How can I render out an mp4 / H.264 with an alpha channel? I want to make an animated overlay for my twitch broadcasts and hopefully for other people but I can't even get it to be transparent.
h264 is unnable to export aplha channel (transparency) so you have to use something else to render it. I'm not familiar with Twitch channel settings but mae there is some other file format that can give you alpha channel f.eg. swf
What formats do support it?
I've already said .eg. SWF. There also other formats but not all are suitable for something like overlays on live footage so it would be much easier if you could tell us what video/animation formats are supported by Twitch/broadcast system.
The overlay is actually a video and I don't know how to get transparency or alpha in adobe media encoder but I was able to render the video with alpha in after effects using avi which made a 6 GB file and Quicktime which made a 700 MB file.
Basically I use a program called OBS which I connect to my twitch and use a plugin to play videos. With the video plugin if I have a transparent video then I can have an overlay animate on with monitor capture or game capture behind the video.
Ok, there's some codecs/formats that can export transparency but most of them are intermediate formats (set for best quality not small size) (small list of those you can see here: List of video formats supporting alpha channels) so it will give you bigger file size but if that is not an issue you can use any of those. If you are on windows you can also check Lagarith - lossless avi codec that gives you transparency. If any of those formats/codecs doesn't satisfy your needs then check as I've said earlier: FLV/SWF format. To export that you need one of earlier versions or AE/AME like CS6 or CC but it will give you transparency.
Honestly, i'm still looking for a clean answer to this myself. For a long time I thought it was possible to make H.264's with transparency.
I use .avi codec, it seems to work pretty well.
What I do is take my existing video file and put it into AE, then re-render through media encoder with AE's render options.
I have strained myself looking for a way to do this in Media Encoder only.
You can render your RGB and alpha (matte) channel separate from each other, that way you can get away with pretty small file sizes. H264 does not support integrated alpha channels, even prores only does that in 4444 quality.
Ok, after 6 hours of messing with this I FINALLY have a solution! (I deal primarily with Twitch graphics and OBS) This confirmed works on OBS
**If you don't have Quicktime, download and install it**
1) Make the animated overlay as you normally would
2) On the Render Screen from the drop down select Photoshop Image Sequence, then select PNG
*make sure you make a separate folder and designate it, a 10 sec animation = 240 still images*
3) Open Premiere Pro
4) Select all of the PNGs that were created, drop them into the project window then drag them all onto the timeline
*timing may be off, if it is select all images, right click, Speed / Duration and mine looked fine at 00;00;00;02*
6) Format: Quicktime Preset: GoProCineForm RGB 12-bit with alpha, change output destination to preferred folder, under video settings, up it to max
6) Click Queue, this will open Encoder
7) Click the Play Button
8) Open the generated .mov file in OBS to make sure it works
It's definitely not the most direct or easy method, but it's the only way I could get it to work even after reading forums. Hope this helps
I like this, thanks!
Settings in Adobe Media Encoder:
- Quicktime (.mov)
- GoPro CineForm RGB 12-bit with alpha at Maximum Bit Depth
Interestingly QuickTime is unable to play this movie.
However, I was able to use these settings to convert a .GIF to a .MOV and use this in the Adobe Photoshop Video Timeline to have animated video layers when creating your animation. Pretty awesome.
Does the standard RGB+Alpha MOV from AE not work in OBS?
Isn't MOV depcrecated now as a format as QuickTime is now no longer supported by Apple?
For Twitch stream overlays, I recommend the WebM container since it provides RGB+A. You can download the codec here for use in Adobe Media Encoder (AME). Install it and it will appear in your list of encoding options in AME. Just remember to check "Include Alpha Channel".