How to export MP4 (media encoder) with a transparent background

[katw81299112]

How do you export a .MP4 video through Adobe Media Encoder with a transparent background?

I understand when you add to render queue you choose the RGB+Alpha channel. But where is this option in Adobe Media Encoder?

Project Specs: Format .MP4

Frame Rate: 60 fps

Frame Size: 1920x1080

Field Order: Progressive

Used codec: H264

Bit Rate: 40 Mbps

Thank you

[OussK]

MP4 not supported alpha channel, so if you need alpha you must use something like apple ProRez, or you can export each channel separately as MP4 so you will get one file for RGB and one For alpha channel .

[katw81299112]

Can you translate that a little simpler please?

[OussK]

Please check this alpha channel in media encoder cc 2018

and let me know if you get the idea 

[Kristian Gabriel]

OussK is correct that an .MP4 in it's current variation and format cannot have transparency at all. Exporting your files into this format will be completely flattened. Just as a side note, there are very few acceptable video files with transparency for web. CSS, Flash and HTML 5 Video which have been used to trick transparency for MP4 files have been used before.  If you want transparency, for web or editorial, here are your best options:

VIDEO OPTIONS FOR TRANSPARENCY:

• Quicktime (.MOV/Cineform): For Offline/Online Video Editing
• Quicktime (.MOV/DNxHD/HR): For Offline/Online Video Editing
• Quicktime (.MOV/Prores 4444): For Offline/Online Video Editing
• Quicktime (.MOV/PNG): For Offline/Online Video Editing
• Quicktime (.MOV/Animation): For Offline/Online Video Editing
• Quicktime (.MOV/J2K): For Offline/Online Video Editing

Of course there are other formats, but these mezzanine or intermediate/smart codecs are some of the best for ongoing editing.

STILL OPTIONS FOR TRANSPARENCY:

PNG (Portable Network Graphics File): PNG was made for transparency on web, however, it is used quite a bit in video as well. This format is best for graphics and videos with high complexity in color.

SVG (Scalable Vector Format): SVG files are a modern day sensation. It can be both Raster and Vector and be used for Print and Web. It can contain transparency as well.

PDF (Portable Document Format): PDFs are a staple for Print and online documents. PDF supports massive amounts of transparency depending on the version.

GIF (Graphic Interchange Format): Index file with the potential for transparency. Best for graphics without color complexity or gradients.

[wendyp77697944]

to have a transparent background, i need to use alpha channel.

however, i found that alpha channel is only available in quicktime

but i need to export the file in mp4 file.

can you tell me a way i can export the file in mp4 and have alpha channel?

thank you.

[Roland Kahlenberg · Accepted solution]

The MP4 file format does not support an Alpha Channel. If you require an Alpha Channel for your MP4, you will need to render the Alpha Channel as a separate movie. IOW, One movie for the RGB Channels and another movie for the Alpha Channel. Use QuickTime Animation or DNxHD CODECs if you want a single file output with both the RGB and Alpha Channels.

[Rick Gerard]

Quicktime JPEG 2000, Cineware - free from GoPro, and several other formats support alpha channels. Compressed formats are 8 bit color per channel for a with a total of 24 bits. For a video format to support Alpha Channels you need at least 8 bits per channel and four (4) channels for a total of 32-bits. I know that's confusing because it is easy to think of 32-bit formats as trillions of colors but when you are describing video formats a 32-bit file is a format with four 8-bit color channels, the fourth one being a grayscale alpha channel. There are formats that support 10-bit, 12-bit, 16-bit and even 32-bit color per channel that also support 4 channels.

It is even more complicated than that.  Red Green Blue and Alpha channels are just the beginning. It is common in professional 3D rendering to also include things like depth, occlusion, specularity and other things in the rendered files. Some formats like Open EXR support even allow you to assign a bunch of random things to the available channels:

OpenEXR's multi-resolution and arbitrary channel format makes it appealing for compositing, as it alleviates several painful elements of the process. Since it can store arbitrary channels—specular, diffuse, alpha, RGB, normals, and various other types—in one file, it takes away the need to store this information in separate files. The multi-channel concept also reduces the necessity to "bake" in the aforementioned data to the final image. If a compositer is not happy with the current level of specularity, they can adjust that specific channel. (from  Wikipedia)

If you want to dabble in video, there is a lot you need to learn about video formats and standards to produce predictable and consistent results when you render.

[FamilialPunch]

Hey, can you please explain how to do this or perhaps refer me to a vid?

[Melany]

MP4 DOES support a transparency (alpha) option. Most people think MP4 uses the H264 codec, however, you can export the video in the H265 codec that supports an Alpha layer (HEVC) on this date (December 2022) Adobe software (premiere and After effects) does not support the export of alpha included H265 mp4. But there is third-party software that does have this option.

[key10reeder]

Melany, Do you have any idea which third party software has an option for this? Thank you. 

[Garry Turner]

Did anyone work out what third-party software it was?

[PurpleSun00]

Adobe Media Encoder has built-in H265 codec, at least in the 2023 version.

[Till Krueger]

While there appears to be no way to create an H264 MP4 file with alpha channel (due to limitations of the codec itself), the one way that I found, to create a video file with alpha channel, is to render a VP9 (.webm) file. To do this, I found an amazing utility called Shutter Encoder, which is free, but supported by donations, so I would strongly suggest to pay a small donation to the author, as it is an incredibly powerful, easy-to-use, and professional utility:

https://www.shutterencoder.com/

[mauro_2921]

Also check out ffmpeg 

[AndrewTheGreat]

The AE script called MP4 + Alpha does the job

[Garry Turner]

Hi Andrew, can you expand on this a bit more? thanks

[OussK]

You can learn more about the script here https://aescripts.com/mp4-plus-alpha/