src/starboard/shared/libjpeg/jpeg_image_decoder.cc - cobalt - Git at Google

 // Copyright 2018 The Cobalt Authors. All Rights Reserved.
 //
 // 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
 //
 // 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.

 #include "starboard/shared/libjpeg/jpeg_image_decoder.h"

 #include <setjmp.h>

 #include <algorithm>
 #include <vector>

 #include "starboard/common/log.h"
 #include "starboard/configuration.h"
 #include "starboard/linux/shared/decode_target_internal.h"

 // Inhibit C++ name-mangling for libjpeg functions.
 extern "C" {
 #include "third_party/libjpeg/jpeglib.h"
 #include "third_party/libjpeg/jpegint.h"
 }

 namespace starboard {
 namespace shared {
 namespace libjpeg {

 namespace {

 JDIMENSION kInvalidHeight = 0xFFFFFF;

 void ErrorManagerExit(j_common_ptr common_ptr) {
   // Returns the control to the setjmp point. The buffer which is filled by a
   // previous call to setjmp that contains information to store the environment
   // to that point.
   jmp_buf* buffer = static_cast<jmp_buf*>(common_ptr->client_data);
   longjmp(*buffer, 1);
 }

 void SourceManagerInitSource(j_decompress_ptr decompress_ptr) {
   SB_UNREFERENCED_PARAMETER(decompress_ptr);
   // no-op.
 }

 boolean SourceManagerFillInputBuffer(j_decompress_ptr decompress_ptr) {
   SB_UNREFERENCED_PARAMETER(decompress_ptr);
   // Normally, this function is called when we need to read more of the encoded
   // buffer into memory and a return false indicates that we have no data to
   // supply yet, but in our case, the encoded buffer is always in memory, so
   // this should never get called unless there is an error, in which case we
   // return false to indicate that.
   return false;
 }

 boolean SourceManagerResyncToRestart(j_decompress_ptr decompress_ptr,
                                      int desired) {
   SB_UNREFERENCED_PARAMETER(decompress_ptr);
   SB_UNREFERENCED_PARAMETER(desired);
   return false;
 }

 void SourceManagerTermSource(j_decompress_ptr decompress_ptr) {
   SB_UNREFERENCED_PARAMETER(decompress_ptr);
   // no-op.
 }

 void SourceManagerSkipInputData(j_decompress_ptr decompress_ptr,
                                 long num_bytes) {  // NOLINT(runtime/int)
   // Since all our data that is required to be decoded should be in the buffer
   // already, trying to skip beyond it means that there is some kind of error or
   // corrupt input data. We acknowledge these error cases by setting
   // |bytes_in_buffer| to 0 which will result in a call to
   // SourceManagerFillInputBuffer() which will return false to indicate that an
   // error has occurred.
   size_t bytes_to_skip = std::min(decompress_ptr->src->bytes_in_buffer,
                                   static_cast<size_t>(num_bytes));
   decompress_ptr->src->bytes_in_buffer -= bytes_to_skip;
   decompress_ptr->src->next_input_byte += bytes_to_skip;
 }

 bool ReadHeader(jpeg_decompress_struct* info) {
   if (jpeg_read_header(info, true) != JPEG_HEADER_OK) {
     return false;
   }

   return true;
 }

 bool StartDecompress(jpeg_decompress_struct* info) {
   // jpeg_has_multiple_scans() returns TRUE if the incoming image file has more
   // than one scan.
   info->buffered_image = jpeg_has_multiple_scans(info);

   // TODO: switch libjpeg version to support JCS_RGBA_8888 output.
   info->out_color_space = JCS_RGB;

   // Compute output image dimensions
   jpeg_calc_output_dimensions(info);

   if (!jpeg_start_decompress(info)) {
     SB_LOG(WARNING) << "Start decompressor failed.";
     return false;
   }

   return true;
 }

 // Responsible for swizzeling and alpha-premultiplying a row of pixels.
 template <int r, int g, int b, int a>
 void FillRow(int width, uint8_t* dest, JSAMPLE* source) {
   for (int x = 0; x < width; ++x, source += 3, dest += 4) {
     dest[r] = source[0];
     dest[g] = source[1];
     dest[b] = source[2];
     dest[a] = 0xFF;
   }
 }

 bool ReadLines(jpeg_decompress_struct* info,
                SbDecodeTargetFormat decode_target_format,
                uint8_t* image_data) {
   // Creation of 2-D sample arrays which is for one row.
   // See the comments in jmemmgr.c.
   JSAMPARRAY buffer = (*info->mem->alloc_sarray)(
       (j_common_ptr)info, JPOOL_IMAGE, info->output_width * 4, 1);

   while (info->output_scanline < info->output_height) {
     // |info->output_scanline| would be increased 1 after reading one row.
     int row_index = static_cast<int>(info->output_scanline);

     // jpeg_read_scanlines() returns up to the maximum number of scanlines of
     // decompressed image data. This may be less than the number requested in
     // cases such as bottom of image, data source suspension, and operating
     // modes that emit multiple scanlines at a time. Image data should be
     // returned in top-to-bottom scanline order.
     // TODO: Investigate the performance improvements by processing
     // multiple pixel rows. It may have performance advantage to use values
     // larger than 1. For example, JPEG images often use 4:2:0 downsampling, and
     // in that case libjpeg needs to make an additional copy of half the image
     // pixels(see merged_2v_upsample()).
     if (jpeg_read_scanlines(info, buffer, 1) != 1) {
       return false;
     }

     // Write the decoded row pixels to image data.
     uint8_t* pixel_data = image_data + info->image_width * 4 * row_index;

     JSAMPLE* sample_buffer = *buffer;
     switch (decode_target_format) {
       case kSbDecodeTargetFormat1PlaneRGBA:
         FillRow<0, 1, 2, 3>(static_cast<int>(info->image_width), pixel_data,
                             sample_buffer);
         break;
       case kSbDecodeTargetFormat1PlaneBGRA:
         FillRow<2, 1, 0, 3>(static_cast<int>(info->image_width), pixel_data,
                             sample_buffer);
         break;
       case kSbDecodeTargetFormat2PlaneYUVNV12:
       case kSbDecodeTargetFormat3PlaneYUVI420:
 #if SB_API_VERSION >= 10
       case kSbDecodeTargetFormat3Plane10BitYUVI420:
 #endif  // SB_API_VERSION >= 10
       case kSbDecodeTargetFormat1PlaneUYVY:
       case kSbDecodeTargetFormatInvalid:
         SB_NOTREACHED();
         break;
     }
   }

   return true;
 }

 // A baseline sequential JPEG is stored as one top-to-bottom scan of the image.
 // Progressive JPEG divides the file into a series of scans. It is starting with
 // a very low quality image, and then following scans gradually improve the
 // quality.
 // TODO: support displaying the low resolution image while decoding
 // the progressive JPEG.
 bool DecodeProgressiveJPEG(jpeg_decompress_struct* info,
                            SbDecodeTargetFormat decode_target_format,
                            uint8_t* image_data) {
   int status;
   do {
     // |jpeg_consume_input| decodes the input data as it arrives.
     status = jpeg_consume_input(info);
   } while (status == JPEG_REACHED_SOS || status == JPEG_ROW_COMPLETED ||
            status == JPEG_SCAN_COMPLETED);

   while (info->output_scanline == kInvalidHeight ||
          info->output_scanline <= info->output_height) {
     if (info->output_scanline == 0) {
       // Initialize for an output pass in buffered-image mode.
       // The |input_scan_number| indicates the scan of the image to be
       // processed.
       if (!jpeg_start_output(info, info->input_scan_number)) {
         // Decompression is suspended.
         return false;
       }
     }

     if (info->output_scanline == kInvalidHeight) {
       // Recover from the previous set flag.
       info->output_scanline = 0;
     }

     if (!ReadLines(info, decode_target_format, image_data)) {
       if (info->output_scanline == 0) {
         // Data is not enough for one line scan, so flag the |output_scanline|
         // to make sure that we don't call |jpeg_start_output| multiple times
         // for the same scan.
         info->output_scanline = kInvalidHeight;
       }
       return false;
     }

     if (info->output_scanline == info->output_height) {
       // Finish up after an output pass in buffered-image mode.
       if (!jpeg_finish_output(info)) {
         // Decompression is suspended due to
         // input_scan_number <= output_scan_number and EOI is not reached.
         // The suspension will be recovered when more data are coming.
         return false;
       }

       // The output scan number is the notional scan being processed by the
       // output side. The decompressor will not allow output scan number to get
       // ahead of input scan number.
       SB_DCHECK(info->input_scan_number >= info->output_scan_number);
       // This scan pass is done, so reset the output scanline.
       info->output_scanline = 0;
       if (info->input_scan_number == info->output_scan_number) {
         // No more scan needed at this point.
         break;
       }
     }
   }

   // |jpeg_input_complete| tests for the end of image.
   if (!jpeg_input_complete(info)) {
     return false;
   }

   return true;
 }

 }  // namespace

 SbDecodeTarget Decode(SbDecodeTargetGraphicsContextProvider* context_provider,
                       SbDecodeTargetFormat decode_target_format,
                       const uint8_t* data,
                       size_t input_byte) {
   jpeg_decompress_struct info = {};
   jpeg_source_mgr source_manager = {};
   jpeg_error_mgr error_manager = {};

   info.err = jpeg_std_error(&error_manager);
   error_manager.error_exit = &ErrorManagerExit;

   // Allocate and initialize JPEG decompression object.
   jpeg_create_decompress(&info);

   info.src = &source_manager;

   // Set up callback functions.
   // Even some of them are no-op, we have to set them up for jpeg lib.
   source_manager.init_source = SourceManagerInitSource;
   source_manager.fill_input_buffer = SourceManagerFillInputBuffer;
   source_manager.skip_input_data = SourceManagerSkipInputData;
   source_manager.resync_to_restart = SourceManagerResyncToRestart;
   source_manager.term_source = SourceManagerTermSource;

   // |client_data| is available for use by application.
   jmp_buf jump_buffer;
   info.client_data = &jump_buffer;

   // int setjmp(jmp_buf env) saves the current environment (ths program state),
   // at some point of program execution, into a platform-specific data
   // structure (jmp_buf) that can be used at some later point of program
   // execution by longjmp to restore the program state to that saved by setjmp
   // into jmp_buf. This process can be imagined to be a "jump" back to the point
   // of program execution where setjmp saved the environment. The return value
   // from setjmp indicates whether control reached that point normally or from a
   // call to longjmp. If the return is from a direct invocation, setjmp returns
   // 0. If the return is from a call to longjmp, setjmp returns a nonzero value.
   // warning C4611: interaction between '_setjmp' and C++ object destruction is
   // non-portable.
   if (setjmp(jump_buffer)) {
     // image data is empty.
     SB_DLOG(WARNING) << "Decoder encounters an error.";
     return kSbDecodeTargetInvalid;
   }

   // Next byte to read from buffer.
   info.src->next_input_byte = reinterpret_cast<const JOCTET*>(data);
   // Number of bytes remaining in buffer.
   info.src->bytes_in_buffer = input_byte;

   if (!ReadHeader(&info)) {
     // Data is not enough for decoding the header.
     return kSbDecodeTargetInvalid;
   }

   if (!StartDecompress(&info)) {
     return kSbDecodeTargetInvalid;
   }

   std::vector<uint8_t> decoded_data(info.image_width * info.image_height * 4);

   if (info.buffered_image) {  // Progressive JPEG.
     if (!DecodeProgressiveJPEG(&info, decode_target_format,
                                decoded_data.data())) {
       return kSbDecodeTargetInvalid;
     }
   } else if (!ReadLines(&info, decode_target_format,
                         decoded_data.data())) {  // Baseline sequential JPEG.
     return kSbDecodeTargetInvalid;
   }

   if (!jpeg_finish_decompress(&info)) {
     // In this case, we did read all the rows, so we don't really have to
     // treat this as an error.
     SB_DLOG(WARNING) << "Data source requests suspension of the decompressor.";
   }

   auto width = info.image_width;
   auto height = info.image_height;
   jpeg_destroy_decompress(&info);

   return DecodeTargetCreate(context_provider, decoded_data.data(), width,
                             height, decode_target_format);
 }

 }  // namespace libjpeg
 }  // namespace shared
 }  // namespace starboard
	// Copyright 2018 The Cobalt Authors. All Rights Reserved.
	//
	// 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
	//
	// 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.

	#include "starboard/shared/libjpeg/jpeg_image_decoder.h"

	#include <setjmp.h>

	#include <algorithm>
	#include <vector>

	#include "starboard/common/log.h"
	#include "starboard/configuration.h"
	#include "starboard/linux/shared/decode_target_internal.h"

	// Inhibit C++ name-mangling for libjpeg functions.
	extern "C" {
	#include "third_party/libjpeg/jpeglib.h"
	#include "third_party/libjpeg/jpegint.h"
	}

	namespace starboard {
	namespace shared {
	namespace libjpeg {

	namespace {

	JDIMENSION kInvalidHeight = 0xFFFFFF;

	void ErrorManagerExit(j_common_ptr common_ptr) {
	// Returns the control to the setjmp point. The buffer which is filled by a
	// previous call to setjmp that contains information to store the environment
	// to that point.
	jmp_buf* buffer = static_cast<jmp_buf*>(common_ptr->client_data);
	longjmp(*buffer, 1);
	}

	void SourceManagerInitSource(j_decompress_ptr decompress_ptr) {
	SB_UNREFERENCED_PARAMETER(decompress_ptr);
	// no-op.
	}

	boolean SourceManagerFillInputBuffer(j_decompress_ptr decompress_ptr) {
	SB_UNREFERENCED_PARAMETER(decompress_ptr);
	// Normally, this function is called when we need to read more of the encoded
	// buffer into memory and a return false indicates that we have no data to
	// supply yet, but in our case, the encoded buffer is always in memory, so
	// this should never get called unless there is an error, in which case we
	// return false to indicate that.
	return false;
	}

	boolean SourceManagerResyncToRestart(j_decompress_ptr decompress_ptr,
	int desired) {
	SB_UNREFERENCED_PARAMETER(decompress_ptr);
	SB_UNREFERENCED_PARAMETER(desired);
	return false;
	}

	void SourceManagerTermSource(j_decompress_ptr decompress_ptr) {
	SB_UNREFERENCED_PARAMETER(decompress_ptr);
	// no-op.
	}

	void SourceManagerSkipInputData(j_decompress_ptr decompress_ptr,
	long num_bytes) { // NOLINT(runtime/int)
	// Since all our data that is required to be decoded should be in the buffer
	// already, trying to skip beyond it means that there is some kind of error or
	// corrupt input data. We acknowledge these error cases by setting
	// \|bytes_in_buffer\| to 0 which will result in a call to
	// SourceManagerFillInputBuffer() which will return false to indicate that an
	// error has occurred.
	size_t bytes_to_skip = std::min(decompress_ptr->src->bytes_in_buffer,
	static_cast<size_t>(num_bytes));
	decompress_ptr->src->bytes_in_buffer -= bytes_to_skip;
	decompress_ptr->src->next_input_byte += bytes_to_skip;
	}

	bool ReadHeader(jpeg_decompress_struct* info) {
	if (jpeg_read_header(info, true) != JPEG_HEADER_OK) {
	return false;
	}

	return true;
	}

	bool StartDecompress(jpeg_decompress_struct* info) {
	// jpeg_has_multiple_scans() returns TRUE if the incoming image file has more
	// than one scan.
	info->buffered_image = jpeg_has_multiple_scans(info);

	// TODO: switch libjpeg version to support JCS_RGBA_8888 output.
	info->out_color_space = JCS_RGB;

	// Compute output image dimensions
	jpeg_calc_output_dimensions(info);

	if (!jpeg_start_decompress(info)) {
	SB_LOG(WARNING) << "Start decompressor failed.";
	return false;
	}

	return true;
	}

	// Responsible for swizzeling and alpha-premultiplying a row of pixels.
	template <int r, int g, int b, int a>
	void FillRow(int width, uint8_t* dest, JSAMPLE* source) {
	for (int x = 0; x < width; ++x, source += 3, dest += 4) {
	dest[r] = source[0];
	dest[g] = source[1];
	dest[b] = source[2];
	dest[a] = 0xFF;
	}
	}

	bool ReadLines(jpeg_decompress_struct* info,
	SbDecodeTargetFormat decode_target_format,
	uint8_t* image_data) {
	// Creation of 2-D sample arrays which is for one row.
	// See the comments in jmemmgr.c.
	JSAMPARRAY buffer = (*info->mem->alloc_sarray)(
	(j_common_ptr)info, JPOOL_IMAGE, info->output_width * 4, 1);

	while (info->output_scanline < info->output_height) {
	// \|info->output_scanline\| would be increased 1 after reading one row.
	int row_index = static_cast<int>(info->output_scanline);

	// jpeg_read_scanlines() returns up to the maximum number of scanlines of
	// decompressed image data. This may be less than the number requested in
	// cases such as bottom of image, data source suspension, and operating
	// modes that emit multiple scanlines at a time. Image data should be
	// returned in top-to-bottom scanline order.
	// TODO: Investigate the performance improvements by processing
	// multiple pixel rows. It may have performance advantage to use values
	// larger than 1. For example, JPEG images often use 4:2:0 downsampling, and
	// in that case libjpeg needs to make an additional copy of half the image
	// pixels(see merged_2v_upsample()).
	if (jpeg_read_scanlines(info, buffer, 1) != 1) {
	return false;
	}

	// Write the decoded row pixels to image data.
	uint8_t* pixel_data = image_data + info->image_width * 4 * row_index;

	JSAMPLE* sample_buffer = *buffer;
	switch (decode_target_format) {
	case kSbDecodeTargetFormat1PlaneRGBA:
	FillRow<0, 1, 2, 3>(static_cast<int>(info->image_width), pixel_data,
	sample_buffer);
	break;
	case kSbDecodeTargetFormat1PlaneBGRA:
	FillRow<2, 1, 0, 3>(static_cast<int>(info->image_width), pixel_data,
	sample_buffer);
	break;
	case kSbDecodeTargetFormat2PlaneYUVNV12:
	case kSbDecodeTargetFormat3PlaneYUVI420:
	#if SB_API_VERSION >= 10
	case kSbDecodeTargetFormat3Plane10BitYUVI420:
	#endif // SB_API_VERSION >= 10
	case kSbDecodeTargetFormat1PlaneUYVY:
	case kSbDecodeTargetFormatInvalid:
	SB_NOTREACHED();
	break;
	}
	}

	return true;
	}

	// A baseline sequential JPEG is stored as one top-to-bottom scan of the image.
	// Progressive JPEG divides the file into a series of scans. It is starting with
	// a very low quality image, and then following scans gradually improve the
	// quality.
	// TODO: support displaying the low resolution image while decoding
	// the progressive JPEG.
	bool DecodeProgressiveJPEG(jpeg_decompress_struct* info,
	SbDecodeTargetFormat decode_target_format,
	uint8_t* image_data) {
	int status;
	do {
	// \|jpeg_consume_input\| decodes the input data as it arrives.
	status = jpeg_consume_input(info);
	} while (status == JPEG_REACHED_SOS \|\| status == JPEG_ROW_COMPLETED \|\|
	status == JPEG_SCAN_COMPLETED);

	while (info->output_scanline == kInvalidHeight \|\|
	info->output_scanline <= info->output_height) {
	if (info->output_scanline == 0) {
	// Initialize for an output pass in buffered-image mode.
	// The \|input_scan_number\| indicates the scan of the image to be
	// processed.
	if (!jpeg_start_output(info, info->input_scan_number)) {
	// Decompression is suspended.
	return false;
	}
	}

	if (info->output_scanline == kInvalidHeight) {
	// Recover from the previous set flag.
	info->output_scanline = 0;
	}

	if (!ReadLines(info, decode_target_format, image_data)) {
	if (info->output_scanline == 0) {
	// Data is not enough for one line scan, so flag the \|output_scanline\|
	// to make sure that we don't call \|jpeg_start_output\| multiple times
	// for the same scan.
	info->output_scanline = kInvalidHeight;
	}
	return false;
	}

	if (info->output_scanline == info->output_height) {
	// Finish up after an output pass in buffered-image mode.
	if (!jpeg_finish_output(info)) {
	// Decompression is suspended due to
	// input_scan_number <= output_scan_number and EOI is not reached.
	// The suspension will be recovered when more data are coming.
	return false;
	}

	// The output scan number is the notional scan being processed by the
	// output side. The decompressor will not allow output scan number to get
	// ahead of input scan number.
	SB_DCHECK(info->input_scan_number >= info->output_scan_number);
	// This scan pass is done, so reset the output scanline.
	info->output_scanline = 0;
	if (info->input_scan_number == info->output_scan_number) {
	// No more scan needed at this point.
	break;
	}
	}
	}

	// \|jpeg_input_complete\| tests for the end of image.
	if (!jpeg_input_complete(info)) {
	return false;
	}

	return true;
	}

	} // namespace

	SbDecodeTarget Decode(SbDecodeTargetGraphicsContextProvider* context_provider,
	SbDecodeTargetFormat decode_target_format,
	const uint8_t* data,
	size_t input_byte) {
	jpeg_decompress_struct info = {};
	jpeg_source_mgr source_manager = {};
	jpeg_error_mgr error_manager = {};

	info.err = jpeg_std_error(&error_manager);
	error_manager.error_exit = &ErrorManagerExit;

	// Allocate and initialize JPEG decompression object.
	jpeg_create_decompress(&info);

	info.src = &source_manager;

	// Set up callback functions.
	// Even some of them are no-op, we have to set them up for jpeg lib.
	source_manager.init_source = SourceManagerInitSource;
	source_manager.fill_input_buffer = SourceManagerFillInputBuffer;
	source_manager.skip_input_data = SourceManagerSkipInputData;
	source_manager.resync_to_restart = SourceManagerResyncToRestart;
	source_manager.term_source = SourceManagerTermSource;

	// \|client_data\| is available for use by application.
	jmp_buf jump_buffer;
	info.client_data = &jump_buffer;

	// int setjmp(jmp_buf env) saves the current environment (ths program state),
	// at some point of program execution, into a platform-specific data
	// structure (jmp_buf) that can be used at some later point of program
	// execution by longjmp to restore the program state to that saved by setjmp
	// into jmp_buf. This process can be imagined to be a "jump" back to the point
	// of program execution where setjmp saved the environment. The return value
	// from setjmp indicates whether control reached that point normally or from a
	// call to longjmp. If the return is from a direct invocation, setjmp returns
	// 0. If the return is from a call to longjmp, setjmp returns a nonzero value.
	// warning C4611: interaction between '_setjmp' and C++ object destruction is
	// non-portable.
	if (setjmp(jump_buffer)) {
	// image data is empty.
	SB_DLOG(WARNING) << "Decoder encounters an error.";
	return kSbDecodeTargetInvalid;
	}

	// Next byte to read from buffer.
	info.src->next_input_byte = reinterpret_cast<const JOCTET*>(data);
	// Number of bytes remaining in buffer.
	info.src->bytes_in_buffer = input_byte;

	if (!ReadHeader(&info)) {
	// Data is not enough for decoding the header.
	return kSbDecodeTargetInvalid;
	}

	if (!StartDecompress(&info)) {
	return kSbDecodeTargetInvalid;
	}

	std::vector<uint8_t> decoded_data(info.image_width * info.image_height * 4);

	if (info.buffered_image) { // Progressive JPEG.
	if (!DecodeProgressiveJPEG(&info, decode_target_format,
	decoded_data.data())) {
	return kSbDecodeTargetInvalid;
	}
	} else if (!ReadLines(&info, decode_target_format,
	decoded_data.data())) { // Baseline sequential JPEG.
	return kSbDecodeTargetInvalid;
	}

	if (!jpeg_finish_decompress(&info)) {
	// In this case, we did read all the rows, so we don't really have to
	// treat this as an error.
	SB_DLOG(WARNING) << "Data source requests suspension of the decompressor.";
	}

	auto width = info.image_width;
	auto height = info.image_height;
	jpeg_destroy_decompress(&info);

	return DecodeTargetCreate(context_provider, decoded_data.data(), width,
	height, decode_target_format);
	}

	} // namespace libjpeg
	} // namespace shared
	} // namespace starboard