Proxy Properties

chezlui
chezlui Website User Posts: 9

Hi.

When you proxy a video file, in which codec hitfilm is transcoding ?  High resolution, 32 bits ?

Thanks

Comments

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,791 Ambassador

    Hitfilm's proxies are a custom, proprietary codec with a lossless compression. Beyond that, I can't say. Bit-depth is probably determined by project setting.

    I'll tag @DannyDev this time, but I doubt a dev will say anything more. 

  • chezlui
    chezlui Website User Posts: 9

    Do you think it's better to transcode to cineform 32 bits before adding files in hitfilm ?

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,791 Ambassador

    Pro or Express? Honestly, what's the source footage from? Cineform 32bbc is a total waste if the source footage is some 8-bjt mp4. 

  • chezlui
    chezlui Website User Posts: 9

    I Use mp4 (8 bits) files.

    Do you think it's better to use Hitfilm Proxy 16 bits, or transcode to Cineform 16 bits before ?

  • NormanPCN
    NormanPCN Website User Posts: 4,043 Enthusiast

    Cineform is never 32-bit or 16-bit. It is only ever 10-bit 422 or 12-bit RGB.

    Hitfilm proxies are generally not good for improving edit performance of media files. This is because they are lossless and thus very very large files. They do decode fast but they have a very high I/O burden due to their very high effective bitrate. It is unfortunate that FxHome chose to use the term "proxy" given how that term is normally used in the video industry.

    You best bet for timeline edit performance is to use Cineform.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,791 Ambassador

    To build from what @NormanPCN writes You could use Cineform 10-bit if you wanted. But you're starting with an 8-bit file. The conversion won't magically give you a full 10-bits of color information. You'll just be wasting data. Maybe a 10-bit encode might preserve minor details that would be lost, but I doubt it.

    12-bit is total overkill.

    8-bit Cineform medium is my recommendation.

    Norman--hear, hear! Hitfilm proxies are really prerenders.

  • chezlui
    chezlui Website User Posts: 9
    edited May 2018

    If you transcode 8 bit video to 10 bits, when you are color grading, i think result is better. Am i wrong ?

    http://wolfcrow.com/blog/should-you-raise-bit-depth-and-color-space-before-color-grading-part-one-8-bit-video/

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,791 Ambassador

    Not quite. The advantage is in editing in a higher bit color space  since the additional bits help in internal processing. 

    Notice the Wolfcrow writer started with an 8-bit image and changed the internal color space of After Effects. In Hitfilm Express access to 16-bit editing is part of several add-ons (you can download a reference sheet of add-ons here: https://fxhome.com/forum/discussion/46921/hitfilm-express-and-add-ons-v8-vs-hitfilm-pro-v8-updated-may-16-2018#latest )

    Editing in a 16-bit color space can help maintain smooth gradients, glows and improve blend modes. However transcoding 8-bit footage to 10-bit does basically nothing. 

    If you're in Express without an add-on for 16-bit color your "10-bit" file is immediately downsampled to 8-bit color. That's a total waste of data. 

  • chezlui
    chezlui Website User Posts: 9

    I have the pro version. So the best is to set renderieng in 16 bits float.  Linear or not ?

    whant is bcc ?  Bits by channel ?  I understand what is an 8 bits image ;-)  

    Thanks for your quick responses. I love Hitfilm.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,791 Ambassador

    Correct, bcc= Bits per Color Channel.

    If working in Hitfilm Pro 16-bit linear is arguably the best mode to work in. There's nice high quality color space in 16-bit without getting too sluggish. You CAN work in 32-bit as well, but I think 16-bit is a good middle ground. You can always toggle back to 32-bit for the final render.

    (Again, noting that the 16 or 32 bit color space is internal. If rendering out to mp4 for youtube upload (for example) you're going back to an 8-bit final render... But the higher bitrate workspace will result in fewer "rounding errors" when downsampling for the mp4 render. For best quality renders, Cineform of PC is the best bet and feel free to crank the bit depth (8/10/12 bits) as high as you want.

  • DannyDev
    DannyDev Staff Administrator, HitFilm Beta Tester Posts: 337 Staff

    @Triem23

    To clarify, yes the proxy/pre render format is a propriety lossless high performance format developed for HF.

    Cineform is an excellent format but we had no support for it back when proxies/pre renders were developed.