c# - How to set the speed of an animated gif in .Net using the GifBitmapEncoder class -

i have used sample code found in answer @ how create animated gif in .net

ie

system.windows.media.imaging.gifbitmapencoder genc = new gifbitmapencoder();  foreach (system.drawing.bitmap bmpimage in images) {     var src = system.windows.interop.imaging.createbitmapsourcefromhbitmap(         bmpimage.gethbitmap(),         intptr.zero,         int32rect.empty,         bitmapsizeoptions.fromemptyoptions());     genc.frames.add(bitmapframe.create(src)); } using(filestream fs = new filestream(path, filemode.create)) {     genc.save(fs); } 

i set speed of animate gif. in area terrible. got idea of how it? must surely possible. seems such basic function of animated gif seem have gone out of way make difficult.

thanks in advance.

i don't think can gifbitmapencoder. theoretically, use bitmapmetadata.setquery set value of /grctlext/delay on each frame (the delay specified in graphic control extension of each frame, explained in the wikipedia article). doc says:

graphics interchange format (gif) images not support global preview, global thumbnails, global metadata, frame level thumbnails, or frame level metadata.

which technically incorrect, because gif format does support global , frame-level metadata; it's gifbitmapencoder class doesn't support it.

so think options use another, more complete image manipulation library, or manually. gif format rather simple; it's described in details on site, including parts animation , lzw compression.

alternatively, instead of doing whole encoding yourself, use gifbitmapencoder heavy lifting, , patch metadata in resuting stream afterwards. code in xamlanimatedgif library might help; won't able use directly, reuse parts of it, implements full gif decoder.