DBSTalk Forum banner
Status
Not open for further replies.
1 - 20 of 63 Posts

·
Banned
Joined
·
49 Posts
Discussion Starter · #1 ·
O.K., I'm finally putting this thing through the paces now that it hasn't frozen up on me since the complete reformatting of the hard drive. Now some questions...jump in here any time Earl...

1)What equivalent processor is this box, the HR20, using? Like a P4 and what ghz? Just a ballpark is fine. Reason I ask is that it chokes on two MP4s being recorded while doing other menu/guide manuevers. I did notice FOX 40, yes I was wrong, we now have FOX 40 in Sacramento on the MP4. Watched House tonight, not bad, not bad, looked pretty good. No OTA to compare, but please, it looked good. While I was recording that and a show on local NBC, I don't know what I just recorded it for fun, I went to the guide to see what time the Laker game was going to start tomorrow and then the fun began...audio drops and jagged picture in the little window.

I've played around with encoding mp2 video into DIVX and other MP4 codecs on my computer for years and the one thing I noticed is that you can't sneeze near the thing without it choking on the mp4 data. Touch the keyboard and the audio goes out of sync or if you are encoding the computer freeze. I have a P4 running at 2.4 ghz with a gig of memory. Plenty to do the encoding if you leave it alone. Are there enough horses in the HR20 to handle all the mp4 data? Dumb question, because why would D* release a box that would be too slow to hand that data.

2) Is D* sending some kind of info down the MP4 stream not related to the current programming and are they sending it only on say the FOX mp4 stream. I don't know...some background guide info or weather info. In a pulse that lasts say...I don't know 7-8 seconds? Just grasping at straws trying to understand what in the world happens on FOX...

D.L.B. and you got me...:)
 

·
Banned
Joined
·
49 Posts
Discussion Starter · #3 ·
jonaswan2 said:
You can't really compare processors for CE devices with computer processors, but the MPEG4 decoding and general processing are done on seperate chips.
You mean like a main processor (P4) and a video processor...(like an ATI card, etc...) I think you can make a "ballpark" comparison, it seems like it's just that no one knows what it is...yet...

Any answers to the other questions?
 

·
Legend
Joined
·
148 Posts
Your question is a non-issue:
1) The HR20 DOES NOT encode data. It is encoded at the source. The HR20 records the bitstream directly from the satellite dish.
2) The DECODING is done by chips that have 1 function: Decode MPEG2/4.

The general purpose chips have no impact on recording satellite bitstreams or decoding the bitstreams from disk.
 

·
Hall Of Fame
Joined
·
1,222 Posts
It would be a meaningless bit of trivia. Consider that the Series 1 standalone TiVo had a 54 MHz CPU (no, that's not a typo) and never had any problem encoding one stream and decoding another (because the heavy lifting is handled by dedicated hardware). The Series 1 DTiVo upped that to around 70-80 MHz (and doubled the memory) to be able to handle dual tuners (even though they were already compressed).

For whatever it's worth, though, I believe they used the same processor as that found in the Series 3 TiVo: Broadcom BCM7038:
http://www.broadcom.com/products/Cable/Digital-TV-Solutions/BCM7038

A 300 MHz 64-bit MIPS (along with a lot of other stuff). That's 0.3 GHz for you kids out there :D
 

·
Banned
Joined
·
49 Posts
Discussion Starter · #6 ·
laxcoach said:
Your question is a non-issue:
1) The HR20 DOES NOT encode data. It is encoded at the source. The HR20 records the bitstream directly from the satellite dish.
2) The DECODING is done by chips that have 1 function: Decode MPEG2/4.

The general purpose chips have no impact on recording satellite bitstreams or decoding the bitstreams from disk.
That's so funny that you state it that way as the HR20 has soooooooooo many issues that I don't know even where to begin.

Do the chips in the box have to chew a little harder on the MP4 stream than they do on say the MP2 stream or is it all just raw data to it? Why do the MP4 channels choke and die, especially when you try to record two of them, more often than the MP2 channels? Maybe it's not chip dependent, but something is grinding inside that box...
 

·
DBSTalk Club Member
Joined
·
251 Posts
jonaswan2 said:
You can't really compare processors for CE devices with computer processors, but the MPEG4 decoding and general processing are done on seperate chips.
Ditto.
 

·
Banned
Joined
·
49 Posts
Discussion Starter · #8 ·

·
DBSTalk Club Member
Joined
·
251 Posts
mlobitz said:
Ditto = I don't know
Uhm, no, it doesn't. You could look up the definition (hint: "as already stated; likewise.") and retract your statement or simply stop being a jerk.

mlobitz said:
That's so funny that you state it that way as the HR20 has soooooooooo many issues that I don't know even where to begin.
You've had a lot of issues. Again, many other people have not.

mlobitz said:
Do the chips in the box have to chew a little harder on the MP4 stream than they do on say the MP2 stream or is it all just raw data to it?
In fact, when writing to the disk, the MPEG-4 is easier to write because it's easier to compress. So, all other things being equal (i.e. the picture, etc.) MPEG-4 is "less intensive" to write to disk than MPEG-2. There are simply less 1s and 0s. Less data to write. Lower bitrates... that's what makes MPEG-4 "better" than MPEG-2.

mlobitz said:
Why do the MP4 channels choke and die, especially when you try to record two of them, more often than the MP2 channels? Maybe it's not chip dependent, but something is grinding inside that box...
Your experiences are likely not representative of the whole, the majority, or of even a large percentage of the minority.

MPEG-4 is often a little more difficult to decode, but not always and not by much. If you want more, use a search engine to answer your questions.
 

·
I used to be a rocket scientist
Joined
·
12,182 Posts
Do the chips in the box have to chew a little harder on the MP4 stream than they do on say the MP2 stream or is it all just raw data to it? Why do the MP4 channels choke and die, especially when you try to record two of them, more often than the MP2 channels? Maybe it's not chip dependent, but something is grinding inside that box...
My MPEG4 streams have never given my box any problems systematically - our CBS local HD is glitchier than the others but it's never crashed my box. In fact, the three GUI lockups we've had over the last 7-1/2 weeks have all come when selecting MPEG2 SD programs to play from the Playlist or telling it to delete an MPEG2 SD program at the end of playing. No HD programs, whether MPEG2 or 4, have been central to any of our real issues with the box.
 

·
Banned
Joined
·
49 Posts
Discussion Starter · #11 ·
iacas said:
Uhm, no, it doesn't. You could look up the definition (hint: "as already stated; likewise.") and retract your statement or simply stop being a jerk.

You've had a lot of issues. Again, many other people have not.

In fact, when writing to the disk, the MPEG-4 is easier to write because it's easier to compress. So, all other things being equal (i.e. the picture, etc.) MPEG-4 is "less intensive" to write to disk than MPEG-2. There are simply less 1s and 0s. Less data to write. Lower bitrates... that's what makes MPEG-4 "better" than MPEG-2.

Your experiences are likely not representative of the whole, the majority, or of even a large percentage of the minority.

MPEG-4 is often a little more difficult to decode, but not always and not by much. If you want more, use a search engine to answer your questions.
Please:lol: stop it...:lol: can't stop:lol: laughing:lol:

It amazes me. People give ME short curt little answers like, "Your question is a none issue..." instead of writing what you just wrote above which actually ANSWERS PART OF MY ORIGINAL QUESTION!!!

Thanks for calling me a jerk and I guess for answering my question?

O.K. I'm back on the floor now:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

You people take yourselves way too seriously. Even when Ironcrap Com. missed four of my appts., yes I was angry, but not a jerk...

Here it comes again...:lol: :lol: :lol: :lol: :lol: :lol:
 

·
Lifetime Achiever
Joined
·
28,939 Posts
walters said:
For whatever it's worth, though, I believe they used the same processor as that found in the Series 3 TiVo: Broadcom BCM7038:
http://www.broadcom.com/products/Cable/Digital-TV-Solutions/BCM7038
DirecTV uses the BCM7411 chip to decode MPEG2/MPEG4. Not sure of the processor because I didn't open the box. The processor should be under the heat sink at the top of this photo. This picture are from Earl.



I checked out the Product Brief from Broadcom and on page 2, the following statement is made:

The BCM7411 supports the following decoding operations:
* 1 HD (MPEG-2, H.264 or VC-1) in real-time
* 2 SD (MPEG-2, H.264 or VC-1) in real-time
H.264 = MPEG4
 

·
Lifetime Achiever
Joined
·
28,939 Posts
iacas said:
In fact, when writing to the disk, the MPEG-4 is easier to write because it's easier to compress. So, all other things being equal (i.e. the picture, etc.) MPEG-4 is "less intensive" to write to disk than MPEG-2. There are simply less 1s and 0s. Less data to write. Lower bitrates... that's what makes MPEG-4 "better" than MPEG-2.
The steam coming from DirecTV is already compressed. I think what you meant to say is that MPEG4 is more compressed than MPEG2, thus taking less space on the disk. The HR20 never encodes the data, it only decodes it. MPEG4 is actually significantly harder to compress to than MPEG2. It's only been in the last few years that people have been able to encode data into MPEG4 in real time making the currently technology possible.

iacas said:
MPEG-4 is often a little more difficult to decode, but not always and not by much. If you want more, use a search engine to answer your questions.
This sounds about right.
 

·
Legend
Joined
·
179 Posts
Doesn't the HR20 only decode the MPEG compression for viewing?

Doesn't it actually store the raw feed to HD?

If that is true, then wouldn't it take very little CPU and no MPEG chip resources to record.

However to watch would be a different issue.

In fact in another discussion about PIP the same picture was shown and stated since it only had one decoder PIP could not work.
 

·
Lifetime Achiever
Joined
·
28,939 Posts
O2BRich said:
Doesn't the HR20 only decode the MPEG compression for viewing?

Doesn't it actually store the raw feed to HD?

If that is true, then wouldn't it take very little CPU and no MPEG chip resources to record.

However to watch would be a different issue.

In fact in another discussion about PIP the same picture was shown and stated since it only had one decoder PIP could not work.
Correct, the "record" function basically reads the data stream from DirecTV or OTA and puts the data directly onto the hard disk drive. DirecTV already knows that this format will be either MPEG2 or MPEG4 because either they encode it themselves or they are receiving a known format over-the-air. There is ZERO encoding on the computer, so there is no need for an encoder chip or a larger processor to handle the encoding.
 

·
DBSTalk Club Member
Joined
·
72 Posts
brott said:
DirecTV uses the BCM7411 chip to decode MPEG2/MPEG4. Not sure of the processor because I didn't open the box. The processor should be under the heat sink at the top of this photo.

I checked out the Product Brief from Broadcom and on page 2, the following statement is made:
This is one of the most direct and informative answers I have read on DBSTalk! Thanks brott!
 

·
Banned
Joined
·
49 Posts
Discussion Starter · #17 ·
brott said:
DirecTV uses the BCM7411 chip to decode MPEG2/MPEG4. Not sure of the processor because I didn't open the box. The processor should be under the heat sink at the top of this photo. This picture are from Earl.



I checked out the Product Brief from Broadcom and on page 2, the following statement is made:

H.264 = MPEG4
Dude...you are awesome. See, the others who didn't really have the info to answer the question just c*apped on me and called me a jerk. You...you waded through and came up with the answer. I thank you for that. I've had some bad experiences with this box and I will be getting a new one, but for the time being I'm just trying to make sense of it all including why D* even released it in the first place. Not trying to offend, but sometimes people who are direct and to the point come off like that.

Thanks again!

Just as an aside, a lot of these "high powered" gaming systems (XBOX, PS2) use 300 mhz processors.
 

·
Lifetime Achiever
Joined
·
28,939 Posts
mlobitz said:
Dude...you are awesome. See, the others who didn't really have the info to answer the question just c*apped on me and called me a jerk. You...you waded through and came up with the answer. I thank you for that. I've had some bad experiences with this box and I will be getting a new one, but for the time being I'm just trying to make sense of it all including why D* even released it in the first place. Not trying to offend, but sometimes people who are direct and to the point come off like that.

Thanks again!

Just as an aside, a lot of these "high powered" gaming systems (XBOX, PS2) use 300 mhz processors.
No worries. We all just want more information.
 

·
Hall Of Fame
Joined
·
1,222 Posts
It's like my post doesn't even exist :(


:D
 

·
Lifetime Achiever
Joined
·
28,939 Posts
walters said:
It's like my post doesn't even exist :(

:D
Yeah, I'm trying to track down whether or not the processor is the BCM7038 or not. I found a post over at TCF that indicated the BCM7038 was in use, but I'm still a doubter - the post also stated that there was only ONE ATSC tuner in the HR20, which is clearly not true from the pictures of the hardware. The BCM7038 has some of the same decoding capabilities of the BCM7411 (it may be less efficient, though). It also has the MIPS processor. It is possible that DirecTV has disabled the decoding routines in the BCM7038 and is doing it externally with the BCM7411. I suspect that a different processor is in use, but I do not know that one way or the other.
 
1 - 20 of 63 Posts
Status
Not open for further replies.
Top