Blue ray render for DVDA

[John Rofrano]

You should use the Sony AVC template Blu-ray 1920-1080-xxx for the video and render the audio separate as Dolby Digital AC-3. This will produce an .AVC file for the video and .AC3 file for the audio. DVD Architect should accept these streams and not re-render.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Jim Kaye]

Thanks, John. I noticed the Vegas render takes about 4 times as long as the Blueray render to m2v. Is this normal? Also, the original is in 60p frame rate. What is lost in the AVC conversion?

Jim

[Jim Kaye]

One last question. I notice some pixelating around edges in the AVC rendered file. This is most evident where there is motion. These are not present in the m2v render. Not horrible, but annoying. Any idea how to eliminate this?

Jim

[John Rofrano]

[Jim Kaye] “I noticed the Vegas render takes about 4 times as long as the Blueray render to m2v. Is this normal?”

Yup. Encoding to AVC/H.264 is way more complicated than encoding to MPEG-2. Feel free to continue to use MPEG-2 if you like the faster render times. As long as you use one of the Blu-ray templates, it should not get re-rendered.

[Jim Kaye] “Also, the original is in 60p frame rate. What is lost in the AVC conversion?”

30 frames per second. 😉

Seriously… your footage is already AVC so it’s just re-encoding AVC-to-AVC. The problem is that Blu-ray does not support 60p so you must render to either 60i or 30p.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[John Rofrano]

[Jim Kaye] ” I notice some pixelating around edges in the AVC rendered file. This is most evident where there is motion. These are not present in the m2v render. Not horrible, but annoying. Any idea how to eliminate this? “

I’m not sure why that’s happening but pixelation is usually a bit-rate issue. If you the MPEG-2 m2v file doesn’t have this then render to MPEG-2. The important point is that you use one of the Blu-ray templates (either AVC or MPEG-2) and you don’t change it.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Dave Haynie]

As John says, could be a bitrate issue. There are Blu-Ray templates for both 8 and 16Mb/s in the standard Sony AVC templates, as I recall. You might also try Main Concept’s 25Mb/s Blu-ray templates, or boosting Sony’s somewhat, assuming you’re already using 16Mb/s and still seeing the artifacting.

Here’s the likely problem — warning, I’m about to go all video encoding geek on you: you’re shooting at 60p. That means you have one I-Frame (the “independent” frame, basically a glorified JPEG) every 1/4 second, and 1/60th of a second of motion between each B or P Frame. Less motion means less “error” video to encode in the AVC stream.

As the amount of “error” video increases, the more bits you need to encode that without showing blocking… really no different than back in the old days of low bitrate MPEG-1. When you take your 60p video to either 60i or 30p to make it Blu-ray compliant (Blu-ray doesn’t actually support 30p, but it’ll happily encode a 60i stream that’s actually 30p), you now have an I-Frame even 1/2 second, and 1/30th of a second between each B and P frame. So in essence, you have to deal with twice as much motion between frames. Thus, fast motion can degrade, where it didn’t before.

The other issue is variable vs. fixed bitrate. Most camcorders these days use variable bitrate encoding — nothing crazy, but they can boost up the bitrate for high motion and drop it for low motion, within limits, to match the bit budget to the needs of the video, while still meeting the AVCHD 2.0 (or whatever) requirements. Sony’s AVC CODEC only does fixed bitrate.. so you may be between a rock and a hard place, dropping your frame rate and your bitrate and your peak bitrate. I have not used the Main Concept CODEC for Blu-ray (Sony only blessed it for that in Vegas 12, before then, it was only recommended for Internet bitrates), but this one allows peaks up to 40Mb/s, from the base 25Mb/s rate.

Another option, if you’re getting no love at 1080/30p, is to try 720/60p — also a legal Blu-ray resolution. I don’t know how much fast motion you have in your video, but I shot quite a bit of high school soccer video, and I got much better quality at 720/60p, due to these issues.

-Dave