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There is a long thread on this. I did it with a jvc with old f/w.

View the thread on this to get all the details from others.


dave
 

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Discussion Starter · #3 ·
Looks like a Sony firmware issue. The unit I have

fails the 5C key exchange after the first step (yes,

I'm a 1394 engineer and have a 1394 bus analyzer).


I'm also very skeptical about the Sony being able

to send to the D-VHS deck. It ignores the plug

control packets from the JVC, which would imply

that isochronous transmission is not implemented.


However, I've just started testing with the Sony. I'll

post any breakthroughs here on the forum.


Ron
 

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Beware that there may be firmware version issues here. I have a working 34xbr2 30k here at this time. It plays back D-Theater tapes (all three) via firewire perfectly. Never a glitch, can do it at anytime, everytime. Others with later firmware (30k) report no firewire out on 1080i D-Theater tapes.

My Sony is an August 2001 model, and my 30k has the original firmware (with no playback glitches/freezes etc). Please keep us informed!


Ray
 

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dr1394,


Welcome to the forum. With your expertise (and 1394 analyzer:)) perhaps some of the firewire mysteries will finally be solved.


As Ray has noted, a number of members have successfully displayed D-Theater tapes via firewire with XBR2's. In my case it was the KD-57XBR2. Why some have been successful and others have not, is a mystery. Is it firmware versions, or some aspect of 5C such as exposure to CRL's?


There's also the question of whether it's possible to record from the XBR2 tuner. Very few here have had success with that.
 

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I have that config working for everything but dtheater tapes. But even when this combo works, I have found it to be less than perfect solution to a non existent problem. Here goes:


I recorded some stuff from my cam to a dvhs tape and then played it back via firewire, to my disappointment, it looked crappy. Same dvhs recording of minidv tape when played back via component looked just fine. Same thing happened to JVC's tuner input when I directed it to my xbr2 via firewire, it looked crappy, but the same source when output via component looked ok, the source for tuner was timewarner cable. What this has done is discouraged me from pursuing any products with firewire based transport as the sole digital outs. My next purchase (probably a projector - 2003) is going to be a component/dvi product.


Perhaps this will not apply to Dtheater tapes, because of better (lesser) compression, higher resolution or even by design, but thats just only one part of the firewire game. I want to be able to plug stuff in and move content at will; in another lifetime perhaps.
 

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Discussion Starter · #7 ·
Playback of D-VHS material from the DH-30000U

to the Sony 34XBR2 over Firewire seems fine here.

However, that's with these video settings:


picture mode = Pro

color temp = neutral

VM = off

DRC mode = progressive


After a reset, the 34XBR2 comes up in picture mode

"Vivid" which is the probably the worst possible

for MPEG. Huge change when going to the above settings.


As for Firewire itself causing degradation, that's

impossible. Firewire is just a means to transport bitstreams

from one box to another. It doesn't change the contents

of the bitstream. Don't kill the messenger because he

brings bad news.


However, in your comparison between Firewire and

component your are looking at the output of two

different signal paths. The component path uses

the JVC (or set-top box) MPEG decoder (and

upsampler if the component output is HD), while

the Firewire path use the Sony MPEG decoder (and

upsampler). It's quite possible that the JVC (and

set-top box) MPEG decoders do a better job of

block filtering / post-processing than the Sony.


Ron
 

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Thats what I thought, except OTA on this television is the best picture I have ever seen anywhere, except DTheater demo tape. OTA definitely goes through MPEG decoder in sony. My second guess is that the firewire path involves mpeg decoding in jvc while reading from tape and then re-encoding to transport it over firewire. That would bring the quality a bit lower.


As for firewire being nothing but a transport, you are absolutely right, except unlike DVI it requires compression to handle the bandwidth required by television content. Sony and JVC's ilinks have a limit of 200 mbps, which os way more than the 19 mbps ota and 28 mbps dtheater, yet keep in mind that both sources are compressed content. DVI on the other hand offers raw uncompressed digital signal transport (with its own caveats ofcourse - like limited max resolution etc.).
 

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The point being, dvi and analog outputs on any device donot need any re-encoding for digital transport. If this is the case of recompression, it would be a bad implementation on part of jvc. I am all ears to any other interpretation though.
 

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But there is "recompression" going on. DV is not isomorphic to MPEG2, and some processing has to take place. The fact that the JVC accepts DV signals at all on its 1394 input constitutes a "feature", since its native format is MPEG2.


Note that it will accept DV format in, but will not produce it on output.


As I've mentioned elsewhere, Greg Rogers goes into this in some detail in his review of the 30000U that appeared in Widescreen Review a couple of months ago.
 

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I do not know if my results are relevent to this discussion, but I thought they might be.


I do not have a DV camera with FW output, so I can't help you there. I have recorded many tapes from a SD Analog S-Video output from a Motorola C-Band Ku Band analog/digital IRD. I use D-VHS mode only, and record in HS speed, using JVC S-VHS tapes. The 480i (source) content delivered to the 30k's S-Video input is just about as good as 480i gets (first generation C-Band analog), and the content recorded on the tape is of DVD quality or better when played back via Firewire or Component ports to my KD-34XBR2. I mean it looks as good as the source material, and the firewire port has a discernibly better video "look" to it. The colors are more vibrant, and IMHO it equals or exceeds the appearance of most 480p content delivered via the component port from my Sony PS DVD player.


This D-VHS digital copy of original analog content, is quite noticably better than S-VHS copies dubbed on my JVC S-VHS deck, using the same S-Video output source. A/B tests show that there is a substantial difference between S-VHS and D-VHS copies, with D-VHS the winner. I can dub copies from my D-VHS deck to my S-VHS deck, and the copies are exactly the same S-VHS quality as those recorded from the Motorola receiver as a first generation signal.


In my situation, FW plays back with better quality on all content viewed on my 30k/34XBR2 combo. The same holds true here for D-Theater content also. All of my content is of excellent quality.


I would use the 30k to view all of my SD analog satellite content through its firewire port full time, if it were not for the delay in audio. I have no digital OTA here yet, but the four OTA stations I view today (analog), have their transmitters less than three miles from me. I have not tried to record any lower resolution content, and then play it back via firewire. Good luck with the testing!


Happy Memorial Day Weekend to all. Thank you to all that have served our great country in the military. God bless them!!!


Ray
 

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Ray, a minor observation: if you're recording analog C-band you'd probably be even better served by using the composite video output rather than the S-video output of the Motorola receiver, given that the signal you're downlinking is composite to begin with.


The Y/C separator in the 4DTV receiver is no great shakes, and I would expect that the JVC deck will do a better job of it.


Of course you should use S-video to record digital C-band (since DCII signals are already Y/C-separated).
 

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Discussion Starter · #13 ·
Using an MPEG-2 bitrate of 28.2 Mbps to record

SD material is a bit of overkill. Do you do this

because you don't like the results with STD speed

(14.1 Mbps)? I would be very interested to know,

since as an old MPEG encoder designer, I consider

14.1 Mbps to actually be a pretty high rate

for SD (at least theoretically).


However, one would expect essentially "transparent"

encoding of any material at 28.2 Mbps for a penalty

of 2 to 1 tape usage. Maybe not a bad trade-off.


Ron
 

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Hi guys!


rrg said: "if you're recording analog C-band you'd probably be even better served by using the composite video output rather than the S-video output of the Motorola receiver, given that the signal you're downlinking is composite to begin with."


The composite output on the DSR922 does not yeild as tight a picture as the S-Video. Since the DSR922 IRD can utilize the S-Video out on analog C-Band content as well as DCII content (the DSR920 only had S-Video in DCII mode), a direct A/B comparison shows that the S-Video has an ever slight edge in performance (this is darn close though). I have tried it both ways, I just call em' as I sees em'. Composite and S-Video out from the 30k, look terrific on the XBR2 when viewing SD recordings (S-VHS included). Component output from the 30k to the XBR2 looks much better than the S-Video or composite. There is no comparison. Firewire is even better still.


I do have to use the composite out to display the menu graphics and guide on the HDD200 decoder, when vewing HD content. It does not pass this data through on its component ports.


There is a new firmware available for the HDD200 that lets one stretch the video out to fit full screen on a 16x9 set (when viewing 4:3 content), but I do not have it in this decoder. It also is inferior to the Wide Zoom on the XBR2.


dr1394 said: "Do you do this because you don't like the results with STD speed (14.1 Mbps)? I would be very interested to know, since as an old MPEG encoder designer, I consider 14.1 Mbps to actually be a pretty high rate for SD (at least theoretically)."


I use the HS speed as to my eye it has a more pleasing look. I can see the difference in STD speed as opposed to HS speed. This difference is not large, but a little improvement here, a little improvement there, and you net a better video experience. I just experimented with all possibilities until I found the one that gave me my best result. I archive three sci-fi shows, and watch them many times for reference and enjoyment. Looking inward, I find HD has spoiled me terribly. I just can't watch anything less than DVD quality anymore, and even this is a compromise! :)


This is just the way I get the best performance from my setup and content delivery systems, with respect to SD viewing/recording. The HDD200 is amazing on HD content. First generation HBO, Showtime, ACSN Sports, and Discovery HD Theater (now testing) look wonderful. The 30k and D-Theater however, is the best 1080i viewing available in the home to date, IMHO.


Ray
 

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Quote:
The composite output on the DSR922 does not yield as tight a picture as the S-Video. Since the DSR922 IRD can utilize the S-Video out on analog C-Band content as well as DCII content (the DSR920 only had S-Video in DCII mode), a direct A/B comparison shows that the S-Video has an ever slight edge in performance (this is darn close though).
Fine, but have you compared the two sources on D-VHS recordings, as opposed to just viewing them using the XBR's internal scaler (or however it is you're viewing them)? It's possible that the 922's comb filter does a better job than the Sony's.


My experience with JVC's VCRs is that they do a pretty good job in this regard. In my system I switch NTSC signals using a Sony SB-V3000 matrix switcher with a built-in Y/C separator. When I record analog C-band I usually use the composite output of a Monterey 95 IRD (which still beats the 4DTV on analog). The signal passes through the Sony switcher and I can choose to record either the Y/C-separated S-video or the unprocessed composite. Invariably the recordings are cleaner when the composite output is used. This is with two different models of JVC (an older pro unit, the BR-S378U, and a more recent consumer model, the HR-S9600U).


I think it's worth trying this experiment if you haven't yet (given your quest to derive the ultimate video quality from the source).

Quote:
...Discovery HD Theater (now testing)...
Has this started then? I hadn't realized. It is on C4, where the rest of the Discovery digital suite was?
 

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Hi Ron,


Yes, C4 transponder 14. It's broadcasts are intermittant (full time color bars and logo when not broadcasting HD content), and it has a logo in the bottom right hand corner that burns like a landing light. Quality has been quite good, and much of what I have viewed has been encoded in DD5.1. I will certainly add it to my suite of programming when available June 17 (I hope). I have read that this is the official launch date. Will play a bit tomorrow, and let you know about the outcome of the testing. I have previously tested, but you have piqued my curiosity.


Ray
 

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Discussion Starter · #17 ·
JVC DH30000U to Sony 34XBR2 via Firewire Update


I can now unequivocally say that the Sony 34XBR2 that I

have been testing with has firmware problems. Specifically,

it is sending a device certificate that doesn't make any

sense at all.


I'm in contact with others in the 1394 community to get

an answer to this issue. Hopefully, we'll get to the bottom

of this soon (next week?).


As to what the bug might be, it's possible that it is

a manufacturing problem. Every single box requires

a different certificate to be burnt into ROM which

is a bit of a logistical nightmare. This would agree

with the fact that some 34XBR2's do work.


In the meantime, I did hook up the 34XBR2 to the

DH30000U with component connections so that I could

watch the HD demo tape. All I can say is WOW!!!!!

I'm utterly impressed with the video and MPEG-2

encoding quality. I will certainly be buying some

of the D-Theatre tapes when they come out June 7.


Ron
 
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