AVID Compression Query

[foxbox]

I currently use the old Liquid Edition 6, which I understand uses DV25, or 5:1 compression.

Apparently this compression cannot be improved, so I wish to upgrade to either AVID XPRESS PRO or AVID MEDIA COMPOSER.

I have spent several hours Googling the subject, but cannot seem to find a straight answer (perhaps it is the hour of the night!), so I thought I would ask those in the know here:-

What is the minimum compression achievable with both AVID XPRESS PRO (5.24), and AVID MEDIA COMPOSER (7.2.0)?

Now I've heard MEDIA COMPOSER can achieve 2:1 or even zero compression, but I've learned I would need 2gb of RAM to run it (anybody know if it can by any chance run on my 1gb...?) so perhaps XPRESS PRO is the more realistic (and cheaper) option at the moment since only 1gb RAM is required.

But can XPRESS PRO achieve at least 2:1 compression?

I use a 3-CCD SD camera, and I want to achieve the best possible picture from my DVD films using one of these AVID products.

As usual, thank you kindly for any advice!

[foxbox]

I've found this page, which states XPRESS PRO HD has "DV50 capture and output over IEEE-1394":-

http://www.editheaven.co.uk/AvidProducts/avidxpresspro.html

Apparently the same for MEDIA COMPOSER:-

http://www.editheaven.co.uk/AvidProducts/mediacomposer.html

However, latest Liquid appears, if I am reading into this correctly, to still only 'capture' in the lower quality DV25. Though the following specification for Liquid 7.2 does seem to highlight possibilities of Uncompressed SD... does this mean one can capture and edit as uncompressed SD video?

RT playback: DV/DVCPRO 25, HDV, IMX, MPEG I/IBP 422P/ML@ML/HL, DVCPRO 50, SD/HD Uncompressed, WM9, DivX, MPEG-4
Native capture (IEEE1394): DV/DVCPRO 25, MPEG2 IBP (MP@ML/HL), HDV
Encode capture: DV/DVCPRO 25, MPEG2 IBP (MP@ML), Uncompressed SD, Uncompressed HD, DivX 5, DV to MPEG
Render: DV/DVCPRO 25, MPEG2 I/IBP MP@ML/HL, 422P@ML, DVCPRO50, SD/HD Uncompressed
Fuse: DV/DVCPRO 25 (MXF, DIF, AVI), MPEG2 I/IBP MP@ML/HL, 422P@ML (M2V, MXF), DVCPRO 50 (MXF,DIF), SD/HD,Uncompressed (YUV, 2VUY), WM9, DivX, MPEG-4

[foxbox]

Just one more thing, my camera is a PANASONIC DVX100A.

I'm new to the DV25/DV50 comparison.

Will my camera 'record' at DV50 standard, and therefore it makes sense to use a DV50 editing package to maintain best quality?

Or is the DV value only a form of 'editing'?

If my camera records at DV50 standard, would using lesser software such as Liquid at only DV25 mean I could never achieve best results unless upgrading to XPRESS or COMPOSER?

Help appreciated.

[edDV]

Just one more thing, my camera is a PANASONIC DVX100A.

I'm new to the DV25/DV50 comparison.

Will my camera 'record' at DV50 standard, and therefore it makes sense to use a DV50 editing package to maintain best quality?

Or is the DV value only a form of 'editing'?

If my camera records at DV50 standard, would using lesser software such as Liquid at only DV25 mean I could never achieve best results unless upgrading to XPRESS or COMPOSER?

Help appreciated.

Slow down and lets discuss this.

Your DVX100A is a DV format camcorder capable of 24p. I know this camcorder for use in 23.976 fps (24PA) but not EuroPAL models. Is this a US spec camcorder or a Euro model? Is film your export format?

This report is the DVX100 bible for the Americas. It may help to understand the points raised.
http://www.adamwilt.com/24p/

Otherwise, explain your project goals.

Backgound. The DVX-100 compresses 5x in the DV encoder. It is a special form of DV format. You can decompress it for editing but ask yourself why? Decompression adds a generation loss. Why do it unless you are editing to an uncompressed source like a telecine film transfer. This would depend on the project plan, filtering goals and export goals.

[foxbox]

My DVX100A was bought here in England, and I use standard miniDV tapes.

Project goals as follows:-

1] To shoot in the highest possible quality with my camera (am I correct in using standard high-street miniDV tapes, and not special DV50 tapes?)

2] To digitise the footage to my chosen Avid software via FireWire without any picture loss (will XPRESS PRO grab the footage and keep it 'exactly as it was recorded', pixel-for-pixel?)

3] To edit my film in Avid, again without any picture loss (will XPRESS PRO not apply any unwanted changes to the quality of my pictures during the cutting and effects process?)

4] To export my edited film to DVD, once more without any picture loss (will XPRESS PRO transfer my original footage - once edited how I like - to DVD exactly as it was captured through my camera?)

I don't know much about 'compression', just that it can be employed to reduce file sizes and make working with images a bit quicker... but using this camera and top Avid software, this is just what I want to avoid. I have a large hard drive, I want maximum possible quality. Even broadcast quality, so far as this SD camera goes.

Thank you for your help!

[edDV]

My DVX100A was bought here in England, and I use standard miniDV tapes.

Project goals as follows:-

1] To shoot in the highest possible quality with my camera (am I correct in using standard high-street miniDV tapes, and not special DV50 tapes?)

Digital tape quality has little to do with video quality as was the case with analog. "Digital" tape quality relates more to whether the tape will play on a different deck than it was recorded. The DVX100A isn't capable of DV50 format.

2] To digitise the footage to my chosen Avid software via FireWire without any picture loss (will XPRESS PRO grab the footage and keep it 'exactly as it was recorded', pixel-for-pixel?)

I'm not familiar with the Euro version of this camcorder. As described in the reference above, this camcorder is about special "film" frame rates but is still standard DV format. A few edit programs work with 24pa (24fps progressive advanced). If you are recording in that format and using a standard editor, you will get crap quality. I for one can't stand looking at 24pa as transfered. Once converted to 24p it looks fine on a Vegas or Premiere time line in a 24fps progressive project. Avid Xpress Pro probably supports 24pa but you need to be in 24 fps progressive project format and import from the camcorder as 24pa.

If you are shooting standard PAL 720x576 interlace at 25fps then you just treat this as a standard DV camcorder. If standard PAL 576i, a DV format capture will exactly duplicate the data on tape to a DV-AVI file on the hard drive.

3] To edit my film in Avid, again without any picture loss (will XPRESS PRO not apply any unwanted changes to the quality of my pictures during the cutting and effects process?)

That depends on what mode you shot that "film" and what project format you are using. If the format is standard PAL DV 576 interlace, simple cuts may be used with no quality loss if you output as PAL 576i. Almost anything else you do to the video will degrade it somewhat no matter what the edit program. Effects processing usually converts the selected frames to RGB and then processes them as you command. Output back to DV format will be somewhat degraded. If instead you encode to DVD MPeg2, that too will be degraded vs. original DV format.

AVID is no different for picture quality than other programs for editing DV format. Avid is more about user interface style.

4] To export my edited film to DVD, once more without any picture loss (will XPRESS PRO transfer my original footage - once edited how I like - to DVD exactly as it was captured through my camera?)

No. DVD (Mpeg2) format is inferior to DV format. Transferring to DVD by definition will lower quality. DV is 25 Mb/s with no motion compression. DVD is 4-9Mb/s with motion compression.

I don't know much about 'compression', just that it can be employed to reduce file sizes and make working with images a bit quicker... but using this camera and top Avid software, this is just what I want to avoid. I have a large hard drive, I want maximum possible quality. Even broadcast quality, so far as this SD camera goes.

First, your camera compresses to DV format ~ 5x before it records to tape.

Second, Avid Xpress DV is the DV format (low end) of the Avid line but well matched to your camcorder. Using higher end Avid software with that camcorder may not improve quality, but may do the opposite.

Third, your camcorder is capable of special modes to output for 24fps film (the chemical stuff). If you aren't using those modes, it is no different than any other mid level 3 CCD camcorder. To use those modes you need a 24pa capable edit program and be using that mode to capture.

Fourth, editing, encoding and distribution always lowers quality. You just need to manage the process for minimal loss.


PS: The Euro AG-DVX100AE can shoot in 24P/25P/30P or 25 PAL interlace modes (AKA 50i). The Japanese/Americas DVX100A shoots 24P/24PA/30P or 29.94fps NTSC (aka 60i).

[foxbox]

Thank you kindly for this information - I'll get back to you if I have further queries.