Really like the new Proxy feature - thank you very much for implementing it! It makes a world of difference to editing performance and works very well even when moving projects between machines and recreating proxy files.
I have one issue - I have some MP4 footage which has previously been converted/compressed using Handbrake software, I have found it is not possible to create proxies for some of these (either automatically or manually from “properties”).
I have run some tests using different Handbrake conversion profiles:
Production Standard (actually designed for editing - 1080p HD) – proxy can be created
General Fast 1080p30 - proxy function not available
General Super HQ 1080p30 - proxy function not available
I guess there is something in the compression format that prevents it - however I’m curious whether it would be possible to automatically reduce these already compressed files from 1080p to 540p proxies to speed up editing (I do a lot of picture-in-picture!). I realise I can do this manually where I need to
It seems the Handbrake Production proxy profiles work fine (which is what I am using to make a proxy manually i.e. the 540p profile preset).
Footage which has previously been compressed with the “General” profiles does not allow/give the “Make proxy” option in clip properties as in this screenshot:
I’m curious as to why it’s not possible to make a 540p proxy within Shotcut from the 1080p file in the example?
Why make a proxies of the converted/compressed versions of the files? Why not make proxies of the original files?
Also, take another screenshot of that Properties tab of that file that Shotcut doesn’t allow to make a proxy of but this time scroll down so we can see what it says for “Format”.
The originals are long gone, the files were compressed for archival purposes and I can work around this, no problem.
Having noticed it’s not possible with these file I’m just curious if this is a function of the compression/headers implemented by Handbrake which prevent Shotcut from making a smaller proxy, a design intent decision in Shotcut devlopment, or an error/something that can be improved?
Thanks for the screenshot. You say that you can create a proxy from the Production Standard Handbrake preset. What’s the format listed in Properties for the Production Standard version of the file into Shotcut?
I’m not sure why Shotcut is not detecting your source file to make a proxy. However, you can use the Production Standard Handbrake preset to do your editing rather than having to create a proxy. It along with the Production Max preset are Handbrake’s intermediate formats. Intermediate formats mean files that are at least visually lossless which means you cannot see with the naked eye any loss of quality in picture. They are used to entirely replace the original file. So unlike proxies which only replace the source files for editing but not for export an intermediate file replaces the source file for both editing and export.
I would just make a couple of adjustments to the Handbrake settings. When you pick either Production Standard or Production Max, go to the Video tab and in the Advanced Options make sure that right at the start it says “keyint=1”. It’ll make the file bigger in size but that will make the file will be much easier to read in an editor so it will play as smooth as a proxy. After that, go to the Audio tab and make sure to pick Auto Pass through that way you aren’t bringing the audio down any generation.
By the way, Shotcut has presets for intermediate formats too. You can find them in two places. One in the Convert to Edit-friendly option that is to the left of the Proxy button in Properties. The intermediate options there are DNxHR and Ut Video.
The second place is at the intermediate category in the Export presets. You’ll see DNxHR HQ which is basically the same as the DNxHR setting in Convert to Edit-friendly as well as two ProRes options. If you want ProRes in your case you’ll probably want ProRes 422 as ProRes HQ will producer much bigger sized files than ProRes 422.
There is also the lossless category of which you’ll find Ut Video and HuffYUV which both can also be used as intermediate files.
The sizes of the files will come out much, much bigger than proxies but the advantage is that you are working with video that is at the full original resolution while having smooth playback in the editor like you would with a proxy. So since you already have the space to produce an intermediate file you might as well just go all the way with the intermediate file in your project.
Many thanks @DRM for the answer and all the additional information - I will do as you suggest in Handbrake in future, that is super useful stuff! I have tried the Shotcut intermediate formats - also a great feature.
The proxy features are still super useful and make for a really nice tidy, workflow (especially being able to specify a global temp folder for proxies) - so in future I will hopefully be working with non-Handbrake compressed footage
The way Handbrake is encoding these triggers Shotcut’s heuristic for cover art, and Shotcut does not permit creating proxy if it thinks the video is simply cover art (popular in mp3 files). I fixed this for the next version 20.09 by making the covert art heuristic more strict to also include codec (cover art is almost always JPEG).
Does MLT Framework provide access to ffmpeg’s stream dispositions? Album art will have DISPOSITION:attached_pic=1 in response to a probe:
ffprobe -i "Music.mp3" -show_entries stream
In some cases, disposition may be more accurate than looking at the codec name because PNG and BMP are also allowed. PNG is often associated with FLAC because they’re committed to the whole lossless vibe. My fear would be mjpeg referring to a legit video clip and it gets blocked from making a proxy.
