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    Hey guys, after years of debating, I have finally purchased a Blu Ray Writer. I have been doing AVCHD 1280x720 at CRF 21. With the extra disc space I will now have, I am going to use 1920 x 1080, but the question is, what CRF? I am thinking 17, maybe 14. I don't think I would go lower than that. What do you guys use?

    Thanks
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    If you want to be Blu-ray Video compatible, do not just use CRF without any restrictions. You will need additional VBV parameters to avoid buffer overflows and underflows. And to fill up your Blu-ray discs, you will probably better use 2-pass encoding with a target size. Also, don't forget the "--bluray-compat" parameter for x264 (and for the 1080 resolution, depending on the frame rate, possibly even "--fake-interlaced" – despite progressive video content).

    Pure CRF encoding is for playback from large media like external harddisks and with a powerful decoder (i.e. a PC's CPU), where you don't care about size and reading/decoding speed (if you encode for a consumer player, you will need to know its limits, known as Profile@Level values).

    Regarding quality alone, for a PC target, your range around 14..17 is probably sufficient. Consider grain tuning for very special movie material (which has grain for artsy purposes, like "300").
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    Originally Posted by LigH.de View Post
    If you want to be Blu-ray Video compatible, do not just use CRF without any restrictions. You will need additional VBV parameters to avoid buffer overflows and underflows. And to fill up your Blu-ray discs, you will probably better use 2-pass encoding with a target size. Also, don't forget the "--bluray-compat" parameter for x264 (and for the 1080 resolution, depending on the frame rate, possibly even "--fake-interlaced" – despite progressive video content).

    Pure CRF encoding is for playback from large media like external harddisks and with a powerful decoder (i.e. a PC's CPU), where you don't care about size and reading/decoding speed (if you encode for a consumer player, you will need to know its limits, known as Profile@Level values).

    Regarding quality alone, for a PC target, your range around 14..17 is probably sufficient. Consider grain tuning for very special movie material (which has grain for artsy purposes, like "300").
    Yeah. I have already made a few. I have burnt a few using TMPGEnc 6 Blu Ray Profiles. I have compliant videos. Just wondering about the CRF.
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    Originally Posted by Anakin View Post
    I have compliant videos.
    Then you may have been lucky until today. Some day you may have one movie that makes your player choke, who knows... But you are probably wasting space anyway.

    BD-R* media are too expensive just for archival, compared to external harddisks. If you want to author a satisfying Blu-ray disc, for playback compatibility in real Blu-ray disc players, do it correctly or waste your money.
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    Originally Posted by LigH.de View Post
    Originally Posted by Anakin View Post
    I have compliant videos.
    Then you may have been lucky until today. Some day you may have one movie that makes your player choke, who knows... But you are probably wasting space anyway.

    BD-R* media are too expensive just for archival, compared to external harddisks. If you want to author a satisfying Blu-ray disc, for playback compatibility in real Blu-ray disc players, do it correctly or waste your money.
    Ok, but I only wanted to know about what CRF level everyone is using. You're answering a question that nobody asked. 1920x1080, what CRF level. That simple.
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  6. Mod Neophyte Super Moderator redwudz's Avatar
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    I don't use CRF for BD discs, but I convert my BD discs to MKV H.264/AC3 at 18.5 CRF with VidCoder. Just the main movie.It works well for display quality on my projection screen and I would use the same settings if I were to burn the files to a BD as the quality is OK.
    The normal file size is about 8GB, but that varies with the length of the video and the type of video.

    But the lower the CRF, the larger the file and if you are burning to a BD disc, you have limited disc room.
    A single layer BD has about 23.3GiB room, so you could go with a much lower CRF. How low? Hard to figure.

    But you may be better off using a 2 pass encode with a set target size if you only want one BD file on a BD disc and
    skip CRF altogether as each CRF encode will be a different size, depending on the BD disc running time and content.
    Last edited by redwudz; 1st Sep 2018 at 05:10.
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  7. It depends partly on what other settings you use. I use 18 for SD, 20 for HD. With the slow preset and --tune appropriate for the material.
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    Originally Posted by redwudz View Post
    I don't use CRF for BD discs, but I convert my BD discs to MKV H.264/AC3 at 18.5 CRF with VidCoder. Just the main movie.It works well for display quality on my projection screen and
    I would use the same settings if I were to burn the files to a BD as the quality is OK.
    The normal file size is about 8GB, but that varies with the length of the video and the type of video.

    But the lower the CRF, the larger the file and if you are burning to a BD disc, you have limited disc room.
    A single layer BD has about 23.3GiB room, so you could go with a much lower CRF. How low? Hard to figure.

    But you may be better off using a 2 pass encode with a set target size if you only want one BD file on a BD disc and
    skip CRF altogether as each CRF encode will be a different size, depending on the BD disc running time and content.
    The reason I like CRF, and even going back over 10 years to when I used DivX, is because I simply don't know what the bitrate should be. I like choosing a quality, no matter the fie size.
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  9. Originally Posted by Anakin View Post
    I simply don't know what the bitrate should be. I like choosing a quality, no matter the fie size.
    You have to know what the quality should be, not bitrate, so give it a test 14, 16, 18 ,20 ask someone to randomly rename it for you and look at it.

    but as was said you have to limit your buffers for BD anyway, so you can choose any CRF if you say that size does not matter for you
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    Originally Posted by _Al_ View Post
    Originally Posted by Anakin View Post
    I simply don't know what the bitrate should be. I like choosing a quality, no matter the fie size.
    You have to know what the quality should be, not bitrate, so give it a test 14, 16, 18 ,20 ask someone to randomly rename it for you and look at it.

    but as was said you have to limit your buffers for BD anyway, so you can choose any CRF if you say that size does not matter for you
    Even if a 2 hour film fills a BR disc, I would be happy as long as the quality is good.
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    CRF 18 has only little visual quality loss, and CRF 15 is almost guaranteed "visually transparent" for me. CRF 12 is good enough for me as long time archival grade. I already told you, your range of 14..17 is probably sufficient.

    And then you dump it because your player doesn't play it.
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  12. I use crf 19 for sd. 20-22 for HD. (preset -slower)
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  13. Depends also on source - see no reason for pushing crf to insane low (like 8 - 12) values where source was already recompressed many times and it looks already like crf 23 - 26.
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    Originally Posted by LigH.de View Post
    CRF 18 has only little visual quality loss, and CRF 15 is almost guaranteed "visually transparent" for me. CRF 12 is good enough for me as long time archival grade. I already told you, your range of 14..17 is probably sufficient.

    And then you dump it because your player doesn't play it.
    Well, I've done a few with 14 and a few with 17, and they all play perfectly. I know all about settings and profiles. You just decided to answer something that I didn't ask. If I asked you which car stereo to get, would you give me advice on tyres?
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    I did the same clip twice. 2 minutes just to test.

    CRF14, 268MB
    https://drive.google.com/open?id=1vxQ0P2e_JVieA2glZBLpGvVO4mebgjvR

    CRF17, 180MB
    https://drive.google.com/open?id=1P14-t1cskiAaEAv7KllPl61z7qqug9tQ

    Can you guys see any difference? If someone has a HUGE ASS TV, I would like to know what they think?

    Thank you!
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    Originally Posted by Anakin View Post
    I did the same clip twice. 2 minutes just to test.

    CRF14, 268MB
    https://drive.google.com/open?id=1vxQ0P2e_JVieA2glZBLpGvVO4mebgjvR

    CRF17, 180MB
    https://drive.google.com/open?id=1P14-t1cskiAaEAv7KllPl61z7qqug9tQ

    Can you guys see any difference? If someone has a HUGE ASS TV, I would like to know what they think?

    Thank you!
    I noticed the red background is a little bit noisier in the CRF17 clip.
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  17. Member Bernix's Avatar
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    As pandy and LigH.de and others mentioned. It depends on your source. You can have source as clean animation with flat colors or old movie with original grainy quality. In second case, you will notice difference in grain i believe even at CRF14 (h264) or CRF 18(h265) say medium presets for both, but probably even lower CRF.
    Grain needn't be just artistic. Try compress for example B&W classic movie with Henry Fonda and 11 other actors Preserve grain in these types of movies is almost impossible. Not talking about lossless.
    Also someone can post avisynth to substract first movie from second movie so you can see the real difference. I'm so primitive to do this, I can do it just in Krita (compare just images) or in some NLE software, but difference there is for sure. Small but is.


    Bernix
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    Originally Posted by MFZ View Post
    Originally Posted by Anakin View Post
    I did the same clip twice. 2 minutes just to test.

    CRF14, 268MB
    https://drive.google.com/open?id=1vxQ0P2e_JVieA2glZBLpGvVO4mebgjvR

    CRF17, 180MB
    https://drive.google.com/open?id=1P14-t1cskiAaEAv7KllPl61z7qqug9tQ

    Can you guys see any difference? If someone has a HUGE ASS TV, I would like to know what they think?

    Thank you!
    I noticed the red background is a little bit noisier in the CRF17 clip.
    Thanks! Is it a huge difference?
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  19. Usually use crf 16 and I watch my stuff on a 5k monitor (hp 5k z27q) from which my eyes are roughly a meter away.
    users currently on my ignore list: deadrats, Stears555
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    Originally Posted by Anakin View Post
    Originally Posted by MFZ View Post
    Originally Posted by Anakin View Post
    I did the same clip twice. 2 minutes just to test.

    CRF14, 268MB
    https://drive.google.com/open?id=1vxQ0P2e_JVieA2glZBLpGvVO4mebgjvR

    CRF17, 180MB
    https://drive.google.com/open?id=1P14-t1cskiAaEAv7KllPl61z7qqug9tQ

    Can you guys see any difference? If someone has a HUGE ASS TV, I would like to know what they think?

    Thank you!
    I noticed the red background is a little bit noisier in the CRF17 clip.
    Thanks! Is it a huge difference?
    No, I'd say it's on the small side.
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    I've used everything from 15 to 26. It really depends on source quality and content. For most things, 19-23 is fine. You just need to encode test clips, view the results.

    And Selur's Hybrid really takes the difficulty and mystery out of x264 encoding, far better than newbieware/dummyware like Handbrake. You're able to tweak so many settings, and really get the most quality and compression out of it.
    Want my help? Ask here! (not via PM!)
    FAQs: Best Blank DiscsBest TBCsBest VCRs for captureRestore VHS
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  22. Also as a side note, just because the difference between two crf values is small with one source, doesn't mean this is the case with all sources.
    -> it's always about using a value you think the potential gain/loss in quality and file size is worth it
    The only objective top notch crf is when crf isn't used and you are doing lossless encoding.
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    Originally Posted by Anakin View Post
    You just decided to answer something that I didn't ask. If I asked you which car stereo to get, would you give me advice on tyres?
    I decided to warn you that you are asking the wrong questions, and I wanted to help you avoiding a mistake that has a low but non-zero chance to ruin your results. I have practical experience in that matter. I once worked in a DVD Video production studio. And I have seen videos which never exceeded a maximum bitrate but still violated the VBV.

    It requires some in-depth understanding of the VBV to know that ignoring these constraints is a risk when your playback device has a limited decoding or reading speed. So I wanted to invest my experience in giving you a good advice. A pity you thought I would mock you; that was never my intention. I only worry about your results.
    _

    In other words: Yes, if I knew that your tyres are imbalanced and cause vibrations, I would recommend you to get them balanced, to avoid plugs falling out of your car stereo jacks, before I even start recommending you a car stereo brand and model.
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    Originally Posted by LigH.de View Post
    Originally Posted by Anakin View Post
    You just decided to answer something that I didn't ask. If I asked you which car stereo to get, would you give me advice on tyres?
    I decided to warn you that you are asking the wrong questions, and I wanted to help you avoiding a mistake that has a low but non-zero chance to ruin your results. I have practical experience in that matter. I once worked in a DVD Video production studio. And I have seen videos which never exceeded a maximum bitrate but still violated the VBV.

    It requires some in-depth understanding of the VBV to know that ignoring these constraints is a risk when your playback device has a limited decoding or reading speed. So I wanted to invest my experience in giving you a good advice. A pity you thought I would mock you; that was never my intention. I only worry about your results.
    _

    In other words: Yes, if I knew that your tyres are imbalanced and cause vibrations, I would recommend you to get them balanced, to avoid plugs falling out of your car stereo jacks, before I even start recommending you a car stereo brand and model.
    The way I usually test the limit is, I use the Marvel Studios opening which has a lot of fast movement. I did that at CRF 14 and authored it and played it on my PS4 and a Blu Ray player and it worked on both. I think I am gonna go with 17. Smaller file sizes, lower bitrate, and I can fit more on a disc.
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    In my time, we had fun with the helicopter flight over the graveyard in the beginning of "Cruel Intentions"... but that's not the point. You can have a minute of high motion without issues. And you can have a minute of stills, followed by a moment of flashback, and this makes the video buffer explode. The fill level of the video buffer is affected by the previous scene as well as by the following, not only the current GOP. And the paradox in case of slow-to-read media is that the meaning of overflow and underflow is opposite to high and low bitrates. Low bitrates may cause too many frames to be read from the disc at once, and skipping on an optical drive is risky.

    Encoding with respect to the VBV will certainly avoid any issues. If I am not completely wrong, x264 even supports VBV-restricted CRF.
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  26. Assuming your player supports h264 in an MKV or MP4 via disc, I'd be forgetting about making Bluray complaint video discs and just burn MKVs or MP4s to disc as data files. Unless you need a particular Bluray feature almost nobody cares about, it'd be much less hassle. Plus you'll be able to easily transfer them to a hard drive for playing with a TVs built-in media player etc, or when you inevitably find yourself hating having to burn discs.

    Although for Bluray video discs, I've often wondered how important it is to use the official Bluray compatibility settings these days.
    There's two Bluray players in this house, both around seven years old. One supports standard Level 4.1 video when playing files via it's USB input, while the other supports Level 4.2. When I torture tested them with a 1080p video at stupidly high bitrates (from a USB thumb drive), the first would stutter unless I kept the VBV settings to around vbv_maxrate=50000 and vbv_bufsize=50000, while the second one happily played through brief bitrate peaks of 100Mb/s.
    My ex own's a Sony Bluray player she bought before anyone was putting USB inputs on them for playing media (I remember it having a USB input on the back for adding extra memory to support some type of interactive Bluray feature nobody cares about), but it'll happily play Level 4.1 in MKVs or MP4s burned to disc.

    Not that I've been motivated to test it, because I stopped burning discs years ago, but I wonder, as long as the bitrate doesn't exceed the drive's read speed, why those players would refuse to play a Bluray video disc because the gop size exceeded the official limit, or it was encoded using four B-frames instead of three etc. I've never met a Bluray player that cares about the official Bluray restrictions via USB.
    Last edited by hello_hello; 3rd Sep 2018 at 04:57.
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    One reason may be that optical drives prefer linear access a lot over random access; skipping an optical track can cause noticable delays. That's also a reason why compliant media are really read at 1x the designed speed: speeding up and down would cause a need to re-sync the laser with the track position.

    And even if you read auxiliary files instead of authored media discs: Often the firmware adds constraints when a clip is read from a physical Blu-ray disc, compared to an obvious copy on an electronical medium.
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    Originally Posted by LigH.de View Post
    One reason may be that optical drives prefer linear access a lot over random access; skipping an optical track can cause noticable delays. That's also a reason why compliant media are really read at 1x the designed speed: speeding up and down would cause a need to re-sync the laser with the track position.

    And even if you read auxiliary files instead of authored media discs: Often the firmware adds constraints when a clip is read from a physical Blu-ray disc, compared to an obvious copy on an electronical medium.

    Ok, I will give it a go. I’m gonna use 8000 average. That seems to fit about 5 hours on a disc. 2 pass. Will the results look ok?
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  29. Originally Posted by Anakin View Post
    I’m gonna use 8000 average... 2 pass. Will the results look ok?
    Some material will look OK. With some material it will be too low a bitrate. On some material it will be a waste of bitrate.
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  30. Member Bernix's Avatar
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    I have movie that overall bitrate of videotrack is bit bellow 8000kbps, but sometimes comes to close 10000kbps only FullHD resolution. But it is grainy and you can easily notice that grain isn't as it can be for example on UHD version. The movie is of course in HEVC. Much more efficient compression. I recorded it from air DVB-T2 with no recompression. Usualy they use bitrate around 4500kbps and for clean or restaured content it is enough. Of course it also depend on other encoder settings. Better (in terms of quality) encoding will last longer.

    100% agree with jagabo + you will spend instead say 100min encoding 200min of encoding.
    CRF is faster, with expectional quality. 2pass i good to fit medium. CD or DVD or BD. Otherwise waste of bits or not enough bits. But this already states Jagabo.


    Edit: I had TV that supported just 4.0 with USB so 4.1 wasn't playable so you will have to test it.



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    Last edited by Bernix; 3rd Sep 2018 at 11:52. Reason: Edit: Level
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