Dish / DirectTV - PVRs / DVRs

[trevlac]

I just got a Dish DVR. It's a combo digital receiver/hard drive all in one box.

In a different thread I saw LordSmurf (who generally knows what he's talking about) say that the recorded shows are different than what is broadcast.

This may imply that recorded 'files' are of lower quality than the original digital broadcast file, aka they are not a streight storage of the original.

This is of interest to me because I would like to record with the DVR and capture later using my computer. If this problem is true, then I may need to go back to using my computer to schedule a cap of the live feed.

I am doing some testing, but I didn't expect this to be a gotcha!

Does anyone know what I am talking about? Has anyone noticed a difference?

Thanks,
Trev

[gNOMEintheRedHat]

With a Dish PVR or a DirecTV Tivo the Digital data from the satalite is recorded directly to the Hard Drive.

The digital video is not altered by the box in any way.

HOWEVER,
The data received by your box is not what was ORIGINALY broadcast.

Dish & DirecTV both receive their programing from analog (a few digital) broadcasts, their equipment digitizes adn compresses the video and audio before it is re-transmited to you.

is that clear as mud?

gNOME

[edit]
the video recorded and stored in the PVR is EXACTLY what Dish broadcast to you.
[/edit]

[trevlac]

That is clear. And what I hope for.


However, how do you know (if you can say), and why would LS say differently? He was clearly talking about what is broadcast to me, not the feed from providers to Dish.

understand that what you see on the hard drive and what is on the stream for playback are not necessarily the same thing. How? I don't know. Why? I don't know. Is it true? Yes, and when I find out the how and why, I'll get back to you. There are many variables in digital satellite, not just a few constants like the naysayers are imagining.

From this thread: https://www.videohelp.com/forum/viewtopic.php?t=183688&start=0&postdays=0&postorder=asc&...h%20resolution

Thanks for clarifing about the providers to Dish. I did not mean that.

[trevlac]

Don't know if the "broadcast" is filtered or changed in any way before getting to the hard drive, and I guess someone told him that there are some differences, maybe not a full encode, but some resolution changes, I don't know.

The original poster wanted to know the resolution to adjust his capture equipment and I don't know if that is relevant because you are capturing the analog signal output from the receiver. I don't capture the analog from my receiver, but if I ever do, I'll test different setings and keep the one that give the best size/picture/resolution from my tests and not the original broadcast resolution because that is lost when converted to analog.

There are standalone Tivos, and you can select different setting, each with different resolution capture and bitrate, but the recording settings in Directivo and Dish DVRs can't be changed. Some people say that Directivo units do not have a encoder chip like the standalone tivos, but I don't know.

At end what if dish broadcast at 480x480 and directv at 544x480 or the other way around? they use different encode hardware, compression ratios, etc. so picture quality changes a lot from one channel to other.

I carried this over from an older thread because I asked the same question there, but it was a bit off topic of that thread.

https://www.videohelp.com/forum/viewtopic.php?t=183688

----------------

@dvdnew

I have also tested 'non-analog' capture from my DVR. It's what I'd like to be my normal process.

However, I'd really like to put LordSmurf's doubt to rest. I have both a DVR and a regular receiver. The implication is that analog capture from my regular receiver (at the right settings) would be better than anything from my DVR.

I guess I'll have to test, but I'm not really sure how. Maybe dish will broadcast a test pattern for me? Any suggestions as to a channel that is 'constant' and has high resolution?

Thanks

[dunamis]

I have two Dish PVRs and three 301 receivers. I cannot see any difference between them in picture quality when viewed on my large screen TV.
I capture to my computer via the S-Video and audio connections, using a Pinnacle DV 500 Plus card, edit as necessary in Adobe Premiere 6.5 and burn to DVDs or VCDs.
The DVD burns are outstanding and the VCD burns are tolerable for some material where quality is not paramount.

[BarryL]

About 8 months ago a friend sold me his Dish PVR, I researched the question you are asking, everything I found said the PVR recorded the full stream unaltered.

Being a born skeptic, I did some test caps from my old receiver, and from the pvr hard drive, of the same 1 hour clip, the file sizes were almost exactly the same size, and the quality was IDENTICAL (to my eyes).

I love the PVR solution, I used ATI and MMC, and setting up the Dish event and Ati scheduler was a pain in the ass, and it seemed you never got the start dead on always previews and stuff. Now I can setup 10 shows to record thru the week in a few minutes, and capture them with precision at my leisure.

[trevlac]

About 8 months ago a friend sold me his Dish PVR, I researched the question you are asking, everything I found said the PVR recorded the full stream unaltered.

Being a born skeptic, I did some test caps from my old receiver, and from the pvr hard drive, of the same 1 hour clip, the file sizes were almost exactly the same size, and the quality was IDENTICAL (to my eyes).

I love the PVR solution, I used ATI and MMC, and setting up the Dish event and Ati scheduler was a pain in the ass, and it seemed you never got the start dead on always previews and stuff. Now I can setup 10 shows to record thru the week in a few minutes, and capture them with precision at my leisure.

Excellent !

I too am a skeptic. However, I really did not want to run a bunch of tests and still question 'my eyes'. I'll trust yours.

Thanks

[lordsmurf]

My information has clearly shown the same as indolikaa's, that DISH is almost always 480x480 with some 640x480, while DirecTV is almost always 544x480, with some 412x480, 352x480, and 640x480 streams...

and both get the rare 704x480 stream for special channels and events.... and that 720x480 and (in the USA) 352x240 streams do not exist...

so how a DISH PVR can supposedly grab a 544x480 stream and a DirecTV DVR supposedly grab a 480x480 stream is what I'm having trouble understanding, as those are not the standards being sent by the transmissions... and my information does come from those that know far more than I do.

My information is not reversed... and I can actually visibly see the resolution differences between the two broadcast dishes on larger higher definition monitors...

DISH (Charlie) uses an easier Nagra system and simpler DVB-II variation... while DirecTV (Dave) uses a NDS system with more complex DSS MPEG standards that were developed proprietarily..

[trevlac]

so how a DISH PVR can supposedly grab a 544x480 stream and a DirecTV DVR supposedly grab a 480x480 stream is what I'm having trouble understanding, as those are not the standards being sent by the transmissions...

Thank you. I now understand what you are saying. Very strange.

I have a Dish PVR. Is there any testing I could do to provide more information?

Can you keep us posted if you find out more?

Thanks,

Trev

[lordsmurf]

Can you keep us posted if you find out more?

Sure, just realize I'm on a "learning hiatus" for a month or two, whilst I finish my video projects and try to complete all guides for lordsmurf.com (still working out some bugs on the server move, gotta fix those before I start to upload new content)

[trevlac]

I wanted to follow up.

From 'my sources', I'd draw different conclusions than LordSmurf and indolikaa. Here is how I see it today.

Dish

Conclusion

Dish transmists in a few different H frame sizes (704, 640, 544, 480...). They low pass/soften their stuff to improve compression. Their DVRs store the stream. They do not change the compression, framesize, ect. of the stream. If you pull the data from the HD, you get what they basically sent.

Sources

Google / Dishrip / Dish 510 DVR and 301 receiver Tests

Reasons for Conclusions

1. When the coolstuff link states Dish is 480. They are talking about Nonencrypted channels in there test. They did not test encrypted channels. They even state things might have changed since their info, and another source they give says dish is 544. I'd like to test some FTA channels to see what the DVR stores, given some time.
2. Dishrip people clearly have files in different H sizes
3. Dish Network people are quoted on 10/13/03 as saying their DVRs do not have encoders. They were asked why people can't record off of other sources such as VCRs using the DVR inputs. If there were encoders, I'd suspect Dish would want to offer this like a regular Tivo unit does.
4. Comparing the Picture Quality of Dish to Direct is not a good test for frame sizes. If Dish filters/softens their source, frame size does not matter. IE, Dish may have a equal Frame size to DTV, but not an equal PQ.
5. Comparisons of PQ from a 301 unit to a DVR is a good test to see if the DVR changes things. BarryL did some tests here and concluded there was no difference.

DirectTV
I don't have DirectTV nor a direcTivo. I'd have to take what people say at face value. There info here seems to have more detail, such as different channels are different. I don't think DirecTivo units have inputs or encoders, but people are saying they only store 480. I'm not sure why they think they only store 480, unless they have a unit and can pull the data out.


Some links
http://www.tivofaq.com/DirecTiVo.html
http://www.spectra-one.com/digitalvideo.html
http://groups.yahoo.com/group/dishrip/
http://ekb.dbstalk.com/index.htm

[Foxbat]

I don't know about Dish, but DirecTV almost always broadcasts using 480x480 MPEG2 streams. Some of the PPV or movie channels may be different.

I own a DirecTiVo and I am able to extract the raw recorded videos from it, and they are always 480x480.

[trevlac]

Lordsmurf says what you say proves that the Tivo units do not record what is broadcast.

If I follow him, his reasoning goes like this:

1. From some source maybe 'testers' hackers he knows DTV mostly sends a 544x480 stream.
2. People seem to mostly pull 480x480 from DirecTivo
3. Conclusion: The Tivo changes the stream

I don't draw the same conclusion about Dish. Smurf and others seem to have more info on DTV. I may try to find out what the Dish 'testers' are saying, although they seem to be more interested in ECM and 'stealing' channels, than recording them.

[Foxbat]

I'm sorry, I just don't buy that. First of all, the DirecTivos are not equipped with an MPEG encoder, so I fail to see how it can change the stream at all.

Unfortunately, I haven't been able to find any authoritive technical information at all on what resolution DTV broadcasts at, and these "sources" sound a bit dubious. However, if anyone reading this thread can find something, please post the link.

[lordsmurf]

A portion of my DirecTV information does come from people that are able to download the entire stream, and yes they are often involved in underground activities, but the stream video decompiles are what I take interest in.

It took forever to get numbers on the LA/NY broadcasts, which I had gotten to around 400x480... thankfully indolikaa got me 412x480 as the extact number... the stream info looked odd at those channel points.

All channels on DISH and DSS are encrypted ... I need to check preview channels again before I stick my foot in my mouth here ... but it still requires a card to access those channels (even without a sub). DISH is Nagra, DSS is NDS (F/P2/P3) and now (P4/D1) NDS-based.

My DISH info comes from other mostly, nothing I can look at too often, though I've done it. Again, all info pointed to 480x480, though that was mostly done last year at this point ... so things may have changed with the introduction of all the PVR units and price drops this year, but I'd be surprised. I fixed a DISH (fixed... hahaha... it wasn't plugged in... old people ) for somebody last week, and the quality was clearly Half-D1 (or nearby range) on that tv (of course, MAYBE it was the 10-year-old tv too).

Sadly, DirecTV's hell-bend rage against dish info has eliminated many of my contacts in past months... and it's becoming harder to get accurate facts.. The person I knew at DirecTV quit too this past summer, so I'm in need of more contacts if I wish to learn more about this odd little quirk.

[Foxbat]

It took forever to get numbers on the LA/NY broadcasts, which I had gotten to around 400x480... thankfully indolikaa got me 412x480 as the extact number... the stream info looked odd at those channel points.

Actually, when I view DirecTivo files on my computer, I do notice a very small black bar on the left side of the video. So it may be that something like 412x480 is the actual resolution of the video stream, and DTV or the TiVO are making the MPEG headers read 480x480. It sounds odd that they would do that, but it does explain a lot.

However, when I author the Dtivo files to DVD, I keep the 480x480 header info intact, and those DVDs will play in my set-top player without any black bar showing up on my tv.

[vhelp]

Here my two cents worth of nonsense to add to the pile of articles..

@ trevlac,

If you know of a channel that airs every weekend for instance (like DirecTV does)
some content, you could use that as a test pattern.


DirecTV airs every weekend, concerts and/or music videos or Live's and these
are sometimes in pretty good condition (to most noobies)

Personally, I don't fuss too much w/ digital vs. analog. To me, there're all
basically the same thing. I mean, really.., when you truely look at it, the
source is first Analog (tapes ie, betamax etc) and they in turn transfer it
to another "standard" medium that everyone can use (Directv for instance) then,
these mediums are distributed to those "outlets" like Directv and Dish and
Cable, and Attenna etc. etc. In some, you have them airing (the Analog source
that was distributed as "standard") after a conversion if Satellite is the
outlet, "digitized", while others ie, Anttenna will pass this same (Analog source
that was distributed as "standard") in an Analog medium (your anttenna)
.
.
So, when you all get right down to it, it's all (LOL) Analog source
Just some are sending it Digitally, while others, Analogy.
.
.
But, lots of peoples out there get carried away w/ "digital" and make it sound like
"oh wow.. it's digital !!" ..giving the illusion that if it's digital, it's gonna
be the best quality, and that just not quite accurate !!!
.
.
It's my opinion (or speculation or theory) that an Analog source (ie, Cable) would
yield better quality, mostly becuase the source is not "digitized" yeilding some
macro-blocks etc. But, the down-side to Cable, is that it's noisey. I think they
call this analigy, "the double edge-sword".

On the subject of Resolutions...
I think that the articles on the, for instance "480x480 with some 640x480, while
DirecTV is almost always 544x480"
is moot too. Only because if these sources are (key word, "sources") are in various
resolutions (assuming this to be true) you still must understand that no matter how
you look at it, you're still going to get your "source" (via capture or dv) in the
resolution that the Outlets air it in, or your device puts out. I can't see my
device (RCA receiver) putting out various contents under different resolutions, as
in the above. So, if DirecTV is airing sources as 544, then it's only and always
going to be 544.., not 480 or 720 or 704 etc.. though the source might look
a little better in detail if you really look/study it. But, it will always be in
544 resolution (from a resolution point of view, even though their is discussion
on the "tv resolution" elsewhere that goes into this in detail, that it's not actually
resolution, but rather scanlines or whatever cross-eyed'sense being discussed)
(but, even if you believe this "scanlines" theory, then you gotta stretch an extra
mile, cause from what barely understood from that article, given scanline as the
theory, there is not limit as to how much resolution one should capture in, even
if your capture/dv card has a set limit) - sorry to make your eyes go crossed.

-vhelp

[trevlac]

@vhelp

Good idea on the test pattern. Maybe some text will do.


However, I think you are missing the point:

An analog source may be better. However, if you are going for digital, you have to go thru the trouble of doing a good conversion.

Digital source is already digital (if you can get at it in digital form). If this source is as good as or better than the analog, you are way ahead. No need to digitize. Just author.

If DVB broadcasters are true to their word, they are providing higher than analog broadcast resolution. This is not really a high bar to cross in the US. After all, they probably do have access to the studio source.

As far as resolution goes, frame size is not resolution. A larger frame can carry a higher resolution, but it doesn't have to. Broadcast TV in the US is generally stated as having a TVLh resolution of 360. This equates to 440x480. Both of these are based on a bandwidth of 4.2MHz. This 4.2MHz is the limiting factor.

Resolution/bandwidth can be limited by lowpass filtering/softening the source. This means you simply remove the high end of the bandwidth. A color TV with a lowpass filter does this. That's why a comb filter is better. This filtering equates to removing the detail (or high frequency events). If the detail is moving like noise, this can achive better mpeg compression. Here again the 'bandwidth' is the limiting factor. It's just not clear what it is without a test pattern like this one.


I'm sorry to rant on resolution vs frame size. It's one of my favorite topics.

Here is a link that 'explains' resoultion frame size and bandwidth

http://www.maxim-ic.com/appnotes.cfm/appnote_number/750

[oldfart13]

Just my 2 cents worth...I use Dishnetwrk a lot these days and I've noticed the compression on some channels has gotten worse and worse, while others are at least tolerable. This is magnified when using the Panasonic E80 to record content. For instance, most of the extended service movie channels have much better compression than "the men's channel" (you all know which one I mean). Just check out any sports (or pseudo-sports) and see the artifacts galore in their credits and any high motion sequences. I generally record these shows for a friend and I'm getting more and more disgusted as I have to use SP mode to record in to fit a show to a disk for economy. Using XP clears up the problem but "blockies" are still evident to my eye. Meanwhile, several of the premium channels I record from exhibit no such problems using the same SP recording speed. What I've love to find out is the actual compression ratio per channel and transponder. That would be a good indicator of how well the picture will look if recorded to HDD/DVD from the various satellite providers. However, I've not seen a site that has that info. Anyone know?

[lordsmurf]

This info is hard to come by, as they guard it like trade secrets.

[indolikaa]

Good Evening!

When I originally posted the resolutions provided by my sources, I was only passing on what had been forwarded to me. I myself pay for multiple subscriptions to both DiSH and DirecTV and have never played with the payloads received by any receiver, so I am not particularly knowledgable on the subject.

I will say this, in my humble defense. While I wouldn't bet the bank unless I had the actual document in my hand, I'd wager a healthy amount on LA/NY being 412x480 (downlinked) for the major networks.

.indolikaa.
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