AVS Forum banner
Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter · #1 ·


Hi everyone,


I have recently been looking at various reviews of the 36XBR450. One review I read, stated that if you send it a 480p or 1080i signal, then the DRC will not be activated. However, on "audioreview" recently, they had a thread going where some guy was arguing that the truth is this: if fed a 480p signal, the DRC WILL upconvert it to 960i.


So, I'm just curious if any of you you out there know the truth about this: will this model TV leave a 480p signal alone or not?


Thanks in advance.
 

·
Registered
Joined
·
239 Posts
I have the 36XBR400 and it is virtually the same as the 36XBR450, with the exception being this - the 450 has built in 3:2 pulldown detection and removal.


Here is what happens with each input signal:


480i - Line doubles to 960i (DRC On)

480p - Displays native 480p (DRC Off)

720p - Not supported

1080i - Displays native 1080i (DRC Off)


Hope this helps.


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

Casey
 

·
Registered
Joined
·
182 Posts
The Sony DRC will not convert 480p to 960i. 480p and 960i have the same bandwidth. In fact you can set the the DRC for progressive or interlaced which tells it to convert 480i to either 480p or 960i. Either way you double the number of lines. Converting from 480p to 960i doesn't add any lines of picture, in fact it would most likely degrade the picture.


Rob
 

·
Registered
Joined
·
261 Posts
Quote:
Originally posted by rleist:
In fact you can set the the DRC for progressive or interlaced which tells it to convert 480i to either 480p or 960i.
How do you do that? Is this a service manual adjustment? I have the 36xbr400, and I'd be interested in changing the DRC setting, if only to see if I can tell the difference.

 

·
Registered
Joined
·
293 Posts
When DRC converts from 480i to 960i, since the signal remains interlaced, how does reverse 3:2 pulldown apply in this situation? I understand the concept of reverse 3:2 while de-interlacing, but not for 960i.


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

Wendell Ocasio
 

·
Registered
Joined
·
80 Posts
Bob, DRC setting is in user menu, not service menu. It is on the very first screen when you press menu button, at the bottom (next to svm setting I recall). It can be set to interlaced(960i) or progressive(480p). In normal viewing, there's not much difference, but for still image, 480p is a bit better.


BTW, I have the XBR400, and haven't seen XBR450 yet. I would assume their menus are similar.


Wendall, DRC and 3:2 reverse pulldown don't work together, it's either/or. I think there is a user setting in menu like on/off/auto or film/video/auto that can control which one is active at the time. But I could be wrong. They may have full auto-detection instead of menu setting.


Hal
 

·
Registered
Joined
·
355 Posts
I too have the 400 and it would be great if you could turn OFF the DRC circuit. It causes artifacts, etc. Maybe the 450 has an on/off for the DRC-if it does, turn it off.
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #8 ·
I have seen the XBR450 on display at a local Audio King. Compared to the XBR400, I noticed that the 450 has an additional option in the DRC menu; it is called "Cinemotion" (or something like that). However, I do not know what the option does, compared to the "interlaced" and "progressive" options. Anybody know?
 

·
Registered
Joined
·
293 Posts
My understanding is that "Cinemotion" IS 3:2 reverse pulldown. If what I'm hearing is correct, for a film-based (24fps) source in 480i, I could choose the video processing to be either DRC (ie 960i) and reverse 3:2 (480p ?). Is that the way it is? (My set is on the way).


One of the complaints some folks had about the XBR400 was the inability to shut off DRC (sometimes it made the final picture quality worse). So, can it be turned off completely?


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

Wendell Ocasio
 

·
Registered
Joined
·
3,340 Posts
Although I don't own an XBR400 or XBR450, I have been researching them for a possible purchase. Here's what I believe:
  • The "interlaced" vs. "progressive" DRC options don't refer to how the DRC OUTPUTs the signal, but rather the type of SOURCE material it optimizes for. DRC always outputs 960i, you would select "progressive" or "interlaced" based on the source of the material. The Sony XBR400 instruction manual (available here ) says to select "interlaced" for moving pictures and "progressive" for still ones.
  • The "cinemotion" setting is a new DRC option on the XBR450 (which, along with "progressive" and "interlaced" now gives it three options). "Cinemotion" is how the 3:2 reverse-pulldown is activated. You would use this DRC setting when viewing source material that was originally progressive (ie, film-based material) but had been received in interlaced format without prior 3:2 pulldown having been applied.


Regarding how DRC can do 3:2 pulldown when it outputs an interlaced signal - the issue here isn't the interlacing, itself but rather which original film frames end up in the interlaced pairs output by the DRC. When you view a film that has been converted to interlaced format without 3:2 pulldown, some of the resulting pairs of interlaced frames are built from different source film frames. The 3:2 reverse-pulldown process will attempt to "resequence" the source interlaced frame pairs as they go into the DRC line doubler so that each pair output 960i interlaced frames contain the information from the same film source frame.
 

·
Registered
Joined
·
293 Posts
My understanding of reverse 3:2 pulldown is a bit different. When film-based, or 24 frames per second, source is adapted to NTSC, which is 30 (29.97 to be exact) frames per second, and interlaced, 3:2 pulldown ALWAYS has to be applied, in order to account for the disparities in frames per second. (long explanation) So the 480i source already has 3:2 pulldown applied. The question is whether the line doubler (DRC in this case) will REVERSE this process in order to produce a progressive signal.


Now, if a line doubler attempts to recreate a progressive signal from an interlaced signal that was created with 3:2 pulldown, by simply taking each pair of interlaced lines in sequence, the end result will have screens composed of lines from 2 different original screens (I cannot explain this in a couple of lines, see the above link). If the 3:2 pulldown process is fully reversed (hence the term reverse 3:2 pulldown), then you fix this problem and get a signal closer to the original. Bottom line: 3:2 pulldown is used to make all 24fps sources into NTSC, and reverse 3:2 pulldown can apply when an 3:2 pulldown interlaced signal is converted into a progressive signal.


Now, if each half of the 960i signal is, in effect, a 480p signal, then that sort of answers the original question (how can reverse 3:2 apply in a 960i signal?).


Anybody please correct my ignorance, if I'm wrong


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

Wendell Ocasio


[This message has been edited by wocasio (edited 07-10-2001).]


[This message has been edited by wocasio (edited 07-10-2001).]
 

·
Registered
Joined
·
15 Posts
Discussion Starter · #12 ·
I followed the link to download the XBR owners manual. After reading through it, I have a question. This may be a real dumb one, but here it goes: When you set the video label on the TV (e.g. VHS, DVD, DTV, etc.), does the TV activate/deactivate certain service menu accessible things to adjust to a specific picture setting, or are these labels just displaying the text without any effect on picture quality?


If I am watching a DVD (with the label on DVD), and I change that input label to say, VHS, I notice no change in the picture. However, I ask this question, because a while ago I remember someone on a message-board, saying that on some TVs, changing the input label will "adjust" the picture. Anyone have any input on this?
 

·
Registered
Joined
·
261 Posts
Mr._Li,


Thanks for the reply. I sat down with the TV last night and found the DRC setting right where you said it was. I found no difference in switching it from interlaced to progressive, but if Sean Nelson's explanation is correct, that's exactly the way it should be.


NewMember,


I don't believe that labelling the video settings does anything except help you find what you're looking for. Only video 5 and 6 have component inputs, so on my set I've labelled those DVD and HD, and I put video 2 (the inputs on the front of the set)on Skip because I don't have anything plugged in there.
 

·
Registered
Joined
·
292 Posts
I have had the 450 for a few weeks now and I agree with Bob, I cannot tell one bit of difference between Interlaced, Progressive, or Cinemotion settings.


I was hoping it would get rid of the horrible "stair-step effect" on some horizontal lines (both still pictures and motion) or while viewing some DVDs, eliminate the "flickering" of some horizontal lines when there is motion - most DVDs look spectacular while a few have this annoying line flickering (e.g., a scene containing shutters on windows - when the camera moves, the shutters look like they are opening and closing). I had hoped one of these settings would have removed this.


Also, on screen, the description for Progressive setting states that this setting is also for Text - I have found that certain text is awful (especially small white/light colored text) and is hard to read - (looks like the letters of each word are broken up and sometimes is surrounded by little black/gray dots). No setting makes ALL text crisp and clear consistently.


[This message has been edited by JimL (edited 07-12-2001).]
 

·
Registered
Joined
·
3,340 Posts
wocasio wrote:

Quote:
Bottom line: 3:2 pulldown is used to make all 24fps sources into NTSC, and reverse 3:2 pulldown can apply when an 3:2 pulldown interlaced signal is converted into a progressive signal
Exactly. Actually there's a typo in my post. The statement:

Quote:
You would use this DRC setting when viewing source material that was originally progressive (ie, film-based material) but had been received in interlaced format without prior 3:2 pulldown having been applied.
should in fact read:

Quote:
You would use this DRC setting when viewing source material that was originally progressive (ie, film-based material) but had been received in interlaced format with prior 3:2 pulldown having been applied.
There's no issue with 3:2 pulldown for a 960i interlaced image. The goal is to make sure that each pair of frames used to generate a 960i image is taken from the same source. In fact there's no real issue with 480i images either - it's the 3:2 pulldown process itself where the problem arises. The real issue is how to map a 24fps presentation into 30fps. If you use a different mapping sequence that keeps the same frame information for each pair of interlaced scans, you can eliminate the interlace artifacts. But you do so at the price of "judder", where the difference in the length of time that each frame is visible may start to be noticable.

New Member wrote:

Quote:
If I am watching a DVD (with the label on DVD), and I change that input label to say, VHS, I notice no change in the picture. However, I ask this question, because a while ago I remember someone on a message-board, saying that on some TVs, changing the input label will "adjust" the picture. Anyone have any input on this?
The separate settings in the XBR450 are per-input (ie, physical connector on the front or back of the set). The labels are just what you want to call those inputs.
 

·
Registered
Joined
·
293 Posts
Sean:


I'm still confused. You say that there is no issue with 3:2 pulldown for a 960i image. But since DRC is 960i, and DRC is always on in the Sony, under which circumstance does the 3:2 reverse pulldown kick in in the XBR450?


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

Wendell Ocasio
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top