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  1. Good Day,

    I am just trying to sort out if what I 'think' I see, is in fact actually true. I use EyeTV (first generation USB model) to capture video in mpeg-1 format, either from television, or other external source. To me, it does not matter whether I use the HQ setting or standard VCD setting, as both appear to be mpeg-1. But, what I don't understand, is that if I make a VCD on CD-R, and play it on my dvd player, it looks pretty nice, (I am using Roxio Toast Titanium 7 for burning) but if I grab the actual mpeg-1 files from the EyeTV archive folder, and drag-and-drop them on Roxio for making a DVD (I have a DVD+R in the burner, and have selected the "Make DVD video" option from the side panel in Toast) the result when played on my DVD player looks kind of pixelated or 'grainy'. So, just for the halibut, I grabbed the 'dat' files from the VCDs, and dragged and dropped them onto Toast to make a DVD, and when I play a DVD with these files, it "appears" to me to look sharper. Does this make sense? I don't quite grasp the concept between the encoding of the mpeg-1 file to VCD and to DVD and why the quality changes when they both originate from the same source file. If anyone can shed light on this I would appreciate it. For now, I think I will invest in a CD-RW to burn all the VCD movies to, so that I can copy the dat files over to DVD and not waste a bunch of CD-Rs...Just like to know what is really happening here... Thanks for any info!! J. S.
    I believe we have established that Ka-Caw Ka-Caw and Tookie Tookie don't work.
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  2. Member AlanHK's Avatar
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    I suspect Roxio is reencoding your MPEG1s to MPEG2.

    You can make compliant DVDs using MPEG1 video and only converting the audio sampling rate.
    See eg SVCD2DVDMPG, the free version works well.
    It does some fakery to the MPEG1 to make it appear to be MPEG2, which hopefully will fool your authoring app so it won't mess with it.
    I use GuiforDVDAuthor, which uses MPEG1 video without complaint.

    I've done this to put the video from up to 10 VCDs onto a single DVD disc.

    VCDGear has some useful functions for extracting and repairing MPEG1.
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  3. Member mats.hogberg's Avatar
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    Use a "real" authoring app for authoring your DVD - I suggest TMPGEnc DVD Author. It won't touch your video in any way, but will automatically upsample the audio to be DVD compliant.

    /Mats
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  4. I appreciate the feedback! I guess what I am getting at, is I would like to know what Toast is (or alternately, is not) doing to the '.dat' file in drag and drop mode? I understand now, the concept of re-encoding the mpeg1 to mpeg2 format when I drag and drop the original file, but why does it not do the same thing to the dat file? Maybe I am making a mountain out of a molehill, but I am perplexed as to why this process happens with one format, but leaves the other better quality. Does anyone know if Toast just happens to "like" dat files and assumes they are already encoded correctly? Maybe I should go outside and just enjoy the fresh air and stop wondering about these things...
    I believe we have established that Ka-Caw Ka-Caw and Tookie Tookie don't work.
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  5. Member mats.hogberg's Avatar
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    Ah - Mac - sorry, I didn't get that part. But as a general principle, don't use anything capable of reencoding to author your source material, if there is no obvious and reliable way to make it not reencode.

    /Mats
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  6. Member AlanHK's Avatar
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    Originally Posted by JakeSherome
    I appreciate the feedback! I guess what I am getting at, is I would like to know what Toast is (or alternately, is not) doing to the '.dat' file in drag and drop mode?
    Sorry, I missed the Mac context too.

    But the basic principle is the same.

    Maybe you could repost under a title like "Why does Toast reencode MPEG1" and get some more specific help.
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  7. Thanks guys for your input. But, I guess I am just digging too deep into this issue. I should have pointed out in my original post that I am a Mac user, but just made the assumption (yes I know, never "assume") that because I mentioned Toast Titanium and EyeTV that it was understood I was using a Mac. My BAD.

    Anyway, the outcome of all this, at least for me, is that I understand that in the Mac world, Toast will automatically encode mpeg1 to mpeg2 if you are making a DVD Video Disc, and because of this, the quality of the video is subject to degradation. And my theory (to at least put my mind at ease) about the dat file, is that once an mpeg1 file has been coded to VCD format, the resulting .dat file can no longer be re-coded when being applied to other video formats, so therefore, is left in it's current state, untouched. This state retains proper resolution, bit rate, audio sampling, etc...so essentially you are just transferring VCD video to DVD 'sans' encoding.

    I am a newbie, and by no stretch of the imagination knowledgeable in this field, so, if I am way off on my theory, just smile and feel good about the fact that you have at least set me in motion for further study on this at a more convenient time. I may be back for further help. Great forum....thanks again![/b]
    I believe we have established that Ka-Caw Ka-Caw and Tookie Tookie don't work.
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  8. Member AlanHK's Avatar
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    Originally Posted by JakeSherome
    my theory (to at least put my mind at ease) about the dat file, is that once an mpeg1 file has been coded to VCD format
    My guess is that Toast is treating the DAT file as data, and burning a data disc, not a DVD video.
    Fortunately your DVD player recognises this as a VCD file and plays it. (As they may do with JPEG, MP3, etc.) You can't author a nicely menued DVD this way, but you could compile a bunch of DAT files (taking care to give them different names, ending in .dat).
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    To summarize what some of the others have already said, if you want to end up with a DVD playable in standalone players, while avoiding the inevitable degradation that comes from transcoding to MPEG2 from MPEG1, you can demux the original MPEG1, and resample the audio to DVD-compliant 48kHz, then remux (and author) *as DVD*. Not only does this avoid the re-encoding problem, it is also very fast. Perhaps not all players will handle it, but in my limited experience, more players will play these than will play the equivalent file muxed/authored as SVCD.

    If you want to do the same thing to the .dat version of the file, you can use VCDgear (mentioned by someone previously) or some similar tool to strip off the .dat-specific bits and convert back to MPEG1 (this is a very fast operation), and then proceed from there.
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  10. Member mats.hogberg's Avatar
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    Originally Posted by tomlee59
    Not only does this avoid the re-encoding problem
    Not necessarily, as many editors/encoder/authoring combos thinks it knows better than you and me, and will reencode anyway.
    Originally Posted by tomlee59
    Perhaps not all players will handle it
    If the player is fully DVD std compliant, it should handle it, as it is a fully compliant DVD.

    /Mats
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    Do you know which tools will insist on re-encoding? I've been lucky to avoid this in the past, and I'd like to keep up that streak!
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