Is this normal DVD player operation?

Open_Circuit · 16-05-2003, 08:10

I have been lent a DVD player to try out - a Scan SC-440LSI Slim DVD player Multiregion PAL/ NTSC/ MP3.

It is the first time I have seen a DVD movie and the quality is superb EXCEPT for one serious defect. Whenever there is movement a judder can be seen. This is not a digital artifact you see on low bit rate transmissions, more like a frame being lost every second or so.

It is best seen when a car travels along a road at gentle speed, it actually appears to jump backwards periodicaly.

Do all DVD players do this?

BTW the DVD films I watched on this machine were spiderman and Men in Black II region 1 DVDs.

Could it be that region 1 DVDs are optimised for NTSC (60Hz) playback and region 2 for PAL (50Hz) ? So if I tried a region 2 DVD i would not see this judder?

comicsansserif · 16-05-2003, 08:39

It sounds to me as though you are watching a region 1 DVD which is being shown in PAL50 mode.

This judder is a common problem with most multiregion players that do PAL50.

If your TV can handle PAL60 or NTSC then you should set the DVD player to output in one of these modes (if it can). This will eliminate the judder.

The judder is caused by the player dropping 1 in every 6 picture frames (I think thats the number) to match the PAL50 frame rate.

The only advantage of PAL50 is you can record it onto video.

Kevo · 16-05-2003, 09:59

Colud be the '3:2 pulldown' effect with ntsc material.

I'll let someone else do the 'science bit'.

It's Friday!

Open_Circuit · 16-05-2003, 10:36

Thanks for the info. I have a PAL50 TV but the owner of the DVD drive may have a more modern set that can cope with 60Hz format. I will advise him accordinly.

On to another point, putting the judder aside, as I said b4 I was very impressed with the picture quality, and a quick calculation asuming a DVD capcaity of about 5Gbyte, I reckon the bitrate for the picture is maybe 5Mbits/sec?

Now that seems kind of low for the quality I expereinced.

BBC1 DTT wich is supposed to be about that bitrate is not the same quality.

So how does the DVD perfom so well?

comicsansserif · 16-05-2003, 11:15

As Kevo says the frame dropping is refered to as the 3:2 pulldown.

As for the bit rates, only theorising here don't know for certain, but I should imagine that the DTT signal has to contain a lot more info than the picture. It probably has a lot of error correction and check data as well as alignment and timing info. The DVD is probably virtually raw compressed video data and hence more bits will be video data than the DTT bits.

crazydave · 16-05-2003, 14:34

Quote:

Originally posted by Open_Circuit

BBC1 DTT wich is supposed to be about that bitrate is not the same quality.

BBC is encoded in realtime in about 0.1 seconds

They spend weeks encoding DVD's

Open_Circuit · 16-05-2003, 16:42

Thanks for the feedback folks.

From what crazydave said it would suggest recordable DVD may only give perhaps 1 hour of "DVD" quality as you would have to record at say 10Mbits/sec

When Hard Discs reach 1 Terabyte capacity and cost a few quid and are silent in operation lets hope there is still some programs worth recording

dodgygeeza · 16-05-2003, 16:49

Quote:

Originally posted by crazydave
BBC is encoded in realtime in about 0.1 seconds

They spend weeks encoding DVD's

Perhaps because the BBC's typical output does not include DD5.1, DTS and several different language audio tracks

topgazza · 16-05-2003, 20:54

Hi all!

Newbie here so I'll tag on this thread if thats ok. Its kind off related.

I have a Sony S550 cinema surrond sound

I have just got Peter Pan DVD region 2. Its my seconddisk as the first one, and the 2nd one, produces poor pictures. Anything that moves produces a broken edge to the image and I get lines across the whole moving object. Its fine when the moving object stops. It also happens on the endless trailers at the front of the film so I guess it must be the disk, again. No other DVD displays this. It plays OK on my PC but my sons Playstation2 barely plays the disk at all with skipping and no disk displayed.

Any ideas?

Its from Play.com who have ben excellant so far.

monkeysoup · 17-05-2003, 01:11

PAL-NTSC conversion can be dodgy. Remember to check how the DVD outputs NTSC - pick Auto for NTSC or forced PAL if your TV won't do proper NTSC (and when your TV is in NTSC mode you should see the scanline structure more, and be able to set the tint in the picture menu).

Bitrates won't cause juddering, but low bitrates will cause blocky pictures. A point to note - TV broadcasts are generally a fixed bitrate for the whole show/channel, so a still title card gets the same as fast action. On DVD, the disc can be encoded so the bitrates vary, and more space is given to busy sections. If you're bored and you've got one of those novelty bitrate counters on your DVD player turn it on and watch the numbers go up and down. I think good TV quality is about 3Mbits/s, and DVDs run anywhere from 3-10Mbits/s.

topgazza · 17-05-2003, 10:01

The disk says it is PAL, as is my TV of course. I guess you are saying that it would have come from an NTSC source.

Intrigued by the bitrate issue. All my other DVDs play fine but I will check if I can monitor the bitrate throughput.

Odd thing is when I just tried to play it the picture froze during the preamble and seemed to move forward frame by frame. Unloaded disk , reloaded and all was fine except for the quality problem. Probably a one off.

Open_Circuit · 17-05-2003, 11:15

If your Peter Pan DVD will not play right in other DVD players, then it would seem that the whole production run is faulty.

Perhaps the technology that was used to produce this DVD was not mature enougth like Peter Pan himself.

topgazza · 17-05-2003, 15:55

Now theres a thought....

My guess is the disk as you say. Its an odd effect as the backgound, non moving, image is fine with good, solid colours. Its only the moving elements that are affected. Play.com did not sound too surprised when I asked to return the first disk and mentioned " is it a ghosting effect?". Like you I suspect a bad batch.

David (2) · 21-05-2003, 16:10

People who have had probs with DVD movie playback on PS2 some times say it is resolved when thay have bought the Sony PS2 Remote - which includes new software.

dodgygeeza · 21-05-2003, 16:30

Quote:

Originally posted by David (2)
People who have had probs with DVD movie playback on PS2 some times say it is resolved when thay have bought the Sony PS2 Remote - which includes new software.

That's all well and good, but this is not about PS2 DVD playback - It's about a standalone model made by Scan, as Open_Circuit says in the first sentece of the first post in the thread.

Schoolboy · 21-05-2003, 16:53

Quote:

Originally posted by Open_Circuit
Thanks for the info. I have a PAL50 TV but the owner of the DVD drive may have a more modern set that can cope with 60Hz format. I will advise him accordinly.

On to another point, putting the judder aside, as I said b4 I was very impressed with the picture quality, and a quick calculation asuming a DVD capcaity of about 5Gbyte, I reckon the bitrate for the picture is maybe 5Mbits/sec?

Now that seems kind of low for the quality I expereinced.

BBC1 DTT wich is supposed to be about that bitrate is not the same quality.

So how does the DVD perfom so well?

DVDs can have more than one layer and can contain upto 9 GB so the bitrate can be higher. Plus you now have superbit versions where absolutely every tiny bit of disc space is used for picture and sound. The lower the compression the better the picture and sound.

Schooly

Open_Circuit · 21-05-2003, 16:58

Thanks for that schoolboy.

IMHO I feel RW-DVD, no matter how high they make them in capacity, is not a workable cusumer format until they put the disks in a protective shell like a zip disc etc.

At present they are easy to ruin with one scratch.

Schoolboy · 21-05-2003, 17:09

Well blue light DVD is on its way with at least 4 times the data and it will be recordable with a minidisc style plastic cover. I also like the sound of DVD RAM as you can watch the DVD while you still recording.

Schooly

16-05-2003, 08:10	#1
Open_Circuit Forum Member Join Date: Dec 2002 Location: London Posts: 213	Is this normal DVD player operation? I have been lent a DVD player to try out - a Scan SC-440LSI Slim DVD player Multiregion PAL/ NTSC/ MP3. It is the first time I have seen a DVD movie and the quality is superb EXCEPT for one serious defect. Whenever there is movement a judder can be seen. This is not a digital artifact you see on low bit rate transmissions, more like a frame being lost every second or so. It is best seen when a car travels along a road at gentle speed, it actually appears to jump backwards periodicaly. Do all DVD players do this? BTW the DVD films I watched on this machine were spiderman and Men in Black II region 1 DVDs. Could it be that region 1 DVDs are optimised for NTSC (60Hz) playback and region 2 for PAL (50Hz) ? So if I tried a region 2 DVD i would not see this judder?

16-05-2003, 08:39	#2
comicsansserif Forum Member Join Date: Feb 2003 Location: In front of my computer! Posts: 2,865	It sounds to me as though you are watching a region 1 DVD which is being shown in PAL50 mode. This judder is a common problem with most multiregion players that do PAL50. If your TV can handle PAL60 or NTSC then you should set the DVD player to output in one of these modes (if it can). This will eliminate the judder. The judder is caused by the player dropping 1 in every 6 picture frames (I think thats the number) to match the PAL50 frame rate. The only advantage of PAL50 is you can record it onto video.

16-05-2003, 09:59	#3
Kevo Forum Member Join Date: Nov 2000 Location: Manchester Posts: 925	Colud be the '3:2 pulldown' effect with ntsc material. I'll let someone else do the 'science bit'. It's Friday!

16-05-2003, 10:36	#4
Open_Circuit Forum Member Join Date: Dec 2002 Location: London Posts: 213	Thanks for the info. I have a PAL50 TV but the owner of the DVD drive may have a more modern set that can cope with 60Hz format. I will advise him accordinly. On to another point, putting the judder aside, as I said b4 I was very impressed with the picture quality, and a quick calculation asuming a DVD capcaity of about 5Gbyte, I reckon the bitrate for the picture is maybe 5Mbits/sec? Now that seems kind of low for the quality I expereinced. BBC1 DTT wich is supposed to be about that bitrate is not the same quality. So how does the DVD perfom so well?

16-05-2003, 11:15	#5
comicsansserif Forum Member Join Date: Feb 2003 Location: In front of my computer! Posts: 2,865	As Kevo says the frame dropping is refered to as the 3:2 pulldown. As for the bit rates, only theorising here don't know for certain, but I should imagine that the DTT signal has to contain a lot more info than the picture. It probably has a lot of error correction and check data as well as alignment and timing info. The DVD is probably virtually raw compressed video data and hence more bits will be video data than the DTT bits.

16-05-2003, 14:34	#6
crazydave Forum Member Join Date: Nov 2002 Location: Glasgow, Black Hill TX Posts: 1,000	Quote: Originally posted by Open_Circuit BBC1 DTT wich is supposed to be about that bitrate is not the same quality. BBC is encoded in realtime in about 0.1 seconds They spend weeks encoding DVD's

16-05-2003, 16:42	#7
Open_Circuit Forum Member Join Date: Dec 2002 Location: London Posts: 213	Thanks for the feedback folks. From what crazydave said it would suggest recordable DVD may only give perhaps 1 hour of "DVD" quality as you would have to record at say 10Mbits/sec When Hard Discs reach 1 Terabyte capacity and cost a few quid and are silent in operation lets hope there is still some programs worth recording

16-05-2003, 16:49	#8
dodgygeeza Forum Member Join Date: Jun 2001 Location: Manchester Posts: 6,151	Quote: Originally posted by crazydave BBC is encoded in realtime in about 0.1 seconds They spend weeks encoding DVD's Perhaps because the BBC's typical output does not include DD5.1, DTS and several different language audio tracks

16-05-2003, 20:54	#9
topgazza Forum Member Join Date: May 2003 Location: Nr Basingstoke Posts: 286	Hi all! Newbie here so I'll tag on this thread if thats ok. Its kind off related. I have a Sony S550 cinema surrond sound I have just got Peter Pan DVD region 2. Its my seconddisk as the first one, and the 2nd one, produces poor pictures. Anything that moves produces a broken edge to the image and I get lines across the whole moving object. Its fine when the moving object stops. It also happens on the endless trailers at the front of the film so I guess it must be the disk, again. No other DVD displays this. It plays OK on my PC but my sons Playstation2 barely plays the disk at all with skipping and no disk displayed. Any ideas? Its from Play.com who have ben excellant so far.

17-05-2003, 01:11	#10
monkeysoup Forum Member Join Date: Apr 2002 Posts: 550	PAL-NTSC conversion can be dodgy. Remember to check how the DVD outputs NTSC - pick Auto for NTSC or forced PAL if your TV won't do proper NTSC (and when your TV is in NTSC mode you should see the scanline structure more, and be able to set the tint in the picture menu). Bitrates won't cause juddering, but low bitrates will cause blocky pictures. A point to note - TV broadcasts are generally a fixed bitrate for the whole show/channel, so a still title card gets the same as fast action. On DVD, the disc can be encoded so the bitrates vary, and more space is given to busy sections. If you're bored and you've got one of those novelty bitrate counters on your DVD player turn it on and watch the numbers go up and down. I think good TV quality is about 3Mbits/s, and DVDs run anywhere from 3-10Mbits/s.

17-05-2003, 10:01	#11
topgazza Forum Member Join Date: May 2003 Location: Nr Basingstoke Posts: 286	The disk says it is PAL, as is my TV of course. I guess you are saying that it would have come from an NTSC source. Intrigued by the bitrate issue. All my other DVDs play fine but I will check if I can monitor the bitrate throughput. Odd thing is when I just tried to play it the picture froze during the preamble and seemed to move forward frame by frame. Unloaded disk , reloaded and all was fine except for the quality problem. Probably a one off.

17-05-2003, 11:15	#12
Open_Circuit Forum Member Join Date: Dec 2002 Location: London Posts: 213	If your Peter Pan DVD will not play right in other DVD players, then it would seem that the whole production run is faulty. Perhaps the technology that was used to produce this DVD was not mature enougth like Peter Pan himself.

17-05-2003, 15:55	#13
topgazza Forum Member Join Date: May 2003 Location: Nr Basingstoke Posts: 286	Now theres a thought.... My guess is the disk as you say. Its an odd effect as the backgound, non moving, image is fine with good, solid colours. Its only the moving elements that are affected. Play.com did not sound too surprised when I asked to return the first disk and mentioned " is it a ghosting effect?". Like you I suspect a bad batch.

21-05-2003, 16:10	#14
David (2) Forum Member Join Date: Mar 2003 Location: S.West England. Posts: 18,037	People who have had probs with DVD movie playback on PS2 some times say it is resolved when thay have bought the Sony PS2 Remote - which includes new software.

21-05-2003, 16:30	#15
dodgygeeza Forum Member Join Date: Jun 2001 Location: Manchester Posts: 6,151	Quote: Originally posted by David (2) People who have had probs with DVD movie playback on PS2 some times say it is resolved when thay have bought the Sony PS2 Remote - which includes new software. That's all well and good, but this is not about PS2 DVD playback - It's about a standalone model made by Scan, as Open_Circuit says in the first sentece of the first post in the thread.

21-05-2003, 16:53	#16
Schoolboy Forum Member Join Date: Jan 2002 Location: Michigan, USA Posts: 2,812	Quote: Originally posted by Open_Circuit Thanks for the info. I have a PAL50 TV but the owner of the DVD drive may have a more modern set that can cope with 60Hz format. I will advise him accordinly. On to another point, putting the judder aside, as I said b4 I was very impressed with the picture quality, and a quick calculation asuming a DVD capcaity of about 5Gbyte, I reckon the bitrate for the picture is maybe 5Mbits/sec? Now that seems kind of low for the quality I expereinced. BBC1 DTT wich is supposed to be about that bitrate is not the same quality. So how does the DVD perfom so well? DVDs can have more than one layer and can contain upto 9 GB so the bitrate can be higher. Plus you now have superbit versions where absolutely every tiny bit of disc space is used for picture and sound. The lower the compression the better the picture and sound. Schooly

21-05-2003, 16:58	#17
Open_Circuit Forum Member Join Date: Dec 2002 Location: London Posts: 213	Thanks for that schoolboy. IMHO I feel RW-DVD, no matter how high they make them in capacity, is not a workable cusumer format until they put the disks in a protective shell like a zip disc etc. At present they are easy to ruin with one scratch.

21-05-2003, 17:09	#18
Schoolboy Forum Member Join Date: Jan 2002 Location: Michigan, USA Posts: 2,812	Well blue light DVD is on its way with at least 4 times the data and it will be recordable with a minidisc style plastic cover. I also like the sound of DVD RAM as you can watch the DVD while you still recording. Schooly

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Is this normal DVD player operation?