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 /*

  *  Copyright 2012 The LibYuv Project Authors. All rights reserved.

  *

  *  Use of this source code is governed by a BSD-style license

  *  that can be found in the LICENSE file in the root of the source

  *  tree. An additional intellectual property rights grant can be found

  *  in the file PATENTS. All contributing project authors may

  *  be found in the AUTHORS file in the root of the source tree.

  */

 #include "libyuv/mjpeg_decoder.h"

 #ifdef HAVE_JPEG

 #include <assert.h>

 #if !defined(__pnacl__) && !defined(__CLR_VER) && !defined(COVERAGE_ENABLED) &&\

     !defined(TARGET_IPHONE_SIMULATOR)

 // Must be included before jpeglib.

 #include <setjmp.h>

 #define HAVE_SETJMP

 #endif

 struct FILE;  // For jpeglib.h.

 // C++ build requires extern C for jpeg internals.

 #ifdef __cplusplus

 extern "C" {

 #endif

 #include <jpeglib.h>

 #ifdef __cplusplus

 }  // extern "C"

 #endif

 #include "libyuv/planar_functions.h"  // For CopyPlane().

 namespace libyuv {

 #ifdef HAVE_SETJMP

 struct SetJmpErrorMgr {

   jpeg_error_mgr base;  // Must be at the top

   jmp_buf setjmp_buffer;

 };

 #endif

 const int MJpegDecoder::kColorSpaceUnknown = JCS_UNKNOWN;

 const int MJpegDecoder::kColorSpaceGrayscale = JCS_GRAYSCALE;

 const int MJpegDecoder::kColorSpaceRgb = JCS_RGB;

 const int MJpegDecoder::kColorSpaceYCbCr = JCS_YCbCr;

 const int MJpegDecoder::kColorSpaceCMYK = JCS_CMYK;

 const int MJpegDecoder::kColorSpaceYCCK = JCS_YCCK;

 MJpegDecoder::MJpegDecoder()

     : has_scanline_padding_(LIBYUV_FALSE),

       num_outbufs_(0),

       scanlines_(NULL),

       scanlines_sizes_(NULL),

       databuf_(NULL),

       databuf_strides_(NULL) {

   decompress_struct_ = new jpeg_decompress_struct;

   source_mgr_ = new jpeg_source_mgr;

 #ifdef HAVE_SETJMP

   error_mgr_ = new SetJmpErrorMgr;

   decompress_struct_->err = jpeg_std_error(&error_mgr_->base);

   // Override standard exit()-based error handler.

   error_mgr_->base.error_exit = &ErrorHandler;

 #endif

   decompress_struct_->client_data = NULL;

   source_mgr_->init_source = &init_source;

   source_mgr_->fill_input_buffer = &fill_input_buffer;

   source_mgr_->skip_input_data = &skip_input_data;

   source_mgr_->resync_to_restart = &jpeg_resync_to_restart;

   source_mgr_->term_source = &term_source;

   jpeg_create_decompress(decompress_struct_);

   decompress_struct_->src = source_mgr_;

   buf_vec_.buffers = &buf_;

   buf_vec_.len = 1;

 }

 MJpegDecoder::~MJpegDecoder() {

   jpeg_destroy_decompress(decompress_struct_);

   delete decompress_struct_;

   delete source_mgr_;

 #ifdef HAVE_SETJMP

   delete error_mgr_;

 #endif

   DestroyOutputBuffers();

 }

 LIBYUV_BOOL MJpegDecoder::LoadFrame(const uint8* src, size_t src_len) {

   if (!ValidateJpeg(src, src_len)) {

     return LIBYUV_FALSE;

   }

   buf_.data = src;

   buf_.len = (int)(src_len);

   buf_vec_.pos = 0;

   decompress_struct_->client_data = &buf_vec_;

 #ifdef HAVE_SETJMP

   if (setjmp(error_mgr_->setjmp_buffer)) {

     // We called jpeg_read_header, it experienced an error, and we called

     // longjmp() and rewound the stack to here. Return error.

     return LIBYUV_FALSE;

   }

 #endif

   if (jpeg_read_header(decompress_struct_, TRUE) != JPEG_HEADER_OK) {

     // ERROR: Bad MJPEG header

     return LIBYUV_FALSE;

   }

   AllocOutputBuffers(GetNumComponents());

   for (int i = 0; i < num_outbufs_; ++i) {

     int scanlines_size = GetComponentScanlinesPerImcuRow(i);

     if (scanlines_sizes_[i] != scanlines_size) {

       if (scanlines_[i]) {

         delete scanlines_[i];

       }

       scanlines_[i] = new uint8* [scanlines_size];

       scanlines_sizes_[i] = scanlines_size;

     }

     // We allocate padding for the final scanline to pad it up to DCTSIZE bytes

     // to avoid memory errors, since jpeglib only reads full MCUs blocks. For

     // the preceding scanlines, the padding is not needed/wanted because the

     // following addresses will already be valid (they are the initial bytes of

     // the next scanline) and will be overwritten when jpeglib writes out that

     // next scanline.

     int databuf_stride = GetComponentStride(i);

     int databuf_size = scanlines_size * databuf_stride;

     if (databuf_strides_[i] != databuf_stride) {

       if (databuf_[i]) {

         delete databuf_[i];

       }

       databuf_[i] = new uint8[databuf_size];

       databuf_strides_[i] = databuf_stride;

     }

     if (GetComponentStride(i) != GetComponentWidth(i)) {

       has_scanline_padding_ = LIBYUV_TRUE;

     }

   }

   return LIBYUV_TRUE;

 }

 static int DivideAndRoundUp(int numerator, int denominator) {

   return (numerator + denominator - 1) / denominator;

 }

 static int DivideAndRoundDown(int numerator, int denominator) {

   return numerator / denominator;

 }

 // Returns width of the last loaded frame.

 int MJpegDecoder::GetWidth() {

   return decompress_struct_->image_width;

 }

 // Returns height of the last loaded frame.

 int MJpegDecoder::GetHeight() {

   return decompress_struct_->image_height;

 }

 // Returns format of the last loaded frame. The return value is one of the

 // kColorSpace* constants.

 int MJpegDecoder::GetColorSpace() {

   return decompress_struct_->jpeg_color_space;

 }

 // Number of color components in the color space.

 int MJpegDecoder::GetNumComponents() {

   return decompress_struct_->num_components;

 }

 // Sample factors of the n-th component.

 int MJpegDecoder::GetHorizSampFactor(int component) {

   return decompress_struct_->comp_info[component].h_samp_factor;

 }

 int MJpegDecoder::GetVertSampFactor(int component) {

   return decompress_struct_->comp_info[component].v_samp_factor;

 }

 int MJpegDecoder::GetHorizSubSampFactor(int component) {

   return decompress_struct_->max_h_samp_factor /

       GetHorizSampFactor(component);

 }

 int MJpegDecoder::GetVertSubSampFactor(int component) {

   return decompress_struct_->max_v_samp_factor /

       GetVertSampFactor(component);

 }

 int MJpegDecoder::GetImageScanlinesPerImcuRow() {

   return decompress_struct_->max_v_samp_factor * DCTSIZE;

 }

 int MJpegDecoder::GetComponentScanlinesPerImcuRow(int component) {

   int vs = GetVertSubSampFactor(component);

   return DivideAndRoundUp(GetImageScanlinesPerImcuRow(), vs);

 }

 int MJpegDecoder::GetComponentWidth(int component) {

   int hs = GetHorizSubSampFactor(component);

   return DivideAndRoundUp(GetWidth(), hs);

 }

 int MJpegDecoder::GetComponentHeight(int component) {

   int vs = GetVertSubSampFactor(component);

   return DivideAndRoundUp(GetHeight(), vs);

 }

 // Get width in bytes padded out to a multiple of DCTSIZE

 int MJpegDecoder::GetComponentStride(int component) {

   return (GetComponentWidth(component) + DCTSIZE - 1) & ~(DCTSIZE - 1);

 }

 int MJpegDecoder::GetComponentSize(int component) {

   return GetComponentWidth(component) * GetComponentHeight(component);

 }

 LIBYUV_BOOL MJpegDecoder::UnloadFrame() {

 #ifdef HAVE_SETJMP

   if (setjmp(error_mgr_->setjmp_buffer)) {

     // We called jpeg_abort_decompress, it experienced an error, and we called

     // longjmp() and rewound the stack to here. Return error.

     return LIBYUV_FALSE;

   }

 #endif

   jpeg_abort_decompress(decompress_struct_);

   return LIBYUV_TRUE;

 }

 // TODO(fbarchard): Allow rectangle to be specified: x, y, width, height.

 LIBYUV_BOOL MJpegDecoder::DecodeToBuffers(

     uint8** planes, int dst_width, int dst_height) {

   if (dst_width != GetWidth() ||

       dst_height > GetHeight()) {

     // ERROR: Bad dimensions

     return LIBYUV_FALSE;

   }

 #ifdef HAVE_SETJMP

   if (setjmp(error_mgr_->setjmp_buffer)) {

     // We called into jpeglib, it experienced an error sometime during this

     // function call, and we called longjmp() and rewound the stack to here.

     // Return error.

     return LIBYUV_FALSE;

   }

 #endif

   if (!StartDecode()) {

     return LIBYUV_FALSE;

   }

   SetScanlinePointers(databuf_);

   int lines_left = dst_height;

   // Compute amount of lines to skip to implement vertical crop.

   // TODO(fbarchard): Ensure skip is a multiple of maximum component

   // subsample. ie 2

   int skip = (GetHeight() - dst_height) / 2;

   if (skip > 0) {

     // There is no API to skip lines in the output data, so we read them

     // into the temp buffer.

     while (skip >= GetImageScanlinesPerImcuRow()) {

       if (!DecodeImcuRow()) {

         FinishDecode();

         return LIBYUV_FALSE;

       }

       skip -= GetImageScanlinesPerImcuRow();

     }

     if (skip > 0) {

       // Have a partial iMCU row left over to skip. Must read it and then

       // copy the parts we want into the destination.

       if (!DecodeImcuRow()) {

         FinishDecode();

         return LIBYUV_FALSE;

       }

       for (int i = 0; i < num_outbufs_; ++i) {

         // TODO(fbarchard): Compute skip to avoid this

         assert(skip % GetVertSubSampFactor(i) == 0);

         int rows_to_skip =

             DivideAndRoundDown(skip, GetVertSubSampFactor(i));

         int scanlines_to_copy = GetComponentScanlinesPerImcuRow(i) -

                                 rows_to_skip;

         int data_to_skip = rows_to_skip * GetComponentStride(i);

         CopyPlane(databuf_[i] + data_to_skip, GetComponentStride(i),

                   planes[i], GetComponentWidth(i),

                   GetComponentWidth(i), scanlines_to_copy);

         planes[i] += scanlines_to_copy * GetComponentWidth(i);

       }

       lines_left -= (GetImageScanlinesPerImcuRow() - skip);

     }

   }

   // Read full MCUs but cropped horizontally

   for (; lines_left > GetImageScanlinesPerImcuRow();

          lines_left -= GetImageScanlinesPerImcuRow()) {

     if (!DecodeImcuRow()) {

       FinishDecode();

       return LIBYUV_FALSE;

     }

     for (int i = 0; i < num_outbufs_; ++i) {

       int scanlines_to_copy = GetComponentScanlinesPerImcuRow(i);

       CopyPlane(databuf_[i], GetComponentStride(i),

                 planes[i], GetComponentWidth(i),

                 GetComponentWidth(i), scanlines_to_copy);

       planes[i] += scanlines_to_copy * GetComponentWidth(i);

     }

   }

   if (lines_left > 0) {

     // Have a partial iMCU row left over to decode.

     if (!DecodeImcuRow()) {

       FinishDecode();

       return LIBYUV_FALSE;

     }

     for (int i = 0; i < num_outbufs_; ++i) {

       int scanlines_to_copy =

           DivideAndRoundUp(lines_left, GetVertSubSampFactor(i));

       CopyPlane(databuf_[i], GetComponentStride(i),

                 planes[i], GetComponentWidth(i),

                 GetComponentWidth(i), scanlines_to_copy);

       planes[i] += scanlines_to_copy * GetComponentWidth(i);

     }

   }

   return FinishDecode();

 }

 LIBYUV_BOOL MJpegDecoder::DecodeToCallback(CallbackFunction fn, void* opaque,

     int dst_width, int dst_height) {

   if (dst_width != GetWidth() ||

       dst_height > GetHeight()) {

     // ERROR: Bad dimensions

     return LIBYUV_FALSE;

   }

 #ifdef HAVE_SETJMP

   if (setjmp(error_mgr_->setjmp_buffer)) {

     // We called into jpeglib, it experienced an error sometime during this

     // function call, and we called longjmp() and rewound the stack to here.

     // Return error.

     return LIBYUV_FALSE;

   }

 #endif

   if (!StartDecode()) {

     return LIBYUV_FALSE;

   }

   SetScanlinePointers(databuf_);

   int lines_left = dst_height;

   // TODO(fbarchard): Compute amount of lines to skip to implement vertical crop

   int skip = (GetHeight() - dst_height) / 2;

   if (skip > 0) {

     while (skip >= GetImageScanlinesPerImcuRow()) {

       if (!DecodeImcuRow()) {

         FinishDecode();

         return LIBYUV_FALSE;

       }

       skip -= GetImageScanlinesPerImcuRow();

     }

     if (skip > 0) {

       // Have a partial iMCU row left over to skip.

       if (!DecodeImcuRow()) {

         FinishDecode();

         return LIBYUV_FALSE;

       }

       for (int i = 0; i < num_outbufs_; ++i) {

         // TODO(fbarchard): Compute skip to avoid this

         assert(skip % GetVertSubSampFactor(i) == 0);

         int rows_to_skip = DivideAndRoundDown(skip, GetVertSubSampFactor(i));

         int data_to_skip = rows_to_skip * GetComponentStride(i);

         // Change our own data buffer pointers so we can pass them to the

         // callback.

         databuf_[i] += data_to_skip;

       }

       int scanlines_to_copy = GetImageScanlinesPerImcuRow() - skip;

       (*fn)(opaque, databuf_, databuf_strides_, scanlines_to_copy);

       // Now change them back.

       for (int i = 0; i < num_outbufs_; ++i) {

         int rows_to_skip = DivideAndRoundDown(skip, GetVertSubSampFactor(i));

         int data_to_skip = rows_to_skip * GetComponentStride(i);

         databuf_[i] -= data_to_skip;

       }

       lines_left -= scanlines_to_copy;

     }

   }

   // Read full MCUs until we get to the crop point.

   for (; lines_left >= GetImageScanlinesPerImcuRow();

          lines_left -= GetImageScanlinesPerImcuRow()) {

     if (!DecodeImcuRow()) {

       FinishDecode();

       return LIBYUV_FALSE;

     }

     (*fn)(opaque, databuf_, databuf_strides_, GetImageScanlinesPerImcuRow());

   }

   if (lines_left > 0) {

     // Have a partial iMCU row left over to decode.

     if (!DecodeImcuRow()) {

       FinishDecode();

       return LIBYUV_FALSE;

     }

     (*fn)(opaque, databuf_, databuf_strides_, lines_left);

   }

   return FinishDecode();

 }

 void MJpegDecoder::init_source(j_decompress_ptr cinfo) {

   fill_input_buffer(cinfo);

 }

 boolean MJpegDecoder::fill_input_buffer(j_decompress_ptr cinfo) {

   BufferVector* buf_vec = (BufferVector*)(cinfo->client_data);

   if (buf_vec->pos >= buf_vec->len) {

     assert(0 && "No more data");

     // ERROR: No more data

     return FALSE;

   }

   cinfo->src->next_input_byte = buf_vec->buffers[buf_vec->pos].data;

   cinfo->src->bytes_in_buffer = buf_vec->buffers[buf_vec->pos].len;

   ++buf_vec->pos;

   return TRUE;

 }

 void MJpegDecoder::skip_input_data(j_decompress_ptr cinfo,

                                    long num_bytes) {  // NOLINT

   cinfo->src->next_input_byte += num_bytes;

 }

 void MJpegDecoder::term_source(j_decompress_ptr cinfo) {

   // Nothing to do.

 }

 #ifdef HAVE_SETJMP

 void MJpegDecoder::ErrorHandler(j_common_ptr cinfo) {

   // This is called when a jpeglib command experiences an error. Unfortunately

   // jpeglib's error handling model is not very flexible, because it expects the

   // error handler to not return--i.e., it wants the program to terminate. To

   // recover from errors we use setjmp() as shown in their example. setjmp() is

   // C's implementation for the "call with current continuation" functionality

   // seen in some functional programming languages.

   // A formatted message can be output, but is unsafe for release.

 #ifdef DEBUG

   char buf[JMSG_LENGTH_MAX];

   (*cinfo->err->format_message)(cinfo, buf);

   // ERROR: Error in jpeglib: buf

 #endif

   SetJmpErrorMgr* mgr = (SetJmpErrorMgr*)(cinfo->err);

   // This rewinds the call stack to the point of the corresponding setjmp()

   // and causes it to return (for a second time) with value 1.

   longjmp(mgr->setjmp_buffer, 1);

 }

 #endif

 void MJpegDecoder::AllocOutputBuffers(int num_outbufs) {

   if (num_outbufs != num_outbufs_) {

     // We could perhaps optimize this case to resize the output buffers without

     // necessarily having to delete and recreate each one, but it's not worth

     // it.

     DestroyOutputBuffers();

     scanlines_ = new uint8** [num_outbufs];

     scanlines_sizes_ = new int[num_outbufs];

     databuf_ = new uint8* [num_outbufs];

     databuf_strides_ = new int[num_outbufs];

     for (int i = 0; i < num_outbufs; ++i) {

       scanlines_[i] = NULL;

       scanlines_sizes_[i] = 0;

       databuf_[i] = NULL;

       databuf_strides_[i] = 0;

     }

     num_outbufs_ = num_outbufs;

   }

 }

 void MJpegDecoder::DestroyOutputBuffers() {

   for (int i = 0; i < num_outbufs_; ++i) {

     delete [] scanlines_[i];

     delete [] databuf_[i];

   }

   delete [] scanlines_;

   delete [] databuf_;

   delete [] scanlines_sizes_;

   delete [] databuf_strides_;

   scanlines_ = NULL;

   databuf_ = NULL;

   scanlines_sizes_ = NULL;

   databuf_strides_ = NULL;

   num_outbufs_ = 0;

 }

 // JDCT_IFAST and do_block_smoothing improve performance substantially.

 LIBYUV_BOOL MJpegDecoder::StartDecode() {

   decompress_struct_->raw_data_out = TRUE;

   decompress_struct_->dct_method = JDCT_IFAST;  // JDCT_ISLOW is default

   decompress_struct_->dither_mode = JDITHER_NONE;

   // Not applicable to 'raw':

   decompress_struct_->do_fancy_upsampling = LIBYUV_FALSE;

   // Only for buffered mode:

   decompress_struct_->enable_2pass_quant = LIBYUV_FALSE;

   // Blocky but fast:

   decompress_struct_->do_block_smoothing = LIBYUV_FALSE;

   if (!jpeg_start_decompress(decompress_struct_)) {

     // ERROR: Couldn't start JPEG decompressor";

     return LIBYUV_FALSE;

   }

   return LIBYUV_TRUE;

 }

 LIBYUV_BOOL MJpegDecoder::FinishDecode() {

   // jpeglib considers it an error if we finish without decoding the whole

   // image, so we call "abort" rather than "finish".

   jpeg_abort_decompress(decompress_struct_);

   return LIBYUV_TRUE;

 }

 void MJpegDecoder::SetScanlinePointers(uint8** data) {

   for (int i = 0; i < num_outbufs_; ++i) {

     uint8* data_i = data[i];

     for (int j = 0; j < scanlines_sizes_[i]; ++j) {

       scanlines_[i][j] = data_i;

       data_i += GetComponentStride(i);

     }

   }

 }

 inline LIBYUV_BOOL MJpegDecoder::DecodeImcuRow() {

   return (unsigned int)(GetImageScanlinesPerImcuRow()) ==

       jpeg_read_raw_data(decompress_struct_,

                          scanlines_,

                          GetImageScanlinesPerImcuRow());

 }

 // The helper function which recognizes the jpeg sub-sampling type.

 JpegSubsamplingType MJpegDecoder::JpegSubsamplingTypeHelper(

     int* subsample_x, int* subsample_y, int number_of_components) {

   if (number_of_components == 3) {  // Color images.

     if (subsample_x[0] == 1 && subsample_y[0] == 1 &&

         subsample_x[1] == 2 && subsample_y[1] == 2 &&

         subsample_x[2] == 2 && subsample_y[2] == 2) {

       return kJpegYuv420;

     } else if (subsample_x[0] == 1 && subsample_y[0] == 1 &&

         subsample_x[1] == 2 && subsample_y[1] == 1 &&

         subsample_x[2] == 2 && subsample_y[2] == 1) {

       return kJpegYuv422;

     } else if (subsample_x[0] == 1 && subsample_y[0] == 1 &&

         subsample_x[1] == 1 && subsample_y[1] == 1 &&

         subsample_x[2] == 1 && subsample_y[2] == 1) {

       return kJpegYuv444;

     }

   } else if (number_of_components == 1) {  // Grey-scale images.

     if (subsample_x[0] == 1 && subsample_y[0] == 1) {

       return kJpegYuv400;

     }

   }

   return kJpegUnknown;

 }

 }  // namespace libyuv

 #endif  // HAVE_JPEG