Progressive Scan on a DV-Camcorder - is it worth using?

[jmone]

Hi,
I've got a JVC DV2000 that can record Progressive Scan in PAL 16:9. I've been using 16:9 PAL settings to date and get good results as a source for burning to DVD on non progressive scan players. (note: I also keep a backup of all my edited AVI files on disk so I can use these as a source to re-encode for future formats without having to go back to tape)

Is it worth me shooting in PS to create my master AVI's then selecting either frame based or interlaced DVD encoding depending on the PS ability of the DVD player?
- Is there any downside to PS in general?
- Are there any problems encoding PS-AVI to interlaced DVD for non PS players?

Thanks
Nathan

[junkmalle]

Is there any downside to PS in general?

When viewed on an interlaced display motion will be a little less fluid in progressive mode recordings. In progressive mode both fields are captured at the same time so you get 25 (PAL) pictures a second. In Interlaced mode there is a 1/50 second time delay between the first and second fields. You get 50 pictures a second, but you only see half (every other scanline) of each picture.

Are there any problems encoding PS-AVI to interlaced DVD for non PS players?

No. In fact there are fewer problems. You no longer have to worry about field order. The frames are saved on DVD as if they are from an interlaced source, but since the two fields were captured at the same time, it doesn't matter which you display first.

I use progressive mode on my camcorder all the time. I gladly give up the slighly more fluid motion of interlace to get rid of issues it creates.

[tadao]

Hi Nathan,

In a word: yes. It is worth using.

In a couple of words: it depends whether or not you like the more filmic look it creates.

There's a bit of confusion over what "progressive" means as it refers to a few different things...

PAL video runs at 50 fields a second. Not 25 frames, as is often said. When film is transferred to PAL, each frame is split across 2 fields.

Progressive camcorders will emulate this process, capturing 25 frames/second and recording them onto DV tape as 50 fields, each frame split across 2 fields, instead of capturing 50 fields/second. This gives a different "look" to your video material on any playback device.

Progressive DVDs code MPEG-2 to optimise the picture quality for 25 frame material. This method of coding is compatible with all machines, but should improve the picture quality at any bitrate.

Progressive DVD players can deliver this to a progressive display all at once, displaying both fields simultaneously, and giving a smoother, clearer picure.

The progressive mode on the camcorder will create a normal, compatible DV stream that can easily be encoded for DVD. When encoding, you don't have to take into account the PS ability of the player: encode PS material as progressive and non-PS material as interlaced. All DVD players can play back PS material, and will play it back the same way as film material (1 frame -> 2 fields).

The upside or downside to PS in general (for material shot with a camcorder) is that it gives film-like motion with a video-like look. Personally, I prefer this as I think it makes video material look more professional. Some people dislike it as it makes video look less like video. Many current UK TV shows are de-interlaced or "filmised" which gives a similar effect. "The Office" and recent series of "League of Gentlemen" are filmised like this.

There are no problems encoding PS AVI to PS MPEG-2 for all DVD players. The only issue is if you don't have the field order set right, will mix up the progressive frames and display them at the same time on a progressive player or PC. Many (but not all) current film DVDs are encoded as PS, and you don't have any problem playing these back.

There are no problems encoding PS AVI to non-PS MPEG-2 for non-PS players, except that it's unneccessary, and won't optimise the image for computer playback or PS players. Encoding PS video with PS settings will give an improved picture quality at the same bitrate.

Test out your camera's PS mode by shooting the similar material in PS and non-PS mode and playing back on your TV. If you prefer the PS look, shoot PS and encode as PS. If not, carry on shooting interlaced and encode interlaced. But there's no reason to ever encode PS as non-PS: it won't do any harm but won't look quite as good as it should.

Best of luck!

[troyvcd1]

I have heard that shooting in progressive mode will not give you as good low light results then shooting with the same camcorder in interlace mode.

[jmone]

Thanks everyone especially tadao! - will do some tests over the W'end and see what it looks like.
Nathan

[p_l]

I use progressive scan mode on my DV camera all the time as well, for all the reasons so eloquently given above, plus the added advantage is that when you extract stills, they are beautiful full framed, and much sharper, since you have twice as much data in each frame. Think of it as shooting 25 (or 29.97 in NTSC land) full-frame stills per second.

[jmone]

Mmmm,
I've tried the following combinations of Recording (Interlaced / PS) and encoding / burning to a DVD (Frame Based / Field Order B) with the following results:
- Interlaced & Field Order B = Good results (eg normal)
- The other 3 combos had very poor output with the TV displaying disjointed fields.

I used VS8 to capture & encode and played on a non PS DVD Player. Unless I'm doing something wrong, Interlaced works best for my set up at the moment.
Nathan

[thor300]

How does the progressive scan mode on that cam really work? Does the cam still shoot interlaced and then use progressive scan to blend the fields to a frame or is it a "real" progressive where both fields are shot at the same time? If the first scenario is the case i would imagine its just as good to shoot it normal interlaced and then use software in the pc to do progressive scan if desired.

[racer-x]

jmone wrote:

I've tried the following combinations of Recording (Interlaced / PS) and encoding / burning to a DVD (Frame Based / Field Order B) with the following results:
- Interlaced & Field Order B = Good results (eg normal)
- The other 3 combos had very poor output with the TV displaying disjointed fields.

Are you sure that "Progressive Scan" setting on your Camcorder is for video and not Pictures? If the Video is Progressive, it would not look worse than Interlaced.

My Panasonic DV-pv953 shoots in "Frame Mode" witch can be used to make Progressive Scan DVD. It works great and always looks better than Interlaced vesion. My camera also has "Progressive" in the Menu, but it refers to Picture Mode.

[junkmalle]

How does the progressive scan mode on that cam really work?

My camcorder (Canon Optura PI) shoots true progressive video -- both fields are from the same exposure. Obviously, for playback on an interlaced TV the fields have to be sent one after the other.

[jmone]

I'm pretty sure that the JVC DV2000EA shoots in Progressive Scan when you select the "PS" option. I've tried encoding the captured footage with TMPGenc as well and get more or less the same resutls. The only bit that looks good is the interlaced portion of the test footage with the output set as Field Order B. The PS footage looks jittery with output based on both Field Order B and Frame Based (likwise does the interlaced footage when output as Frame Based). (note: I only have a non-PS DVD Player so can not test on a PS one)
Thanks
Nathan

[racer-x]

Just did a search on your camera. This is what I've found:

By far the most impressive feature of the JVC GR-DV2000EA camera is the 1.92 megapixel progressive scan CCD which equates to an effective pixel resolution of 1,600 x 1,200 (UXGA). This incredible resolution is possible due to the cutting edge high quality optics in the JVC unit, utilising Accurate Image Shift (AIS) lens technology that effectively doubles the image data made available for the CCD to sample. The lens setup includes two optical low-pass filters, one dedicated for motion capture and one for digital still images to fully utilise the CCD in both modes. The CCD resolution of the JVC for motion is 0.8 megapixels - still an impressively large number - equalling the best the labs has to offer. Combine this with the fact that the image device is a progressive scan CCD, which basically enables the JVC to render complete frames while recording, without the use of interlacing techniques between frames to complete the image. However it is limited to 25 frames per second and is thus best put to use in taking action stills free from motion blur.

I'm not convinced that the footage you recorded is Progressive. Open the Mpeg file you made in VirtualDub Mod. Preview a fast actin scene, the image should be whole with no Interlaced artifacts. If there are any, then your footage is Interlaced. You can also extract a frame from the original avi during high action. That will also tell the tail. If it is Progressive, then any fast moving object will be blured not broken up by lines.

[tadao]

Hi Nathan,
it sounds like there's something wrong with the settings in your edit/encode program. Just to make sure, play back your progressive footage straight from your camera to TV. It will look slightly more "jittery" than interlaced video, but I'm sure that's not what you're talking about. If you get the settings in the encoder right, the DVD output will look the same as this.

I've never used VS8, but had a similar problem the first time I tried encoding progressive video. Your problem probably lies in conflicting settings: presumably VS8 has seperate project settings and output settings. The project settings should be set as 16:9, PAL, and "no fields" or progressive. The output should match this.

One stand alone program I've used gives seperate options for "field a"/"field b" and "progressive frame". For some reason, I think progressive DV footage needed to be set as "field_a first" and "progressive frame" on that program. It sounds likely that the frame based output of VS8 is combining the wrong pairs of frames, and it could be something to do with the fact that normally DV uses field B first. I'd hazard a guess that progressive DV might be field A first, and this could be why we've both experienced jitter on the image... so try outputting your progressive footage as field A first, and see if that plays normally.

Racer-x is right about the suggestion to check your footage in VirtualDub Mod for interlace lines, but I am convinced you have genuine progressive video, and that it's just the configuration that is set wrong somewhere.

The JVC DV-2000 certainly does offer progressive scan for video, it's one of very few consumer cameras to do so. With the correct settings, your DVD output should look identical to playing back progressive footage straight from your camera to your TV.

If you have the time, check your project settings are correct, try any advanced settings the VS8 MPEG-2 encoder has and try "field a first" together with progressive if possible. If you can get it right, the results are worth it.

[eriks]

I use a Panasonic DS9 for 5 years, at the mean time I always turn on the Progressive Scan mode but I got interlaced avi (I convert all film I take to Divx ), last month I buy a new SONY PC330 & hope Progressive Scan Mode work, but this time I am really confused! the captured(thru. 1394) still interlaced & much "jittery" than ever, I check my PC's software & setting(from codec to mpeg2 encode, now I have a DVD burner) finally I try to play my tape in PC330 on my TV, I got a terrible result on the screen(much better when PS mode off), Why?? does SONY make some big mistake, or I need a PS TV ? now I do'nt know problem come from
DV,TV,PC's CODEC or Encoder??? how I can check for this??