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Thread: Adjusting bitrate over time

  1. #1

    Adjusting bitrate over time

    I saw a similar thread from way back but I didn't quite understand it so I'm starting a new one. I have a question regarding dbpoweramp and its mp3 compression. I've not used the software before but it seems really good.

    Here's what I'm curious about:

    Let's say we have a ten-minute wave file, uncompressed, and we want to encode it to mp3. It's got mixed audio in it - the first 5 minutes are straight talk, then there's three minutes of complex music and then talk again till the end. Now suppose I want to encode this with a fixed bitrate, but I want the first and last part (the talk) to be, for example, 128kbps. Then I want the music in the middle to be twice that, just to make sure it's good quality. Is it possible to adjust this so that a file starts off as 128kbps, then turns 256 for awhile and then goes back? If so, how does one go about achieving it? I know you can always use VBR but then the computer will decide what bitrate to use at any given time. I was thinking of setting this myself, but using two separate values for non-complex and complex audio.

    Thanks.

  2. #2
    Administrator
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    Re: Adjusting bitrate over time

    It is not possible to manually specify bit rate for part of the file, VBR is the way to go.

  3. #3

    Re: Adjusting bitrate over time

    Thanks. Alright, then I'll have to come up with something else, VBR doesn't really work. Bitrate's all over the place, not my cup of tea. Guess I'll have to go 256 for the whole file.

  4. #4
    dBpoweramp Guru
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    Re: Adjusting bitrate over time

    Quote Originally Posted by n00bkillaz View Post
    VBR doesn't really work.
    Can you explain why 'VBR doesn't really work'?

  5. #5

    Re: Adjusting bitrate over time

    because the bitrate is all over the place. you can have a file with straight talk, just one person. and the bitrate will go from zero to a hundred and just bounce around like that even though there's no need for it. i'd prefer to have a fixed bitrate (lower) for the non-sensitive material in a file and a fixed higher for the sensitive stuff, thus ensuring that i've got a sufficiently high or low compression all the time. if that's not possible, i'll go for a higher cbr instead. vbr's just too "dumb" i guess is my answer.

  6. #6

    Join Date
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    Re: Adjusting bitrate over time

    I'd use an audio editor to split the WAV up into multiple files. Seperate the spoken portions from the music. Convert each invidivual WAV as you like. Create an m3u to play them in the correct order.

    Many audio players support gapless playback, so you wouldn't even notice a difference.

  7. #7

    Re: Adjusting bitrate over time

    Thanks. Yeah, that could've worked but this is a podcast so multiple files is not an option.

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