[PATCH v3 0/1] MR11149: windowscodecs: Decode GIF frames on demand.

[zhengyong chen (＠chenzhengyong)]

The GIF decoder currently calls DGifSlurp() during initialization, which decodes and stores pixel data for every frame in the image.

For animated GIFs with a large number of frames this can result in significant startup time and memory consumption, even when only a single frame is requested by the application.

Change the decoder to scan GIF headers during initialization and defer frame pixel decoding until CopyPixels() is called for a specific frame. This avoids eagerly decoding unused frames while preserving existing decoder behavior.

Signed-off-by: chenzhengyong [e-mail]

tested on deepin v25 & UOS V20.

--
  v3: windowscodecs: Decode GIF frames on demand.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/11149