Required DD bitrate for 2.0 PCM conversion

Discussion in 'Computers' started by Rob Gillespie, Jun 10, 2003.

  1. Rob Gillespie

    Rob Gillespie Producer

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    Does anyone know what the 'necessary' DD bitrate is for converting a 2.0 PCM soundtrack with minimal (or no) loss of quality?

    I know most of the 2.0 DD tracks found on commercial DVDs are 192 but I was wondering if it's worth giving it a bit more.
     
  2. Ken Chan

    Ken Chan Producer

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    Do you find DVDs at 192 lacking? Aren't many 5.1s at 384, only double for nearly three times as many channels?

    Not directly related: are you going to attempt to set the Dialog Normalization value?

    //Ken
     
  3. Rob Gillespie

    Rob Gillespie Producer

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    I've found a lot of 2.0 tracks on DVD lacking, especially compared to their LD counterparts. I suspect that's more to do with the mix than the bits though.

    I don't think there's an option in BeSweet to set DN.
     
  4. Ken Chan

    Ken Chan Producer

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    Too bad about the DN; stuff from captured from TV is really loud without it. Maybe laserdisc is better.

    You could certainly add another 50% or even 100% to the audio; shouldn't make too much of a difference to the total bitrate, or what's available for the video. Seems like you'd get diminishing returns after that, though -- but that's just a guess.

    //Ken
     
  5. Rob Gillespie

    Rob Gillespie Producer

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    I was wondering if there was any 'official' guidelines on it.
     
  6. Jeff Kleist

    Jeff Kleist Executive Producer

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    Everyone I've talked to in the authoring biz says that 192 is more than adequate for 2.0, and that it's mostly the mix that is lacking to people's ears.
     
  7. Wayne Bundrick

    Wayne Bundrick Cinematographer

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    Dolby Digital has about the same level of sophistication as MP3, that might give you an idea of what to expect from 192 Kbps. Bumping it up to 256 Kbps will cost only 57.6 megabytes for a 2-hour movie so if you have some space leftover on the disc, go for it.
     
  8. John_Berger

    John_Berger Cinematographer

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    Rob, for what it's worth, I encode my DVDs at 192 unless the audio is particularly good in which case I use 224. I can't say that I've noticed any problems using them. Once I dropped to 160, and then noticed that higher frequencies and sounds from brass instruments in particular suffer from a bit of a tinny quality. I went back up to 192 and I can't say that I notice any distortion.
     

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