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  1. Please keep in mind that I'm new to all of this - just a day ago I knew nothing about colorspace.

    Okay, I've got some VHS tapes which I have converted to DV AVI (NTSC Interlaced) using Pinnacle Studio 12 and Dazzle. I had no options in Studio when selecting DV AVI. I would like to load these files into CCE and create DVD compliant .mpv files. Here's the problem: I have discovered that CCE absolutely will not work with files encoded in the YV12 colorspace. Using the Info() Avisynth script, VirtuaDub tells me that these DV AVI files are YV12. That means that it will not work in CCE.

    Here's where things really confuse me. According to avisynth.org, "YV12 is a 4:2:0 format" and "DV is 4:2:0 (PAL) and 4:1:1 (NTSC)".

    Okay, but here's the problem: If I drop these DV AVI files into MediaInfo, it lists colorimetry as 4:1:1. But does that make any sense? AviSynth reports the file as YV12, so how can it be 4:1:1 also? I'm very confused over this.

    I really need to know what this file really is because if it is YV12, I have found that there is an AviSynth script I can use when loading the file into CCE which will convert the file to YUY2 which CCE works with:

    ConvertToYUY2(interlaced=true)

    Apparently, I am able to load the file into CCE anyways because I have some YV12 codecs installed on my computer, but during my reading, I have found that it is a bad idea to allow the codec to convert YV12 to YUY2 because all the YV12 codecs assume progressive video, and mess up the chroma if you are using interlaced. According to the YV12 faq:

    "If YV12 video is stored in an AVI container, there is no metadata to indicate whether the video is interlaced or progressive. This means that an application or component doing color space conversion has no easy way of choosing the correct conversion method (interlaced or progressive). Most color space converters assume progressive which can lead to chroma upsampling/downsampling errors when interlaced video is processed in such an environment.

    Capturing in YV12 is not recommended due to issues of interlacing and chroma; YUY2 will generally pose fewer problems."


    Also, the CCE faq talks about this problem:

    "Also, the external codecs may assume progressive video (at least DivX and XviD do) and mess up chroma for interlaced video for reasons outlined above. So for the time being, my advice is to stick to the conversion in AVISynth, eliminating another source for possible problems by minimizing the number of video processors involved.

    If in doubt, use ConvertToYUY2(interlaced=true) because it ensures interlaced coded material is handled correctly and the negative impact on progressive coded material is negligible."

    And AviSynth.org says"MPEG-2 encoders such as CCE, Procoder and TMPGEnc can't handle YV12 input directly. CCE and Procoder needs YUY2, and TMPGEnc RGB24".

    So it seems pretty important that I know what colorspace these files are. So do I believe AviSynth when it tells me that it is YV12, or MediaInfo that tells me it is 4:1:1 (they can't be both, can they)?

    Any help would be appreciated, since I'm stuck until I can figure out what I'm dealing with here for colorspace.
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  2. Originally Posted by sasuweh View Post
    .So do I believe AviSynth when it tells me that it is YV12, or MediaInfo that tells me it is 4:1:1 (they can't be both, can they)?
    It's definitely YV12. Is the video from a PAL or NTSC source?
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  3. Its from an NTSC VHS. Gspot and Mediainfo both report the DV AVI files as NTSC 4:3 Interlaced 720x480 Type 2 DV AVI, DVD format. MediaInfo says Digital Video (Sony).

    A test .mpv file output by CCE reads as 4:2:0 for colorimetry in MediaInfo. (Isn't that what YV12 is? From what I've read DVD uses YV12 so I guess that makes sense). So why would MediaInfo say my DV files are 4:1:1? From what I've read, if you're capturing DV, then it will be 4:1:1 for NTSC. So then that would mean it isn't YV12. This is making me nuts.

    Is there some other software that can take a look at these files and give me any info?
    Last edited by sasuweh; 30th Sep 2010 at 05:21.
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  4. Apparently your codec (Cedocida?) is set up to decode it to YV12. You're right that NTSC DV is itself YUV 4:1:1 (he says, after researching it a little bit). People such as jagabo and edDV know way more about this particular subject than do I.

    CCE outputs YV12 (4:2:0), yes, but as I said earlier it'll first convert the input to YUY2 and I do the conversion myself in the AviSynth script.
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  5. So then the file isn't really YV12, it is just being decoded as that by whatever codec is doing it? Is that why it reports YV12 using the AviSynth info script? Does that mean I wouldn't need to use the AviSynth script (ConvertToYUY2(interlaced=true)) for CCE? If I use this script and the DV file isn't YV12, will it mess things up, or will it not matter? Would I be better off to just use it anyways in case, or could that cause a problem if the file is already YUY2?
    Last edited by sasuweh; 30th Sep 2010 at 06:56.
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