I know there have been similar posts on this topic, but I still do not get clear answers. Here are my questions (including beginner questions, forgive me):

1. I have many blu-ray discs, and I noticed that there are 1080p blu-ray discs and 1080i blu-ray discs (the latter that I saw was documentary, not a movie). Do 1080p blu-ray discs have more information than 1080i blu-ray discs?

2. Let's forget about 1080i discs, which are rarely found (I have seen only one). If I set my blu-ray player (Samsung BD-P1500) to feed 1080i signal to my display (Mitsubishi HC5500 projector) from 1080p blu-ray discs (especially movies with 24fps), am I losing certain information or will I have inferior picture quality by doing so?

3. My ultimate question: if I feed video processor (DVDO, Lumagen or other video processor) with 1080i from 1080p movie blu-ray discs, then can I get better picture quality or loss in picture quality? Will the difference be negligible?

4. Do recently introduced video processors process 1080p/24fps input signal when they output the signal to display or just pass it through?

Thank you in advance!!

1. I have many blu-ray discs, and I noticed that there are 1080p blu-ray discs and 1080i blu-ray discs (the latter that I saw was documentary, not a movie). Do 1080p blu-ray discs have more information than 1080i blu-ray discs?

The difference is the source material. Movies shot on film are transferred to disc at 1920 x 1080 pixels progressive (that is, every horizontal line recorded) at 24 frames per second. Anything shot with a video camera is (can be up to) 1920 x 1080 pixels interlaced (that is the first field will have the odd lines, the next the even ones) at 60 fields per second. So yes, the 1080p discs have more information because every "frame" has all 1080 lines in it. A "field" of a 1080i disc has only 540 (every other.)

2. Let's forget about 1080i discs, which are rarely found (I have seen only one). If I set my blu-ray player (Samsung BD-P1500) to feed 1080i signal to my display (Mitsubishi HC5500 projector) from 1080p blu-ray discs (especially movies with 24fps), am I losing certain information or will I have inferior picture quality by doing so?

What your player is doing is performing a process called telcine to convert the 24 frames to 60 interlaced fields. Your display device will deinterlace the 60i to 60p. (It may also have the ability to do 3:2 pulldown and reconvert the 60p to 24p. I'm not familiar with that model.) So if your display will take 24p material as it is recorded on the disk (and your method of connection can, too (HDMI, not component)) then that will give you the least amount of image conversion. In a theory, there should be no difference.

3. My ultimate question: if I feed video processor (DVDO, Lumagen or other video processor) with 1080i from 1080p movie blu-ray discs, then can I get better picture quality or loss in picture quality? Will the difference be negligible?

It's all in the implementation. Video content is interlaced. That is one field has 540 lines (of 1080) from one point in time. 1/60 of a second later the other 540 lines are captured. Somebody has to put the two half-pictured together. Some algorithms are better at that than others. The price you pay for high-end processors typically goes for better programming. Two devices (say, a scaler and a projector) may have the same Gennum chip in them but get different results. If your source is 1080p the feed that to the scaler. Otherwise, you're having your player interlace the content only to have your scaler deinterlace it.

4. Do recently introduced video processors process 1080p/24fps input signal when they output the signal to display or just pass it through?

That depends on how you configure them. (Another advantage of scalers.) Often, a scaler is used to correct color inaccuracies in the display device, so in that instance, yes, a scaler will "process" the image. If the source and display device are both 1920 x 1080 then obviously no "scaling" will have to be done. If you have 480i content (SD DVD) then I'd feed it to the scaler and have it resize and deinterlace it, rather than have the player do it, because a good scaler will do it better.

P.S. I have a Crystallio II.

Thank you, c-not-k!! Cannot be more clear!! Just have one more question.

Does your Crystallio II or other video processors (scalers) process 1080p/24fps signal in terms of noise reduction in addition to color calibration you mentioned above?

Does your Crystallio II or other video processors (scalers) process 1080p/24fps signal in terms of noise reduction in addition to color calibration you mentioned above?

Yes. Mine does not do block artifact reduction due to the version of the chip in it, but I think the newer ones do (DVDO Edge, Lumagen Radiance XD). Otherwise, it has the usual set of tools; you can tell it how much edge enhancement to use and/or noise reduction.

Each scaler comes with its own set of tools. I'd suggest downloading the user manuals to see what each one can do, as well as surfing the forums (both here and at the manufacturer's sites) to see what the actual owners of the devices have to say.

Thank you, c-not-k!!

You're quite welcome.

By the way, another beginner question:

Should 1080i/60 field have more information than 1080p/24fps? I.e., 1080i/60 = 540 x 60 = 32400 vs. 1080p/24 = 1080 x 24 = 25920

Am I missing something? When you calculate the information of 1080i/60, should it be 540 x 30? instead of 540 x 60?

Please enlighten me. Thank you.

By the way, another beginner question:

Should 1080i/60 field have more information than 1080p/24fps? I.e., 1080i/60 = 540 x 60 = 32400 vs. 1080p/24 = 1080 x 24 = 25920

Am I missing something? When you calculate the information of 1080i/60, should it be 540 x 30? instead of 540 x 60?

Please enlighten me. Thank you.

You are correct! 1080i/60 has more info than 1080p/24. 1080i/60 when deinterlaced becomes 1080p/30. However progressive sources should look better. Interlaced fields do not always line up perfectly into progressive frames.

By the way, another beginner question:

Should 1080i/60 field have more information than 1080p/24fps? I.e., 1080i/60 = 540 x 60 = 32400 vs. 1080p/24 = 1080 x 24 = 25920

Am I missing something? When you calculate the information of 1080i/60, should it be 540 x 30? instead of 540 x 60?

Please enlighten me. Thank you.

If you're talking about one second of images then...

1080i/60: 1920 * 540 = 1036800 pixels per field * 60 fields per second = 62208000 pixels per second.

1080p/24: 1920 * 1080 = 2073600 pixels per frame * 24 frames a second = 49766400 pixels per second.

So, in terms of data rate, yes 1080i/60 puts out more pixels per second than 1080p/24. However, remember video (1080i/60) only ever captures ever other line. Half of each "picture" is thrown away. Recovering this on a digital display device requires either some clever thinking on the part of the electronics to guess what was missing and fill it in (usually by comparing 3 or so fields to see what changed) or worse, simply stretching each single-pixel row to two rows. This, in effect, halves you vertical resolution. Either way, deinterlacing errors are quite visible (jaggies, moiré patterns, etc.) Film, on the other hand, has no missing information.

Thank you, c-not-k and Ronomy for educating me!! Now I got clear answers that were not easily obtainable from reading so many articles.

Actually, I was thinking buying an "inexpensive" video processor ("old" models) which can only accept up to 1080i for subtitle issues (zooming and panning). However, I realized from your answers to my questions that unless I feed 1080p into the video processor, I may have to sacrifice the picture quality to some degree (even though, as you pointed out, theoretically no loss of picture quality may be possible in ideal circumstances).

Thank you again!! Best regards,

You are correct! 1080i/60 has more info than 1080p/24. 1080i/60 when deinterlaced becomes 1080p/30. .

1080i60 is deinterlaced to 1080p60 not 1080p30.

The overall data rate of 1080i60 is equivalent to 1080p30 but that's about the extent of the similarity. With movement, 1080i60 has twice the temporal resolution but half the spatial resolution of 1080p30. That's why 1080i looks OK with faster motion but 1080p30 does not.

Thank you, c-not-k and Ronomy for educating me!! Now I got clear answers that were not easily obtainable from reading so many articles.

Actually, I was thinking buying an "inexpensive" video processor ("old" models) which can only accept up to 1080i for subtitle issues (zooming and panning). However, I realized from your answers to my questions that unless I feed 1080p into the video processor, I may have to sacrifice the picture quality to some degree (even though, as you pointed out, theoretically no loss of picture quality may be possible in ideal circumstances).

Thank you again!! Best regards,

I use a Lumagen HDQ VP and couldn't be happier. It passes my 1080p/24 Blurays just fine. 1080i/60 to film 1080p/60 is perfect. You will omly lose a little bit with 1080i/60 video conversion to 1080p/60 but I think its still good enough for me. You can pass 1080i in and out if you want.

Ron

Isn't there an inconsistency with the notation system?

I mean isn't 1080p60 just 1030p with each frame repeated [refreshed]? Shouldn't the refresh rate be specified as another parameter, like 1080p60x2?

Wikipedia states, "Higher frame rates, such as 1080p50 and 1080p60, are foreseen as the future broadcasting standard." By 1080p60 they mean 60 different frames. Today 1080p60 means 30 different frames. Confusing to me.

1080p24 is rarely shown as 1080p24. My pj refreshes each frame 3x for a refresh rate of 72 Hz but it is not called 1080p72.

Am I understanding all this correctly?

Movies are filmed at 24 frames per second. This is captured to a Blu-ray disk at 1080p24. So there is a one-to-one correspondence between the film frames and the images captured to the disk.

1080i, 1080p24 and 1080p60 include exactly the same information, just arranged in a different order. 1080p60 has a higher bandwidth because some of the information is repeated.

For watching movies, to get smooth motion on your display, set your Blu-ray player to output 1080i or 1080p24. Then set the output of a Lumagen video processor to drive the display at 1080p24 or 1080p48. Use whichever rate works best with your display. You will have smooth motion. If you drive your displays at 1080p60 you will see judder on pans, zooms and moving objects.

Randy Freeman
support@lumagen.com

Isn't there an inconsistency with the notation system?

I mean isn't 1080p60 just 1030p with each frame repeated [refreshed]? Shouldn't the refresh rate be specified as another parameter, like 1080p60x2?

Wikipedia states, "Higher frame rates, such as 1080p50 and 1080p60, are foreseen as the future broadcasting standard." By 1080p60 they mean 60 different frames. Today 1080p60 means 30 different frames. Confusing to me.

1080p24 is rarely shown as 1080p24. My pj refreshes each frame 3x for a refresh rate of 72 Hz but it is not called 1080p72.

Am I understanding all this correctly?


1080p24 is really only germaine to film sources.

1080i can be either film (originally at 24 frames per sec) or video (orginally at 60 FIELDS per sec).

With a 1080i film source deinterlacing should recreate the original frames in the process yielding 24 complete frames/sec somewhere along the line. This is then typically displayed at some multiple of the original framerate i.e. 1080p48, p72, p96, p120 or p60. Integer multiples have the advantage of elimination of 3/2 cadence judder. Framerate judder will still be present (due to lack of sufficient framerate to represent faster motion images). Frame interpolation can be an option to decrease apparent framerate judder but purists object to it as it "makes film appear more like video".

The result of properly deinterlacing a 1080i video source will be 1080p60 with each successive frame potentially being distinctly different. That's because the deinterlacing is done on successive fields which are taken at differing points in time 1/60 sec apart. With still images (or still parts of the image) the frames may be the same, but with movement (or in moving parts of the image) the frames should be distinct with properly performed deinterlacing.

Movies are filmed at 24 frames per second. This is captured to a Blu-ray disk at 1080p24. So there is a one-to-one correspondence between the film frames and the images captured to the disk.

1080i, 1080p24 and 1080p60 include exactly the same information, just arranged in a different order. 1080p60 has a higher bandwidth because some of the information is repeated.

Randy Freeman
support@lumagen.com

To clarify, 1080P/24 has less bandwidth than 1080i/60 or 1080p/30. But yes the information is all the same provided it's just repeated when 3/2 pulldown is inserted. 1080p/24 is padded out with null data to equal 1080i/60 for interface purposes (SMPTE292 HDSDI). Otherwise 1080p/24 would be a different clock frequency and not be compatable with 1080i/60 systems. However once inside a device such as BluRay, 1080p/24 yields more storage space than 1080i/60.

So for example if you had just enough space for a 2 hour movie at 1080p/24, you could not fit a 2 hour video program captured at 1080i/60 in the same space. Of course we are talking uncompressed or fixed compression ratios here.