Workflow for AVCHD for best quality SD DVD

[Shakeitta McCord]

Hi guys,

I'm new to the forums and just started working with HD footage. I am using the Panasonic HMC 150 which uses AVCHD. I would really like to know what the best workflow is for outputting to SD DVD for the best possible quality.

The HMC 150 creates .MTS files which of course have to be transcoded for import into Avid. I want to know what is the best workflow from transcoding to exporting for the best SD quality DVD if I'm editing on Avid Xpress 5.72.

What programs do I need? What steps to take?

I am able to get additional software so please just tell me what is best and I will try to get the programs. At the moment I am only dealing with Avid Xpress 5.72 as an NLE so please keep that in mind. Currently, I have been using the Main Concept Transcoder Panasonic provides. I transcode to DVCPRO HD but I have heard of Cineform which produces better quality. How does Cineform work with Avid Xpress?

What I have:
Sony Vaio PC
Avid Xpress 5.72
TMPGENC 4.7 (I think)
Sorenson Squeeze 6
DVD it Pro HD
DVD Flick

[Robert M Wright]

I've never touched AVID, but basically, editing at full resolution, and then downsizing the result, using Lanczos resizing, is about as good as it gets, with any NLE. I don't know what method AVID uses for resizing, but no NLE I've ever tried (and I've tried most the rest) comes with very good resizing algorithms (most suck). I export the final result at full resolution (either uncompressed, or real high quality lossy method encoding), and then use Virtual Dub to resize. (Then export, usually with lossless encoding, from Virtual Dub, and import into whatever encoder you want to use to do the final encoding, if you want something other than an AVI using a codec available to Virtual Dub for the final encoding.)

[Perrone Ford]

Let Avid transcode into DNxHD. I don't know if Xpress has all the same modes and Media Composer, but it should. So just select the one appropriate to the size and frame rate of your source. If you are shooting 1080p, you'll probably be using DNxHD 175 or 220.

Finish your edit in Avid. You can either choose to export the full size HD file to your DVD program, and let that program do the rescale, or you can rescale in Avid, or you can use a third party tool like VirtualDub. I have not yet done an HD to SD scale from inside Avid, though I will be doing one this week. I can let you know my results if you're not in a hurry.

If you are, then I would suggest you export a full sized sequence to a .AVI file, then use VirtualDub to rescale to SD. It does a terrific job using either the Lanczos scaler or the Bicubic. These are just options you select in the rescale menu. They both work well, but one is better for certain kinds of video.

You do not need Cineform, nor should you be transcoding to DVCProHD. Stay with the native codec to Avid and you'll get MUCH better results.

[Robert M Wright]

As Perrone mentioned, bi-cubic resizing also produces excellent results in Virtual-Dub. I've found that Lanczos usually yields equal or slightly better results (much more often than not), and don't even bother comparing the two, for a particular video, anymore, but if you want the absolute best quality, Perrone is right that sometimes the bi-cubic method will work a tad better, so if you want the absolute best quality for any particular video, best to try both methods and compare them for that video (you may have to look pretty close to see a difference).

Also, when exporting from Virtual Dub, for DVD video, choose 4:2:0 (YV12) output from "Video" > "Color Depth..." on the menu.

Perrone: I'd be real interested to know how well resizing within AVID works, compared to Virtual Dub. AVID is pretty dang pricey, but it sure would be really nice to find an NLE that can actually "do it all" instead of having to flip-flop from app to app for accomplishing different tasks. It floors me that major NLEs, costing hundreds and hundreds of dollars, can't even resize images properly. That's absurd - almost makes me want to dust off my software development skills and write an NLE! (That would take a lot of dusting though - been over a decade now since I wrote a line of code.)

[Shakeitta McCord]

Thanks so much guys I will keep this all in mind and give it a shot.

Perrone, I find that I am unable to export an AVI. Avid gives me a message saying I've hit the 2gig limit. Is there a way around this? If not, what is my next best option? Does this problem exist in Media Composer?

I am not in a rush so I will wait to hear from you about your experiment. :)

I am still interested in Cineform, I won't be getting it now, if at all but can you tell me how it fits into the Avid workflow anyway?

Also, what is the best transcoder for AVCHD to DNXHD? I have TMPGENC is there a better program?

[Perrone Ford]

Is your drive formatted FAT32 or NTFS?

[Shakeitta McCord]

Perrone,

I am definitely formatted to NTFS.

Also, I know you said I shouldn't be transcoding to DVCPRO HD but I already have projects in this format and would still like to output them to DVD with best possible quality. I remember reading that dvcpro hd actually down grades the resolution of 1920x1080 so my question is when I want to export my sequence from Avid as a QT movie using the DNXHD codec what do I put as my resolution dimensions when I choose "custom" ? The default is 1920x1080 but since I am not actually working with footage with that resolution anymore what do I put?

Am I mistaken, don't you have to transcode to an acceptable format before importing even into Avid Media Composer? You said to let Avid do the transcoding for me. How so?

[Perrone Ford]

When you export, you'll export as 1920x1080. The Panasonic cameras that use this codec do the same thing. They stretch their 1280x1080 image to 1920x1080, much like HDV stretches 1440x1080 to 1920x1080.

When you import into Media Composer it does the transcode for you if necessary. Some file types it can handle natively. Like DVCProHD.

-P

Originally Posted by Shakeitta McCord

Perrone,

I am definitely formatted to NTFS.

Also, I know you said I shouldn't be transcoding to DVCPRO HD but I already have projects in this format and would still like to output them to DVD with best possible quality. I remember reading that dvcpro hd actually down grades the resolution of 1920x1080 so my question is when I want to export my sequence from Avid as a QT movie using the DNXHD codec what do I put as my resolution dimensions when I choose "custom" ? The default is 1920x1080 but since I am not actually working with footage with that resolution anymore what do I put?

Am I mistaken, don't you have to transcode to an acceptable format before importing even into Avid Media Composer? You said to let Avid do the transcoding for me. How so?

[Perrone Ford]

And by the way, I hit the 2GB limit on an Avid export on Monday.. I'll look into that more tomorrow or Friday.

[Shakeitta McCord]

Thanks so much for looking into it. I looked on the internet but only thing I saw was about Avid not being able to go beyond 2gbs if you're on like some old version of Windows OS. Like, seriously? How useless.

Also, I downloaded and installed the Lagarith codec and used to it export a small size AVI from avid but the video wouldn't play in Windows Media Player. There was only audio. Do you know what may be the problem? I thought I'd try out the Huffyuv codec instead but it doesn't show up in either my avid or my TMPGENC as a codec choice after installation. Would you happen to know why?

Finally, are you saying that Media Composer can handle the MTS files? It will just transcode them when I go to import? I'm really sorry to bug you with this. I appreciate the help.

It occurred to me that not everybody feels like helping people so I really appreciate it!