How do I write/export my Natron video with an alpha channel?

Software Natron
1

Hi. I am new to Natron. I was working on a stinger transition for OBS and SLOBS in Natron 2.3.14. Everything was easy, except for the write/export action. I tried various containers with codecs, including MOV with QTRLE, MP4 with PNG, Matroska with H264, AVI with FFV1, etc. No luck. The supposed transparency was replaced with a single black color. Why does this happen, and how can I fix it?

2

I always export image sequences, e.g. *.png

Then you can use ffmpeg to create a movie or most video softwares instantly support importing folders containing image sequences.

BTW.
with this approach you will never have frame rate trouble and when you change something in your comp, you would only have to re-render this particular bit. If you get used to it, you will love it.
For preview you could use DJV.

3

Please also check this topic: Problems with transparency

4

How do I export it however, so that the transparency remains?

5

If you’re using OBS or any custom of it (like SLOBS), I suggest container QuickTime, codec pro res 4444.

Choose your export location and file name. Then click render.

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6

I did that, however it remains opaque

7

please post screenshot of your write node’s settings

8

I haven’t checked alpha, so it didn’t work. That was the problem.

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9

There’s also Quicktime RLE also known as Quicktime Animation, which supports an alpha channel without the large size of ProRes 4444. This is especially useful when your source material is 8bit footage and does not benefit from 4444.

Alternatively there’s GoPro Cineform, OpenEXR and DnxHD/DnxHR of which the first two are open source.

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