avi files for flv at DVinfo.net

Jeff Harper · January 22nd, 2008, 10:15 AM

I am preparing SD Vegas projects for flv and I'm new at it. For optimal quality later in the flv encoding process should I render my avi files 680x480 or 720x480? It seems 680x480 is a more natural starting point.

Do I need to size my uncompressed avi files with an eye toward what they will be later?

I haven't chosen a final flash movie size, another issue altogether, but I'm thinking 480x360.

Jeffrey Lovell · January 22nd, 2008, 10:59 AM

While I don't use Vegas, the FLV converter I use is FFMPEG.

It will do the down conversion for you. I output normal DV quality AVI files at the normal 720x480 and output to 320x240 at 600kbs data rate with MP3 audio. Works great!

Jeff

Jeff Harper · January 22nd, 2008, 11:32 AM

Thanks Jeffrey. Vegas doesn't do flv conversion, I use Flash Pro CS3. I understand Flash will do a down conversion as yesterday I rendered literally dozens of times using different settings, and it seemed when I started out with 680 instead of 720 by 480 it was better when I encoded to sizes like 340 x 240, even numbers. When I start with 720 to convert to 340 width the the height numbers become odd, and also I read that 680 x 480 .avi (square pixels) are more suitable for computer monitors, but I cannot verify that.

I know very little (read nothing) about resolution standards and stuff, so I'm kind of finding my way in the dark here.

The issue is I'm trying to prepare the files the best possible way previous to encoding to flv since the source file is where it all begins.

When I was delivering .wmv files is was a non-issue since I was rendering directly from the Vegas timeline and I was extremely happy with the results.

But I'm finding really large quality differences cause by numerous factors encoding with flash, and I am confused as heck. With some dimensions the quality seems better with a lower file size, and other dimensions are worse even with a higher bit rate.

It's all very confusing.

I've considered using Premier to recreate projects so I can render directly from that timeline, but I do so many uploads and changes it is not at all feasable. One day hopefully Vegas will support flv encoding. But then one day maybe it will also support dual layer discs.

Jon Fairhurst · January 22nd, 2008, 12:02 PM

Yes, computer monitors use square pixels. With FLVs you can choose most any frame rate, aspect ratio and resolution.

We render to widescreen DV format and use Sorenson Squeeze to render 480x270 widescreen FLVs. We shoot in 30p and render to 30p FLVs when there is fast action, like a single frame muzzle flash. For slower stuff, we render the FLV at 15 fps to improve picture quality for the same bandwidth. Squeeze simply drops every other frame when going from 30 to 15.

So... match frame rates, don't worry about exact pixel resolution, and render to square pixels in the end.

One thing to watch out for - Sqeeze (and maybe Flash 8) changes your black levels. It assumes the conversion from video black (level 16 out of 255) to computer black (0 of 255), and it crushes the blacks further to reduce noise.

You might need to experiment to find the exact settings that you want.

Jeff Harper · January 22nd, 2008, 01:37 PM

Thanks Jon! I will play with frame rates!

Jeff Harper · January 22nd, 2008, 01:40 PM

I have sent you an e-mail to ask you about the player you use on your website.

Jon Fairhurst · January 22nd, 2008, 04:42 PM

Quote:

Originally Posted by Jeff Harper

I have sent you an e-mail to ask you about the player you use on your website.

And I've responded...

All the best!

Jeff Harper · January 22nd, 2008, 06:09 PM

Found out I that when I deinterlaced when encoding in CS3 it ruined the videos and increased file size. Things are much better now since I unchecked deinterlace. Thanks for your help guys.

January 22nd, 2008, 10:15 AM	#1
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	avi files for flv I am preparing SD Vegas projects for flv and I'm new at it. For optimal quality later in the flv encoding process should I render my avi files 680x480 or 720x480? It seems 680x480 is a more natural starting point. Do I need to size my uncompressed avi files with an eye toward what they will be later? I haven't chosen a final flash movie size, another issue altogether, but I'm thinking 480x360.

January 22nd, 2008, 10:59 AM	#2
Jeffrey Lovell Regular Crew Join Date: Sep 2005 Location: Bloomington, IL Posts: 61	While I don't use Vegas, the FLV converter I use is FFMPEG. It will do the down conversion for you. I output normal DV quality AVI files at the normal 720x480 and output to 320x240 at 600kbs data rate with MP3 audio. Works great! Jeff __________________ Created Design Video Video production for the common man

January 22nd, 2008, 11:32 AM	#3
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Thanks Jeffrey. Vegas doesn't do flv conversion, I use Flash Pro CS3. I understand Flash will do a down conversion as yesterday I rendered literally dozens of times using different settings, and it seemed when I started out with 680 instead of 720 by 480 it was better when I encoded to sizes like 340 x 240, even numbers. When I start with 720 to convert to 340 width the the height numbers become odd, and also I read that 680 x 480 .avi (square pixels) are more suitable for computer monitors, but I cannot verify that. I know very little (read nothing) about resolution standards and stuff, so I'm kind of finding my way in the dark here. The issue is I'm trying to prepare the files the best possible way previous to encoding to flv since the source file is where it all begins. When I was delivering .wmv files is was a non-issue since I was rendering directly from the Vegas timeline and I was extremely happy with the results. But I'm finding really large quality differences cause by numerous factors encoding with flash, and I am confused as heck. With some dimensions the quality seems better with a lower file size, and other dimensions are worse even with a higher bit rate. It's all very confusing. I've considered using Premier to recreate projects so I can render directly from that timeline, but I do so many uploads and changes it is not at all feasable. One day hopefully Vegas will support flv encoding. But then one day maybe it will also support dual layer discs. Last edited by Jeff Harper; January 22nd, 2008 at 06:07 PM. Reason: addition

January 22nd, 2008, 12:02 PM	#4
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Yes, computer monitors use square pixels. With FLVs you can choose most any frame rate, aspect ratio and resolution. We render to widescreen DV format and use Sorenson Squeeze to render 480x270 widescreen FLVs. We shoot in 30p and render to 30p FLVs when there is fast action, like a single frame muzzle flash. For slower stuff, we render the FLV at 15 fps to improve picture quality for the same bandwidth. Squeeze simply drops every other frame when going from 30 to 15. So... match frame rates, don't worry about exact pixel resolution, and render to square pixels in the end. One thing to watch out for - Sqeeze (and maybe Flash 8) changes your black levels. It assumes the conversion from video black (level 16 out of 255) to computer black (0 of 255), and it crushes the blacks further to reduce noise. You might need to experiment to find the exact settings that you want. __________________ Jon Fairhurst

January 22nd, 2008, 01:37 PM	#5
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Thanks Jon! I will play with frame rates!

January 22nd, 2008, 01:40 PM	#6
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	I have sent you an e-mail to ask you about the player you use on your website.

January 22nd, 2008, 06:09 PM	#8
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Found out I that when I deinterlaced when encoding in CS3 it ruined the videos and increased file size. Things are much better now since I unchecked deinterlace. Thanks for your help guys.