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1. Re: Maximum project length for Blu-Ray using H.264 and 5.1 Audio
JSS1138 Aug 17, 2012 8:53 AM (in response to BJBBJB1)Here's the problem with your question.
There are too many variables that affect the maximum allowable length for anyone to provide a coherent answer. It will depend on the frame rate of your program (24p will need fewer bits to look good than will 30i or 60p), the resolution of your program (1080 needs more bits than does 720), the content of your program (static scenes need fewer bits than high motion), the encoder you use (x264 can do a better job at fewer bits than other encoders), the encoding method used (CQ vs Constant Bitrate vs Variable Bitrate), whether or not your have single or dual-layer BDs, what level of quality you find acceptable, etc.
There's just no possible way anyone can predict how much content you can fit on a disk with any degree of accuracy. You'll just have to do the work, see how it turns out, and make any adjustments as needed.
About the only thing we can say with certainty is that H.264 will give you better quality at the same bitrate, or the same quality at a lower bitrate, over traditional MPEG2. So yes, use H.264.
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2. Re: Maximum project length for Blu-Ray using H.264 and 5.1 Audio
Harm Millaard Aug 17, 2012 8:52 AM (in response to BJBBJB1)You may want to have a look at DVD-HQ Bitrate & GOP calculator and try out some different time-lengths to get a feel for what fits on what disk.
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3. Re: Maximum project length for Blu-Ray using H.264 and 5.1 Audio
cfg_2451 Aug 17, 2012 12:47 PM (in response to BJBBJB1)Well, the blu-ray spec. says that a single layer blu-ray disc can hold as much as 25GB. Dual layer can hold 50GB. You can of course fit your entire project into a single layer blu-ray disc... if you use a low enough bit rate so you don't exceed its 25GB capacity.
So your question devolves down to a question of how much quality you want, however you choose to define quality. And the only person who can answer that question, is you.
I suggest you get yourself some BD-RE disks, burn some examples from your project at different bit rates, shove it into a blu-ray player and have a look. Iterate as required (that's the joy of the re-writable disks) to find out how much quality you want. Once you know that, you've got a basis to use to start trying to figure out how to get the full project on disk(s).
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4. Re: Maximum project length for Blu-Ray using H.264 and 5.1 Audio
BJBBJB1 Aug 17, 2012 3:05 PM (in response to Harm Millaard)Harm,
Thanks for the calculator, and thanks to everyone for their thoughts! As always they are most appreciated.
Another calulator I had found did not consider H.264 and 5.1 audio.
All of my questions revolve around how much can fit at highest quality per my post. I am not trying to squeeze as much as I can on a disc and try to subjectively evaluate the quality. I don't really try to do A/B comparisons with bitrates for quality, I just render at highest bitrates/quality and know it's the best I can make it!
I absolutely know you can't calculate exactly how much can fit on a disc. However after a good amount of time making SD and then BD discs(with the MPEG2 encoder) and even a few HD-DVD's, I can pretty much guess how much I can fit with high quality rendering settings based on my source.
I was just trying to determine if there was a similar rule of thumb for H.264 and 5.1 at high quality. I mean +/- a 15 minutes or a half hour. Not a granularity of 5 minutes.
Thanks again,
BJBBJB1



