HDV downconvert to SD avi
 

I prefer shooting everything in HDV with my camera, which records in 1080i. I will be shooting some news-type assignments and need to deliver 4:3 standard def AVI's to a TV station. I will be using the standard pan/crop tool and select the standard 4:3 aspect ratio.

I have been testing downconverting in Vegas Pro 8. Problem is if I use the standard 1080i template (settings are: fielder order = upper field first and deinterlace method = none) and then render to 4:3 using the "video for windows" AVI default template which is "lower field first", I get severe interlacing artifacts when output to a CRT broadcast monitor. Is this because I'm going from upper field first to lower field first?

Anyhow, what I've found to work, I believe, is changing the standard 1080i template to: field order = none (progressive) and interlace method = blend (or interpolate, which is better?). I then render using the default "video for windows" AVI template which is "lower field first".

Is this the best way to do this?

Thanks much,

Duane

I think the easiest way is to set the project setting to SD 4x3 then place the HDV on the timeline and crop as needed with keyframes. Then just output to interlace DV to tape. At least that is what I have done in the past.

Ron Evans

I don't have a problem with the cropping, my problem is the horrible interlacing, and this does not fix that.

Thanks anyhow,

Duane

Duane, I don't shoot HDV yet so I haven't had to deal with these issues but there's a thread on the Sony Vegas forum called HDV to SD deinterlace: surprise! that I suggest you read as it discusses this issue extensively..

The most important part is to set project settings to SD 4x3 NOT HD 1080i. Do all your editing on an SD timeline but with the HD clips using cropping with the 4x3 SD preset. Export to an AVI SD 4x3 DV file preset which will be interlaced just like the original with none of the artifacts you have mentioned. What you then do with the AVI file is up to you, go to tape or to some other form as needed.
I have done this in the past and have just tried again with a short clip to confirm. Made this clip as described in Vegas 8, then played back file out to a monitor from both Edius 5 and CS3 with no problems as well as export to DV tape and playback.
The problem you have is using a HD 1080i timeline instead of an SD timeline. Don't play around with field order use the appropriate project settings for the output and let Vegas set everything. The TV station will need an interlace source likely on tape?
Ron Evans

The key I have found is that in Project Properties I have to set the Deinterlace method to either blend or interpolate, not the default none, and that fixes the problem. I have to do that whether the project properties is set to HDV 1080i or SD NTSC. I then render out to the default NTSC DV. More testing shows I do not have to change the field order setting.

Ron, read the thread that Mike posted and that describes what my problem was to a "T". I will be FTP'ing the files.

Mike - thanks much for the link, it anwered a lot of questions.

Cheers,

Duane

Duane that is precisely my point. That thread pointed out that the editing had been done in 1080i NOT SD, just like you had done with exactly the same outcome. IF you edit in a 4x3 interlace SD DV project you will not get this problem or have to change anything. Just change you project settings to 4x3 interlace SD DV and the problem will go away. IF you just change the project settings you may need to move the cursor away and back again to force Vegas to regenerate the preview. The cropping and scaling will be different though as now the 16x9 image is much bigger in pixel count than the project settings so Vegas will scale down the 1080i image to a normal 4x3 interlace output as I think you require. I have done this many times with absolutely no problems. I even created what appeared to be a multicam edit from just one fixed FX1 file by pan and scan of the 1080i image and have never had this problem or played with field order or deinterlace method because I do not want it to deinterlace and for your application I do not think you do either.

Ron Evans

I have just done some more test with fast motion video and I have to admit that with Vegas 8 on fast motion there are motion artifacts with "none" selected but not with "blend" or "interpolate". I have checked on the videos I did of pan and scan and I do not see any artifacts but they were done I think with Vegas 6 four years ago when I first got my FX1 and was full of exploiting it!!! I am tempted to load up Vegas 6 again and check. Will report back.
Apologies for not fully checking.

Ron Evans

Ron,

As I said in my previous post, if I do not set the project properties to Deinterlace method of either blend or interpolate (whether I have project properties set to 1080i or SD), I will have horrible interlace "dogs teeth" as described in the thread Mike posted a link to.

Since you have no problem with using the defaults I have continued my tests. I have found I can leave everything at the default except "Full resolution rendering quality" must be changed from "good" to "Best" and my interlacing problems go away. This is required for both a SD project or a 1080i project.

Duane

Hi Duane, I too have tried to figure out why it worked in the past and I think you have identified the key. It is several years ago now that I did the multicam video and I have tried to find the project file to see if it would give me a clue. However I likely did use Best when I rendered so that may be the key. I did some tests comparing Vegas 8 at defaults( none, blend and interpolate at good , so I will repeat tomorrow at Best, its bedtime now!!!), CS3 and Edius 5 with exactly the same input file and using a fixed 4x3 SD output. File was of quick arm movements so with the Vegas "none" it was terrible, blend was Ok and interpolate better, CS3 was smoother but colour was way off and Edius 5 was the most pleasing but needed a little sharpening. I guess none of them are perfect!!!
Will report more tomorrow.

Ron Evans

Hi Duane
I have repeated the tests and can confirm that using Best does remove interlace artifacts but not motion blurring of fast motion. For fast motion it seems that "interpolate" needs to be used. Looking back at the three little projects I did there wasn't any real fast motion so I don't see the motion artifacts that I have introduced deliberately using fast arm actions in this test. There doesn't seem much difference using 4x3 or 16x9 that I can tell. I found a section in the manual that describes the issue since Vegas has to deinterlace to apply ANY effects. So I now wonder what Best actually does in the process? I mainly use Vegas for audio and export to Architect for Bluray as my main video editor has been Edius for the last three or four years. I had used Vegas to do this pan and zoom because until Edius 5 the layout tool was not keyframable. Repeating all these tests has been interesting but raises the issue of default settings in Vegas. Personally I think the effects controls should apply the appropriate controls to give the best output without intervention by the user. Clearly this is not the case with Vegas though I guess by default/good luck I got what I wanted in the past.
Colour space was handled in much the same way by Vegas and Edius but CS3 was not as good. Motion was handled best by Edius, and about the same by CS3 and the "interpolate" setting of Vegas. Vegas at defaults and "good" rendering was not useable as you had noted.
I have to admit that I don't normally run into this these days as everything is edited in Edius in HDV. All my audio editing is done in Vegas/Sound Forge and SD DVD encoding is done by TMPGenc from the HDV file all in 16x9.
I do use Vegas for my AVCHD editing but of course end up making Bluray from these family videos and it is usually a cuts only edit. But I will look into the effects on this editing too now.
Ron Evans