From 237eab6764722adb00643c981802eb4be10b2bbe Mon Sep 17 00:00:00 2001
From: Vikas Arora <vikasa@google.com>
Date: Wed, 23 May 2012 12:08:44 +0530
Subject: [PATCH] Add two more color-spaces for lossless decoding.

Added color-spaces (RGBA_4444 and RGB_565), required for Android device
to lossless decoding.

Change-Id: I229832edd4deca59e066f463e7454f77457c5bcd
---
 src/dec/vp8l.c     |  4 ++--
 src/dsp/lossless.c | 34 ++++++++++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/src/dec/vp8l.c b/src/dec/vp8l.c
index 63b0d8b1..148dac40 100644
--- a/src/dec/vp8l.c
+++ b/src/dec/vp8l.c
@@ -946,8 +946,8 @@ int VP8LDecodeImage(VP8LDecoder* const dec) {
   params = (WebPDecParams*)io->opaque;
   assert(params != NULL);
   output = params->output;
-  // RGBA_4444 & RGB_565 are unsupported for now & YUV modes are invalid.
-  if (output->colorspace >= MODE_RGBA_4444) {
+  // YUV modes are invalid.
+  if (output->colorspace >= MODE_YUV) {
     dec->status_ = VP8_STATUS_INVALID_PARAM;
     goto Err;
   }
diff --git a/src/dsp/lossless.c b/src/dsp/lossless.c
index f40c698c..42576a0f 100644
--- a/src/dsp/lossless.c
+++ b/src/dsp/lossless.c
@@ -966,7 +966,7 @@ static int is_big_endian(void) {
 
 static void ConvertBGRAToRGB(const uint32_t* src,
                              int num_pixels, uint8_t* dst) {
-  const uint32_t* src_end = src + num_pixels;
+  const uint32_t* const src_end = src + num_pixels;
   while (src < src_end) {
     const uint32_t argb = *src++;
     *dst++ = (argb >> 16) & 0xff;
@@ -977,7 +977,7 @@ static void ConvertBGRAToRGB(const uint32_t* src,
 
 static void ConvertBGRAToRGBA(const uint32_t* src,
                               int num_pixels, uint8_t* dst) {
-  const uint32_t* src_end = src + num_pixels;
+  const uint32_t* const src_end = src + num_pixels;
   while (src < src_end) {
     const uint32_t argb = *src++;
     *dst++ = (argb >> 16) & 0xff;
@@ -987,9 +987,29 @@ static void ConvertBGRAToRGBA(const uint32_t* src,
   }
 }
 
+static void ConvertBGRAToRGBA4444(const uint32_t* src,
+                                  int num_pixels, uint8_t* dst) {
+  const uint32_t* const src_end = src + num_pixels;
+  while (src < src_end) {
+    const uint32_t argb = *src++;
+    *dst++ = ((argb >> 16) & 0xf0) | ((argb >> 12) & 0xf);
+    *dst++ = ((argb >>  0) & 0xf0) | ((argb >> 28) & 0xf);
+  }
+}
+
+static void ConvertBGRAToRGB565(const uint32_t* src,
+                                int num_pixels, uint8_t* dst) {
+  const uint32_t* const src_end = src + num_pixels;
+  while (src < src_end) {
+    const uint32_t argb = *src++;
+    *dst++ = ((argb >> 16) & 0xf8) | ((argb >> 13) & 0x7);
+    *dst++ = ((argb >>  5) & 0xe0) | ((argb >>  3) & 0x1f);
+  }
+}
+
 static void ConvertBGRAToBGR(const uint32_t* src,
                              int num_pixels, uint8_t* dst) {
-  const uint32_t* src_end = src + num_pixels;
+  const uint32_t* const src_end = src + num_pixels;
   while (src < src_end) {
     const uint32_t argb = *src++;
     *dst++ = (argb >>  0) & 0xff;
@@ -1001,7 +1021,7 @@ static void ConvertBGRAToBGR(const uint32_t* src,
 static void CopyOrSwap(const uint32_t* src, int num_pixels, uint8_t* dst,
                        int swap_on_big_endian) {
   if (is_big_endian() == swap_on_big_endian) {
-    const uint32_t* src_end = src + num_pixels;
+    const uint32_t* const src_end = src + num_pixels;
     while (src < src_end) {
       uint32_t argb = *src++;
 #if !defined(__BIG_ENDIAN__) && (defined(__i386__) || defined(__x86_64__))
@@ -1043,6 +1063,12 @@ void VP8LConvertFromBGRA(const uint32_t* const in_data, int num_pixels,
     case MODE_ARGB:
       CopyOrSwap(in_data, num_pixels, rgba, 0);
       break;
+    case MODE_RGBA_4444:
+      ConvertBGRAToRGBA4444(in_data, num_pixels, rgba);
+      break;
+    case MODE_RGB_565:
+      ConvertBGRAToRGB565(in_data, num_pixels, rgba);
+      break;
     default:
       assert(0);          // Code flow should not reach here.
   }