max bitrate of 2.5Mbps. However I know they recently started streaming some 1080p stuff, which I suspect has about double the bitrate so between 4-5Mbps.

SD is only 1.3Mbps.

No idea if TW throttles Amazon or not.


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## christheman (Feb 21, 2013)

Dan203 said:


> Best info I can find is that Amazon is only using 720p with a max bitrate of 2.5Mbps. However I know they recently started streaming some 1080p stuff, which I suspect has about double the bitrate so between 4-5Mbps.
> 
> SD is only 1.3Mbps.
> 
> No idea if TW throttles Amazon or not.


Thanks Dan.

Is that PQ satisfactory, compared to other sources like cable or satellite?


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## Dan203 (Apr 17, 2000)

Yeah, the quality is better or equal to HD cable in most cases. 

There are some differences that make it so they can get the bitrates that low without losing quality. First off they use H.264 which gives them a 40-50% more compression then MPEG-2 used by cable. Next cable is encoded in realtime, meaning as the show is being transmitted, so the compression can't be as efficient. Streaming services pre-encode the video, so they can use multi-pass encoding for a more efficient encode reducing the bitrate even further. Also movies are actually shot at 24fps, but because of the limited standards in broadcast they have to be converted to 60fps for TV. Streaming services can use the native 24fps format which saves them some bits.


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## pdhenry (Feb 28, 2005)

christheman said:


> as a Tivo qualifies to stream Amazon Instant Video.


Which TiVo models stream Amazon Instant video?


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## christheman (Feb 21, 2013)

pdhenry said:


> Which TiVo models stream Amazon Instant video?


Here's the list. Upon reviewing it, I see that some of the Tivo models are listed but will not actually work. Strange... I am planning on using a Blu-Ray player myself.
http://www.amazon.com/gp/video/ontv/devices/ref


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## christheman (Feb 21, 2013)

Dan203 said:


> Yeah, the quality is better or equal to HD cable in most cases.
> 
> There are some differences that make it so they can get the bitrates that low without losing quality. First off they use H.264 which gives them a 40-50% more compression then MPEG-2 used by cable. Next cable is encoded in realtime, meaning as the show is being transmitted, so the compression can't be as efficient. Streaming services pre-encode the video, so they can use multi-pass encoding for a more efficient encode reducing the bitrate even further. Also movies are actually shot at 24fps, but because of the limited standards in broadcast they have to be converted to 60fps for TV. Streaming services can use the native 24fps format which saves them some bits.


Okay, thanks again Dan. I usually post over on the other forum. My setup includes a Hauppauge HD-PVR among other things, and of course a computer loaded with VRD. With that setup I produce a 13.5 Mbps H264 video and usually knock it down to about 4-6 Mbps H264 with VRD (dual-pass, actual bitrate varies). Anything less than that starts to become noticeable to me. So it will be interesting to play around with.

Chris


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## socrplyr (Jul 19, 2006)

pdhenry said:


> Which TiVo models stream Amazon Instant video?


None yet of course, but Tivo has announced it. We will see how long it takes to get here. Some people had prematurely received access to a nonfunctional App (could navigate, but not stream). I presume when it hits, it will be on both the Premiere and Roamio models as they are running essentially the same software.


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## pdhenry (Feb 28, 2005)

ah.



christheman said:


> Here's the list. Upon reviewing it, I see that some of the Tivo models are listed but will not actually work. Strange... I am planning on using a Blu-Ray player myself.
> http://www.amazon.com/gp/video/ontv/devices/ref


Yeah, for years TiVo's implementation of Amazon Instant Video has been to download the title and then let you watch it (and no coverage for Prime Instant Video, just paid rentals). Streaming has been "coming soon" for as long as Amazon has offered streaming. Good to see that it might finally arrive. Personally, I use a Roku but having streaming as a TiVo app would mean not having to change HDMI inputs..


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## ncted (May 13, 2007)

Both my Samsung Smart TV and my Panasonic Blu-Ray player claim 1080p streaming from Amazon on some titles, although neither report any bitrates. Picture quality is on a par or better than the H.264 content from Dish. TWC does not seem to throttle Amazon Instant at all where I live.


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## tenthplanet (Mar 5, 2004)

I've seen reports of 9-10mps at 1080p streaming with an Amazon Fire with some programs, speed is good but rates like that eat up bandwidth in no time.
My guess is Tivo won't be quite that fast.


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## christheman (Feb 21, 2013)

Dan203 said:


> Yeah, the quality is better or equal to HD cable in most cases.
> 
> There are some differences that make it so they can get the bitrates that low without losing quality. First off they use H.264 which gives them a 40-50% more compression then MPEG-2 used by cable. Next cable is encoded in realtime, meaning as the show is being transmitted, so the compression can't be as efficient. Streaming services pre-encode the video, so they can use multi-pass encoding for a more efficient encode reducing the bitrate even further. Also movies are actually shot at 24fps, but because of the limited standards in broadcast they have to be converted to 60fps for TV. Streaming services can use the native 24fps format which saves them some bits.


Dan, I just was thinking through the bitrates here, as I have done so many times before. With the Hauppauge HD-PVR2 (all H264), 720p (60fps) is highly similar to 1080i (30fps) in regards to disc space consumed. I usually record to either 1080i or 720p at the full 13.5Mbps. Then I compress to ~ 4-5Mbps using VRD. Any more compression and the compression artifacts generally outweigh the benefits for me. Having said that, I don't see how the Amazon bitrate of 2.5 Mbps at 720p could be acceptable, as it is half the bitrate that I find to be acceptable. That is, unless either their encoder or multi-pass compressor is doing something much different in the background. I don't see the 24 fps of the source file making that much of a difference on its own though. I haven't tried it yet though but, as you can see, others report it to be very good.


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## samccauley (Mar 4, 2002)

christheman said:


> Here's the list. Upon reviewing it, I see that some of the Tivo models are listed but will not actually work. Strange... I am planning on using a Blu-Ray player myself.
> http://www.amazon.com/gp/video/ontv/devices/ref


Curious. No Roamio models are listed there.


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## rainwater (Sep 21, 2004)

samccauley said:


> Curious. No Roamio models are listed there.


That is because technically Amazon isn't suppose to work on newer Roamios. Once the new Amazon streaming app is available that will change of course.


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## Dan203 (Apr 17, 2000)

christheman said:


> I don't see the 24 fps of the source file making that much of a difference on its own though.


It makes a HUGE difference. That's less then half the number of pixels per second that need to be compressed. It's completely scalable, so if you use 4.5Mbps for 720p/60 you could use 1.8Mbps for 720p/24 and get the same quality. In fact 1080p/24 actually has less pixels then 720p/60 so you could compress a full 1080p/24 at about 4Mbps and get roughly the same quality you're getting with 4.5Mbps for 720p/60.

Encoding is all about bits per second in relation to pixels per second. If you have less pixels per second then you can use less bits to encode them.

This is likely why a use above reported an Amazon Fire TV using 9-10Mbps for some HD content. I'm betting that content was TV programs, which are shot natively at 60fps, so they are sent down at full 108op/60 which requires a higher bitrate. Only movies are shot at 24fps.


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## christheman (Feb 21, 2013)

Dan203 said:


> It makes a HUGE difference. That's less then half the number of pixels per second that need to be compressed. It's completely scalable, so if you use 4.5Mbps for 720p/60 you could use 1.8Mbps for 720p/24 and get the same quality. In fact 1080p/24 actually has less pixels then 720p/60 so you could compress a full 1080p/24 at about 4Mbps and get roughly the same quality you're getting with 4.5Mbps for 720p/60.


If you use 720p/60, that is easier for me to wrap my head around, but would it be realistic to say the same thing about 24Fps film transfers (VOD) versus 1080i/30(network broadcast)?



> Encoding is all about bits per second in relation to pixels per second. If you have less pixels per second then you can use less bits to encode them.
> 
> This is likely why a use above reported an Amazon Fire TV using 9-10Mbps for some HD content. I'm betting that content was TV programs, which are shot natively at 60fps, so they are sent down at full 108op/60 which requires a higher bitrate. Only movies are shot at 24fps.


Yes, that would be huge.


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## Dan203 (Apr 17, 2000)

christheman said:


> If you use 720p/60, that is easier for me to wrap my head around, but would it be realistic to say the same thing about 24Fps film transfers (VOD) versus 1080i/30(network broadcast)?


Interlaced video is half resolution, so 1080i has about the same number of pixels as 720p. This is why they are basically interchangeable from a broadcasting standpoint. Although progressive video is a bit more efficient to encode, and 720p does have slightly less pixels (equivalent to about 4fps worth), so that's why the bitrates for 720p channels are typically a bit lower then 1080i channels.

24fps makes a big difference because it has way less pixels. Think of it this way. The bitrate is in megabits *per second*. So if you have 24 frames per second rather then 60 frames per second then your bits are spread a lot less frames. So you can lower your bitrate to about 40% and get the same number of bits per frame.


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## christheman (Feb 21, 2013)

Thanks Dan, now I think I understand that. In order to compare 24Fps, I must bear in mind that it is progressive, and not interlaced. Then if I am comparing it to interlaced (1080i/30), I first need to convert the interlaced to progressive (720p/60), which doubles the FPS, so that I am comparing apples to apples.


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## Dan203 (Apr 17, 2000)

Yes. 1080i actually has 60 fields per second, so if you combine those it basically equates to 30 progressive frame per second. So a 1080i still has more pixels then a 1080p/24.


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## nooneuknow (Feb 5, 2011)

Dan203 said:


> Yes. 1080i actually has 60 fields per second, so if you combine those it basically equates to 30 progressive frame per second. So a 1080i still has more pixels then a 1080p/24.


Are "fields" and "frames" per second interchangeable terms (FPS)? Is there any time they are so in one setting, but not in another, like streaming from an internet source, versus Live/Recorded TV delivered via QAM, versus IPTV?


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## christheman (Feb 21, 2013)

nooneuknow said:


> Are "fields" and "frames" per second interchangeable terms (FPS)? Is there any time they are so in one setting, but not in another, like streaming from an internet source, versus Live/Recorded TV delivered via QAM, versus IPTV?


For progressive, yes. Not for interlaced, no. 30 frames per second would be drawn twice, hence 60 "fields" (based on the way the NTSC TV format did).


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## Dan203 (Apr 17, 2000)

nooneuknow said:


> Are "fields" and "frames" per second interchangeable terms (FPS)? Is there any time they are so in one setting, but not in another, like streaming from an internet source, versus Live/Recorded TV delivered via QAM, versus IPTV?


Fields apply to interlaced. With interlaced video each picture the camera takes only contains half the vertical lines. Every other one, alternating odd and even. They do this a full 60 times per second, but because only half the lines are captured the bandwidth requirements are half that of 60fps progressive. If you were to combine any two adjacent fields you could get a complete progressive frame, resulting in essentially a 30fps progressive video. However because each field is shot at a slightly different moment in time there will be a mismatch, especially in high motion areas, which will produce an artifact known as tearing. So while a 60 field per second interlaced video technically has the same number of pixels/lines as a 30fps progressive video they are slightly different. Because each field in an interlaced video is taken at a different moment in time it provides smoother motion then a 30fps progressive video would, which is why interlaced video was chosen for early broadcasting. Today they continue to use it for 1080i because of bandwidth restrictions which prevent them from being able to broadcast full 1080p/60.


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## nooneuknow (Feb 5, 2011)

I follow, except for what happens when I set my Roamio to 1080p/60, which gives me a much crisper picture on my menus, but lesser effect on actual content.
I understand that a 1080p/60 native LCD converts to it's native resolution, not always doing so very well, but the panel only truly does one resolution.
I'm still kind of lost on the upconversion process that takes place, when it be via TiVo, auto-upconverting HDMI switch, or the TV. I can certainly see that all upconversion is not equal.
Now I'm wondering if I'm interchanging upscaling and upconversion, and shouldn't be.
I have been observing a lot of what appears to be loss of interlace sync with CBS for a few months now. It started 2 days before the summer update rolled. Every time the scene changes, like a conversation where the scene keeps switching from a wall to a landscape, the person who is talking changes, but the background behaves like some cheesy old computer screensaver, having interlaced lines of both scenes, then a pull-apart to the right background scene, but late.
I'm spoiled by the PQ I get letting the Roamio stay fixed at 1080p, compared to other means. Now I hate 1080i, but I have to use it, or suffer this background lag and all the bizarro effects...
It seems, yet again, some channels are being broadcast in a way that does not work well with TiVo. I'm also seeing a lot of trickplay issues, like 1x RW only holding the picture, like it is paused, 2x jerkily jumping worse than a netflix/Hulu RW, and 3x acting more like 1x should, but still jumping to random frames...
I'm about to begin digging into this matter, so the more I know, the better.
If this should go to another thread, just name it, and I'll take it there. TCF search function is utterly useless to me...


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## Dan203 (Apr 17, 2000)

Your LCD panel is 1080p, period. So when it receives interlaced video it has to feed it into a deinterlacer. The deintrlacer is designed to remove the tearing you'd normally see if you simply combined two interlaced fields into a progressive frame. It does this through a process of blurring and interpolation. It looks fine for moving video, but for static menus and fonts it can cause a bit of fuzzy effect.

When you set your TiVo to output 1080p it's processing everything internally and sending your panel a pure 1080p signal that bypasses it's internal deinterlacer and scaler. This works best for TiVos because the menus can be rendered at the native resolution essentially making your TV a computer monitor for the UI. For video it requires less processing then 1080i because for actual 1080i it's doing the deinterlacing internally, which is probably similar to what your TV is doing anyway. And for 720p it's able to keep the frames progressive and simply upscale them, whereas if you had it set to 1080i it would upscale them, then throw away every other line to create an interlaced video, then your TV would recombine the interlaced frames to recreate a 1080p image which results in extra processing and a loss of detail.


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## nooneuknow (Feb 5, 2011)

OK, I'm still following.
Any helpful advice on how I try to get to a solution for the problem I described? Fall TV is coming into full-swing. I did some more experiments and found that it really doesn't matter if I use 1080i or 1080p, or what device does it. The AV "stream" seems to be recording with the problems there, and it's on Live TV also. Neighbor's leased STB is not exhibiting the behavior, and the coax feed over there is less optimal than here.

If you had a 1080p TV, and had to pick (Roamio setting) between using 1080p fixed, or 720p fixed, because 1080i just looks bad, which would you use? AFAICT, the Roamio's true UI resolution is still 720p, and there tends to be less loss of sound, when transitioning around using 720p.

One thing that is odd, is I tended to have more audio issues, over all these years, and all the different TiVos, going back to TiVo HD. Now, the audio issues are clearly limited to menu nav and TP, not the feed. My audio tends to drop less bites of sound than ever. But, I'm also getting parts where the video seems to lose many frames, while the audio goes on flawlessly, and often do the captions. This is a new problem, I've never seen before. If it gets much worse, I'll be using Hulu+ a lot more, and giving Amazon a look. Odd, the timing of this issue, and how the episodes I'd want to stream, are "exclusively on Amazon". The problems, and the deluge of Amazon ads, share a nearly identical starting time.

DVR diags isn't showing any data that looks less than ideal. I have the most recent cablecard firmware (rolled about a month ago), most recent TA firmware (rolled a few days ago), and most recent 20.4.4a software. All the issues started before all these updates. There just wasn't much on, so it wasn't worrying me until now.

No rest for the guy who is usually busy trying to help others fix their problems...


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## telemark (Nov 12, 2013)

Not an straightforward topic, but maybe a little history will provide some overview. A graphical example available here:
http://www.faroudja.com/faroudja/brands/dcdi.jsp

NTSC Video cameras, produced interlaced video. And your old CRT TV was an interlaced display. So those two things went well together.

Movies on film (the medium with sprockets) has no inherent lines nor pixels. To make it into an electronic signal (for broadcast or DVD), it goes through a scanner process called TeleCine. The telecine machine, could be set to generate an interlaced or progressive, 480 or 4k resolution signal.

What gets weird is when converting a film to NTSC. The NTSC is suppose to be 60 fields per second and film was usually 24 frames per second. What feels like a bizarre algorithm called "3:2 pulldown" is used to make those two numbers match up by inserting duplicate fields.

There were eventually some progressive displays, most commonly LCD projectors. Let's assume 640x480 at first. When connected to a computer, that's progressive to progressive, so nothing to do there. (unless the resolutions don't match, then there would have to be a scaling up or scaling down just in resolution)

Now feed the projector an NTSC signal, and it can get messy. If the video is originally from film converted using 3:2 pull down, a "good" processor notices the duplication and reassembles a full (progressive) frame, from 2 corresponding fields (half frames). That might sound a bit hackish, but works well when it works. The bigger problem comes with a video signal that came from a NTSC video camera... 2 fields never match up so can not be combined. The reason it worked for film is 2 of the telecine output fields (240 lines), came from a single film frame. So using two fields combined produces a single higher res frame (480 lines). Two NTSC camera fields however, are from different points in time, 1/60s apart. A stationary subject is fine, but a moving subject, would never match up. A simple way then to display the video signal is double each of the 240lines to get 480lines, for each field, which has obvious downsides. There are a many more advanced methods to do that that gives better results, the best covered by patents by the video processor companies. Some of those chips end up in high end TV's and the low end TV's with low end chips might use the simpler methods.

When the ATSC/HD standards were being drafted, they had a chance to end this. But, the TV people wanted interlaced and the Computer people wanted progressive. They couldn't agree on one and the compromise was to approve both and let the market decide.

It wasn't clear then that LCD was going to supplant CRT. Now it's clearer progressive is the future, virtually all displays are progressive now. And the 4K spec agrees, interlaced days are numbered.

Sorry, I don't have an actual answer. But saying it might depend on how the video was generated, transmitted, and which devices does the conversion if needed.

If you want to take apart a video artifact, you could try transfering it from Tivo to a PC and run it through VLC. The conversion algorithms are then run in software and a different algorithm might give different results.


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## Dan203 (Apr 17, 2000)

nooneuknow said:


> OK, I'm still following.
> Any helpful advice on how I try to get to a solution for the problem I described? Fall TV is coming into full-swing. I did some more experiments and found that it really doesn't matter if I use 1080i or 1080p, or what device does it. The AV "stream" seems to be recording with the problems there, and it's on Live TV also. Neighbor's leased STB is not exhibiting the behavior, and the coax feed over there is less optimal than here.
> 
> If you had a 1080p TV, and had to pick (Roamio setting) between using 1080p fixed, or 720p fixed, because 1080i just looks bad, which would you use? AFAICT, the Roamio's true UI resolution is still 720p, and there tends to be less loss of sound, when transitioning around using 720p.
> ...


TiVos always record the incoming video as-is, the resolution setting only effects output. The problem you're describing sounds like a signal issue. Because the TiVo has six tuners it needs a better signal then a single tuner STB might need. You should look into getting an amplifier, that might help the issue.


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## nooneuknow (Feb 5, 2011)

Dan203 said:


> TiVos always record the incoming video as-is, the resolution setting only effects output. The problem you're describing sounds like a signal issue. Because the TiVo has six tuners it needs a better signal then a single tuner STB might need. You should look into getting an amplifier, that might help the issue.


I have three base Roamios, and my signal is so strong I have to use 6 way splitters just to attenuate the signal down to 90% & 36 SNR. I keep tabs on my signal, daily. I look at my cable modem levels, daily. Heck, sometimes I actually check the status of everything, wondering how it's all holding up so well. The problem has now jumped to Fox and 720p channels as well. The neighbor has a leased DVR system, four tuners, at least, whole home rig.

My signal from Cox has never been better, especially for holding stable, rather than always being in AGC stress mode. Even my tuning adapters are running solid, and reading well. Should I call Cox and ask them to roll a truck, for a solid signal, and a problem that's only messing up TiVos?


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## Dan203 (Apr 17, 2000)

I've been having trouble with Fox lately too. Lots of pixelation and audio drop outs. I recorded the exact same show on my Wife's Roamio and it had pixelation/audio issues in the exact same places. According to the signal strength meter it's hovering between 93-98%, so I don't think it's a signal issue. The only thing I can conclude is that it's an issue with the cable company itself. 

But if you want to know for sure if it's the recording or a TiVo playback problem download the show to your PC and play it there. If you get the same pixelation and audio issues then it's an issue with the recording itself. If it's not then it's a playback issue.


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## Bigg (Oct 31, 2003)

I can't say what the bitrates are, but subjectively, their HD looks really good. VUDU seems to have gone downhill, now with 1080p Amazon is really good. I've got it on my Roku, and the experience with the RF Roku remote and the Roku interface is excellent. The Apple TV and iTunes can crank out some great video quality too, but the remote on that thing is almost unusable.


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## Dan203 (Apr 17, 2000)

I have it on good authority that both VUDU and Amazon are coming to TiVo very soon, so soon enough you'll be able to use whichever one you prefer.


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## waynomo (Nov 9, 2002)

Dan203 said:


> I have it on good authority that both VUDU and Amazon are coming to TiVo very soon, so soon enough you'll be able to use whichever one you prefer.


Did I read a rumor that HBOGO is planned also? I thought I saw that, but can't confirm it anywhere.


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## waynomo (Nov 9, 2002)

Dan203 said:


> TiVos always record the incoming video as-is,...


Small quibble... 
Don't you mean since the digital days? 
With the old TiVo's and analog signals you could select different video qualities to record.


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## Bigg (Oct 31, 2003)

waynomo said:


> Small quibble...
> Don't you mean since the digital days?
> With the old TiVo's and analog signals you could select different video qualities to record.


Any of the four or six tuner TiVos don't even have analog tuners even if you found somewhere with an analog source to record from...


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