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PostPosted: Thu Jul 25, 2002 3:42 am 
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Thanks to moi Friend for letting me know of this technique :-

You have often wondered if your DVD has been encoded in a Progressive or Interlaced mode. There are expensive players which can tell you this information but how abt doing a simple test on your low end DVD player and determining the same ? Is it possible ? ... In fact it sure is possible but first some rules :-
1.) We make an assumption ( and that is a reasonably safe assumption to make) that all DEI DVDs are encoded in progressive mode. So take a DEI DVD ( the best amongst them).. say Kaho Na Pyar Hai.. go a lil bit into a scene and freeze frame it a partocular moment. Advance it frame by frame so that the timer now reads a whole number (say 00:05:20)... now go on increasing step by step till the timer reads 00:05:21.. In doing this calculate the number of times you had to press (step increase.. for advancing the film frame by frame)... Well
Here are the results of what my friend and I found :-
In 1 sec, for any DEI encoded disc (KNPH, Deewar etc).. the number of times we had to press (step forward) was 24 i.e 24 frames in one second.. and that made the disc a progressively encoded DVD ...
You can check out all DEI encoded DVDs.. and on an average u get 24

2.) Now check any other EROS DVDs (Eros B4U dvds ) or the recent SPARK dvds (encoded by Media Dimensions).. and you will get a number on an avg = 30 (i.e more frames are being encoded in second).. i.e They are all interlaced (? I may be wrong here but am always ready to be corrected) and also they have lower bit rates when compared to DEI encoded DVDs...

So based on the above tests.. I concluded :-
KNPH = progressive ( 24 base value)
Company (Eros, Media Dimensions , 30+ , Interlaced)
Kuch Kuch Hota Hai (?Interlaced/Progressive though the avg was 25-26)
Ek Duje Ke Liye (Yashraj - Prasad Digital 30+, interlaced)
Dil Chahata Hai (Spark-Soven-Media Dimensions 30+, interlaced)
Prem Rog (Shemaroo - 30, interlaced)
Ram teri Ganga Maili (Yashraj - SuperDigital - 26-27....?interlaced/progressive)
Mission kashmir ( CTHV - 24- Progressive)
Barsaat Ki Ek Raat (EVP - Sai Digital Base - 24 - Progressive)

From this we can conclude that only EVP ( when they got their DVDs encoded by Sai Digital Base) & DEI have been encoding their DVDs in a progressive manner. (CTHV cant be called a desi film studio anyways)...
So before you buy any DVD...check out these values also....

So folks can you check up other dvds and post these values ...

Ali :- In future DVD reviews can you also include this number so that folks are informed (approximately) abt the quality of DVDs (P/I) before they buy the DVD...


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PostPosted: Thu Jul 25, 2002 8:10 am 
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Sounds logical to me...I have to try it out later...


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PostPosted: Thu Jul 25, 2002 12:49 pm 
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The technique works.

You get consistent (exact 24, or exact 30; for NTSC) count if you exclude those frames where the step button is pressed but the frame doesn’t change (as you know, often, frames are repeated in progressive recording). This counting removes the uncertainty that sknath mentioned above as 27 fps.

Rana

P.S.
For DVDs of Indian 24 fps Films, this is a good technique.
But, be careful about wrong conclusions for 25 or 30 frames per second digital camera filming.



Edited By rana on July 25 2002 at 12:50


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PostPosted: Mon Jul 29, 2002 4:38 am 
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Some more results :-
Judwaa (Videosound- 24fps) ! (progressive mode)
Yalgaar (Eros-B4U 30fps)
Sangam, Shree 420 (Shemaroo - 30fps)
Aradhana (EVP - 30fps :gob: which is strange )

The YRF versions of Sangam/Shree 420 also have 30fps but they are (much) inferior in quality when compared with the Yashraj version of the same films



Edited By sknath on July 29 2002 at 13:51


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PostPosted: Mon Jul 29, 2002 12:42 pm 
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sknath wrote:
Some more results :-
Judwaa (Videosound- 24fps) ! (progressive mode)
Yalgaar (Eros-B4U 30fps)
Sangam, Shree 420 (30fps)
Aradhana (EVP - 30fps :gob: which is strange )

Note that Aradhana is EVP # 1001, you found it 30 steps per sec.
EVP # 1002 is Kashmir Ki Kali. That too is 30 steps per sec.

Amar Prem and others where the EVP #s are > 1002 are 24 steps per sec.

Aradhana and Kashmir Ki Kali were EVP's first few Hindi Films. It looks like EVP started progressive (24 steps per sec, sometime after that.

Rana

P.S.

Which verssion of Sangam and Sh 420 did you mean. Shemaroo or YRF? YRF versions are 30 steps per sec.



Edited By rana on July 29 2002 at 08:45


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PostPosted: Mon Jul 29, 2002 1:24 pm 
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I know 2 EVP Telugu dvd’s that are not authorized in film mode: 1) Hello Brother 2) Allari Alludu.
In general I don’t believe any Indian dvd author is using film mode on their dvd’s except DEI.


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PostPosted: Sun Aug 11, 2002 3:26 am 
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Hi folks have done a lil bit of checking up on a couple of DVDs.. In addition to the above 2 specific cases of determining whether a DVD is progressive or interlaced, I have come up with another case. This was partly explained by Michael Hafner when he discussed abt the Na Tum Jano Na Hum DVD (by EROS)... We will call this Pseudo progressive / Pseudo Interlaced... (50-50)

One more DVD that I checked up was the ZAKHMEE dvd by EROS-B4U (*ing Sunil Dutt)
IN this DVD, I do the above step operation by pressing the remote button. However at the 5th press of the step button, the frame on the TV doesnt progress. It restarts again from the 6th press till it comes till the 10th press...
So eventually between a specific time interval, I had to press on my remote 30 times. However if I ignore the number of times the Frame didnt advance on the screen i can see that :-
1 - 5
2 - 10
3 - 15
4 - 20
5 - 25
6 - 30

hence 6 times the frame didnt move... i.e the actual moving frames within a particular time interval happens to be 30 - 6 = 24 frames !! ( the same number as a progressive transfer)

Did anyone else notice this with any other DVD ?


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PostPosted: Sun Aug 11, 2002 4:12 pm 
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sknath,
check out the dvd of HUMRAAZ by Eros
it does this
in frame where the picture does not move, but there is a movement :doze:
what i mean is that frame does not move, yet colors move
just check it out and see if it has this case
b/c when i tested it, that is what i found


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PostPosted: Sun Aug 11, 2002 5:27 pm 
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has anyone else found that when fast forwarding an eros dvd to 2X the normal speed, that it doesn't seem to work?

usually, when i press my fast forward button once, i hear the sound (moving at twice the speed) and see the picture moving at twice (2X) the speed. but with eros dvds, the picture moves at the same, normal speed (1X) speed, and there is no sound.

this only seems to happen with eros dvds.


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PostPosted: Sun Aug 11, 2002 6:40 pm 
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dvd_pankhaa wrote:
sknath,
check out the dvd of HUMRAAZ by Eros
it does this
in frame where the picture does not move, but there is a movement :doze:
what i mean is that frame does not move, yet colors move
just check it out and see if it has this case
b/c when i tested it, that is what i found

Hey Pankha, I will concur with you on that. Even in the Zakhmee / NTJNH dvds the colors of the frame changed but the frame didnt advance. My question to Michael Hafner would be :- Does this constitute a Frame advance or does this indicate poor encoding ? (i.e repeating frames)...

Please do give us your feedback ...

*ps :- Pankhaa thats why i said, I am not sure as to what this means... hence I have named it as Pseudo Progressive / Pseudo Interlaced.. I should recheck some of my other dvds using this criteria and then will post my results here also.


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PostPosted: Wed Aug 14, 2002 2:55 am 
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I talked with EVP Sudhakar and explained him about 24 frames/sec and his 30 frames/sec. I also mentioned his Sai Digital authored DVDs were all 24 frames/sec. He didn't know what he did different but he said he will mention it to his people in India to check into it and make all his future work to 24 frames/sec. He sounded like he had no idea about it. But when I mentioned how the film has 24 frames/sec he paid some attention to investigate into it.

I also mentioned about his DVDs showing as Video mode on Progressive Scan DVD Players while those from DEI and all English titles showing as Film mode. He doesn't agree with that and he claims he does his DLTs from film negatives. So, is there something they are doing wrong while making DLTs?



Edited By kpolina on Aug. 13 2002 at 22:56


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PostPosted: Wed Aug 14, 2002 2:00 pm 
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Thanks Kp,
I am really grateful to you about this. I am certainly hoping Sudhakar will do the needful.

Folks imagine this: after some time we are all going to have a progressive display and we want to enjoy movies as we do now with an enhanced joy of owing a bigger TV or Projector.
Guess what: we can’t experience the magic, because of the simple mistake of buying dvd’s from the people who does not know about the basics of dvd making. we are all feel depressed and want to kick our tv and/or your dvd collection. But it is too late…

Again come to the point of what might be wrong with Indian dvd’s?


when film is transferred to video, 24 frames per second of film must be converted to 60 fields (30 frames) per second of video. The way this is accomplished is to show the first frame of film for 3 fields, then show the second frame of film for 2 fields, then the third frame of film for 3 fields, and so forth. This sequence, or “cadence” of 3, 2, 3, 2, 3, 2 is what is called 3-2 pulldown. (Sometimes this is written as 3/2 or 3:2, but this looks like a ratio, so we prefer it written as “3-2.”)

Again, it’s important to note that there is no requirement to follow this 3-2 sequence. The DVD decoder doesn’t care. It just follows the flags as written on the disc. As long as there are 60 fields in each second of video, everything is fine.

Most of the Indain dvd’s shows an artifact called combing when trying to watch in film mode.
The way there are spiky lines, like the tines of a comb, on the sides of the moving person in the frame. This is because the first field (the odd numbered scan lines) is from one frame of film, and the second field (the even numbered scan lines) is from the next frame of film.

To eliminate this combing we have to instruct the decoder to go to video mode which uses different algorithm to show them properly but with the loss of sharpness and detail.

I am sure EVP claim of use of film negative to DLT is true as their dvd’s show better color, contrast and sharpness than EROS/YRF and Videosound.



Edited By ganti on Aug. 14 2002 at 10:51


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PostPosted: Wed Aug 14, 2002 2:58 pm 
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ganti wrote:
Folks imagine this: after some time we are all going to have a progressive display and we want to enjoy movies as we do now with an enhanced joy of owing a bigger TV or Projector.
Guess what: we can’t experience the magic, because of the simple mistake of buying dvd’s from the people who does not know about the basics of dvd making. we are all feel depressed and want to kick our tv and/or your dvd collection. But it is too late…

Well said Ganti.
Most likely our next TV purchase, in the very near future, will be HDTV (or at least progressive) TV, if we don’t have it already. That’s all that will be available. At that time we will want to see the improved picture from the DVDs that we buy today. If the DVDs are encoded properly (we are paying for it) we will get that.

The most difficult task in getting a higher res. is proper recreation of the orig. film frames. After that, the standard DVD matrix of 640 x 480 (or may be it is 720 X 480) can easily be converted (computed) to a much higher computer res. of say 1600 x 1200 or even 1920 x 1440 or even higher.

Rana


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PostPosted: Wed Aug 14, 2002 8:28 pm 
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sknath wrote:
Now dont get startled...just wanted to catch ur attention :)

Allrite, the real bad news is that I finally got a progressive scan DVD player (JVC - XV502-SL)..and got a chance to recheck all the DVDs as to whether they are progressive or not.

Here is an update on most of them.
I was wrong vis-a-vis EVP dvds ( the ones authored by Sai Digital Base). When I change my Progressive SCAN settings to auto ( so that it can detect if the DVD source was film based - green , or video based - red).
With DEI, DEI-EROS, Columbia Tristar, and all Hollywood DVDs, the indicator turned Green. Of course I couldnt see anything on the TV as I have simple P&S TV.. (but the indicator light changed quite a few myths)...

Judwaa - Videosound ( Film based)
All DEI, DEI-EROS dvds (Film based)
KKHH - SuperDigital (Film Based)
DDLJ (Lousy piece of shit) - SuperDigital (Film Based)

All EVP (Sai Digital Base) and (Media Dimensions) are all Video sources... (However why do some of them give us 24fps between an interval mystifies me )

& yeah I have finally ditched APEX as of today :)

Most of the EVP HINDI DVDs are Film sourced and are properly flagged. It is just that your DVD player has failed to detect it.

Source indicators depend on what are they looking for and how they look for it.

Rana.


UPDATE:

This is what my Sony DVD player (550) indicates:-

Category 1:-
In one second: For all properly encoded and flagged DVDs (NTSC), I need to press step button 24 times and the frame advances 24 times and "STEP" flashes on the TV screen. (DEI, most of the EVP Hindi DVDs).

Category 2:-
In one second: I press the step button 30 times and the frame advances 24 times, as well as, “STEP” also flashes only 24 times.

Category 3:-
In one second: I press the step button 30 times “STEP” flashes 30 times but the frames advance only 24 times. In this category, when the frame mainly doesn’t change but there are some changes. It could be noise, it could be color or ----.

Category 4:-
In one second: I press the step button 30 times “STEP” flashes 30 times and the frames also advance 30 times.

In my opinion, Category 1 is the best, and Category 2 is also good. Any simple line doubler or Progressive DVD player will re-create proper Film frames for outputting the progressive signal.

Expensive line doublers or progressive DVD players may do a decent job (but not as good as for Category 1 & 2) in re-creating the original film frames for category 3. Note that the line doubler has to accept certain amount of noise when comparing frames. Depending upon how much noise is accepted, even a 10th generation VHS may be workable but needless to say that the results will be terrible.

It will only be computed line doubling for category 4. How good a job it does, depends on how sophisticated the processor is.

Rana


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PostPosted: Wed Aug 14, 2002 8:43 pm 
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Rana,
I would like you to try testing this with the PowerDVD.
Change the PowerDVD setting to Force Weave and see
whether you can find any combing on action scenes.


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