Metadata for AVIF, format returned as 'heif'

[tomgallagher]

Using Sharp 27, which now supports AVIF and is great. Thanks!

Downloading this image and then extracting metadata with sharp(inputavif).metadata()

http://download.opencontent.netflix.com.s3.amazonaws.com/AV1/Chimera/AVIF/Chimera-AV1-10bit-1280x720-2380kbps-100.avif

The format returned is heif as that's the encoder used by libvips.

Is it true that this metadata format will be returned for both avif and heic images?

If so, it's not going to be possible to use the metadata to distinguish between the two, one of which is patent-encumbered and cannot be processed without globally installed libvips, as I understand it.

Would it be possible for the libvips metadata to return avif as the format, for consistency with mime type headers and Sharp output format strings?

[lovell]

libvips v8.11.0 will contain logic to expose the heif-compression metadata - see libvips/libvips#1850

[tomgallagher]

Not sure if this is related, but metadata throws error for this animated avif image

https://colinbendell.github.io/webperf/animated-gif-decode/2.avif

I'm guessing not supported at the moment.

[lovell]

$ hexdump -C 2.avif | head -1
00000000  00 00 00 20 66 74 79 70  61 76 69 73 00 00 00 00  |... ftypavis....|

Please see strukturag/libheif#377

[lovell]

v0.29.0 now available.

[adityapatadia]

When we use https://sharp.pixelplumbing.com/api-output#tobuffer with resolveWithObject, it does not return the new compression property.

[lovell]

@adityapatadia This issue relates to the metadata() function - please see d000f57#diff-7593ef01ed4401c670c4acf3cc96c2fbaee20979169fb66f81dddb45b91ec132 for a usage example.

[adityapatadia]

Yes, but ideally resolveWithObject should also return same data as metadata(). For example, when an image is compressed inside a function, its return info should ideally have all info about how was the image encoded.

[lovell]

The object returned/resolved by toBuffer() contains properties that are calculated or might change during processing. The compression property of avif() is known before processing and does not change during.