libwebp: update to 0.5.0

This commit imports libwebp 0.5.0, including AUTHORS, COPYING, ChangeLog,
NEWS, PATENTS, README and src directories. In src, only includes header
and source files.

The patches required to build it in Qt will follow in separate
commit(s).

Change-Id: I96b4961ba63c75cc7fbab158c36a0f403f254c14
Reviewed-by: aavit <eirik.aavitsland@theqtcompany.com>

1 files changed, 29 insertions, 32 deletions

diff --git a/src/3rdparty/libwebp/src/enc/alpha.c b/src/3rdparty/libwebp/src/enc/alpha.c
index 79cb94d..3c970b0 100644
--- a/src/3rdparty/libwebp/src/enc/alpha.c
+++ b/src/3rdparty/libwebp/src/enc/alpha.c
@@ -15,6 +15,7 @@
 #include <stdlib.h>
 
 #include "./vp8enci.h"
+#include "../dsp/dsp.h"
 #include "../utils/filters.h"
 #include "../utils/quant_levels.h"
 #include "../utils/utils.h"
@@ -61,21 +62,16 @@ static int EncodeLossless(const uint8_t* const data, int width, int height,
   if (!WebPPictureAlloc(&picture)) return 0;
 
   // Transfer the alpha values to the green channel.
-  {
-    int i, j;
-    uint32_t* dst = picture.argb;
-    const uint8_t* src = data;
-    for (j = 0; j < picture.height; ++j) {
-      for (i = 0; i < picture.width; ++i) {
-        dst[i] = src[i] << 8;  // we leave A/R/B channels zero'd.
-      }
-      src += width;
-      dst += picture.argb_stride;
-    }
-  }
+  WebPDispatchAlphaToGreen(data, width, picture.width, picture.height,
+                           picture.argb, picture.argb_stride);
 
   WebPConfigInit(&config);
   config.lossless = 1;
+  // Enable exact, or it would alter RGB values of transparent alpha, which is
+  // normally OK but not here since we are not encoding the input image but  an
+  // internal encoding-related image containing necessary exact information in
+  // RGB channels.
+  config.exact = 1;
   config.method = effort_level;  // impact is very small
   // Set a low default quality for encoding alpha. Ensure that Alpha quality at
   // lower methods (3 and below) is less than the threshold for triggering
@@ -87,11 +83,10 @@ static int EncodeLossless(const uint8_t* const data, int width, int height,
   WebPPictureFree(&picture);
   ok = ok && !bw->error_;
   if (!ok) {
-    VP8LBitWriterDestroy(bw);
+    VP8LBitWriterWipeOut(bw);
     return 0;
   }
   return 1;
-
 }
 
 // -----------------------------------------------------------------------------
@@ -143,10 +138,10 @@ static int EncodeAlphaInternal(const uint8_t* const data, int width, int height,
       if (output_size > data_size) {
         // compressed size is larger than source! Revert to uncompressed mode.
         method = ALPHA_NO_COMPRESSION;
-        VP8LBitWriterDestroy(&tmp_bw);
+        VP8LBitWriterWipeOut(&tmp_bw);
       }
     } else {
-      VP8LBitWriterDestroy(&tmp_bw);
+      VP8LBitWriterWipeOut(&tmp_bw);
       return 0;
     }
   }
@@ -166,7 +161,7 @@ static int EncodeAlphaInternal(const uint8_t* const data, int width, int height,
   ok = ok && VP8BitWriterAppend(&result->bw, output, output_size);
 
   if (method != ALPHA_NO_COMPRESSION) {
-    VP8LBitWriterDestroy(&tmp_bw);
+    VP8LBitWriterWipeOut(&tmp_bw);
   }
   ok = ok && !result->bw.error_;
   result->score = VP8BitWriterSize(&result->bw);
@@ -175,16 +170,6 @@ static int EncodeAlphaInternal(const uint8_t* const data, int width, int height,
 
 // -----------------------------------------------------------------------------
 
-// TODO(skal): move to dsp/ ?
-static void CopyPlane(const uint8_t* src, int src_stride,
-                      uint8_t* dst, int dst_stride, int width, int height) {
-  while (height-- > 0) {
-    memcpy(dst, src, width);
-    src += src_stride;
-    dst += dst_stride;
-  }
-}
-
 static int GetNumColors(const uint8_t* data, int width, int height,
                         int stride) {
   int j;
@@ -218,8 +203,9 @@ static uint32_t GetFilterMap(const uint8_t* alpha, int width, int height,
     const int kMaxColorsForFilterNone = 192;
     const int num_colors = GetNumColors(alpha, width, height, width);
     // For low number of colors, NONE yields better compression.
-    filter = (num_colors <= kMinColorsForFilterNone) ? WEBP_FILTER_NONE :
-             EstimateBestFilter(alpha, width, height, width);
+    filter = (num_colors <= kMinColorsForFilterNone)
+        ? WEBP_FILTER_NONE
+        : WebPEstimateBestFilter(alpha, width, height, width);
     bit_map |= 1 << filter;
     // For large number of colors, try FILTER_NONE in addition to the best
     // filter as well.
@@ -250,6 +236,7 @@ static int ApplyFiltersAndEncode(const uint8_t* alpha, int width, int height,
   uint32_t try_map =
       GetFilterMap(alpha, width, height, filter, effort_level);
   InitFilterTrial(&best);
+
   if (try_map != FILTER_TRY_NONE) {
     uint8_t* filtered_alpha =  (uint8_t*)WebPSafeMalloc(1ULL, data_size);
     if (filtered_alpha == NULL) return 0;
@@ -274,7 +261,16 @@ static int ApplyFiltersAndEncode(const uint8_t* alpha, int width, int height,
                              reduce_levels, effort_level, NULL, &best);
   }
   if (ok) {
-    if (stats != NULL) *stats = best.stats;
+    if (stats != NULL) {
+      stats->lossless_features = best.stats.lossless_features;
+      stats->histogram_bits = best.stats.histogram_bits;
+      stats->transform_bits = best.stats.transform_bits;
+      stats->cache_bits = best.stats.cache_bits;
+      stats->palette_size = best.stats.palette_size;
+      stats->lossless_size = best.stats.lossless_size;
+      stats->lossless_hdr_size = best.stats.lossless_hdr_size;
+      stats->lossless_data_size = best.stats.lossless_data_size;
+    }
     *output_size = VP8BitWriterSize(&best.bw);
     *output = VP8BitWriterBuf(&best.bw);
   } else {
@@ -324,7 +320,7 @@ static int EncodeAlpha(VP8Encoder* const enc,
   }
 
   // Extract alpha data (width x height) from raw_data (stride x height).
-  CopyPlane(pic->a, pic->a_stride, quant_alpha, width, width, height);
+  WebPCopyPlane(pic->a, pic->a_stride, quant_alpha, width, width, height);
 
   if (reduce_levels) {  // No Quantization required for 'quality = 100'.
     // 16 alpha levels gives quite a low MSE w.r.t original alpha plane hence
@@ -336,6 +332,7 @@ static int EncodeAlpha(VP8Encoder* const enc,
   }
 
   if (ok) {
+    VP8FiltersInit();
     ok = ApplyFiltersAndEncode(quant_alpha, width, height, data_size, method,
                                filter, reduce_levels, effort_level, output,
                                output_size, pic->stats);
@@ -376,6 +373,7 @@ static int CompressAlphaJob(VP8Encoder* const enc, void* dummy) {
 }
 
 void VP8EncInitAlpha(VP8Encoder* const enc) {
+  WebPInitAlphaProcessing();
   enc->has_alpha_ = WebPPictureHasTransparency(enc->pic_);
   enc->alpha_data_ = NULL;
   enc->alpha_data_size_ = 0;
@@ -430,4 +428,3 @@ int VP8EncDeleteAlpha(VP8Encoder* const enc) {
   enc->has_alpha_ = 0;
   return ok;
 }
-