New drop of Skia. This is up to CL 121320.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@6925 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 262 insertions, 105 deletions

diff --git a/skia/images/SkImageDecoder_libjpeg.cpp b/skia/images/SkImageDecoder_libjpeg.cpp
index 0d8da7ef..492de23 100644
--- a/skia/images/SkImageDecoder_libjpeg.cpp
+++ b/skia/images/SkImageDecoder_libjpeg.cpp
@@ -1,16 +1,16 @@
 /*
- * Copyright 2007, Google Inc.
+ * Copyright 2007, The Android Open Source Project
  *
- * Licensed under the Apache License, Version 2.0 (the "License"); 
- * you may not use this file except in compliance with the License. 
- * You may obtain a copy of the License at 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
  *
- *     http://www.apache.org/licenses/LICENSE-2.0 
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * Unless required by applicable law or agreed to in writing, software 
- * distributed under the License is distributed on an "AS IS" BASIS, 
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
- * See the License for the specific language governing permissions and 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 
@@ -25,6 +25,7 @@
 #include <stdio.h>
 extern "C" {
     #include "jpeglib.h"
+    #include "jerror.h"
 }
 
 // this enables timing code to report milliseconds for an encode
@@ -49,8 +50,21 @@ protected:
                           SkBitmap::Config pref, Mode);
 };
 
-SkImageDecoder* SkImageDecoder_JPEG_Factory(SkStream* stream) { 
-    // !!! unimplemented; rely on PNG test first for now
+SkImageDecoder* SkImageDecoder_JPEG_Factory(SkStream* stream) {
+    static const char gHeader[] = { 0xFF, 0xD8, 0xFF };
+    static const size_t HEADER_SIZE = sizeof(gHeader);
+
+    char buffer[HEADER_SIZE];
+    size_t len = stream->read(buffer, HEADER_SIZE);
+
+    if (len != HEADER_SIZE) {
+        return NULL;   // can't read enough
+    }
+    
+    if (memcmp(buffer, gHeader, HEADER_SIZE)) {
+        return NULL;
+    }
+
     return SkNEW(SkJPEGImageDecoder);
 }
 
@@ -77,10 +91,12 @@ private:
 /* our source struct for directing jpeg to our stream object
 */
 struct sk_source_mgr : jpeg_source_mgr {
-    sk_source_mgr(SkStream* stream);
+    sk_source_mgr(SkStream* stream, SkImageDecoder* decoder);
 
     SkStream*   fStream;
-
+    const void* fMemoryBase;
+    size_t      fMemoryBaseSize;
+    SkImageDecoder* fDecoder;
     enum {
         kBufferSize = 1024
     };
@@ -111,11 +127,13 @@ static void sk_init_source(j_decompress_ptr cinfo) {
 
 static boolean sk_fill_input_buffer(j_decompress_ptr cinfo) {
     sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
+    if (src->fDecoder != NULL && src->fDecoder->shouldCancelDecode()) {
+        return FALSE;
+    }
     size_t bytes = src->fStream->read(src->fBuffer, sk_source_mgr::kBufferSize);
     // note that JPEG is happy with less than the full read,
     // as long as the result is non-zero
     if (bytes == 0) {
-        cinfo->err->error_exit((j_common_ptr)cinfo);
         return FALSE;
     }
 
@@ -129,11 +147,13 @@ static void sk_skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
 
     sk_source_mgr*  src = (sk_source_mgr*)cinfo->src;
 
-    long skip = num_bytes - src->bytes_in_buffer;
+    long bytesToSkip = num_bytes - src->bytes_in_buffer;
 
-    if (skip > 0) {
-        size_t bytes = src->fStream->read(NULL, skip);
-        if (bytes != (size_t)skip) {
+    // check if the skip amount exceeds the current buffer
+    if (bytesToSkip > 0) {
+        size_t bytes = src->fStream->skip(bytesToSkip);
+        if (bytes != (size_t)bytesToSkip) {
+//            SkDebugf("xxxxxxxxxxxxxx failure to skip request %d actual %d\n", bytesToSkip, bytes);
             cinfo->err->error_exit((j_common_ptr)cinfo);
         }
         src->next_input_byte = (const JOCTET*)src->fBuffer;
@@ -150,22 +170,69 @@ static boolean sk_resync_to_restart(j_decompress_ptr cinfo, int desired) {
     // what is the desired param for???
 
     if (!src->fStream->rewind()) {
-        printf("------------- sk_resync_to_restart: stream->rewind() failed\n");
+        SkDebugf("xxxxxxxxxxxxxx failure to rewind\n");
         cinfo->err->error_exit((j_common_ptr)cinfo);
         return FALSE;
     }
+    src->next_input_byte = (const JOCTET*)src->fBuffer;
+    src->bytes_in_buffer = 0;
     return TRUE;
 }
 
 static void sk_term_source(j_decompress_ptr /*cinfo*/) {}
 
-sk_source_mgr::sk_source_mgr(SkStream* stream)
-        : fStream(stream) {
-    init_source = sk_init_source;
-    fill_input_buffer = sk_fill_input_buffer;
-    skip_input_data = sk_skip_input_data;
-    resync_to_restart = sk_resync_to_restart;
-    term_source = sk_term_source;
+///////////////////////////////////////////////////////////////////////////////
+
+static void skmem_init_source(j_decompress_ptr cinfo) {
+    sk_source_mgr*  src = (sk_source_mgr*)cinfo->src;
+    src->next_input_byte = (const JOCTET*)src->fMemoryBase;
+    src->bytes_in_buffer = src->fMemoryBaseSize;
+}
+
+static boolean skmem_fill_input_buffer(j_decompress_ptr cinfo) {
+    SkDebugf("xxxxxxxxxxxxxx skmem_fill_input_buffer called\n");
+    return FALSE;
+}
+
+static void skmem_skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
+    sk_source_mgr*  src = (sk_source_mgr*)cinfo->src;
+//    SkDebugf("xxxxxxxxxxxxxx skmem_skip_input_data called %d\n", num_bytes);
+    src->next_input_byte = (const JOCTET*)((const char*)src->next_input_byte + num_bytes);
+    src->bytes_in_buffer -= num_bytes;
+}
+
+static boolean skmem_resync_to_restart(j_decompress_ptr cinfo, int desired) {
+    SkDebugf("xxxxxxxxxxxxxx skmem_resync_to_restart called\n");
+    return TRUE;
+}
+
+static void skmem_term_source(j_decompress_ptr /*cinfo*/) {}
+
+///////////////////////////////////////////////////////////////////////////////
+
+sk_source_mgr::sk_source_mgr(SkStream* stream, SkImageDecoder* decoder) : fStream(stream) {
+    fDecoder = decoder;
+    const void* baseAddr = stream->getMemoryBase();
+    if (baseAddr && false) {
+        fMemoryBase = baseAddr;
+        fMemoryBaseSize = stream->getLength();
+        
+        init_source = skmem_init_source;
+        fill_input_buffer = skmem_fill_input_buffer;
+        skip_input_data = skmem_skip_input_data;
+        resync_to_restart = skmem_resync_to_restart;
+        term_source = skmem_term_source;
+    } else {
+        fMemoryBase = NULL;
+        fMemoryBaseSize = 0;
+
+        init_source = sk_init_source;
+        fill_input_buffer = sk_fill_input_buffer;
+        skip_input_data = sk_skip_input_data;
+        resync_to_restart = sk_resync_to_restart;
+        term_source = sk_term_source;
+    }
+//    SkDebugf("**************** use memorybase %p %d\n", fMemoryBase, fMemoryBaseSize);
 }
 
 #include <setjmp.h>
@@ -187,14 +254,29 @@ static void sk_error_exit(j_common_ptr cinfo) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-static void skip_src_rows(jpeg_decompress_struct* cinfo, void* buffer,
+static bool skip_src_rows(jpeg_decompress_struct* cinfo, void* buffer,
                           int count) {
     for (int i = 0; i < count; i++) {
         JSAMPLE* rowptr = (JSAMPLE*)buffer;
         int row_count = jpeg_read_scanlines(cinfo, &rowptr, 1);
-        SkASSERT(row_count == 1);
+        if (row_count != 1) {
+            return false;
+        }
     }
-}    
+    return true;
+}
+
+// This guy exists just to aid in debugging, as it allows debuggers to just
+// set a break-point in one place to see all error exists.
+static bool return_false(const jpeg_decompress_struct& cinfo,
+                         const SkBitmap& bm, const char msg[]) {
+#if 0
+    SkDebugf("libjpeg error %d <%s> from %s [%d %d]", cinfo.err->msg_code,
+             cinfo.err->jpeg_message_table[cinfo.err->msg_code], msg,
+             bm.width(), bm.height());
+#endif
+    return false;   // must always return false
+}
 
 bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
                                   SkBitmap::Config prefConfig, Mode mode) {
@@ -207,7 +289,7 @@ bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
 
     jpeg_decompress_struct  cinfo;
     sk_error_mgr            sk_err;
-    sk_source_mgr           sk_stream(stream);
+    sk_source_mgr           sk_stream(stream, this);
 
     cinfo.err = jpeg_std_error(&sk_err);
     sk_err.error_exit = sk_error_exit;
@@ -215,7 +297,7 @@ bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
     // All objects need to be instantiated before this setjmp call so that
     // they will be cleaned up properly if an error occurs.
     if (setjmp(sk_err.fJmpBuf)) {
-        return false;
+        return return_false(cinfo, *bm, "setjmp");
     }
 
     jpeg_create_decompress(&cinfo);
@@ -224,7 +306,10 @@ bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
     //jpeg_stdio_src(&cinfo, file);
     cinfo.src = &sk_stream;
 
-    jpeg_read_header(&cinfo, true);
+    int status = jpeg_read_header(&cinfo, true);
+    if (status != JPEG_HEADER_OK) {
+        return return_false(cinfo, *bm, "read_header");
+    }
 
     /*  Try to fulfill the requested sampleSize. Since jpeg can do it (when it
         can) much faster that we, just use their num/denom api to approximate
@@ -236,55 +321,128 @@ bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
     cinfo.scale_num = 1;
     cinfo.scale_denom = sampleSize;
 
+    /* this gives about 30% performance improvement. In theory it may
+       reduce the visual quality, in practice I'm not seeing a difference
+     */
+    cinfo.do_fancy_upsampling = 0;
+
+    /* this gives another few percents */
+    cinfo.do_block_smoothing = 0;
+
+    /* default format is RGB */
+    cinfo.out_color_space = JCS_RGB;
+
+    SkBitmap::Config config = prefConfig;
+    // if no user preference, see what the device recommends
+    if (config == SkBitmap::kNo_Config)
+        config = SkImageDecoder::GetDeviceConfig();
+
+    // only these make sense for jpegs
+    if (config != SkBitmap::kARGB_8888_Config &&
+        config != SkBitmap::kARGB_4444_Config &&
+        config != SkBitmap::kRGB_565_Config) {
+        config = SkBitmap::kARGB_8888_Config;
+    }
+
+#ifdef ANDROID_RGB
+    cinfo.dither_mode = JDITHER_NONE;
+    if (config == SkBitmap::kARGB_8888_Config) {
+        cinfo.out_color_space = JCS_RGBA_8888;
+    } else if (config == SkBitmap::kRGB_565_Config) {
+        if (sampleSize == 1) {
+            // SkScaledBitmapSampler can't handle RGB_565 yet,
+            // so don't even try.
+            cinfo.out_color_space = JCS_RGB_565;
+            if (this->getDitherImage()) {
+                cinfo.dither_mode = JDITHER_ORDERED;
+            }
+        }
+    }
+#endif
+
     /*  image_width and image_height are the original dimensions, available
         after jpeg_read_header(). To see the scaled dimensions, we have to call
         jpeg_start_decompress(), and then read output_width and output_height.
     */
-    jpeg_start_decompress(&cinfo);
+    if (!jpeg_start_decompress(&cinfo)) {
+        return return_false(cinfo, *bm, "start_decompress");
+    }
 
     /*  If we need to better match the request, we might examine the image and
         output dimensions, and determine if the downsampling jpeg provided is
         not sufficient. If so, we can recompute a modified sampleSize value to
         make up the difference.
-        
+
         To skip this additional scaling, just set sampleSize = 1; below.
     */
     sampleSize = sampleSize * cinfo.output_width / cinfo.image_width;
 
-    // check for supported formats
-    bool isRGB; // as opposed to gray8
-    if (3 == cinfo.num_components && JCS_RGB == cinfo.out_color_space) {
-        isRGB = true;
-    } else if (1 == cinfo.num_components &&
-               JCS_GRAYSCALE == cinfo.out_color_space) {
-        isRGB = false;  // could use Index8 config if we want...
-    } else {
-        SkDEBUGF(("SkJPEGImageDecoder: unsupported jpeg colorspace %d with %d components\n",
-                    cinfo.jpeg_color_space, cinfo.num_components));
-        return false;
-    }
-    
-    SkBitmap::Config config = prefConfig;
-    // if no user preference, see what the device recommends
-    if (config == SkBitmap::kNo_Config)
-        config = SkImageDecoder::GetDeviceConfig();
-
-    // only these make sense for jpegs
-    if (config != SkBitmap::kARGB_8888_Config &&
-            config != SkBitmap::kARGB_4444_Config &&
-            config != SkBitmap::kRGB_565_Config) {
-        config = SkBitmap::kARGB_8888_Config;
-    }
 
     // should we allow the Chooser (if present) to pick a config for us???
     if (!this->chooseFromOneChoice(config, cinfo.output_width,
                                    cinfo.output_height)) {
-        return false;
+        return return_false(cinfo, *bm, "chooseFromOneChoice");
+    }
+
+#ifdef ANDROID_RGB
+    /* short-circuit the SkScaledBitmapSampler when possible, as this gives
+       a significant performance boost.
+    */
+    if (sampleSize == 1 &&
+        ((config == SkBitmap::kARGB_8888_Config && 
+                cinfo.out_color_space == JCS_RGBA_8888) ||
+        (config == SkBitmap::kRGB_565_Config && 
+                cinfo.out_color_space == JCS_RGB_565)))
+    {
+        bm->setConfig(config, cinfo.output_width, cinfo.output_height);
+        bm->setIsOpaque(true);
+        if (SkImageDecoder::kDecodeBounds_Mode == mode) {
+            return true;
+        }
+        if (!this->allocPixelRef(bm, NULL)) {
+            return return_false(cinfo, *bm, "allocPixelRef");
+        }
+        SkAutoLockPixels alp(*bm);
+        JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels();
+        INT32 const bpr =  bm->rowBytes();
+        
+        while (cinfo.output_scanline < cinfo.output_height) {
+            int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1);
+            // if row_count == 0, then we didn't get a scanline, so abort.
+            // if we supported partial images, we might return true in this case
+            if (0 == row_count) {
+                return return_false(cinfo, *bm, "read_scanlines");
+            }
+            if (this->shouldCancelDecode()) {
+                return return_false(cinfo, *bm, "shouldCancelDecode");
+            }
+            rowptr += bpr;
+        }
+        jpeg_finish_decompress(&cinfo);
+        return true;
+    }
+#endif
+    
+    // check for supported formats
+    SkScaledBitmapSampler::SrcConfig sc;
+    if (3 == cinfo.out_color_components && JCS_RGB == cinfo.out_color_space) {
+        sc = SkScaledBitmapSampler::kRGB;
+#ifdef ANDROID_RGB
+    } else if (JCS_RGBA_8888 == cinfo.out_color_space) {
+        sc = SkScaledBitmapSampler::kRGBX;
+    //} else if (JCS_RGB_565 == cinfo.out_color_space) {
+    //    sc = SkScaledBitmapSampler::kRGB_565;
+#endif
+    } else if (1 == cinfo.out_color_components &&
+               JCS_GRAYSCALE == cinfo.out_color_space) {
+        sc = SkScaledBitmapSampler::kGray;
+    } else {
+        return return_false(cinfo, *bm, "jpeg colorspace");
     }
 
     SkScaledBitmapSampler sampler(cinfo.output_width, cinfo.output_height,
                                   sampleSize);
-    
+
     bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
     // jpegs are always opauqe (i.e. have no per-pixel alpha)
     bm->setIsOpaque(true);
@@ -293,38 +451,51 @@ bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
         return true;
     }
     if (!this->allocPixelRef(bm, NULL)) {
-        return false;
+        return return_false(cinfo, *bm, "allocPixelRef");
     }
 
-    SkAutoLockPixels alp(*bm);
-    
-    if (!sampler.begin(bm,
-                      isRGB ? SkScaledBitmapSampler::kRGB :
-                              SkScaledBitmapSampler::kGray,
-                      this->getDitherImage())) {
-        return false;
+    SkAutoLockPixels alp(*bm);                          
+    if (!sampler.begin(bm, sc, this->getDitherImage())) {
+        return return_false(cinfo, *bm, "sampler.begin");
     }
 
-    uint8_t* srcRow = (uint8_t*)srcStorage.alloc(cinfo.output_width * 3);
+    uint8_t* srcRow = (uint8_t*)srcStorage.alloc(cinfo.output_width * 4);
+
+    //  Possibly skip initial rows [sampler.srcY0]
+    if (!skip_src_rows(&cinfo, srcRow, sampler.srcY0())) {
+        return return_false(cinfo, *bm, "skip rows");
+    }
 
-    skip_src_rows(&cinfo, srcRow, sampler.srcY0());
+    // now loop through scanlines until y == bm->height() - 1
     for (int y = 0;; y++) {
         JSAMPLE* rowptr = (JSAMPLE*)srcRow;
         int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1);
-        SkASSERT(row_count == 1);
+        if (0 == row_count) {
+            return return_false(cinfo, *bm, "read_scanlines");
+        }
+        if (this->shouldCancelDecode()) {
+            return return_false(cinfo, *bm, "shouldCancelDecode");
+        }
         
         sampler.next(srcRow);
         if (bm->height() - 1 == y) {
+            // we're done
             break;
         }
-        skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1);
+
+        if (!skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1)) {
+            return return_false(cinfo, *bm, "skip rows");
+        }
     }
 
-    // ??? If I don't do this, I get an error from finish_decompress
-    skip_src_rows(&cinfo, srcRow, cinfo.output_height - cinfo.output_scanline);
-        
+    // we formally skip the rest, so we don't get a complaint from libjpeg
+    if (!skip_src_rows(&cinfo, srcRow,
+                       cinfo.output_height - cinfo.output_scanline)) {
+        return return_false(cinfo, *bm, "skip rows");
+    }
     jpeg_finish_decompress(&cinfo);
 
+//    SkDebugf("------------------- bm2 size %d [%d %d] %d\n", bm->getSize(), bm->width(), bm->height(), bm->config());
     return true;
 }
 
@@ -383,11 +554,11 @@ static void rgb2yuv_4444(uint8_t dst[], U16CPU c) {
     int r = SkGetPackedR4444(c);
     int g = SkGetPackedG4444(c);
     int b = SkGetPackedB4444(c);
-    
+
     int  y = ( CYR*r + CYG*g + CYB*b ) >> (CSHIFT - 4);
     int  u = ( CUR*r + CUG*g + CUB*b ) >> (CSHIFT - 4);
     int  v = ( CVR*r + CVG*g + CVB*b ) >> (CSHIFT - 4);
-    
+
     dst[0] = SkToU8(y);
     dst[1] = SkToU8(u + 128);
     dst[2] = SkToU8(v + 128);
@@ -397,11 +568,11 @@ static void rgb2yuv_16(uint8_t dst[], U16CPU c) {
     int r = SkGetPackedR16(c);
     int g = SkGetPackedG16(c);
     int b = SkGetPackedB16(c);
-    
+
     int  y = ( 2*CYR*r + CYG*g + 2*CYB*b ) >> (CSHIFT - 2);
     int  u = ( 2*CUR*r + CUG*g + 2*CUB*b ) >> (CSHIFT - 2);
     int  v = ( 2*CVR*r + CVG*g + 2*CVB*b ) >> (CSHIFT - 2);
-    
+
     dst[0] = SkToU8(y);
     dst[1] = SkToU8(u + 128);
     dst[2] = SkToU8(v + 128);
@@ -519,9 +690,9 @@ static boolean sk_empty_output_buffer(j_compress_ptr cinfo) {
 
 //  if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize - dest->free_in_buffer))
     if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize)) {
-        sk_throw();
+        ERREXIT(cinfo, JERR_FILE_WRITE);
+        return false;
     }
-    //  ERREXIT(cinfo, JERR_FILE_WRITE);
 
     dest->next_output_byte = dest->fBuffer;
     dest->free_in_buffer = sk_destination_mgr::kBufferSize;
@@ -534,7 +705,8 @@ static void sk_term_destination (j_compress_ptr cinfo) {
     size_t size = sk_destination_mgr::kBufferSize - dest->free_in_buffer;
     if (size > 0) {
         if (!dest->fStream->write(dest->fBuffer, size)) {
-            sk_throw();
+            ERREXIT(cinfo, JERR_FILE_WRITE);
+            return;
         }
     }
     dest->fStream->flush();
@@ -547,23 +719,6 @@ sk_destination_mgr::sk_destination_mgr(SkWStream* stream)
     this->term_destination = sk_term_destination;
 }
 
-class SkAutoLockColors : public SkNoncopyable {
-public:
-    SkAutoLockColors(const SkBitmap& bm) {
-        fCTable = bm.getColorTable();
-        fColors = fCTable ? fCTable->lockColors() : NULL;
-    }
-    ~SkAutoLockColors() {
-        if (fCTable) {
-            fCTable->unlockColors(false);
-        }
-    }
-    const SkPMColor* colors() const { return fColors; }
-private:
-    SkColorTable*    fCTable;
-    const SkPMColor* fColors;
-};
-
 class SkJPEGImageEncoder : public SkImageEncoder {
 protected:
     virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) {
@@ -585,6 +740,10 @@ protected:
         sk_error_mgr            sk_err;
         sk_destination_mgr      sk_wstream(stream);
 
+        // allocate these before set call setjmp
+        SkAutoMalloc    oneRow;
+        SkAutoLockColors ctLocker;
+
         cinfo.err = jpeg_std_error(&sk_err);
         sk_err.error_exit = sk_error_exit;
         if (setjmp(sk_err.fJmpBuf)) {
@@ -606,17 +765,15 @@ protected:
         jpeg_set_defaults(&cinfo);
         jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
         cinfo.dct_method = JDCT_IFAST;
-        
+
         jpeg_start_compress(&cinfo, TRUE);
 
         const int       width = bm.width();
-        SkAutoMalloc    oneRow(width * 3);
-        uint8_t*        oneRowP = (uint8_t*)oneRow.get();
+        uint8_t*        oneRowP = (uint8_t*)oneRow.alloc(width * 3);
 
-        SkAutoLockColors alc(bm);
-        const SkPMColor* colors = alc.colors();
+        const SkPMColor* colors = ctLocker.lockColors(bm);
         const void*      srcRow = bm.getPixels();
-        
+
         while (cinfo.next_scanline < cinfo.image_height) {
             JSAMPROW row_pointer[1];    /* pointer to JSAMPLE row[s] */