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  1. 1 minute Sample Bluray

    1080i MKV file

    The above Bluray is a 1 minute 1080i PAL sample copied directly from my Sky box and a 720p 50fpsconversion. They were muxed to a Bluray with MultiAVCHD. Also above is the 1080i.mkv source file.

    If you look at around the 45 sec mark and the 49 second mark, when the player fakes a shot, there's a skipping glitch or whatever you want to call it. Does anybody know why that happens in the Bluray yet it doesn't happen in the MKV when playing it in a media player? I'm playing the Bluray in a PAL Bluray player (PS3).

    The BBC apparently say they use an "efficient" encoder to get really low file sizes without effecting the quality. For example the EastEnders soap is around 4Mbps at 1080i PAL. I think they're lying because I doubt they can do anything special as the x264 codec can only do so much - they're using low bitrates because they're losing money and have to do budget cuts. But what concerns me is that whatever weird encoder they're using is causing the glitch I mentioned.

    When I re-encode the video I don't get any glitches but I'd rather not have to re-encode as the quality is already low.
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  2. Member
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    It's not a blu-ray compliant stream. Too many consecutive b-frames; some GOP's have 7. BD only allows 3.

    Many BD players can play out of spec streams, but a spec compliant authoring tool will reject this stream
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  3. Is there any way to make the videos compliant without re-encoding them?
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  4. Member
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    Originally Posted by VideoFanatic View Post
    Is there any way to make the videos compliant without re-encoding them?
    Not for blu-ray . You need to re-encode this to make it compatible

    Or just forget about authoring blu-ray and use a media player, or get a BD player that can play MKV files with different specs



    BTW - that's probably what BBC means by "efficient" blah blah blah - because they're using an extraordinary number of b-frames, and MBAFF instead of PAFF
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  5. Will the default x264 codec settings make it compatible?
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    Originally Posted by VideoFanatic View Post
    Will the default x264 codec settings make it compatible?
    No, you need to use BD compliant settings . Default x264 switches are NOT BD compliant
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    Take a look here: http://forum.doom9.org/showthread.php?t=154533

    And look at the examples linked at the end of the first post.
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    Originally Posted by VideoFanatic View Post
    they're using low bitrates because they're losing money and have to do budget cuts.
    Maybe. But here in the USA we see similar bit rates or lower (yes, lower) for HD streaming and it doesn't have anything to do with losing money or budget cuts. Most consumers don't care - not even a little bit - and the lower file sizes have advantages in that they take up less bandwidth to stream and are smaller to store. Having higher bit rate encodes won't accomplish much here if the streams keep timing out or the consumer hits his download limit for the month and can't get any more because he doesn't want to pay extra for exceeding the limit.

    One thing though - I'm not aware off hand of US streams using that high number of consecutive b-frames and that may be a BBC only thing.

    The PS3 isn't known for being a very forgiving BluRay player, so I'm not completely shocked that it's giving you problems, but then again if the video complied with the standards I would think it would play it fine. Most other manufacturers have more forgiving players.
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  9. These aren't streams. They are satellite TV. A lot of people in the UK complained about the low quality and all that happened was BBC did their own investigation which surprise surprise said that the quality was fine and that the new encoder gave the same quality as higher bitrate encodes but in half the file size! What a joke.

    Originally Posted by poisondeathray View Post
    It's not a blu-ray compliant stream. Too many consecutive b-frames; some GOP's have 7. BD only allows 3.

    Many BD players can play out of spec streams, but a spec compliant authoring tool will reject this stream
    Could you please tell me what tool you used to find that out? So is that all I need to check to stop those glitches - make sure my GOPs have 3 b-frames?

    I noticed the Doom9 page said this:
    Output file must be in raw 264 elementary stream (extension .264) otherwise settings will not applied correctly. DO NOT USE MKV OR MP4.
    I'm encoding to MKV with MeGUI and Avisynth. Does MeGUI encode to .264 file first then mux with audio to MKV. If so, will that be OK?
    Last edited by VideoFanatic; 16th Jul 2014 at 09:22.
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    Originally Posted by VideoFanatic View Post


    Could you please tell me what tool you used to find that out? So is that all I need to check to stop those glitches - make sure my GOPs have 3 b-frames?
    There might be other things "wrong" with it in addition to the b-frames. But right away those b-frames make it non compliant

    You can determine with many different ways, stream analyzers, ffdshow's osd, ffindex, ffmpeg/ffprobe

    Probaby an easy way is to open your mkv with ffvideosource() and use ffinfo() , step through a few frames , it will tell you the frame type

    e.g

    FFVideoSource("video.mkv")
    FFInfo()


    I noticed the Doom9 page said this:
    Output file must be in raw 264 elementary stream (extension .264) otherwise settings will not applied correctly. DO NOT USE MKV OR MP4.
    I'm encoding to MKV with MeGUI and Avisynth. Does MeGUI encode to .264 file first then mux with audio to MKV. If so, will that be OK?

    Many authoring programs will accept if it's in a container, but for strict Blu-ray compliance you should be using elementary streams only. Only pro authoring applications will complain because they are more strict. Basically some information in the header is changed as soon as you put it into an MKV container. You can set megui to output elementary .264 stream if you want (you should be if you're authoring blu ray)
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  11. Thanks. OK so you said I can use that method to find out the frame type but is there a way I can find out if it has the other things to make it compliant or not?

    What's the point of just authoring the .264 stream in MultiAVCHD if it doesn't have audio? If I encoded to M2TS with MeGUI would it be compliant then if M2TS is the format Blurays are in?
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    The authoring program is supposed to check if things are compliant or not. But many consumer authoring programs are very relaxed, not as strict

    When you author DVD or Blu-ray, you usually import elementary streams, ie. video & audio separately
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  13. I don't get you, op. I think this BBC stream is very good quality, it's around 7.5 mbits average and I know for sure that BBC uses better encoder than most which produces in my view "real" vbr streams that has high bitrate peaks (~17-18mbits) for scenes that require more bits. I think they use something simillar to CRF mode in x264 with VBV buffer of course, instead of fixed rate which is more common in TV world. In my country national broadcaster uses exactly 6 mbps average bitrate with relatively low peaks (~8mbit) in ALL video scenarios which in my view is more "cbr" encode. For that reason Eurosong broadcast for example looked like shit because it required much more than that, and I've seen that some satellite channels use even lower.

    I know for sure that spanish canal + deportes HD uses same GOP setting with 7 consecutive b frames with similar bitrate so bbc is not the only one. Why do u need to convert these already good streams to blu-ray format that enforces few limitations when every decent player can decode these regular h.264 streams just fine?
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  14. Obviously every player can NOT decode the streams fine as I muxed them to Bluray and saw glitches on the Bluray. So they need to be re-encoded to make them Bluray compliant.

    What you said is nonsense. If you watch an F1 race for example that's shown on both BBC1 and Sky Sports F1 you'll see that Sky Sports F1 has a much better picture quality with negligible artifacts. The BBC1 race was half the file size of the Sky Sports F1 and the picture quality was worse.
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  15. Dude whatever, if you think you know better than me I can live with that

    I said every decent player can decode the file as is, either in mkv or in original ts file, not in a blu-ray format. Also since you probably know better than me you would know that your "blu-ray" file is not true blu-ray but avchd. Maybe it's same thing for you but I like to be more precise when I talk about different formats. I do something similar with sports recordings like you, It's just that I don't care for fancy menus like you. I store them as mkv or in some case ts.

    Sky probably doesn't have to worry for bandwidth and it's a commercial platform. BBC probably has more constraints but you are probably right, SKY's high bandwidth video probably beats it in some more complex scenes but I don't agree that BBC is much worse, no way. It's uses more efficient encoder for sure. Not every tv station has ~15 mbit to throw on one HD channel.

    I played your avchd iso file on Total Media Theatre 3 and TMT 5 and version 5 crashes after playing 720p video, no idea why. No signs of any glitches, so it's probably PS3 issue. VLC and MPC HC play individual m2ts files fine with no glitches as well.

    Cheers
    Last edited by badyu17; 16th Jul 2014 at 13:26.
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  16. Sorry I thought you meant every Bluray player, didn't realize you were talking about media players playing the raw file.

    None of the files have glitches when played in a media player. It's the 1080i not the 720p Bluray file that had glitches when I played the Bluray on my PS3. That's because like poisondeathray said, it's not Bluray compliant as it has too many consecutive b-frames.

    I don't use TMT 5 as that program has glitches (I have Windows 7 64-bit). Only TMT 3 seems to work properly. I don't use software for playing Blurays as I much prefer to get true picture of what they look like on a hardware Bluray player.

    I don't have fancy menus! They are very basic and allow you to choose a title and chapter. Chapters are useful if in a wrestling event you want to select a particular match to view. Otherwise I just keep MKV files for movies.

    Yes I know how to spell Bluray but it's easier to type without a hyphen!

    I'm well aware that it's AVCHD and not a true Bluray but I've never had problems playing the discs before. I've not seen any software better than MultiAVCHD that can mux videos to Bluray, allow menu creation and supports text file chapter import.
    Last edited by VideoFanatic; 16th Jul 2014 at 13:38.
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  17. Did you try with Sky recordings? maybe that 7 b-frame gop is the culprit? Some avchd b frame limit on hardware players? Maybe it's too much for them?

    Can you better describe what kind of glitch is on a ps3? Lost frames or blocking?
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  18. Originally Posted by poisondeathray View Post
    Originally Posted by VideoFanatic View Post


    Could you please tell me what tool you used to find that out? So is that all I need to check to stop those glitches - make sure my GOPs have 3 b-frames?
    There might be other things "wrong" with it in addition to the b-frames. But right away those b-frames make it non compliant

    You can determine with many different ways, stream analyzers, ffdshow's osd, ffindex, ffmpeg/ffprobe

    Probaby an easy way is to open your mkv with ffvideosource() and use ffinfo() , step through a few frames , it will tell you the frame type

    e.g

    FFVideoSource("video.mkv")
    FFInfo()
    Is there another way that doesn't involve using FFVideoSource as whenever I try to load the video in AvsPmod, AvsPmod takes a couple of minutes before it loads the video so it's not very practical. VirtualDub is the same. I'm trying to read 1080i 15 Mbps satellite TV TS/mkv files.
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    You mean to check for b-frames ?

    You can set up ffdshow with the osd overlay to show the frametype, and use mpc or some directshow player to view

    Not as accurate, because if you scrub back & forth, you can "lose your place". Direcshow isn't necessarily frame accurate. FFMS2 is slow because it indexes the file
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  20. Any idea how to do either of those methods?
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  21. Member
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    Set ffdshow as the preferred decoder use win7dsfiltertweaker or codec tweak tool or some similar tool. You will know ffdshow is working as the decoder, if the ffdshow icon pops up when you play a video in mpc. Under ffdshow's directshow configuration, checkmark the OSD box. In the OSD settings, checkmark frametype plus any other info you want. Search for "ffdshow OSD" there should be guides, screenshots
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