Configuration for 1080p@60fps

Hi,

I would want to edit 1080p@60fps@28MBps footages (from an action cam).

My laptop have a Intel Core i5 5200U CPU and 4 GB RAM. Also, there's a dedicated AMD Radeon graphic card.

First, I must wait for the rush to be "charged" in the timeline in order to play normally.

Preview a transition is laggy (even when the two footage are "charged" in the timeline).

And preview effects (mostly speed effects for slow motion) is a pain.

Is it a video quality problem relative to my configuration?

If yes, what is the bottleneck: RAM or CPU (tell me it's RAM, I can add some more).

Thank you

Comments

  • Triem23Triem23 Moderator

    More RAM would help, but your bottleneck is the footage. You're importing 1920x1080 @60 fps in. 

    Ok, for that footage your computer is processing about 356MBps--megaBYTES per second--of data. A 28mbps--megaBITS--file... 28mbps= 3.5MBps. The data file is compressed to be 1% of the space. 

    Media players (usually) play with ease, but that's straight playback, nothing else going on. Hitfilm has a lot more overhead. 

    You would get better performance from converting your footage to an "editing format"  file.  Basically you create a less compressed file and take the load off the CPU. 

    It's better explained here: telestreamblog.telestream.net/2012/04/save-yourself-frustration-use-editing-formats-when[-editing-2/

    *Rubs the VFX Lamp, summoning @Aladdin4d with his video on converting files with MPEG Streamclip. 

  • Aladdin4dAladdin4d Moderator

    ***POOF*** cough cough hack.......Ok I'm here. Now what are your other two wishes?

    The Avid codecs are available here:

    http://www.videohelp.com/software/Avid-DNxHD

    Mpeg Streamclip is available here:

    http://www.squared5.com/

    This video covers how to use Mpeg Streamclip. It shows how to encode to ProRes but the basics are the same for DNxHD. If you're on a Mac stick to ProRes

    https://www.youtube.com/watch?v=Rxmqs6aL_3E

    DNx has specific bit rates based on quality, resolution and frame rate. This is the table for 1080p @ 60 fps

    1080p/60

    ResolutionFrame SizeChroma SubsamplingBitsFrames Per SecondMegabits per secondMinutes per Gigabyte
    Avid DNxHD 440x 1920 x 1080 4:2:2 10 60 440 0.325
    Avid DNxHD 440 1920 x 1080 4:2:2 8 60 440 0.325
    Avid DNxHD 290 1920 x 1080 4:2:2 8 60 291 0.492
    Avid DNxHD 90 1920 x 1080 4:2:2 8 60 90 1.585

     

     

     And this is the page where that table came from with all the other tables for future reference.

    https://en.wikipedia.org/wiki/List_of_DNxHD_codec_resolutions

    Test a clip with DNxHD 90 first and if you're happy with the quality go for it. If not then try 290. You shouldn't need to go all the way up to 440 but it is possible.

    You didn't mention what action cam you have but you might be able to use GoPro Studio to convert your clips too and if you can then you're going to be using the Cineform codec which also performs very well.



     

  • Hi,

    Thank you for the answers. I made a few tests and research.

    With MPEG StreamClip and Avid Codec, I "export to Quicktime" and choose "AVID DNxHD Codec".

    Then, there's not 1080p/60 in combinations, I must choose bitrate in 1080p/29.97 category. But it's OK because there's AVID DNxHD 8 bits 45, 145 or 220. Multiply by two (like the FPS) and you have AVID DNxHD 90/290/440.

    I see FFMPEG can also transcode to DNxHD:

    ffmpeg -i <source> -vcodec dnxhd -b <bitrate> -acodec pcm_s16le -f mov <destination>

    Where you replace bitrate by the "preset" you want, according to the table you mention, with a "M" (for Megabits): 45M/50M/60M/75M/90M/110M/etc...

    pcm_s16le is here to get an uncompressed pcm audio stream (like a .wav)

    example: ffmpeg -i mysourcevideo.mp4 -vcodec dnxhd -b 90M -acodec pcm_s16le -f mov myvideoforediting.mov

    FFMPEG seems faster than Avid codec (???).

    I don't try this format for my edit yet. It's well advanced now, I don't know if I can relink all the files (and extension changes from MP4 to MOV). But I keep the trick for future edits.

    One more thing, DNxHD uses a lot of space. What about using an external USB 3 drive for editing (speed and is it possible to fix a letter in Windows) since I have a laptop?

  • Colorspace of my source is YUV 4:2:0. DNxHD are YUV 4:2:2. No matter I suppose?

  • An other question, if I edit with DNxHD, is it useful to relink with original files (h264 here) before export?

    Is quality difference will be visible? (if audience just watch the final video, without looking for artifacts or other problems)

  • Will MPEG Streamclip also convert to DNxHR?

  • Yes, it must be provided by the AVID codec.

  • Aladdin4dAladdin4d Moderator

    It looks like you figured out Streamclip ok.  YUV 4:2:0 vs 4:2:2 shouldn't matter. FFMpeg can make DNxHD files but there are some limitations. One is if there is a color space conversion like RGB to YUV then FFMpeg still uses the older Rec 601 matrix instead of Rec 709 causing a color shift. Another is support for DNxHR for UHD/4k is limited and the last has to do with color depth. DNx supports 10 bit color but depending on how FFMpeg was built it will only support 8 or 10 bit color requiring a different build for each or a complicated dynamically linked version. None of this should be an issue for what you are doing though just be aware of it in case things change.

    If you are satisfied with the quality then it probably isn't useful to relink to the original files. If you were making low bitrate, lower resolution copies to use as a proxy then it would be.

  • DNxHD and FFMPEG

    Colorspace

    I read some threads and it's possible to be in Rec709 with FFMPEG: http://community.avid.com/forums/p/60895/412838.aspx#412838

    Do you know this trick? (but I'm sure I won't see difference between rec601 and rec709, and I'm not sure about the color fidelity of my action cam)

    Bit depth

    My cam captures in 8bits so 10bits support is not an issue

    DNxHR

    I have problems with 1080p so I won't go to 4K now ;-)

    Conclusion / final question

    As FFMPEG is faster, does it worth to transcode with it?

    Relink and intermediate files

    So, if I produce DNxHD 290 video (and maybe DNxHD 90), relink original files is useless for "holidays/family" video

    But, can I produce less quality DNxHD intermediate files than DNxHD 90 for 1080p/60fps video (supported by the codec and Hitfilm Express 3)? If yes, I'm interested, because I just cut, apply some transitions and add some overlays, no need of precision.

  • You don't have to worry about colorspace conversions in ffmpeg if your source/input files are in YUV format. Nearly all video is already in YUV.

    The thing with ffmpeg and colorspace is an RGB to YUV conversion. That RGB->YUV conversion has been hardcoded to rec601 in ffmpeg.

  • I have a question. I shoot on a Canon 600D. If I convert the files to DNxHD 175x, is 10 bit going to offer a better finished product than 8 bit, in this case just DNxHD 175?

    Since they're the same bit rate, it wont matter as far as the storage is concerned, right?

     

     

    Kevin

  • Triem23Triem23 Moderator

    10-bit won't help since the source footage is 8-bit. 

  • ...not that it's really important to the discussion, but I just figured out why my DNxHD file sizes were so astronomically huge thanks to the info in this thread.  Thanks for talking about this stuff so in-depth that even people who aren't in the conversation get something out of it. 

  • was wondering who would need such a high bit rate though?

    I did the math on blu ray discs and they can't take more than 5 MB/s.

    Doesn't that mean that using DNxHD 36 should be enough, worst case 11% worse than blu ray?

     

    Kevin

  • Triem23Triem23 Moderator

    Some people say DNxHD 36 looks great. Especially since most DSLRs shoot between 28 and 35. What you're doing with the DNxHD is trying to find the balance between file size and smoothness of editing. Take a short 15 second clip, batch it out with a whole bunch of different bitrates, slap 'em on a same timeline and compare. If the 36 looks good and responds smoothly, use it. Besides, by the time Youtube's done with it, it'll end up closer to 8. ;-)

  • I've learned so much just from this thread.

    Yeah, I believe the best balance for me would be the 36, because of the file sizes.

    500 * 3,94 = 3980 / 60 = 66

    If you followed me it should give me 66 hours at that bitrate for 500 GB of hard drive space. I don't have anything to worry about as long as you can re convert but I'm assuming that's not a very good idea? Still, overthinking, 66 hours is a lot. It's definitely fun to learn though. 2 hours ago these were just a different language to me.

     

    Kevin

  • OK, after more tests, this is some results:

    DNxHD

    DNxHD codec matches preset with the resolution/FPS combination.

    I tried to transcode 1080p/60fps video to DNxHD 36 or DNxHD 45 in order to save space (I wanted to use intermediate files like proxies, and relink original files for final export). The two encodings results in a DNxHD 90 video.

    So just use presets which matches with your resolution/FPS, according the reference table put above.

    I use FFMPEG because it's faster (it's up to you)

    My config, my 1080p/60fps footage, Hitfilm and DNxHD

    OK, H264 is shit for editing. Everything is smooth with DNxHD format in Hitfilm 3 Express with my i5 5200U and 4GB RAM (playback and effects)

    Now, last dilemna: do I use DNxHD 90 for editing and relink original H264 files for final export or do I use DNxHD 290 for editing and final export (no relinking but I will need to buy an external drive)

  • @KevinTheFilmmaker "was wondering who would need such a high bit rate though? I did the math on blu ray discs and they can't take more than 5 MB/s."

    You cannot compare the bitrate of one codec type to another. Specifically in this case DNxHD to Blu-ray. Blu-ray is typically AVC video. DNxHD must have a much higher bitrate than typical AVC for a similar level of visual quality. DNxHD bitrates are also biased a little on the higher side since the format is designed to be an intermediate format. Meaning to survive multiple renders during the edit process with less visual loss on each render.

  • Long GOP formats may be less than ideal for editing, but HitFilm could do much, much better in this area than it does.   Have you tried h.264 in Premiere?  It is even smoother than HF is with proxies.

    I personally find it disappointing that intermediate formats are being used as a crutch to not bother optimizing editing with formats like h.264.

  • @tack +1 In fact, I have literally use the word "crutch" as well.

    I'm not sure it is LongGOP that is Hitfilm's problem. XDCAM works quite well and it is LongGOP but it is MPEG-2. MPEG-2 has a low decode overhead.

    I think Hitfilm's issue is that is has some basic level of decode+playback+unknown overhead that other editors often mentioned do not have. Vegas and Premiere are often cited. AVC most often has a higher decode overhead than all other formats and that extra addition to all other other stuff often tips Hitfilm over the edge to unusable playback.

    The only thing we users can do to work around the Hitfilm performance thing is go for source formats with a lower decode overhead.

  • @Triem23 ironically, when my clips are as short as 15 seconds I don't even need to use DNxHD.  It's only when they start clocking in at 2 or 3 minutes that a format like .m2ts starts bogging down my machine.

    As an aside, using proxies doesn't seem to improve performance for me at all.  Wonder why that is...

  • @SteveKartensen Hitfilm proxies have a very high burden on hard disk throughput. That may be what you are seeing in that instance. Hitfilm proxies are full resolution, full quality, lossless files. This is why proxy files are so large.

  • Aladdin4dAladdin4d Moderator

    @Whoever ;)

    AVID's official recommendation for footage with a bit rate below 36 is go with the lowest DNx bit rate that matches your resolution and frame rate and use it throughout the pipeline. This route is very common with DSLR /AVCHD type footage. While comparing bit rates of different types of codecs isn't necessarily the best idea it's what we have so it's used as a general rule of thumb and the higher the bit rates the more relevant the comparison becomes i.e. if DNx worked at 10 mb comparing that to 10 mb AVC wouldn't be very relevant but comparing AVC-Intra 100 to DNxHD 115 would be. If your footage has a higher bit rate then you can:

    1. Make a lower DNx bit rate version to use as a proxy and re-link to the original clips at render time in an offline workflow, This is how 50 Mbps news footage is usually handled.
    2. Make a higher DNx bit rate (or one that's close) version and use that throughout the pipeline. Pretty common across the board.
    3. Make a really really high bit rate version and a low bit rate version to use as a proxy re-linking to the high bit rate clips at render time in an offline workflow. You'll see this in serious film and VFX work and the really high bit rates also give you 10 bit color but this workflow isn't quite as common as you might think.

    Now some people say the lower DNx bit rates aren't any good for low bit rate footage like AVCHD while others say it looks great like Triem23 mentioned and I can say from my personal experience DNxHD 36 is good most of the time with no real noticeable loss in quality but I've also seen it produce banding and some odd anti aliasing artifacts on occasion. There's no rhyme or reason for it that I've been able to figure out but it can and does happen so the moral of the story is test your footage. If you're happy with the results go for it and don't look back. If you're not then try again with the next higher bit rate. If you're still not happy then try the first offline approach with a proxy and re-linking to the original footage or step up to the next higher bit rate. Beyond that with the really high bit rates you start running into diminishing returns real quick and if you feel you have to go with a really high bit rate just to maintain quality then you probably want to try another codec like Cineform or even MagicYUV  first before going for the max with DNxHD. The max bit rates take a lot of storage and bandwidth overhead to work with and more often than not at that level image sequences like CinemaDNG, DPX and OpenEXR are used instead of a video codec. The advantages to that are the compression can be lossless, even greater color bit depth and potentially needing less storage.

    High bit depth color can be advantageous but getting that advantage takes extra work so you won't gain much by transcoding straight from 8 bit color to 10 bit or higher. On the other hand if you had 4k footage in a 16 bit project and you were ultimately exporting that to 1920 x 1080 then 10 bit color would be handy and there is a way to get there from HitFilm but that's a topic for another day........

    @SteveKarstensen HitFilm proxies are lossless which means really big file sizes so it's possible you're experiencing a drive bottleneck

     

  • CNKCNK
    edited March 2016

    25 mb source = use 36 mb DNxHD? I don't see a reason why I would use anything higher, because a higher bit rate can't improve the quality, right?

    Well, that sucks. It sounds better being able to match blu-ray, but then there's YouTube... :(

    RickH33 , did you find a good combination yet? I'm shooting 24p though, so I don't think I'¨ll run into as many problems, seem to already have it figured out.

     

     

    Kevin

     

  • Aladdin4dAladdin4d Moderator

    @KevinTheFilmmaker If you're happy with the quality then run with it.

  • @KevinTheFilmmaker "25 mb source = use 36 mb DNxHD? I don't see a reason why I would use anything higher, because a higher bit rate can't improve the quality, right?"

    You cannot equate bitrate across differing codecs. 36Mbps is different across DNxHD, AVC/H.264, MPEG-2 (aka XDCAM type stuff) and others.

    So how does one determine equivalent bitrates for codec X to codec Y. Wars start from such discussions. 

     

  • Triem23Triem23 Moderator

    @KevintheFilmaker in my first post in this thread I linked to a blog post talking about the differences between Editing and Delivery codecs. They compress in different ways. Mp4/AVC are designed to cram data into a tiny space, but they do in using a nasty compression scheme that's a bitch to decode. Editing codec use a less extreme compression fir ease of decode. This means bitrates don't directly compare. 

  • @NormanPCN oh dear, I didn't know... :(

    Well, that's unfortunate. It's fun to discuss though, can't blame them. 

    @Triem23 I will take a look at that link, thanks. Unfortunately I missed that one. :)

     

    Kevin

  • KevinTheFilmmaker

    I still need to test exporting time using H264 original files in the timeline or DNxHD.

  • OK, problem solved. It's more difficult for my laptop to handle DNxHD 220 (playback in the timeline is not smooth, but more than with H264).

    I will use a proxy and relink before the final export.

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