Techincal limitations preventing PnP/PiP

[rmc_ss]

I started a thread elsewhere regarding the HR20 and trying to use it for picture-in-picture (PnP). I was advised the HR20 will not support this and I was curious as to why from a techincal standpoint.

Later, after much frustration and confusion, I found Brott's "wish-list" thread that stated in the introduction:
PIP (or Picture in Picture) is not a viable option on the HR20. There simply isn't enough hardware for that to be done.

Since he stated that, I obviously didn't bother to add it to the wish-list. Brott seems to be exceptionally heavy on these so I have no doubt that his info is dead-on, but I am curious what's the actual technical limitation preventing this.

Since the HR20 is a dual-tuner and already has outputs on the back of the unit for rcvr 1 and rcvr 2 (which are in fact live), why can't they be used in support of PnP? The tuners inside the unit obviously can tune independently since you can easily record with one and view another and 2 sat feeds are connected to the unit.

I am not talking about trying to get 2 HD video signals out of the unit for PnP (even if it did there are no single monitors that would support it); I am talking about 2 SD video signals (which the jacks are already on the back if the unit), just tuned independently or, more to the point have the ability to change the channel on rcvr 2!

I apologize if this has been addressed elsewhere, but I understand some very technically heavy folks are here and Direct sometimes reads threads here. With all of the capabilities of the HR20 and what seems to be available, this would be a HUGE function that would seem to be HIGHLY marketable!

Thanks in advance!

Allen

[carl6]

The HR20 only has the built in circuitry to decode and output one video stream. While it has multiple output connectors, they all send out the same thing.

The two tuners do not decode the signal. They either send it directly to the hard drive to be recorded, or they send it to the live buffer. When you select the channel/program/recording that you want to watch, that is what is decoded and sent out as an audio/video signal. It's that circuitry that there is only one of.

In order to provide pip, the HR20 would need significant additional electronic components, an additional, or different processor, and much more complex programming. Combining all of those makes it a complex and costly change to try and implement.

Much easier and cheaper just to add a second receiver. If you want pip with only an SD signal, add a D11 or D12 standard receiver to your account and hook it up to your second (pip) input on your tv.

Carl

[Doug Brott]

Yup, decoding is the problem. There is only a single MPEG-4 decoder inside the HR20. Therefore only a single MPEG-4 data stream can be decoded at any one point in time. If both of the channels you want to view are MPEG-4, then you would not be able to see one of the channels (it would be black) and would defeat the purpose of PIP.

All of the video files from DIRECTV are stored directly on the HDD, they are not decoded until they are sent to your television.

Steve has hypothesized that there is a method that could potentially work (although I suspect that it would be LiveTV only for the small screen no matter what). This method would require DIRECTV to send an alternate "PIP" data stream in addition to the existing full-format data stream.

[rmc_ss]

So if I understand correctly, the 2 receivers get the signal (MPEG 4 file) and store it (to the HDD) or buffer it. When viewing, the file is sent to the MPEG decoder for display. You are not actually recording the "video program" per se, just the file that must be decoded at playback for viewing.

I'm not sure I worded that right, but I think I understand....

So why are seperate 2 SD video (and audio) outputs on the back of the unit?!

I guess I thought the "dual-tuner" from Direct was the same as dual-tuner with Dish; one box able to feed two TVs....

:confused:

Anyone have an extra dirt-cheap receiver for sale?

[gblues]

I'm not sure I worded that right, but I think I understand....

So why are seperate 2 SD video (and audio) outputs on the back of the unit?!
:confused:


Well, one is for using the audio outputs if you're not using digital outputs; the other is handy to route to a VCR/video capture/whatnot.

[rmc_ss]

Understand all....

I guess that makes sense to give a cleaner signal (less attenuation) for multiple devices.

Thanks for the responses and info!

Allen

[GollyGee]

Yup, decoding is the problem. There is only a single MPEG-4 decoder inside the HR20. Therefore only a single MPEG-4 data stream can be decoded at any one point in time. Are you sure about that?

The HR20 uses the BCM7038. According to Broadcom's Product Brief, one feature is "Two Complete HD/SD Video/Audio Channels", and the benefit of this feature is, "Dual video/audio channels allow dual TV support, along with independent PIP support on main and secondary."

Maybe DirecTV didn't include enough RAM to run both decoders, which would prevent the feature from working. Other than that, it appears that it could work (a "small matter of software"), unless I'm missing something else.

[P Smith]

Then read again - SD, and look into your HR20 for second chip BCM7411. Now tell me what the 7411 DOING there ?

[rmc_ss]

Can someone heavy on these translate...... before I get my hopes up again! :(

Allen

[GollyGee]

Then read again - SD, and look into your HR20 for second chip BCM7411. Now tell me what the 7411 DOING there ?Ahh.. the 7411 is there for the H.264, and it can only decode one HD stream at a time. So they don't want to offer PIP b/c they can't make it work w/two HD H.264 channels at once.

Then again, Echostar manages to decode 2 streams at once with this chipset... there's usually an SD version of the channel available(everything but HDNet??), so as long as one of the channels is SD, it ould work.

[P Smith]

E* used two (2) BCM7411 in each HD box.

[rmc_ss]

Awwww crap.... :(

Well, I figured I'd ask and get the right answer here!

Allen