I'm implementing a image renderer on an external device and want to include GIF animation support. So far this is working fine, but I've found a difficulty that comes from for image.Decode's file type detection is registered.
What I have is shim type that wraps *gif.GIF but also implements image.Image. Registering the decoder for this for "GIF8?a" does not work because the registration function, image.RegisterFormat appends the registration details to the existing registered formats. Since my code depends on "image/gif", the package registration has already happened during init and I don't see a way to ever beat the "image/gif" registration call during init. The workaround is to seek to the start of the file if image.Decode finds a gif, which is inefficient and will not handle the case of a non-seekable io.Reader. The alternative is to replicate the image.Decode functionality, including registration which seems ugly. The existing behaviour is somewhat surprising since there is no indication in the docs that a new registration of the same magic bytes will not work. Is there a commonly used work-around for this? Would a change to image.RegisterFormat that did a replacement of existing registrations that are identical to a new registration rather than an append be entertained (I can see good reasons for a no here)? Dan -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/63152ea80145ea3076f68772e3d03156ba23f680.camel%40kortschak.io.
