Blu-ray render question

Galeng wrote on 8/14/2009, 9:13 AM
Hobbyist here.

In rendering HD clips for eventual use with DVDA to make Blu-ray discs I have followed the advice I have found at this forum and the DVDA forum. I shoot with a Sony HC7 and footage is interlaced. In V9, I select mpeg2 and the template Blu-Ray 1440x1080-60i, 25mbps video stream. Works good, no re-compression in DVDA.

In the most recent issue of Videomaker magazine there was an article about authoring Blu-ray discs. The author states that "MPEG-2 (Blu-ray) is the first generation HD codec and is more akin to the limited 4.7GB DVD format. As such, the quality is compromised". He suggests using MPEG-4 because it is "newer and much stronger in both quality and effeciency in use of the available bits on the Blu-ray disc". He uses Premiere and Encore.

I tried this, but found that DVDA recompresses every time. Am I doing something wrong?

Is there someone out there using Encore that uses this technique?
Does Encore recompress also?

I think I'm getting confused!!

Thanks,

Galen

Comments

PerroneFord wrote on 8/14/2009, 10:27 AM
My AVCHD does not recompress when I create BluRays, so it's quite possible you are doing something wrong.

I also wouldn't use Mpeg2 for anything but SD DVDs.
vtxrocketeer wrote on 8/14/2009, 11:02 AM
PF, is your bias against MPEG-2 for Blu-Ray delivery because of space considerations, quality considerations, or both? For instance, if space was no concern, which would you choose for best quality?
PerroneFord wrote on 8/14/2009, 11:54 AM
I would choose Mpeg4 regardless of space considerations. It's a better codec. Don't believe it? Put a high quality source on the timeline. Render it to Mpeg2 and Mpeg4 with the same bit rate. Use the 8Mbps common for DVDs. See which one looks cleaner. It's no contest.
Galeng wrote on 8/14/2009, 1:08 PM
PF,

My HC7 is mini dv and I shoot in HD 1440 x 1080-interlaced. After I capture I have m2t files.

After editing in Vegas I used the Main Concept ACC/AAC (.mp4) with the default template to render. The resulting file is a .mp4.

Then I move to DVDA. For the project I select Blu-ray disc as the disc format and AVC 1440 x 1080-60i, 16:9.

I still get a warning for recompression.

I sure would appreciate it if you could point in the right direction or give me a clue if this workflow is not accurate.

Thanks so much.

Galen

CClub wrote on 8/14/2009, 1:17 PM
I don't have the time to Search this forum right now, but I'm pretty sure there were some very informative previous discussions about the required format for a Blu-Ray render. I don't believe that DVDA can take an mp4 file and NOT recompress. I believe that it MUST be an mpeg-2 Blu-Ray template or DVDA will recompress every time. MP4 is distribution format, not a good format to re-edit/re-render in (i.e., not for burning to a Blu-Ray disc).
Galeng wrote on 8/14/2009, 1:32 PM
CClub,

Yes you are right. I normally render to MPEG2 with the result being a .m2v file and then render audio to ac3 and never have to recompress in DVDA.

As a hobbyist, I'm able to afford the time to mess around and I found the article I mentioned above interesting. Then when PF said he could do it, I got more interested. But, maybe he is not using DVDA.

Thanks,

Galen

Marco. wrote on 8/14/2009, 2:08 PM
A DVD Architect Blu-ray project does not recompress video if it is rendered in Vegas as Sony AVC using the Blu-ray template or using AVCHD.

Marco
PerroneFord wrote on 8/14/2009, 2:11 PM
I am using DVDA, and I don't remember having to recompress, but I will test this tonight. I burn a bunch of BluRay, but not much for video.

Ok, so I just did it. Here's what I did.

Select Sony AVC
Select BluRay 1920x1080 60i 16mbps template
Render.

The AUDIO HAS TO RENDER SEPARATELY!

I pulled this into DVDA5, used the 1080/60i template, chose "Create BluRay disk" and it did not ask to recompress.

Simple as that.
Galeng wrote on 8/14/2009, 2:35 PM
Thanks for your help and method.

I can see now that my problem was that I was selecting MainConcept mp4 and not Sony AVC.

Thanks for giving me the info.

Galen