Quality issues for animated images

Description

My code includes the setting of this limitation:

/// Limits scale down to 24MB.
SDImageCoderHelper.defaultScaleDownLimitBytes = 24 * 1_024 * 1_024

When I get an animated image data that weighs 1.8 MB, the quality is severely degraded, and if I saw correctly my final image was 0.5 MB. I tried to play around with setting the value and in the end I got an image of 7200 bytes with the 1 MB limit set.

This was strange to me, so I tried exploring the codebase and seemed to find the problem in this line: https://github.com/SDWebImage/SDWebImageWebPCoder/pull/75/files#diff-e9c046b25a4d1b5fd2e490c2ebc802f1a63ef0459e0ad74dd3647f72d9c68323R94

Am I misunderstanding the expected behavior? Because it looks like a bug to me. Since it is strange that by setting the limit to 24 MB I get image quality degradation and image size reduction when its image data size is only 1.77 MB.

Also maybe you can tell me why when I try to download a heavy image and several small images, if the heavy image was added earlier, I don't get a response for the small images until the large one is downloaded? (It is important to note that I am considering the case of downloading an image from disk or over the network, only in these cases this happens).

Beginne mit SDImageCoderHelper.defaultScaleDownLimitBytes und prüfe den verknüpften SDWebImageWebPCoder-Pull-Request in der referenzierten Zeile. Reproduziere das Verhalten hinsichtlich Qualität und Größe animierter Bilder mit den angegebenen Limits und untersuche anschließend die Reihenfolge der Downloads von der Festplatte bzw. aus dem Netzwerk separat. Die Aufgabe ist erledigt, wenn die beobachteten Verhaltensweisen erklärt sind und alle bestätigten Regressionen gezielte Tests haben.