Export ProRes 4444 with Alpha Channel using FFmpeg

Exporting video with transparency is essential for professional motion graphics and post-production workflows. This guide provides the exact FFmpeg command needed to export Apple ProRes 4444 video while preserving its alpha channel, along with a clear explanation of how each parameter works to ensure a high-quality, transparent video output.

To export a video with ProRes 4444 and an alpha channel, run the following FFmpeg command in your terminal:

ffmpeg -i input.mov -c:v prores_ks -profile:v 4 -pix_fmt yuva444p10le output.mov

Command Parameter Breakdown

• -i input.mov: Specifies the path to your input file. Note that your source file must already contain transparency (such as a PNG sequence, a transparent WebM, or a green-screen keyed video) for the alpha channel to carry over.
• -c:v prores_ks: Selects the Kostya ProRes encoder (prores_ks). This specific encoder is highly recommended for handling alpha channels and ensuring accurate color profiles.
• -profile:v 4: Sets the ProRes profile to ProRes 4444. In FFmpeg, profile 4 represents the standard 4444 codec, which is the minimum profile required to support alpha transparency.
• -pix_fmt yuva444p10le: Sets the pixel format to 10-bit YUV with an Alpha channel. The “a” in yuva is the critical component that tells FFmpeg to write the transparency data into the final file.
• output.mov: The destination path for your exported video. ProRes files must be wrapped in a QuickTime .mov container.

Key Considerations

• Verify Source Transparency: If your input source does not contain an alpha channel, the resulting ProRes video will render with a solid black background instead of transparency.
• File Size: ProRes 4444 is an intermediate, visually lossless codec. Be prepared for large file sizes, as this format is designed for maximum quality during editing rather than web delivery.