libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/dec/idec.c

 // Copyright 2011 Google Inc. All Rights Reserved.
 //
 // This code is licensed under the same terms as WebM:
 //  Software License Agreement:  http://www.webmproject.org/license/software/
 //  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
 // -----------------------------------------------------------------------------
 //
 // Incremental decoding
 //
 // Author: somnath@google.com (Somnath Banerjee)
@@ skipping 407 matching lines @@
       SaveContext(dec, token_br, &context);
 
       if (!VP8DecodeMB(dec, token_br)) {
         RestoreContext(&context, dec, token_br);
         // We shouldn't fail when MAX_MB data was available
         if (dec->num_parts_ == 1 && MemDataSize(&idec->mem_) > MAX_MB_SIZE) {
           return IDecError(idec, VP8_STATUS_BITSTREAM_ERROR);
         }
         return VP8_STATUS_SUSPENDED;
       }
+      // Reconstruct and emit samples.
       VP8ReconstructBlock(dec);
-      // Store data and save block's filtering params
-      VP8StoreBlock(dec);
 
       // Release buffer only if there is only one partition
       if (dec->num_parts_ == 1) {
         idec->mem_.start_ = token_br->buf_ - idec->mem_.buf_;
         assert(idec->mem_.start_ <= idec->mem_.end_);
       }
     }
     if (!VP8ProcessRow(dec, io)) {
       return IDecError(idec, VP8_STATUS_USER_ABORT);
     }
@@ skipping 148 matching lines @@
   ClearMemBuffer(&idec->mem_);
   WebPFreeDecBuffer(&idec->output_);
   free(idec);
 }
 
 //------------------------------------------------------------------------------
 // Wrapper toward WebPINewDecoder
 
 WebPIDecoder* WebPINewRGB(WEBP_CSP_MODE mode, uint8_t* output_buffer,
                           size_t output_buffer_size, int output_stride) {
+  const int is_external_memory = (output_buffer != NULL);
   WebPIDecoder* idec;
+
   if (mode >= MODE_YUV) return NULL;
+  if (!is_external_memory) {    // Overwrite parameters to sane values.
+    output_buffer_size = 0;
+    output_stride = 0;
+  } else {  // A buffer was passed. Validate the other params.
+    if (output_stride == 0 || output_buffer_size == 0) {
+      return NULL;   // invalid parameter.
+    }
+  }
   idec = WebPINewDecoder(NULL);
   if (idec == NULL) return NULL;
   idec->output_.colorspace = mode;
-  idec->output_.is_external_memory = 1;
+  idec->output_.is_external_memory = is_external_memory;
   idec->output_.u.RGBA.rgba = output_buffer;
   idec->output_.u.RGBA.stride = output_stride;
   idec->output_.u.RGBA.size = output_buffer_size;
   return idec;
 }
 
 WebPIDecoder* WebPINewYUVA(uint8_t* luma, size_t luma_size, int luma_stride,
                            uint8_t* u, size_t u_size, int u_stride,
                            uint8_t* v, size_t v_size, int v_stride,
                            uint8_t* a, size_t a_size, int a_stride) {
-  WebPIDecoder* const idec = WebPINewDecoder(NULL);
+  const int is_external_memory = (luma != NULL);
+  WebPIDecoder* idec;
+  WEBP_CSP_MODE colorspace;
+
+  if (!is_external_memory) {    // Overwrite parameters to sane values.

[fbarchard, 2013/03/22 18:56:44]

2 spaces before //

[jzern, 2013/03/22 19:10:36]

minimum. horizontal whitespace is allowed if it adds readability. I'll admit
that some of this may have gotten ragged in it's own right, but this is a
snapshot update of a stable release. cosmetics can go upstream...

+    luma_size = u_size = v_size = a_size = 0;
+    luma_stride = u_stride = v_stride = a_stride = 0;
+    u = v = a = NULL;
+    colorspace = MODE_YUVA;

[fbarchard, 2013/03/22 18:56:44]

planar YUV with alpha?
i may want to support this via fourcc in libyuv, if you have a standard, for
high speed conversion to argb.

[jzern, 2013/03/22 19:10:36]

Just a full plane (WxH) of alpha [0, 255] here

+  } else {  // A luma buffer was passed. Validate the other parameters.
+    if (u == NULL || v == NULL) return NULL;
+    if (luma_size == 0 || u_size == 0 || v_size == 0) return NULL;
+    if (luma_stride == 0 || u_stride == 0 || v_stride == 0) return NULL;
+    if (a != NULL) {
+      if (a_size == 0 || a_stride == 0) return NULL;
+    }
+    colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA;
+  }
+
+  idec = WebPINewDecoder(NULL);
   if (idec == NULL) return NULL;
-  idec->output_.colorspace = (a == NULL) ? MODE_YUV : MODE_YUVA;
-  idec->output_.is_external_memory = 1;
+
+  idec->output_.colorspace = colorspace;
+  idec->output_.is_external_memory = is_external_memory;
   idec->output_.u.YUVA.y = luma;
   idec->output_.u.YUVA.y_stride = luma_stride;
   idec->output_.u.YUVA.y_size = luma_size;
   idec->output_.u.YUVA.u = u;
   idec->output_.u.YUVA.u_stride = u_stride;
   idec->output_.u.YUVA.u_size = u_size;
   idec->output_.u.YUVA.v = v;
   idec->output_.u.YUVA.v_stride = v_stride;
   idec->output_.u.YUVA.v_size = v_size;
   idec->output_.u.YUVA.a = a;
@@ skipping 147 matching lines @@
   idec->io_.setup = setup;
   idec->io_.teardown = teardown;
   idec->io_.opaque = user_data;
 
   return 1;
 }
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif