DVDs. Interlaced or progressive?

[HeavyHitter]

Originally Posted by mntwister

Please don't forget another famous poster: "Truthteller" :

Seriously, maybe these upscalers will work slightly better than upscalers we have now but as I have said all along since Toshiba announced this,

You simply cannot make prime rib out of hamburger, Toshiba!

What about the thousands of dvd's out there with sub-par and poor quality transfers? Is this upscaler going to magically perfect those too? Is it going to take those very lossy soundtracks and uncompress them all for us?

Thanks but no thanks, me be blu!

I've said this before, but if one really wants to improve DVD it's in the deinterlacing more than upscaling. There is no way Toshiba is going to create a deinterlacer that, for example, matches Realta and ABT...especially at the price range they are targeting. And even something like those top deinterlacers cannot produce an image anywhere near real 1080p.

Just like HD DVD was a scam in all reality when you think about it, so is "super" upscaling.

[WickyWoo]

People keep thinking that DVDs are 480i

They're not

They're 480p

In fact most 480i sources are converted to 480p in the studio and then encoded that way because it makes compression easier

That's an interesting factoid if true. It's been several months since the plug was pulled, and while we can banter about the exact date (maybe Twister's release on HD DVD at the end of May) being the swan song, I'm surprised to hear that those who were responsible still haven't gotten what was coming around.

Japanese culture is very much about face saving. I wouldn't expect any of them to be around for next fiscal year's report, but they will allow enough time for "seperation", and probably take into account the success/failure of SUC

[HeavyHitter]

Originally Posted by WickyWoo

People keep thinking that DVDs are 480i

They're not

They're 480p

In fact most 480i sources are converted to 480p in the studio and then encoded that way because it makes compression easier

Are you sure about this? I thought DVD was 480i60 which is why you needed progressive scan players....the MPEG decoders output 480i only on DVD players.

I thought the player would typically deinterlace 480i to 480p and then upscale to whatever resoluton.

[WickyWoo]

Are you sure about this? I thought DVD was 480i60 which is why you needed progressive scan players....the MPEG decoders output 480i only on DVD players.

You needed progscan players because the previous ones weren't designed to output progressive scan

In fact there's the infamous Wings of Honneamise disc from Manga that came from a 480i source was zoomed to 16:9 than flagged as progressive so the end product was actually DOUBLE interlaced.

I have friends who have authored DVD for years, even helped some of them get hired into the job. Oh the epic tales of the Mary Kate and Ashley library...did I meantion in 5 different editions each? In different languages, all of which had to be tested over..and over...and over?

[JimSD]

Originally Posted by HeavyHitter

Are you sure about this? I thought DVD was 480i60 which is why you needed progressive scan players....the MPEG decoders output 480i only on DVD players.

I thought the player would typically deinterlace 480i to 480p and then upscale to whatever resoluton.

I think this is the case too. Isn't that why the deinterlacer that is used is so important? That was a key factor in Kris Deering's Secrets tests.

[Paul H]

Originally Posted by JimSD

I think this is the case too. Isn't that why the deinterlacer that is used is so important? That was a key factor in Kris Deering's Secrets tests.

DVD Benchmark Part 5-Progressive Scan

Why Deinterlacing is Necessary

A common question we get asked is, "Why can't the DVD player just take the progressive frames off the disc and send them out without ever converting them to interlaced in the first place?" The reason, in a nutshell, is that there are too many examples of discs where some or all of the frames are not stored progressively. Even if the original material was sourced from film, there is no requirement at all that the frames be stored like Example 1, above. It's relatively common for films to be dumped onto the disc using an encoding similar to Example 3. As mentioned before, most major Hollywood releases look more like the first example, but it's just that they have better encoding software, which recognizes the 3-2 pattern and removes the extra repeated fields for compression efficiency. It's not done to improve progressive playback; that just happens to be a useful side-effect.

And, of course, there's plenty of material on DVD that was originally shot on video, or was shot on film, converted to video, and then edited on video. This material requires fairly sophisticated video-mode deinterlacing algorithms if it's going to look good. Cheaper deinterlacing chips skimp in this area.

Paul

[HeavyHitter]

Originally Posted by WickyWoo

You needed progscan players because the previous ones weren't designed to output progressive scan

In fact there's the infamous Wings of Honneamise disc from Manga that came from a 480i source was zoomed to 16:9 than flagged as progressive so the end product was actually DOUBLE interlaced.

I have friends who have authored DVD for years, even helped some of them get hired into the job. Oh the epic tales of the Mary Kate and Ashley library...did I meantion in 5 different editions each? In different languages, all of which had to be tested over..and over...and over?

But, if the DVD source/disc is progressive 480p......why would you need to deinterlace it (when in fact we know you have to on film for better PQ)? If not, all it would need to do is pass it to the display (as BD does with 1080p/24, for example).

I'd like Kris to chime in on this.

[Kris Deering]

DVDs are not authored as 480p, they are 480i. This is why an SDI output is 480i. They are flagged so that 480p can be derived but normally these flags vary in quality.

I am not aware of a single DVD to date that has video information stored at 480p. I'm not aware of a single DVD player to date that would be compatible with a native 480p signal on a DVD disc.

[Alan Gordon]

Originally Posted by HeavyHitter

But, if the DVD source/disc is progressive 480p......why would you need to deinterlace it (when in fact we know you have to on film for better PQ)? If not, all it would need to do is pass it to the display (as BD does with 1080p/24, for example).

I'd like Kris to chime in on this.

Originally Posted by Kris Deering

DVDs are not authored as 480p, they are 480i. This is why an SDI output is 480i. They are flagged so that 480p can be derived but normally these flags vary in quality.

I am not aware of a single DVD to date that has video information stored at 480p. I'm not aware of a single DVD player to date that would be compatible with a native 480p signal on a DVD disc.

WHOA WHOA WHOA!!! WHAT?!

I'm sorry for going off-topic on your thread Penton, but my world has gone all askew!!

EVERYTHING I have ever read stated (as Wicky said) that all DVDs are recorded onto DVD in 480p! Non-progressive scan DVD players convert the 480p picture into 480i (I think via the DACs?) so that people can view the disc on their non-Progressive scan TVs.

Progressive Scan DVD players however allow one the option of outputting EITHER a 480i conversion (for those with 480i TVs) as well as the option of bypassing the 480p to 480i conversion allowing one to see the original 480p picture (for those with TVs that can accept it).

~Alan

[Kris Deering]

Originally Posted by Alan Gordon

WHOA WHOA WHOA!!! WHAT?!

I'm sorry for going off-topic on your thread Penton, but my world has gone all askew!!

EVERYTHING I have ever read stated (as Wicky said) that all DVDs are recorded onto DVD in 480p! Non-progressive scan DVD players convert the 480p picture into 480i (I think via the DACs?) so that people can view the disc on their non-Progressive scan TVs.

Progressive Scan DVD players however allow one the option of outputting EITHER a 480i conversion (for those with 480i TVs) as well as the option of bypassing the 480p to 480i conversion allowing one to see the original 480p picture (for those with TVs that can accept it).

~Alan

That is definitely not the case and the reason there is such a huge difference in quality in regards to displaying a 480p image. The 480i content needs to be converted to 480p properly by de-interlacing the image. There are a lot of options out there from names like Faroudja, Silicon Optix, Anchor Bay, and Silicon Image. Most player decoders offer this function as well, but all do it to varying degrees of quality.

I would suggest reading the DVD Benchmark that was linked in this thread above. I don't know of a more complete document on DVD video processing and de-interlacing.

[WickyWoo]

I called my friend, and I made a mistake

I was crossing in my mind a specfic process they were using to repair old and worn master tapes

The suffering of doing the entire Olsen Twins library in 5 languages still stands

[Penton-Man]

Originally Posted by WickyWoo

I made a mistake

You know, the internet would be a much, much better place if people used those four words more frequently.

[jd213]

Hollywood DVDs are usually encoded as 24fps 480p "soft telecined" with flags telling the player to convert back to 480i, 60 fields per second. When it's encoded as 480i, it's called "hard telecined". Soft telecining also has the benefit of having less data per second so it's easier to compress within the DVD bitrate restrictions.

But when you take a look at a soft telecined DVD in a PC software player with "force weave" selected for the deinterlacing, or analyze the frames with software such as DGIndex, you will sometimes see combing which indicates that some portions weren't encoded as 480p correctly (usually just during scene/reel changes, but some DVDs like the Superbit for Leon the Professional have whole hard telecined segments). And of course, most supplementary material is hard telecined (or was shot on video to begin with).

[milou6]

This is all news to me, a layman who believed film was 720x480p on DVD. But my ignorance aside (and to cut to the point here for many of us at home): if my TV or Receiver (or outboard decoder etc) is upscaling my DVD player's output to 1080p, am I better off disabling progressive scan to avoid "double" processing of the source? In other words, is progressive scan applying a process to de-interlace films from 480i to 480p that then would be re-processed to make it 1080p? In my case I have a basic progressive scan player and an XBR4 monitor.

Originally Posted by jd213

Hollywood DVDs are usually encoded as 24fps 480p "soft telecined" with flags telling the player to convert back to 480i, 60 fields per second. When it's encoded as 480i, it's called "hard telecined". Soft telecining also has the benefit of having less data per second so it's easier to compress within the DVD bitrate restrictions.

But when you take a look at a soft telecined DVD in a PC software player with "force weave" selected for the deinterlacing, or analyze the frames with software such as DGIndex, you will sometimes see combing which indicates that some portions weren't encoded as 480p correctly (usually just during scene/reel changes, but some DVDs like the Superbit for Leon the Professional have whole hard telecined segments). And of course, most supplementary material is hard telecined (or was shot on video to begin with).

[Elvis Is Alive]

Sorry for the thread hijack P-man.

I set my Oppo to output DVD's at 480i and use the Reon chip in my Onkyo 875 to upscale and deinterlance to 1080P. I find this yields the best results in my testing. The Reon chip does a better job than the Oppo player, as it should. I find it helps most with SD TV content.

From all my research, most people in the know recommend a player than can output 480i to a proper scaler/deinterlacer for best results. There aren't that many DVD players that can send out 408i via HDMI though. Here is a list of players that can do this: http://www.avsforum.com/avs-vb/showthread.php?t=614206

It is recommended to stay with an all digital pathway (no analogue conversions) for best results.

[Kris Deering]

Originally Posted by jd213

Hollywood DVDs are usually encoded as 24fps 480p "soft telecined" with flags telling the player to convert back to 480i, 60 fields per second. When it's encoded as 480i, it's called "hard telecined". Soft telecining also has the benefit of having less data per second so it's easier to compress within the DVD bitrate restrictions.

But when you take a look at a soft telecined DVD in a PC software player with "force weave" selected for the deinterlacing, or analyze the frames with software such as DGIndex, you will sometimes see combing which indicates that some portions weren't encoded as 480p correctly (usually just during scene/reel changes, but some DVDs like the Superbit for Leon the Professional have whole hard telecined segments). And of course, most supplementary material is hard telecined (or was shot on video to begin with).

Again, this is anything but the case. DVDs are encoded as 4:2:0 YCbCr with a resolution of 480i60. They are flagged for their cadence to allow for de-interlacing to a progressive resolution of 480p60. Obviously players now offer scaling abilities that can offer various resolutions up to 1080p.

One would only wish they were encoded as 24p as that would offer judder free playback. Right now there are a few video processing solutions that can take the video and strip it down to 24p, but most don't do a very good job. Tearing and dropped frames are typically seen because the again the flags are incorrect.

I honestly don't don't where so many people are getting the idea that DVDs are encoded progressively, this has never been the case and there is no data even out there to support it

[Kris Deering]

For anyone that wants to learn more about our aging DVD format I would suggeset Jim Taylor's excellent book, DVD Demystified. Great information in there and a must read for DVD techies!

DVD Demystified

[jd213]

Originally Posted by Kris Deering

Again, this is anything but the case. DVDs are encoded as 4:2:0 YCbCr with a resolution of 480i60. They are flagged for their cadence to allow for de-interlacing to a progressive resolution of 480p60. Obviously players now offer scaling abilities that can offer various resolutions up to 1080p.

One would only wish they were encoded as 24p as that would offer judder free playback. Right now there are a few video processing solutions that can take the video and strip it down to 24p, but most don't do a very good job. Tearing and dropped frames are typically seen because the again the flags are incorrect.

I honestly don't don't where so many people are getting the idea that DVDs are encoded progressively, this has never been the case and there is no data even out there to support it

Sorry, you're wrong. I've had much experience with PC software players who could never properly deinterlace a 480i signal, yet they play progressively encoded DVDs perfectly. And you do get judder-free playback when you have a CRT monitor with you're PC's output set to 72 or 120Hz, I used to watch DVDs like this all the time.

Download the freeware DGIndex some time and use it to play around with the vobs of a Hollywood disc (I won't tell you how to get the vobs, but if you want to be US legal about it I'm sure there's one or two discs without CSS out there), you'll see that the flags are ignored when the video stream is analyzed, and it will report what percentage is progressive as well as the framerate.

[jd213]

From the DVD Faq, which was linked in your above link to DVD Demystified:

For NTSC display, the solution is to spread 24 frames across 60 fields by alternating the display of the first film frame for 2 video fields and the next film frame for 3 video fields. This is called 2-3 pulldown. The sequence works as shown below, where A through D represent film frames; A1, A2, B1, and so on represent the separation of each film frame into two video fields; and 1 through 5 represent the final video frames.

Film frames: | A | B | C | D |
Video fields: |A1 A2|B1 B2|B1 C2|C1 D2|D1 D2|
Video frames: | 1 | 2 | 3 | 4 | 5 |

For MPEG-2 encoding, repeated fields (B1 and D2) are not actually stored twice. Instead, a flag is set to tell the decoder to repeat the field. (The inverted order of C2 and C1, and D2 and D1 are because of the requirement that top and bottom fields alternate. Since the fields are from the same film frame, the order doesn't matter.) MPEG-2 also has a flag to indicate when a frame is progressive (that the two fields come from the same instant in time). For film content, the progressive_frame flag should be true for every frame.

[milou6]

Thanks, Elvis! Will tinker with this tonight. I believe my Harman/Kardon DVD-38 can output 480i over hdmi (but it resets to its maximum every time you turn it on, which is a poorly upcoverted 1080i -- arg).