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  1. Broadcaster bigass's Avatar
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    I've rendered broadcast masters of a TV series to 1080i as per the station's requirements. Now I'm looking ahead to DVD and BD production.

    I want to keep my options open for how many episodes I'll put on each disc, at what bitrate, etc. I *could* render each from Vegas, but rendering the timeline has been an utter PITA and I'd rather not do that again.

    To that end, I'd like an intermediate master that I can use to derive future downsized or alternate-bitrate/alternate compression versions.

    Yes, yes, you'll shout me down for re-rendering something, but I'm sure there's a compromise that'll serve the purpose.

    The broadcast masters are at 1080i, 35mbps mpeg2, currently in MXF container that I can demux.

    Am I correct in assuming 1080i is not a good thing to generate future generations from? Like, if I go from 1080i down to a DVD-resolution format, I'm just asking for trouble from the deinterlace step, yes?

    If that's the case, what would you recommend as a master format for future re-rendering? Something I can bump down to a YouTube video, or DVD, or Blu-Ray, or...
    Last edited by bigass; 13th Mar 2014 at 14:08.
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  2. Member
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    I bet your current masters are pretty good -- essentially XDCam compatible. What was your source material? Nothing wrong with 1080i if that's what you started with.
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  3. Broadcaster bigass's Avatar
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    Originally Posted by smrpix View Post
    I bet your current masters are pretty good -- essentially XDCam compatible. What was your source material? Nothing wrong with 1080i if that's what you started with.
    Source is mostly 1080p with some 720p and some 2k Gopro. Only went 1080i because that's what was asked for.
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  4. my 2cents:
    a. HEVC has no specific interlaced support and newer formats will probably also not really support interlacing (interlacing should just die out )
    b. switching between interlaced and deinterlaced content always kills details
    -> if your content is progressive, there should be no sane reason to store content which you later want to reencode interlaced
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  5. Member
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    In that case, I agree with Selur here. If your source is progressive, make a progressive master. 1080p is probably a good compromise.

    Also, as long as you have your original sources and your Vegas project, you can always "reconstitute" it in the 8k future.
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  6. Broadcaster bigass's Avatar
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    Thanks, folks ... perhaps I wasn't clear -- by 'format', I'm meaning codec and container. Something that's still compressed but will withstand recompression; something generic enough that I won't have to cherry-pick conversion software or worry about finding obscure codecs in the future... My instincts tell me a high-bitrate 1080p mpeg2 would fit the bill, but I bet the bright minds of videohelp have opinions on how I could ensure the best result.
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  7. Well, if you feel you need to compress it for future use, I think I would go with either h.264 (mp4) or XVid (avi), I think either will be around a long time, they should allow you to reproduce a blu ray or a dvd, of course bitrate is everything when using either codec, I use a fairly high bitrate with both. I've made nice reproductions of HD material with both codecs on dvd and BD. Just my 2 cents in a nutshell.
    I am not responsible, and it's been proven over and over again.
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  8. Member Cornucopia's Avatar
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    You don't say what codec format the source masters are, but assuming they are like the GoPro, which is AVC 4:2:0, your best bet would be an intermediate that is either VERY EFFICIENT at medium high bitrates, or LESS EFFICIENT at very high bitrates.

    So I would say to NOT use MPEG2, but rather AVC/h.264 at say 25-50Mbps. Or go the other way and use ProRes, Cineform, or DNxHD at ~150-300Mbps.
    MPEG2 is certainly acceptable as a capture format and as a transmission/delivery format, given enough bitrate, but I wouldn't use it as an intermediate/archive format (though many have).
    Of course, you limiting factor probably has more to do with your bitdepth & color sampling - most higher-end intermediates are going for at least 10 bit and 4:2:2 if not 4:4:4. Particularly if you are using FX and/or Color Grading, you would avoid blockiness & banding.

    Scott
    "When will the rhetorical questions end?!" - George Carlin
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  9. how about frame rates for those 720p and 1080p, they should be the same, if not .... it complicates things a lot ...
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  10. Member Cornucopia's Avatar
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    If they're multiples (or near multiples) in a family, it shouldn't be too bad: 29.97p/30p/29.97i(aka 59.94i)/30i(aka 60i)/59.94p/60p, or 25p/25i(aka50i)/50p. And 24->25 speedup would probably be ok, too. It's just the changing families: 24<-->30 (judder) and 25<-->30 (blending/interpolation, or judder) that really mess things up.

    Scott
    "When will the rhetorical questions end?!" - George Carlin
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  11. I would say 120 fps is standardized by BT.2020 and 300 fps is recommended as 50/60Hz compatible but reasonable format for today... not sure... probably you are limited by recording/capturing device - i.e. everything can be master... i.e. not processed source file is a master as later you can always use similar to already used or better techniques to create "master"...

    "Our observations were as follows. The most striking differences were seen in the panning shots –
    real and simulated – where the loss of spatial resolution in the detail of the background was
    particularly marked, particularly in the 720p Kiel Harbour simulated pan sequence. In the standard
    definition pan shot, lettering that was clearly legible in a static image was unreadable during the
    pan at frame rates below 100fps. The reduced motion blur on the tracked pan shot also gave a
    greater sense of realism and “three-dimensionality” as the improved dynamic sharpness of both
    the moving objects and the background improved the quality of the occlusion depth cue. The
    table-tennis sequence demonstrated that even 100fps was manifestly insufficient for coverage of
    this and similar sports when viewed perpendicular to the action. Motion blur was also still in
    evidence in the juggling sequence at 300fps, played back at 1/3 speed.
    It is striking that significant improvements were discernable even at resolutions similar to standard
    definition television. This implies that high frame-rate capture and display is a technique that can
    improve the quality of television in its own right, as well as a necessary consideration as the spatial
    resolutions of proposed television standards continue to increase."


    http://www.christiedigital.com/supportdocs/anonymous/christie-high-frame-rate-technolo...y-overview.pdf
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  12. Broadcaster bigass's Avatar
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    Originally Posted by Cornucopia View Post
    You don't say what codec format the source masters are, but assuming they are like the GoPro, which is AVC 4:2:0, your best bet would be an intermediate that is either VERY EFFICIENT at medium high bitrates, or LESS EFFICIENT at very high bitrates.

    So I would say to NOT use MPEG2, but rather AVC/h.264 at say 25-50Mbps. Or go the other way and use ProRes, Cineform, or DNxHD at ~150-300Mbps.
    So, a Sony 422 MXF (mpeg2) at 50Mbps, 1080, 29.97p, would be a bad ides?

    Most of my source files are Canon DSLR camera video...a sprinkling of GoPro...a Sony prosumer camera I didn't take note of...a cheap Chinese dashcam I recklessly transcoded....but mostly Canon DSLR.

    The reason I hadn't considered AVC to begin with...is the higher processor load when encoding or decoding....and I'd assumed it was, well, a highly-compressed format. I hadn't thought of using it at high bitrates. Interesting!
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  13. Most of my source files are Canon DSLR camera video...a sprinkling of GoPro...a Sony prosumer camera I didn't take note of...a cheap Chinese dashcam I recklessly transcoded....but mostly Canon DSLR.
    then you need to determine and decide which format/spec to shoot video in, for each equipment, and then use that as the master source. each of these equipment have there pros and cons. you need to discover them first before moving on to a destination archival format.

    and, when creating a permenant master source -- for future reworks -- you want those archives to be at the highest quality (bitrate) available to that format, be it mpeg2, avc, or whatever. i highly suggest cbr in this case because this is not about how much you can fit in an xvid or mpeg or cdr or dvr or what have you, its about archiving as a final master for future reworks or other such video projects, or else, leave the video in the original format/container and that is your master for archving..and i recommend that of all because that is the best master. but if you want to reduce some space, then you have to experiement for each video equipment to learn which is best, for each and go with that.

    VHELP's - Sample Clips [last: 12.29.06],
    my YouTube videos
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  14. Broadcaster bigass's Avatar
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    Originally Posted by vhelp View Post
    Most of my source files are Canon DSLR camera video...a sprinkling of GoPro...a Sony prosumer camera I didn't take note of...a cheap Chinese dashcam I recklessly transcoded....but mostly Canon DSLR.
    then you need to determine and decide which format/spec to shoot video in, for each equipment, and then use that as the master source. each of these equipment have there pros and cons. you need to discover them first before moving on to a destination archival format.
    I don't quite understand your logic. The show is shot, edited, done. I'm looking to do one more render of the whole show to a single-format file, from which I can derive further conversions for distribution formats, rather than doing a fresh source-based render for each destination.
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    The truth is, there's no right answer. Broadcasters and movie studios all have different solutions and it changes all the time.

    Your Sony 422 MXF (mpeg2) at 50Mbps, 1080, 29.97p will almost certainly be adequate for most purposes for the next 5-10 years. Beyond that, keep your camera original sources and your Vegas project files -- you will never have better than that.
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  16. Member 2Bdecided's Avatar
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    Originally Posted by bigass View Post
    The broadcast masters are at 1080i, 35mbps mpeg2, currently in MXF container that I can demux.
    It's quite common for broadcasters to ask for interlaced encoding, but what you have there is pretty low spec.

    Normal UK HD requirements are 100Mbit/s AVC High 4:2:2 Intra profile@level 4.1.
    http://dpp-assets.s3.amazonaws.com/wp-content/uploads/specs/bbc/TechnicalDeliveryStandardsBBC.pdf
    (page 22, and the documents it links to).

    If you have 24fps progressive content and a 24fps progressive project, render that out to high bitrate AVC at 24fps.
    Keep the original files and the project too.

    If you have a mixture of progressive framerates, I'm guessing a 60fps progressive project will be better. If any of the content is interlaced, then a natively interlaced project, or decent deinterlacing to 60fps, would work.

    Cheers,
    David.
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  17. Broadcaster bigass's Avatar
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    Ok, thanks, all.

    The consensus opinion tells me that since everything was shot progressive, stay progressive. A bit of material was shot at 60p, but not much, and not intended to be represented at 60p.

    So, 29.97p, 1920x1080.

    I'll look a little further into the 422 MXF or AVC options.

    Will definitely save all the original material. Oh, that's a lesson learned long ago -- no matter how good you think the copy is, keep the originals!

    Thanks, as always, for the wisdom and insight.
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  18. So all your potential DVD's will be 29.97p or Blu-Ray's will be fake 29.970i then?
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  19. Broadcaster bigass's Avatar
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    Originally Posted by _Al_ View Post
    So all your potential DVD's will be 29.97p or Blu-Ray's will be fake 29.970i then?
    ...? DVD is interlaced, isn't it? Same goes for Blu-Ray, as I've understood it. Given that all but a small fragment of my source is shot in 29.97p, I don't see myself having much choice in that regard.

    Since I have [predominantly] progressive raw HD footage, I'm best off rendering that to a same-framerate progressive HD intermediate, then ultimately to whichever destination format -- be it widescreen DVD, 29.97i HD on Blu-Ray, 1080p30 YouTube, etc. Am I missing something here?
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  20. DVD can be 29.97p, I never experienced any problem in any player, but 29.97p as 1080p for Blu-Ray is not in specs, so interlace flag is introduced (fake interlace by x264), so footage is encoded as progressive but flagged as interlace

    I do not want to confuse you though, maybe it does not even have to concern you, you are right, a believe most people make 29.970 interlace DVD out of 29.97p source, where encoding software (Vegas) will do things right I hope, just flags it interlace, Blu-Ray the same, if software interprets footage as progressive, there should not be a problem encoding for DVD or BD. But I guess this is important to know while encoding outside of NLE, using Avisynth and external encoders like x264 or HcEncoder.
    Last edited by _Al_; 14th Mar 2014 at 11:27.
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