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Invelos Forums->General: General Discussion |
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Choosing between PAL and NTSC releases. |
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Registered: May 30, 2008 | Posts: 445 |
| Posted: | | | | I have a multi-region player, and so I can sometimes pick between an NTSC vs PAL release of the same film.
If for sake of argument we assume the transfer is the same for both, and I don't care about being limited in who else could view it, I'm trying to figure out what would determine my choice for greatest viewing accuracy / pleasure.
It is an oversimplification, but NTSC is something like 720x480, and PAL 720x576, and if each transfer is encoded anamorphically, it would seem that the PAL transfer might give me a higher resolution playback.
I know that the original video source sometimes makes a difference as well, so I want to look at a specific example.
Mad Max 2 - The Road Warrior was produced in Australia. I'm going to take a wild guess here and say that it was probably sourced with PAL equipment.
Is there any way it doesn't look better played back on a PAL player?
And as a general rule: When does 576 vs 480 NOT give you better resolution, forgetting entirely the issue of PAL's more faithful rendering of color.
Opinions appreciated. |
| Registered: March 14, 2007 | Reputation: | Posts: 6,744 |
| Posted: | | | | There's another point to consider. PAL runs with 25 frames per second, NTSC with 30. When regular movies (filmed with 24 FPS) are transferred to PAL, you'll get a 4% speedup. You won't notice it if you never knew any different but when you start to mix you'll notice the same actor speaking in a slightly higher pitch due to the speed-up. http://en.wikipedia.org/wiki/PAL_speedup#PAL_speed-up | | | Karsten DVD Collectors Online
| | | Last edited: by DJ Doena |
| Registered: December 10, 2007 | Reputation: | Posts: 3,004 |
| Posted: | | | | Quoting lasitter: Quote: It is an oversimplification, but NTSC is something like 720x480, and PAL 720x576, and if each transfer is encoded anamorphically, it would seem that the PAL transfer might give me a higher resolution playback. It depends what you are playing it back on. What kind of TV and player are you using? If you have an NTSC TV, or if your player is converting PAL to NTSC at some point, PAL won't look any better. Quote: I know that the original video source sometimes makes a difference as well, so I want to look at a specific example.
Mad Max 2 - The Road Warrior was produced in Australia. I'm going to take a wild guess here and say that it was probably sourced with PAL equipment. PAL and NTSC are television standards. Movies aren't sourced with either. Mad Max was made on analog strips of film, which are scanned into a computer and converted to NTSC or PAL. Either way, it has a lot less resolution than the movie originally did. And as a general rule: When does 576 vs 480 NOT give you better resolution, forgetting entirely the issue of PAL's more faithful rendering of color. Color is stored the same way for PAL or NTSC DVDs. Broadcast TV in PAL has better color fidelity, but DVD is not dependent on the broadcast standards. It uses the same framerate and resolution as local broadcast TV so it will be compatible with the televisions, but is stored quite differently. This does mean that PAL TVs are easier to calibrate for color, but that's your set. It makes no difference for the DVD itself. As DJ Doena mentioned, there's also the issue of playback speed. Films are made at 24 frames per second. NTSC runs at 30 frames. Each frame is made of two fields, each containing every other line. NTSC DVD double every-other field to convert the framerate. It's the correct speed, but slightly jerky. PAL is 25 frames per second and just speeds the movie up with no doubling. It's smoother, but shifts pitch up by a semitone. Again, this is comparing an NTSC DVD on an NTSC TV to a PAL DVD on a PAL TV. How it works for you depends on what TV you and player you have. My advice is just get a Blu-ray player if you have an HD TV. They are five times the resolution of PAL and six time the resolution of NTSC and play everything back at the correct speed. |
| Registered: March 19, 2007 | Reputation: | Posts: 6,018 |
| Posted: | | | | Ehm, no they don't. Blu-ray players playing PAL DVDs will still have the PAL speedup, unless the player is converting to NTSC first.
My preference in PAL vs NTSC would depend on the contents of the disc you're playing. If the contents are video-based, I would recommend to match the system in which the original video recordings took place (so NTSC for US video recordings and PAL for e.g. British TV series). If the contents are film-based, then it all comes down to weighing the various factors, e.g. do you prefer PAL's higher resolution in favour of the PAL speedup, or vice versa? |
| Registered: March 13, 2007 | Reputation: | Posts: 3,197 |
| Posted: | | | | In my years of experience watching hundreds of DVDs in both PAL and NTSC I have come to the conclusion that there exists no significant difference in image quality between them. If anything NTSC DVDs in general seem to be better mastered (maybe due to less compression since it has fewer lines to render) which can give them a slight edge. But in practice the only thing you might want to consider is the 4% PAL-speedup, if that bothers you. | | | First registered: February 15, 2002 |
| Registered: May 30, 2008 | Posts: 445 |
| Posted: | | | | One of my panels is brand new and the other is fairly new. Both are multi-source and can play PAL directly.
Lots of films made it to DVD before the advent of film scanning. They relied on various different telecine technologies for their transfers, and I suspect that here is where the 576 vs 480 might matter.
I know that modern Blu-ray equipment up-samples, but if the original image is sharper to begin with, I think that matters.
I've already read through many of these links, some multiple times:
http://en.wikipedia.org/wiki/Category:Film_and_video_technology
I suspect that the answer is not so cut and dried as some might think. |
| Registered: March 31, 2007 | Posts: 662 |
| Posted: | | | | Quoting KinoNiki: Quote: maybe due to less compression since it has fewer lines to render PAL: 576 lines/picture * 25 pictures/second = 14,400 lines/second NTSC: 480 lines/picture * 30 pictures/second = 14,400 lines/second | | | |
| Registered: March 13, 2007 | Reputation: | Posts: 3,197 |
| Posted: | | | | Quoting StaNDarD: Quote: Quoting KinoNiki:
Quote: maybe due to less compression since it has fewer lines to render PAL: 576 lines/picture * 25 pictures/second = 14,400 lines/second NTSC: 480 lines/picture * 30 pictures/second = 14,400 lines/second Yes, but that calculation only holds true when the source material is video based. Films are (almost) always sourced from 24 frames per second, in which case we only need to consider the number of lines to encode per frame. By inserting control flags in the videostream the player will be able to perform the 3:2 pulldown necessary to create an NTSC-image from the original 24p film content. At least that's the proper way to do it but I know that some DVDs are improperly authored in interlaced mode, although that's probably more a thing of the past. More details here: http://www.dvddemystified.com/dvdfaq.html#3.4 Note: "Because film transfers for NTSC and PAL usually use the same coded picture rate (24 fps) but PAL resolution is higher, the PAL version takes more space on the disc. The raw increase before encoding is 20% (480 to 576), but the final result is closer to 15%, depending on encoder efficiency. This translates to an increase of 600 to 700 megabytes on PAL discs compared to NTSC discs." Unfortunately the extra space required for PAL transfers to maintain the same quality often go to extra audio and subtitle tracks instead. | | | First registered: February 15, 2002 |
| Registered: May 30, 2008 | Posts: 445 |
| Posted: | | | | Quoting KinoNiki: Quote: Unfortunately the extra space required for PAL transfers to maintain the same quality often go to extra audio and subtitle tracks instead. I suspected that there might be more data, but was hoping it would be allocated to video. That means in order to reach more people thru audio and subtitle tracks, the additional video information is compressed more. There's never one right answer in video, is there? |
| Registered: March 13, 2007 | Reputation: | Posts: 3,197 |
| Posted: | | | | There are so many factors to consider (single vs. dual-layer discs for example) that you really have to compare disc to disc. Sites like DVDBeaver often does exactly this, but I haven't seen any evidence that PAL discs would generally produce a better picture quality than NTSC discs. | | | First registered: February 15, 2002 | | | Last edited: by Nexus the Sixth |
| Registered: March 31, 2007 | Posts: 662 |
| Posted: | | | | Quoting KinoNiki: Quote: Quoting StaNDarD:
Quote: Quoting KinoNiki:
Quote: maybe due to less compression since it has fewer lines to render PAL: 576 lines/picture * 25 pictures/second = 14,400 lines/second NTSC: 480 lines/picture * 30 pictures/second = 14,400 lines/second
Yes, but that calculation only holds true when the source material is video based. Films are (almost) always sourced from 24 frames per second, No, the mpeg2 video on a dvd has 25 frames on a PAL DVD and 30 frames on a NTSC DVD. 24 is not a valid framerate for a DVD. On the other hand the video resolution may vary: Allowed PAL resolutions for DVD: 720x576x25 704x576x25 352x576x25 352x288x25 352x288x25 MPEG1 Allowed NTSC resolutions: 720x480x30 704x480x30 352x480x30 352x240x30 352x240x30 MPEG-1 I saw a few DVDs with a width of 704pixels but none with a lower resolution. You may need a little less bitrate at NTSC because of MPEG's motion compression, but I doubt this is enough to mention. | | | |
| Registered: March 13, 2007 | Reputation: | Posts: 3,197 |
| Posted: | | | | Quoting StaNDarD: Quote:
No, the mpeg2 video on a dvd has 25 frames on a PAL DVD and 30 frames on a NTSC DVD. 24 is not a valid framerate for a DVD.
At playback yes, I'm talking about the actual encoding on the disc. Please try again. Did you even bother to read the DVD FAQ? | | | First registered: February 15, 2002 |
| Registered: March 31, 2007 | Posts: 662 |
| Posted: | | | | Quoting KinoNiki: Quote: Quoting StaNDarD:
Quote:
No, the mpeg2 video on a dvd has 25 frames on a PAL DVD and 30 frames on a NTSC DVD. 24 is not a valid framerate for a DVD.
At playback yes, I'm talking about the actual encoding on the disc. Please try again. Did you even bother to read the DVD FAQ? Believe me I encoded and mastered quiet a few PAL DVDs - you need 25 frames to do it. Before encoding the video has to be converted to the correct framerate. The 24fps you're talking about is only valid on Blu-rays. Hm, maybe you're right on NTSC-DVDs... But the few NTSC-discs I've seen have all been in 30fps. | | | | | | Last edited: by StaNDarD |
| Registered: March 13, 2007 | Reputation: | Posts: 3,197 |
| Posted: | | | | Quoting StaNDarD: Quote:
Believe me I encoded and mastered quiet a few PAL DVDs - you need 25 frames to do it. Before encoding the video has to be converted to the correct framerate.
The 24fps you're talking about is only valid on Blu-rays. Not at all. 24p has been possible on DVD since day 1, but since playback equipment was usually limited to 25 or 30 frames per second in those days, playback used to default to one those. Creating an industry standard that would not allow most of the world's available film content to be stored in an efficient manner would have been quite stupid to put it mildly. Why would you needlessly create a 25 frames per second conversion and then encode that when all you need to do is playback the 24p source a little faster, say by 4%? It would make no sense at all, and of course that's why it isn't done that way. Let me iterate: "A disc has one track (stream) of MPEG-2 constant bit rate (CBR) or variable bit rate (VBR) compressed digital video. A restricted version of MPEG-2 Main Profile at Main Level (MP@ML) is used. SP@ML is also supported. MPEG-1 CBR and VBR video is also allowed. 525/60 (NTSC, 29.97 interlaced frames/sec) and 625/50 (PAL/SECAM, 25 interlaced frames/sec) video display systems are expressly supported. Coded frame rates of 24 fps progressive from film, 25 fps interlaced from PAL video, and 29.97 fps interlaced from NTSC video are typical. MPEG-2 progressive_sequence is not allowed, but interlaced sequences can contain progressive pictures and progressive macroblocks. In the case of 24 fps source, the encoder embeds MPEG-2 repeat_first_field flags into the video stream to make the decoder either perform 2-3 pulldown for 60Hz NTSC displays (actually 59.94Hz) or 2-2 pulldown (with resulting 4% speedup) for 50Hz PAL/SECAM displays. In other words, the player doesn't "know" what the encoded rate is, it simply follows the MPEG-2 encoder's instructions to produce the predetermined display rate of 25 fps or 29.97 fps. This is one of the main reasons there are two kinds of discs, one for NTSC and one for PAL." | | | First registered: February 15, 2002 |
| Registered: March 13, 2007 | Reputation: | Posts: 3,197 |
| Posted: | | | | Quoting StaNDarD: Quote:
Hm, maybe you're right on NTSC-DVDs... But the few NTSC-discs I've seen have all been in 30fps. There are certainly discs out there that has been sourced from old broadcast masters that may already have been converted to 25 or 30 frames per second before encoding. Even on blu-ray there are some of those 25 fps broadcast transfers with PAL-speedup, but all those discs are in 1080i and not progressive. Maybe this is more common for PAL discs (maybe another reason to avoid them?) but it's still not the best way to go about it. | | | First registered: February 15, 2002 |
| Registered: March 31, 2007 | Posts: 662 |
| Posted: | | | | My PAL-DVDs all have 25 fps, there's not a single one with 24fps. I've never even seen bonus material which is not in 25 fps. But of course it's easy on PAL because there's no real 'conversion' but a simple speed-up. | | | |
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Invelos Forums->General: General Discussion |
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