DVD Studio/Compressor?

[Jeff Chandler]

Explain then why the disk manufacturers say "may be recorded at 1x up to 16x speed".
All I can tell you is that I have burned 1000's of disks at half speed without a problem.

[Rickey Brillantes]

It is generally acknowledged as good practice to burn Dvd at speeds no higher than 4x, but it is also important that you use good-quality blank media specifically designed for low-speed burning. Most computer media these days is designed for very high-speed burning, usually over 16x. Such discs may not give reliable results when burned at low speeds.

So, matching media and burning speed is critical. However, burning at very fast speeds is inherently less accurate than burning at low speeds. Precision will certainly fall as the speed increases — it's a necessary consequence of the physics of the burning process. Within reasonable limits, this reduced precision in the way the pits are burned isn't a problem for data discs because of the enhanced error protection they employ. Consequently, error checks on data discs will generally confirm that there is no significant increase in error rates when burned at high speeds when the media and burner are up to the task.

However, Dvd's work in a different way, they have a much lower error protection capability and rely on the spacing between the bumps and the angle of their edges to retrieve and decode the data properly. High-speed burning makes the problem much harder to resolve, and hence most experienced mastering engineers prefer to copy discs at relatively low speeds.

Don't underestimate the importance of the chemistry of the Dvd itself. Just like Dvd burners, not all are created equal and there is a significant difference in the quality of the media from different manufacturers, sometimes even from batch to batch from the same manufacturer.

[Jeff Chandler]

Well, since I've had good success the way I currently burn, and until I see something official from a disk manufacturer, I will continue to do it the way that I have.

[Chris Korrow]

In regards to the audio. Compressor prompts to make an AIFF and a dolby.
The dolby is about a quarter the size.
If you have the room on the disc, should one go with the AIFF file?
I guess my question is, which is better to use if you have the disc space?
Thanks,
Chris

[David Knaggs]

Originally Posted by Chris Korrow

In regards to the audio. Compressor prompts to make an AIFF and a dolby.
The dolby is about a quarter the size.
If you have the room on the disc, should one go with the AIFF file?
I guess my question is, which is better to use if you have the disc space?
Thanks,
Chris

Hi Chris.

Yes, you can definitely go with AIFF if you have the disc space.

Dolby is compressed and AIFF (according to my understanding) is pretty much uncompressed.

So the strict answer to your question would be that AIFF is "better" (less compression).

However, I should mention that I find Dolby quality to be outstanding. The sound files are both efficient and outstanding. Others might be able to tell the difference between AIFF and Dolby, but I can't. I always use Dolby. Most Hollywood DVDs (if not all) use Dolby as well.

[Martin Pauly]

Originally Posted by David Knaggs

AIFF (according to my understanding) is pretty much uncompressed.

It is uncompressed. On the DVD, this is known as "PCM" sound. If your goal is the highest possible sound quality, this may be the way to go.

Having said that, I agree that Dolby Digital (AC3) sounds pretty darn good. I have used it on all DVDs I have created so far, because even if space on your DVD is not a problem, maximum bitrate at playback may still be. In other words, the higher bitrate required to play PCM audio takes a precious amount away from the total managable bitrate, so there's less of it left for the video portion of your project.

Bottom line: unless you can state that perfect audio is key for your project and that video quality is not very important, use AC3 (Dolby Digital).

- Martin

[Chris Korrow]

Thanks Martin,
Unfortunately I already sent the disc out.
On the positive side, I viewed it first (of course) & the image quality was far superior to the other discs burned on iDVD.
Played it on a 3-4 year old "cheap" player, so I'm hoping that all is okay.
Thanks to all for the help.

[Sam Rosado]

Originally Posted by Rickey Brillantes

It is generally acknowledged as good practice to burn Dvd at speeds no higher than 4x, but it is also important that you use good-quality blank media .

i have to agree with jeff. I have never had a problem with burning a disk at diff speeds. but, wouldnt your burner be set to automatically detect the speed of the disk? I use a mac and its set to auto. I do agree you have to use quality media. if youre using cheap media then I could see the problem. but thats like putting pleather in a mercedes!

[David Scattergood]

Just wrenching this post back up from the depths (rather than start a new one).
I need to pick up some blank master DVD-R's this morning. Reading this thread (and others) it seems that it might be wise to pick up decent quality media.
However, locally (and I need them this morning) I can only really source either Verbatim or TDK - they need to be printable for a start but the only ones I can source are 16x. If this is my only choice might it be wise to set the mac to auto or set the burning speed much lower (which may then be less reliable?)?

Cheers.

[David Scattergood]

Whilst on this topic I also seem to be having problems exporting a sequence to Compressor.
Have selected the whole sequence and mark the in and out point.
The File - Export - Compressor...which brings compressor up.

I keep finding that I either recieve a message stating:

"selection contains no media" (I have tried selecting all of the sequence/timeline) or I get as far as compressor and when selecting the preferable encoding option: 16:9 90 mins best in this case I then have yellow exclamations advising me that data (along those lines) is locked??

See error: http://i56.photobucket.com/albums/g1...essorerror.jpg

Any ideas? I can happily export as a QT ref file but would prefer to export/compress this way.

Many thanks.

[David Knaggs]

I noticed on your JPEG that it says, "Destination is invalid or write protected".

Go to the "Destination" column and change it from "Source" to somewhere else (even if you need to make a new folder to put it in).

[David Scattergood]

Originally Posted by David Knaggs

I noticed on your JPEG that it says, "Destination is invalid or write protected".

Go to the "Destination" column and change it from "Source" to somewhere else (even if you need to make a new folder to put it in).

Ah, ok I'll give that a whirl.
Apparantly there are similar problems with compressor which may mean deleting library files (hopefully not in my case - there is no background error on my notification):

http://docs.info.apple.com/article.html?artnum=93234

Cheers.

[David Scattergood]

Ok....that seems to be working (and thankfully no sifting through library commands and system reboots).
Created a new folder for Compressor files but not sure whether I should've pointed this at FCP projects?
Also unsure as to why using compressor over QT mov file would use barely any (if at all) memory? i.e. creating a huge QT self contained mov file, unless this is for showing on the web or another machine?

Thanks again David...

[David Knaggs]

Hi David.

I'm glad it is now all working!

Hopefully, this will answer your question:

1/ FCP sequence > Compressor > .m2v and .ac3 files

2/ FCP sequence > QT movie or QT reference movie > Compressor or DVD SP > .m2v and .ac3 files

As you can see in 1/, the direct to Compressor workflow eliminates the need to create a QT or QT ref movie and so will use less space.

Mind you, the QT ref movie might use very little space (especially if it is short and simple) so it might even prove "negligible" concerning your space requirements.

[David Scattergood]

Originally Posted by David Knaggs

Hi David.

I'm glad it is now all working!

Hopefully, this will answer your question:

1/ FCP sequence > Compressor > .m2v and .ac3 files

2/ FCP sequence > QT movie or QT reference movie > Compressor or DVD SP > .m2v and .ac3 files

As you can see in 1/, the direct to Compressor workflow eliminates the need to create a QT or QT ref movie and so will use less space.

Mind you, the QT ref movie might use very little space (especially if it is short and simple) so it might even prove "negligible" concerning your space requirements.

Cheers David....just nipped out and left compressor to do it's thing (movie/s is/are around an hour long). That was over an hour ago...is this usual for it to take around 2 hours to compress (for a 1 hour movie set to Best 90 min?).
Wondering if when I then import this/these .m2v and .ac3 files into DVDSP then burn the completed project that this will then take another couple of hours....I have 5 projects to compress and burn today!?!