What bit rates for Blu-Ray, DVD Architect

[Randall Leong]

Originally Posted by Tom Roper

I've said this before, but I find the AVC output from DVDA to be exceptional in quality, you just don't get much control with so few parameters beyond bit rate, and it's slow. But being mired at 16mbps is not necessary. The AVC encoder that sucks is the one in Vegas, not DVDA. And for sure, that sorry piece of junk does confine you to 16mbps.

I partly agree on this. However, being mired at 16 Mbps is perfectly fine if the end result is going to be HD content on red-laser DVD (aka BD9/"BD5" or "AVCHD" DVD) - but IMHO too low if the end result is going to be authored onto true BD-R/RE disc. But the Vegas' Sony AVC encoder may cause crashes on some systems, and does error out when the overall bitrate is set above 17 Mbps. This is what sucks about the encoder, not the image quality (unless the overall bitrate is set too low for the content being encoded).

The version of the MainConcept AVC encoder included in Vegas Pro, on the other hand, sucks for a different reason: It was intended primarily for low-definition or standard-definition encodes for use in a portable media player (e.g. an MP3 audio player with video playback capability). High-definition encodes are possible, but will never be compliant with Blu-Ray standards. (MainConcept does sell a version of the AVC encoder that is Blu-Ray compliant, but that encoder will set you back a couple of thousand bucks.)

And yes, 16 Mbps AVC encoded with the Sony AVC encoder does produce superior image quality over the typical 25 Mbps MPEG-2 HD encode, especially with the right content.

[Tom Roper]

Originally Posted by Randall Leong

I partly agree on this. However, being mired at 16 Mbps is perfectly fine if the end result is going to be HD content on red-laser DVD (aka BD9/"BD5" or "AVCHD" DVD) - but IMHO too low if the end result is going to be authored onto true BD-R/RE disc. But the Vegas' Sony AVC encoder may cause crashes on some systems, and does error out when the overall bitrate is set above 17 Mbps. This is what sucks about the encoder, not the image quality (unless the overall bitrate is set too low for the content being encoded).

I agree.

The version of the MainConcept AVC encoder included in Vegas Pro, on the other hand, sucks for a different reason: It was intended primarily for low-definition or standard-definition encodes for use in a portable media player (e.g. an MP3 audio player with video playback capability).

Also agree.

[Tom Roper]

I took 100 mbps 4:2:2 mxf file from the EX1 with Nanoflash, dropped it onto the Vegas timeline. Since the Nano changes the header to make Vegas recognize the file as 50 mbps XDCAM 422, it also smart renders it out with no recompression. The smart rendered MXF is not accepted by DVDA 5.0 as compliant, so it recompresses it. It would have to anyway, nothing in the optical realm (Blu-ray) can play 50 mbps. So it's not really worth it to smart render at this stage, unless your intent is to let DVDA use its superb AVC final render from this native MXF source, to AVC h.264 Blu-ray.

On the other hand, if I used the Main Concept Mpeg-2 encoder inside Vegas, it output a nice quality 35 mbps (average) using the 2-pass encoder, which is fairly quick. I set the max bitrate for 40 mbps, av 35 mbps, min 30 mbps. This file when rendered from Vegas was accepted by DVDA 5.0 for smart rendering with no recompression.

So I dunno. It works without much problem for me, especially well as Perrone noted with MXF source files, either straight from the cam (EX1/EX3/PMW350), or from the Nanoflash at 100 mbps 4:2:2.

But again, this is Vegas 8.0(c) and DVDA 5.0 running under Microsoft Vista.

[Mark P. Stuart]

Old thread this I know, to clarify fro previous posts on this thread

1) Is 16Mb/s the max AVC Blu-ray rate Architect 5.2 will build without the mux error?
2) Is there a maximum for MPEG 2 blu-ray? I've used 25mb/s successfully. Anything 28mb/s or above gives a warning during build about being above max rate for HD on DVD, guess that warning can be ignored if burning to BD disc? Is there a max for MPEG2 BD?

[John Peterson]

Use a CBR of 16MB/s for AVC (although I avoid AVC usually - too iffy). 16MB/s is the max.

Calculate your bitrate for Mpeg 2 using the only Blu-ray bitrate calculator on the net I am aware of. Again, I recommend CBR.

DVD-HQ : Bitrate & GOP calculator

John

[Mark P. Stuart]

Shame AVC is so iffy with Architect. Even if 16mb/s works, we'd rather use a higher rate, max the quality and use up the disc space.

So there is no Architect limitations or bugs with MPEG2 then.

With 384kb/s ac3 the calculators state a max of 46.2mb/s. Thats asking for trouble IMO, depending on the encoder and the player. Perhaps 40mb/s CBR leaves a suitable margin. Have you done much around 40 mb/s and been successful?

[Mark P. Stuart]

Just noticed this

http://www.dvinfo.net/forum/what-hap...architect.html

Originally Posted by Perrone Ford

Simon,

This is why I mentioned last night... if you are going to do AVC BluRay in DVDA, make the bit rate no higher than 16Mbps. If you are making an Mpeg2 Bluray, then keep the rate at or under 25Mbps.

You can take my advice and make it work.. or you can keep getting errors. I've been and done that. Doing it again tomorrow with a DNxHD .MOV file coming out of FCP.

maybe 40mb/s will be problematic and safer sticking to 25?

[Rob Wood]

i create 720p BD's and use MPEG-2 format @ 25mbps... it's been great and is more than enough for quality. i use CBR not VBR as the text fades suck for me using VBR; the sharp edges crumble as it drops towards black whenever i use variable bit-rate no matter what sweetening i do to the font.

-

that said, i haven't made any 1080p BD's (2.4x larger screen-size than 720p) using MPEG-2 25mbps... my guess is it should be enough; but i'd wanna see before saying yes :)


anyway, think i'd be inclined to go AVC or VC-1 rather than MPEG-2 for 1080p; haven't researched this yet tho, and probably won't til i have to go that way (don't wanna figure something out only to have it go out-of-date before i get around to using it)

[Phil Lee]

Hi

You can always give a bit of software I wrote a go, it makes it easy to use the very good and free x264 encoder.

There is a bug with DVD Architect where it will not support interlaced footage output by x264, so I tend to use MultiAVCHD, another free application that makes Blu-ray discs without re-encoding compatible footage.

Instructions and post is here http://www.dvinfo.net/forum/what-hap...4-encoder.html, read further in the post to get a link to the latest version.

Regards

Phil

[Mark P. Stuart]

Looks an impressive piece of software Phil. I haven't tried it out yet. What BD authoring software have you tested or know accepts the final .mts files without transcoding? Or best demux software to pull out the elementary streams?

[Phil Lee]

Hi

To pull out the elementary streams use TSMuxer, this is used internally by the program to mux them together, so will work fine to demux them.

The encoder the software uses is X264, this produces valid Blu-ray files that have been used on professional discs, but I know what you mean, authoring software seems to be very specific and often wants to interfere and re-encode, often had the same problem with DVD. The one authoring software I've used that seems pretty happy without re-encoding streams that are compliant is MultiAVCHD, this is free although isn't as user friendly as more commercial offerings but has made discs that have played perfectly in different Blu-ray players for me.

Best Regards

Phil