Proxy file

Autograph's cache system aims to optimize loading and processing images by generating mipmaps. However, file reading itself can require a lot of time and even fill up the cache folder rather quickly.

Two factors can influence reading efficiency:

  • Very large images, such as 4K, 8K, or 12K formats, putting a lot of strain on storage and the CPU.
  • The codec used to encode the file, which can require a lot of power during decoding, especially when the codec uses GOP (Group of Pictures).

The solution to be able to work with these formats smoothly is to produce a smaller, lightweight replacement file known as a Proxy that uses faster decoding codecs.

For example: If you work with a single-pass 4K EXR image sequence to be read at 24 FPS, compressed with ZIPS scheme, and encoded in 32bpc float (full), you could use a proxy with the following specs:

  • Format: FullHD/1080p or 720p
  • 24 FPS
  • Codec: ProRes 422

In the Reader parameters, use the Proxy File to set the path to this video file which works in the same way as the File parameter.

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The output image size will remain 4K in our example, but the original file won't be used under certain conditions. The proxy will automatically be stretched and filtered according the Filter parameter of the layer using this source. No need to temporarily scale your layers to compensate for the size difference. Everything is undetectable. You can assume that you are still working with the original 4K footage and only notice definition loss based on the size difference.

With the Proxy Mode parameter, you can define the rule used for switching from the original file to the proxy and back:

  • Always: the proxy is always used
  • Never: the proxy is never used
  • Greater or Equal: if the final size of the layer using the Source in the Viewer (after Transform) is greater than or equal to the proxy size, the original file is used.
  • Nearest: same concept as Greater or Equal, but compares the current size in the Viewer to the original file and proxy, then uses the nearest in terms of definition.

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Manage proxies in the Render Manager:

Proxies can be turned ON or OFF when you render the final sequence. This way, you can work smoothly with proxies, check details from time to time in the Viewer by switching to your original footage, then render your final sequence with full definition footage.

For more detail, refer to the Render Manager section.