Multi Page pdf conversion

First of all, this project is amazing.

I have a question is about sharp api.

I am converting multi-pages pdf files to jpeg (each page is a separate file). What would be most efficient way to do this? This is a sample implementation that I am using now.

const input = getBufferSomeHow()
const metatada = await sharp(input).metadata()
const conversions = []
for (let i = 0; i < metadata.pages; i++) {
  conversions.push(
   sharp(input, {
       density: myDensity,
       pages: 1,
       page: i,
   }.jpeg().toBuffer())
}
const buffers = await Promise.all(conversions)

When I say most efficient I mean that “given an input buffer that is a multipage pdf, what is the best way to use that buffer to convert its pages in single jpeg files? Is the approach of instantiating sharp every time valid?”. Would sharp.clone help in any way?

Thank you 😄 .

[lovell]

Both your approaches look good to me given the complete PDF/GIF is already in memory, or at least on a fast local filesystem. libvips’ default caching should help too - use sharp.cache() to check.

[dnlup]

@brecke Last thing, you might find this useful