libwebp: upstream animation cherry-picks

third_party/libwebp/webp/mux.h

 // Copyright 2011 Google Inc. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the COPYING file in the root of the source
 // tree. An additional intellectual property rights grant can be found
 // in the file PATENTS. All contributing project authors may
 // be found in the AUTHORS file in the root of the source tree.
 // -----------------------------------------------------------------------------
 //
 //  RIFF container manipulation for WEBP images.
@@ skipping 181 matching lines @@
 struct WebPMuxFrameInfo {
   WebPData    bitstream;  // image data: can either be a raw VP8/VP8L bitstream
                           // or a single-image WebP file.
   int         x_offset;   // x-offset of the frame.
   int         y_offset;   // y-offset of the frame.
   int         duration;   // duration of the frame (in milliseconds).
 
   WebPChunkId id;         // frame type: should be one of WEBP_CHUNK_ANMF,
                           // WEBP_CHUNK_FRGM or WEBP_CHUNK_IMAGE
   WebPMuxAnimDispose dispose_method;  // Disposal method for the frame.
-  uint32_t    pad[2];     // padding for later use
+  WebPMuxAnimBlend   blend_method;    // Blend operation for the frame.

[fbarchard, 2013/08/21 02:00:13]

Is WebPMuxAnimBlend   blend_method; a full int?

[urvang (Google), 2013/08/21 02:16:51]

I guess the question comes from the fact that we decremented padding size by 1.

IIRC, the size of WebPMuxAnimBlend is not guaranteed to be that of an int (as 1
byte can hold it too), but most implementations would make the size to be that
of an int.

+  uint32_t    pad[1];     // padding for later use
 };
 
 // Sets the (non-animated and non-fragmented) image in the mux object.
 // Note: Any existing images (including frames/fragments) will be removed.
 // Parameters:
 //   mux - (in/out) object in which the image is to be set
 //   bitstream - (in) can either be a raw VP8/VP8L bitstream or a single-image
 //               WebP file (non-animated and non-fragmented)
 //   copy_data - (in) value 1 indicates given data WILL be copied to the mux
 //               and value 0 indicates data will NOT be copied.
@@ skipping 135 matching lines @@
 WEBP_EXTERN(WebPMuxError) WebPMuxAssemble(WebPMux* mux,
                                           WebPData* assembled_data);
 
 //------------------------------------------------------------------------------
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif
 
 #endif  /* WEBP_WEBP_MUX_H_ */