Bit rate

Discussion in 'Computing and Networks' started by Lightfire, Jan 23, 2012.

  1. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    Source: Wikipedia

    Please help me.

    What does this mean.

    How to determine/know the number of bits of a certain video??

    Thnx
     
    zumiao likes this.
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    For video, think of the data rate required for a low resolution, say, 800x600 pixels. Each pixel has 3 color values, so you end up with 24 bits per pixel.

    If the display is refreshed 60 times per second, how many bits per second does the video card need to transmit to the display?

    How much more data is needed to be transferred when displaying 1720x1080 at 30 frames per second?

    Calculate that out and you'll see why HDTV can't be effectively broadcast with the old analog standards.
     
  3. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    691,200,000 bits per second or 86,400,000 bytes per second?

    So I need at least 86.4 megabytes per second internet connection? I can't afford that. ;)

    Am i right anyway?

    thnx
     
  4. MrChips

    Moderator

    Oct 2, 2009
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    3,353
    That is why video data is compressed.
     
  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Yes, that's why HDTV is 100% incompatible with the older TVs and analog broadcast methods.

    Now the data is converted to digital, where it can be rather highly compressed, with some loss of quality, but sent over a much smaller bandwidth connection, be it radio waves, cable TV, or Internet.
     
  6. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    Thnx MrChips and thatoneguy.
    I looked up the details of my recorded video and here what I saw.

    Length: 00:02:43
    Frame width: 640
    Frame height: 480
    Data Rate: 12,544kbps
    Total bit rate: 12,632kbps

    Frame rate:20 frames/second

    What's the difference between the two, data rate and total bit rate. thnx

    anyway, how to know how many frames are there in video? thnx again

    thnx
     
  7. Markd77

    Senior Member

    Sep 7, 2009
    2,803
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    Number of frames is about length X frame rate = 163 seconds X 20 = 3260
    Length has probably been rounded to the nearest second so it could be up to 20 frames higher or lower.
     
  8. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    Ok,.

    pls help me where i can stream videos online. pls

    thnx
     
  9. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    www.ustream.com

    That's how a bunch of people in Japan got their video out of the Tsunami and earthquake before services were lost, same goes for the Egypt riots before Egypt killed the Internet routers there.
     
  10. Lightfire

    Thread Starter Well-Known Member

    Oct 5, 2010
    690
    21
    Thnx thatoneguy.

    I dont know how can i stream a recorded(not live) video.

    Help pls.

    Thnx
     
  11. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    Sign up for a free account, and they have instructions on how to walk you through it.

    Using something like VLC player will allow you to make a streaming video from a pre-recorded source.
     
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