capturing mpeg2 video at 12mbit/sec - how fast a pc do I need?

Discussion in 'Other video questions' started by cduval04, Jul 29, 2006.

  1. cduval04

    cduval04 Member

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    Hi, I just bought a wintv pvr usb2 from hauppauge, a tv tuner/video recorder/capture device.

    this device allows you many different output/compreesion options for your recordings, many of which are recorded at different datarates.

    some of the options include
    -mpeg1 (VCD)
    -mpeg2 2.0 mbit/sec
    -mpeg2 12.0 mbit/sec and a bunch more

    anyway, they say that the one that will prduce the highest quality video is mpeg2 12.0 mbit/sec. The manual quotes, "if you have a fast pc and would like the highest quality video, then use this setting" if you have a slower pc, then use the mpeg2 2.0 mbit/sec"

    they dont clairfy what a "fast pc" is compared to a slow pc. I am running windows xp home sp2 with a 1.4 ghtz pentium M processor and 512 mb of ram.

    could someone tell me how fast a pc do you need to record video at this rate and would mine suffice, or succumb to a system crash or other error? could I multi task while recording or do I not have enough memory. I'm just trying to get an idea of how much memory/processor speed if takes to record video at this rate.

    any answers would be appreciated
     
  2. hermes_vb

    hermes_vb Regular member

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    Well, I have a Dell Inspiron 6000 laptop and use ADS Tech DVDXpress to capture via USB port. I have 1 GB of RAM and a Pentium M 1.6 CPU. Although both the capture device and system are not the same, they are similar. Right now I'm capturing at 5.5 MB/sec with DVD specs (720x480, Constant Bitrate and Dolby 2.0 @ 48 KHz with 192 KBps). At the begining I had a few crashes with 10 MB/sec so I brought it down to 4. I began to increase the bitrate and right now I'm using 5.5 MB/sec. Soon I'll be experimenting with 6 MB/sec. One thing I noticed in my system is that Variable bitrate usually crashed my PC. I don't know if it's a device problem or what. My advice to you is experiment with different settings. Other thing you can do is close all unnecessary apps when capturing. That way you have more RAM available.
     
  3. hermes_vb

    hermes_vb Regular member

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    I just finished capturing a 45 minutes show @ 6.5 MB/sec with the settings I mentioned before. Everything worked fine. There's also something I should had mentioned. My laptop has a 128 MB ATI Video Card which increases performance. Maybe that's why I'm succesful.

    Anyway I found some info that may be useful for you. These excerpts were taken from my capture device documentation.

    "The MPEG-2 standard allows for bit rates from 2 mb/sec. up to 15 mb/sec. If your goal is to capture video for burning to DVD disk, don’t capture at a rate higher than 9 Mb/sec. because DVD Players cannot process bit rates higher than this. Also, if your goal is to get the most video on a DVD disk, you will want to select 4 or 5 MB/sec. using a variable bit rate."

    "Keep in mind that most Hollywood DVD’s are produced at 4.5 mb/sec. this allows up to 133 minutes of audio and video on a DVD disk. With the ability to capture MPEG-2 and create DVD movies at 4 or 5 mb/sec. with variable bit rate you can produce video with the same high quality achieved on Hollywood DVD movies."

    Note: The second statement is true for Single Layer DVD's. Today's DL DVD's use a higher Bit Rates.
     

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