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  1. Member
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    Hello everyone. Just curious I downloaded a few movies /tv shows and they are in mpg format and some in avi format. I would assume that they are DVD rips files converted into these two different formats. If I want to burn them back to DVD format MPEG-2 which file format contains the best quality when played on a DVD player ? Or would the MPEG-2 quality come out the same ?

    Hope the above is clear.

    Thanks
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  2. aBigMeanie aedipuss's Avatar
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    buy the dvds. downloaded movies/tv shows are illegal warez and not supported here.
    --
    "a lot of people are better dead" - prisoner KSC2-303
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  3. The one that looks better. MPG and AVI may contain low quality or high quality video.
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    just wanted to know using most dvd ripping software allow you to choose the quality level and also the format to save the decoded video data ? If the software does allow the format which format saves the best quality or is the quality level adjustable ?
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  5. Originally Posted by victor43 View Post
    If I want to burn them back to DVD format MPEG-2 which file format contains the best quality when played on a DVD player ? Or would the MPEG-2 quality come out the same ?
    Usually MPEG-2 (H.262) video can be recorded on DVD-Video without transcoding.
    AVI rarely will have H.262 video so transcoding will be required.
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  6. Member
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    Originally Posted by pandy View Post
    Originally Posted by victor43 View Post
    If I want to burn them back to DVD format MPEG-2 which file format contains the best quality when played on a DVD player ? Or would the MPEG-2 quality come out the same ?
    Usually MPEG-2 (H.262) video can be recorded on DVD-Video without transcoding.
    AVI rarely will have H.262 video so transcoding will be required.
    Ok then my question with transcoding is there a loss in quality going from MPEG-2 to AVI ?
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  7. is there a loss in quality going from MPEG-2 to AVI ?
    This makes no sense. MPEG-2 is a video codec and AVI is a container. In the AVI container there could be a video with MPEG-2 codec as shoen below.

    General
    Complete name : D:\mpeg2.avi
    Format : AVI
    Format/Info : Audio Video Interleave
    File size : 32.1 MiB
    Duration : 56s 720ms
    Overall bit rate mode : Variable
    Overall bit rate : 4 749 Kbps

    Video
    ID : 0
    Format : MPEG Video
    Format version : Version 2
    Format profile : Main@Main
    Format settings, BVOP : Yes
    Format settings, Matrix : Custom
    Format settings, GOP : Variable
    Format settings, picture structure : Frame
    Codec ID : MPEG
    Codec ID/Info : Chromatic MPEG 1 Video I Frame
    Duration : 56s 720ms
    Bit rate mode : Variable
    Bit rate : 4 052 Kbps
    Maximum bit rate : 9 800 Kbps
    Width : 720 pixels
    Height : 576 pixels
    Display aspect ratio : 16:9
    Frame rate : 50.000 fps
    Original frame rate : 25.000 fps
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Interlaced
    Scan order : Top Field First
    Compression mode : Lossy
    Bits/(Pixel*Frame) : 0.195
    Stream size : 27.4 MiB (85%)

    Audio
    ID : 1
    Format : AC-3
    Format/Info : Audio Coding 3
    Mode extension : CM (complete main)
    Format settings, Endianness : Big
    Codec ID : 2000
    Duration : 56s 704ms
    Bit rate mode : Constant
    Bit rate : 640 Kbps
    Channel(s) : 6 channels
    Channel positions : Front: L C R, Side: L R, LFE
    Sampling rate : 48.0 KHz
    Frame rate : 31.250 fps (1536 spf)
    Bit depth : 16 bits
    Compression mode : Lossy
    Stream size : 4.33 MiB (13%)
    Alignment : Aligned on interleaves
    Interleave, duration : 32 ms (1.60 video frames)
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  8. Member
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    Originally Posted by videobruger View Post
    is there a loss in quality going from MPEG-2 to AVI ?
    This makes no sense. MPEG-2 is a video codec and AVI is a container. In the AVI container there could be a video with MPEG-2 codec as shoen below.
    So I understand but does that mean that there would be no loss in quality since AVI is a container for the MPEG-2 encoding ?
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  9. If the DVD MPEG 2 video is simply remuxed into a different container the quality is exactly the same as the source. It's like taking a cake out of one box and putting it into another -- the cake isn't changed. If the video is reencoded the quality will vary depending on the codec and settings used.

    So there's no way of predicting the answer to your original question. The AVI and MPG file could both contain the original MPEG 2 video or they could contain high quality reencoded video or crap. The only way to determine which source is better is to view them.
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  10. Originally Posted by victor43 View Post
    Ok then my question with transcoding is there a loss in quality going from MPEG-2 to AVI ?
    Ok, let's try to do pragmatic approach.
    MPEG-2 (H.262) is a video codec, MPEG (MPG) is usually container (properly MPEG PS - Program Stream).
    AVI is only container so it can be compared to MPEG PS (files with extension .mpg).
    MPEG-2 (video codec) can be used with MPEG PS (this is native container for MPEG) or with AVI however usually AVI contain different video codecs than MPEG-2).
    Video quality is something not directly related with codecs and containers and at this level of abstraction your question is somehow incorrect.

    Question about transcoding - if lossy video codec used as a source to another lossy video coding almost always there is quality loss (exception if some lossless transformation can be performed but this is only theoretical - i'm not aware of existing for this kind of converter but it should be feasible).
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