avi quality diminishing after render

s k r o o t a y p wrote on 3/13/2011, 3:15 PM
hi,
rendered an avchd clip to avi for editability. after editing, rendered again to avi and it came out thoroughly deteriorated looking like when you jack up the sharpen effect too high. i thought avi is uncompressed and can be rendered numerous times without affecting quality. where is the deterioration coming from?

david

Comments

Steve Grisetti wrote on 3/13/2011, 3:36 PM
AVIs (assuming you mean DV-AVIs) certainly are compressed. About 5:1 to be exact. So, yes, every time you re-render one, you do see a slight downgrade in quality.

But that's not likely what's going on here.

You say you output your AVCHD as an AVI? Which project settings did you select for your original AVCHD project? Then which settings did you select when you output your AVI?

For best results, your originally project should have been set up as AVCHD (1920x1080 or 1440x1080, depending on your camcorder). And with your Project Properties set up for Best quality interpretation and Blended interlacing.

Then your Make Movie/To Hard Drive output should have been an AVI using the NTSC DV template.
s k r o o t a y p wrote on 3/13/2011, 4:01 PM
Steve,
camera settings were 1440x1080 (the lowest the vixia will go). brought in and rendered in avi, quality: best, at 720x480, NTSC DV template, like i could've sworn i've done dozens of times before. can't figure why now suddenly different results.

david
Eugenia wrote on 3/13/2011, 4:20 PM
Well, is it not normal to have the diminishing quality? You exported in a DV resolution, while your original was HD. You can only have the "smart rendering" if your original file is DV-AVI too, yours wasn't, it was AVCHD.

First, use the right intermediate codec to convert your AVCHD files to and edit. I'd suggest Cineform, although it's not free. You can use Cineform NeoSCENE's utility to do the conversion, in "high" quality, AVI.

Then, bring the files on Vegas, setup the right project properties, and edit.

At the end, you can export again as Cineform, with the exact same export properties as the project properties for archiving reasons. For casual viewing you export at 1080i or 720p in MP4.

If you don't want to pay for Cineform, you can use the Avid DNxHD, although the best idea is to upgrade to Platinum 10, which doesn't require re-encodings in an intermediate codec on a modern PC. Provided you own such a modern PC.
s k r o o t a y p wrote on 3/13/2011, 4:36 PM
i do plan on the upgrade before starting next big project. and yes, you would expect an acceptable degree of deterioration going from hd to dv. but this is crazy, raunchy grainy deterioration like someone turned up the sharpen affect all the way. the strange thing is that the avi render looks fine until imported back into VMS. at that point it looks as described in preview and goes on to render that way as well.

btw, i don't see "blended interlace" option, is that in VMS?

thanks
david
Steve Grisetti wrote on 3/13/2011, 5:36 PM
It's in the Project/Properties panel, under the Video tab.

But it's only going to work if your original project was set up to match your original source video.
s k r o o t a y p wrote on 3/13/2011, 10:58 PM
changing this thread title to: quality of rendered clip degenerates when added to timeline

switched to rendering the project in quicktime. once again, i import the clip and it plays clean even when previewing in the project media bin, but as soon as i drag onto the timeline the clip turns to degenerated mess. so i guess my thread title is really rather misleading. the avi and quicktime renders look great until the moment they are drug onto the timeline. bizarre. completely frustrating. any clues appreciated.

david

Eugenia wrote on 3/13/2011, 11:58 PM
Maybe your preview window is set to "draft/auto" and not "preview/auto"?
s k r o o t a y p wrote on 3/14/2011, 8:58 AM
thanks, but no, it renders in the described way beyond preview (preview is set to best)

david
s k r o o t a y p wrote on 3/14/2011, 9:27 AM
and get this, the video portion of the clip rendered in quicktime does not even appear when played in WMP—only audio. the only place it plays properly and looks good is in the VMS project media bin preview. could this have anything to do with Windows 7 at all?

david
Former user wrote on 3/14/2011, 10:10 AM
WMP will not play QT files.

Dave T2
s k r o o t a y p wrote on 3/14/2011, 10:34 AM
ahh . . . that was my first quicktime use : )
s k r o o t a y p wrote on 3/14/2011, 3:36 PM
put me out of my misery and tell me VMS8 just doesn't work w Win7. twice rendered files in lossless formats look fine in preview but then change when placed on timeline. what in the world? this is ridiculous.
s k r o o t a y p wrote on 3/16/2011, 6:10 PM
upgraded to VMS 10 and results are still unchanged. clips that have been rendered just once to avi or any other format look great in media bin preview but totally distort w/ graininess once placed on timeline as well as going on to render this way. does anyone have any idea what's happening?

thanks,
david
Eugenia wrote on 3/16/2011, 7:30 PM
Please upload screenshots from best/FULL in media bin and timeline, and a screenshot of the exported clip. Preferably a frame with some motion, roughly the same frame in all three cases. Also, a shot of the project properties dialog, and the dialog that explains what one of these source files are.
s k r o o t a y p wrote on 3/18/2011, 6:19 PM
thanks Eugenia. i opened the once rendered file in a new project, brought it on the timeline and it rendered from there fine. is there any obvious track setting i could have inadvertantly set or f/x on track in original proj causing discrepancy. same discrepancy when tried on all video tracks of orig proj

thanks,
david