Quantcast Bitrate question - digitalFAQ Forum
  #1  
06-30-2005, 08:07 PM
manthing manthing is offline
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LS or any of you old wise ones, how do you get dvd quality at say 6Mbps bitrate?

i've noticed that a lot of movie dvds have a setting of about 6Mbps or thereabouts. and the quality is very good if not outstanding (at least to my tired old eyes).

however, when i capture something, even from a digital source (ie digital tv box), i don't get quite the same sharpness. sometimes i even ramp up the bitrate to say 15Mbps and still, the image is good, but not as good as released movies.

so how do the pros do it? do they do a 2 pass whereby in pass 1 they capture at 25Mbps then resample to 6Mbps or what?

or purely down to equipment used? superior hardware gives superior pictures?
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  #2  
06-30-2005, 08:26 PM
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lordsmurf lordsmurf is offline
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6Mb/s is not necessarily required. You just have to allocate enough to satisfy the resolution and compression factor (determined by content).

Also, analyze an MPEG in software called "BITRATE VIEWER" and watch the true curve and peaks. What you see in other software or DVD players may not be accurate.

About bitrate allocation, read this:
http://www.digitalfaq.com/dvdguides/...tm#mpegbitrate

You have "used" sources. They have been encoded/transferred probably 2-3 times now before you get them on tv. Studios have perfect film or digital. Yours will never look 100% as good, but it's still close enough to not be overly critical about it. You also have far inferior video equipment compared to them.

Simply stated, pros don't capture. They don't need to. They scan film or use digital sources they shot from.

I use 352x480 with a 2.0-4.5 VBR hardware compression on a lot of my stuff, and I have good hardware, so I can achieve outstanding results. And that's about as good as it'll get for any of us. Even if I upped it to 10+ MB/s, it won't do anything, overkill and unused, serves only to bloat discs.



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06-30-2005, 08:54 PM
manthing manthing is offline
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i see.

scanning the image - laugh if you will, but just the other day i was talking to a friend of mine and suggesting something similar but from a vhs source. of course you can scan a film reel/cell but not a vhs tape. shame eh?

i was even thinking of programming a remote control to pause each frame on the vcr, capture each still image to the pc, then forward 1 frame, then capture again etc. "perfect" still frame capture and no loss of frames. then convert to dvd format offline.

ah well, i can always dream can't i? no?????
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06-30-2005, 09:08 PM
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lordsmurf lordsmurf is offline
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Well, that's flawed thinking because VHS is interlace, there are no frames. There are fields. Won't work.

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