Format Sizes and Quality

Hi.

This question is mostly for NormanPCN but anybody's welcome to chip in of course. I've been searching forever for a format to convert to from MTS , which edits very smoothly in Vegas but is unworkable in HF (crashes HF at almost every move I make).

The best format I came upon yet that works well and is very smooth is DNxHD. However, the only setting that gives me the same quality as the original file is 185 bitrate, and the converted files are huge. Is there any other smaler format that results in smaller files and yet edits great in HF?

Norman, you said in some other post: "This is in part why I figured out AVC encode settings that edit very well, even in Hitfilm. .

What exactly do you mean by that, and how can I transcode to that from MTS (either directly from Vegas 13 or from some other converter)?

Thanks

Comments

  • edited January 2016

    "What exactly do you mean by that..."

    It means specific encoding settings used to transcode from whatever to AVC in an MP4 file. I mentioned those settings in your previous thread. Hitfilm has a high basic playback overhead and AVC can and does often tip the scales to stuttery playback.

    I have command scripts which use ffmpeg to do the transcode. Reading those files is a little technical. Using them is trivial. I'll make them available if you are interested. Also, I could work up a screenshot with settings using Handbrake that does the same thing.

    Using these settings the playback utilization overhead is the same as DNxHD and Cineform and much smaller files. With the new JKL playback, 2x playback and even 2x backwards is smooth. This is on, my system, with my files. I make no claims beyond that.

  • Aladdin4dAladdin4d Moderator
    edited January 2016

    One thing to keep in mind with DNx is that the bit rates are also somewhat locked to specific frame rates, resolutions, color depths and whether the material is progressive or interlaced so trying a lower bit rate that doesn't match what's needed can give you some strange results. Since you mention 185 and that's for 1920 x 1080 25p or 50i the other lower bit rate options for 8 bit color would be 120, 85, and 36 with 365 being the only higher bit rate option. For any AVCHD footage AVID always specifies the lowest available bit rate and says there's no improvement in going higher. Whether or not that's true is open to debate.

  • If you want good quality retention and performance, the price is larger files. If you want smaller files, the price is reduced performance and quality retention. Its just the nature of video editing. You can't get quality, good performance and small file size all in one file. You can pick two out of three.

  • Thank you guys very mucho.

    @NormanPCN: Yes, please do post that screenshot of Handbrake. As you might have already noticed, I'm not the most technically minded guy :)

    Aladdin4d: I'm at 1920x1080 - 60p, but I don't mind transcoding to 30p, so it might not be the 185 setting that I chose, but something close to that. Does it have any influence if I'm transcoding to a lower FR?

    AxelWilkinson: Axel, it's Carlos, I presently have a support ticket open with you about the crashing. I think that AVCHD is the source of most of my problems so large file sizes don't bother me too much, as long as I can work smoothly in HF (HDs are cheap these days). However, I don't mind losing just a bit of quality in exchange of greatly reduced file sizes.

     

    Thanks again.

  • Or I could also try proxies. I've read in another post by Axel about using proxies instead of transcoding, and I don't mind that either since I only need to transcode the clips that I'll be using in HF (MTS works fine in Vegas). 

    I also read in that recent post about new feature requests that proxies don't integrate in Vegas. So here's my question;

    1- I open a clip (MTS format) in HF from Vegas (right click - Edit in HF), 2- Proxy that clip in HF
    3- Composite the clip
    4- Save and close HF

    Will that composite still show in Vegas as if I had worked directly with the MTS file?

    If I work on the composite after proxiying the MTS, will it invalidate the proxy (go back to using the MTS)?

    Thanks

  • @Ireground - This is the table for 1920 x 1080p @29.97 fps 

    ResolutionFrame SizeColor SpaceBitsFrames Per SecondMegabits per secondMinutes per Gigabyte
    Avid DNxHD 440x 1920 x 1080 4:4:4 10 29.97 440 0.325
    Avid DNxHD 220x 1920 x 1080 4:2:2 10 29.97 220 0.651
    Avid DNxHD 220 1920 x 1080 4:2:2 8 29.97 220 0.651
    Avid DNxHD 145 1920 x 1080 4:2:2 8 29.97 145 0.985
    Avid DNxHD 100 1920 x 1080[3] 4:2:2 8 29.97 100 1.429
    Avid DNxHD 45 1920 x 1080 4:2:2 8 29.97 45 3.18

     And this is for 1920 x 1080p @59.94 fps (Full 60 fps uses the same table)

    ResolutionFrame SizeColor SpaceBitsFrames Per SecondMegabits per secondMinutes per Gigabyte
    Avid DNxHD 440x 1920 x 1080 4:2:2 10 59.94 440 0.325
    Avid DNxHD 440 1920 x 1080 4:2:2 8 59.94 440 0.325
    Avid DNxHD 290 1920 x 1080 4:2:2 8 59.94 291 0.493
    Avid DNxHD 90 1920 x 1080 4:2:2 8 59.94 90 1.58

    Since you were encoding to 185 but with a higher frame rate you were probably getting even larger than normal file sizes. I would try DNx 90 and see if you're happy with the result before moving up to 290 or changing the frame rate but lowering the frame rate will dramatically reduce the file size.

  • Here is a Handbrake screenshot for a fast(er) decoding AVC file.

    Checking "fast decode" is the big one for basic playback performance.

    Choose any RF value you want but be sensible. A lower RF (higher bitrate) will only slow things down.

    You can choose any preset you want. This screen has it at "Fast". Slower presets will decrease filesize (bitrate) slightly but increase encode time dramatically.

    I have High profile selected which enables a feature that will reduce file size a little. Feel free to try Main if you want. I've not tested how it affects decode performance, if at all. High works fine for me.

    keyint=30. This affects timeline seek and scrubbing performance. For a 60p file a keyint value of 30 is about 1/2 second max length for GOP (group of pictures). Feel free to drop this to 15 if you like on 30p files. A .5-1 second GOP scrubs on the Hitfilm timeline pretty well.

    Note: I would prefer to use keyint=1, but Hitfilm and/or its native Mainconcept AVC decoder crashes in some intermittent circumstances with files like those in my tests using ffmpeg conversions.

    No comment on any other settings like frame size, deinterlacing, audio settings and such.

  • Aladdin4d: I went to looking for this chart after reading your post, didn't find it. I was actually going to ask you if you had something like that. I'M saving it in a doc. Thanks

    NormanPCN: Thanks. I'll try that.

    Again, big big thanks for your generosity on this forum guys. Really appreciate it.

  • edited January 2016

    @Ireground Here is an even bigger chart than Aladdin4D listed. Well, the chart is within the PDF file starting at page 9.

    edit: forgot to add the PDF link.

    http://www.avid.com/static/resources/US/documents/DNxHD.pdf

  • Did you forget to attach the PDF?

  • Yep. I edited my post.

  • I'm testing Handbrake right now. I'll let you know.

  • Cool. Thanks.

  • I copied and pasted this Wikipedia entry I should have included the link the first time. Sorry about that.

  • Thanks. I tried at 145 and I think I'll go with it. However, it brightens up the video a lot. I have to crush the blacks to compensate. But it edits smooooooothly in HF. Even the composited clip back in Vegas previews smoothly at the best previewing setting.

  • What did you use to convert to DNx? Sometimes the tool used can cause a shift in Y values. The other thing that can happen is the camera records out of range values and DNxHD only accepts REC 709 legal values so a shift happens. There are things you can do to manage that but they kind of depend on what you're using to get to DNx.

  • Sorry for the late reply.

    It was recorded with a Sony a57 and transcoded with Vegas pro.

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