// Copyright 2012 Google Inc. All Rights Reserved.

//

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

// that can be found in the COPYING 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.

// -----------------------------------------------------------------------------

//

// JPEG decode.

#include "./jpegdec.h"

#ifdef HAVE_CONFIG_H

#include "webp/config.h"

#endif

#include <stdio.h>

#ifdef WEBP_HAVE_JPEG

#include <jpeglib.h>

#include <jerror.h>

#include <setjmp.h>

#include <stdlib.h>

#include <string.h>

#include "webp/encode.h"

#include "./imageio_util.h"

#include "./metadata.h"

// -----------------------------------------------------------------------------

// Metadata processing

#ifndef JPEG_APP1

# define JPEG_APP1 (JPEG_APP0 + 1)

#endif

#ifndef JPEG_APP2

# define JPEG_APP2 (JPEG_APP0 + 2)

#endif

typedef struct {

  const uint8_t* data;

  size_t data_length;

  int seq;  // this segment's sequence number [1, 255] for use in reassembly.

} ICCPSegment;

static void SaveMetadataMarkers(j_decompress_ptr dinfo) {

  const unsigned int max_marker_length = 0xffff;

  jpeg_save_markers(dinfo, JPEG_APP1, max_marker_length);  // Exif/XMP

  jpeg_save_markers(dinfo, JPEG_APP2, max_marker_length);  // ICC profile

}

static int CompareICCPSegments(const void* a, const void* b) {

  const ICCPSegment* s1 = (const ICCPSegment*)a;

  const ICCPSegment* s2 = (const ICCPSegment*)b;

  return s1->seq - s2->seq;

}

// Extract ICC profile segments from the marker list in 'dinfo', reassembling

// and storing them in 'iccp'.

// Returns true on success and false for memory errors and corrupt profiles.

static int StoreICCP(j_decompress_ptr dinfo, MetadataPayload* const iccp) {

  // ICC.1:2010-12 (4.3.0.0) Annex B.4 Embedding ICC Profiles in JPEG files

  static const char kICCPSignature[] = "ICC_PROFILE";

  static const size_t kICCPSignatureLength = 12;  // signature includes '\0'

  static const size_t kICCPSkipLength = 14;  // signature + seq & count

  int expected_count = 0;

  int actual_count = 0;

  int seq_max = 0;

  size_t total_size = 0;

  ICCPSegment iccp_segments[255];

  jpeg_saved_marker_ptr marker;

  memset(iccp_segments, 0, sizeof(iccp_segments));

  for (marker = dinfo->marker_list; marker != NULL; marker = marker->next) {

    if (marker->marker == JPEG_APP2 &&

        marker->data_length > kICCPSkipLength &&

        !memcmp(marker->data, kICCPSignature, kICCPSignatureLength)) {

      // ICC_PROFILE\0<seq><count>; 'seq' starts at 1.

      const int seq = marker->data[kICCPSignatureLength];

      const int count = marker->data[kICCPSignatureLength + 1];

      const size_t segment_size = marker->data_length - kICCPSkipLength;

      ICCPSegment* segment;

      if (segment_size == 0 || count == 0 || seq == 0) {

        fprintf(stderr, "[ICCP] size (%d) / count (%d) / sequence number (%d)"

                        " cannot be 0!\n",

                (int)segment_size, seq, count);

        return 0;

      }

      if (expected_count == 0) {

        expected_count = count;

      } else if (expected_count != count) {

        fprintf(stderr, "[ICCP] Inconsistent segment count (%d / %d)!\n",

                expected_count, count);

        return 0;

      }

      segment = iccp_segments + seq - 1;

      if (segment->data_length != 0) {

        fprintf(stderr, "[ICCP] Duplicate segment number (%d)!\n" , seq);

        return 0;

      }

      segment->data = marker->data + kICCPSkipLength;

      segment->data_length = segment_size;

      segment->seq = seq;

      total_size += segment_size;

      if (seq > seq_max) seq_max = seq;

      ++actual_count;

    }

  }

  if (actual_count == 0) return 1;

  if (seq_max != actual_count) {

    fprintf(stderr, "[ICCP] Discontinuous segments, expected: %d actual: %d!\n",

            actual_count, seq_max);

    return 0;

  }

  if (expected_count != actual_count) {

    fprintf(stderr, "[ICCP] Segment count: %d does not match expected: %d!\n",

            actual_count, expected_count);

    return 0;

  }

  // The segments may appear out of order in the file, sort them based on

  // sequence number before assembling the payload.

  qsort(iccp_segments, actual_count, sizeof(*iccp_segments),

        CompareICCPSegments);

  iccp->bytes = (uint8_t*)malloc(total_size);

  if (iccp->bytes == NULL) return 0;

  iccp->size = total_size;

  {

    int i;

    size_t offset = 0;

    for (i = 0; i < seq_max; ++i) {

      memcpy(iccp->bytes + offset,

             iccp_segments[i].data, iccp_segments[i].data_length);

      offset += iccp_segments[i].data_length;

    }

  }

  return 1;

}

// Returns true on success and false for memory errors and corrupt profiles.

// The caller must use MetadataFree() on 'metadata' in all cases.

static int ExtractMetadataFromJPEG(j_decompress_ptr dinfo,

                                   Metadata* const metadata) {

  static const struct {

    int marker;

    const char* signature;

    size_t signature_length;

    size_t storage_offset;

  } kJPEGMetadataMap[] = {

    // Exif 2.2 Section 4.7.2 Interoperability Structure of APP1 ...

    { JPEG_APP1, "Exif\0",                        6, METADATA_OFFSET(exif) },

    // XMP Specification Part 3 Section 3 Embedding XMP Metadata ... #JPEG

    // TODO(jzern) Add support for 'ExtendedXMP'

    { JPEG_APP1, "http://ns.adobe.com/xap/1.0/", 29, METADATA_OFFSET(xmp) },

    { 0, NULL, 0, 0 },

  };

  jpeg_saved_marker_ptr marker;

  // Treat ICC profiles separately as they may be segmented and out of order.

  if (!StoreICCP(dinfo, &metadata->iccp)) return 0;

  for (marker = dinfo->marker_list; marker != NULL; marker = marker->next) {

    int i;

    for (i = 0; kJPEGMetadataMap[i].marker != 0; ++i) {

      if (marker->marker == kJPEGMetadataMap[i].marker &&

          marker->data_length > kJPEGMetadataMap[i].signature_length &&

          !memcmp(marker->data, kJPEGMetadataMap[i].signature,

                  kJPEGMetadataMap[i].signature_length)) {

        MetadataPayload* const payload =

            (MetadataPayload*)((uint8_t*)metadata +

                               kJPEGMetadataMap[i].storage_offset);

        if (payload->bytes == NULL) {

          const char* marker_data = (const char*)marker->data +

                                    kJPEGMetadataMap[i].signature_length;

          const size_t marker_data_length =

              marker->data_length - kJPEGMetadataMap[i].signature_length;

          if (!MetadataCopy(marker_data, marker_data_length, payload)) return 0;

        } else {

          fprintf(stderr, "Ignoring additional '%s' marker\n",

                  kJPEGMetadataMap[i].signature);

        }

      }

    }

  }

  return 1;

}

#undef JPEG_APP1

#undef JPEG_APP2

// -----------------------------------------------------------------------------

// JPEG decoding

struct my_error_mgr {

  struct jpeg_error_mgr pub;

  jmp_buf setjmp_buffer;

};

static void my_error_exit(j_common_ptr dinfo) {

  struct my_error_mgr* myerr = (struct my_error_mgr*)dinfo->err;

  dinfo->err->output_message(dinfo);

  longjmp(myerr->setjmp_buffer, 1);

}

typedef struct {

  struct jpeg_source_mgr pub;

  const uint8_t* data;

  size_t data_size;

} JPEGReadContext;

static void ContextInit(j_decompress_ptr cinfo) {

  JPEGReadContext* const ctx = (JPEGReadContext*)cinfo->src;

  ctx->pub.next_input_byte = ctx->data;

  ctx->pub.bytes_in_buffer = ctx->data_size;

}

static boolean ContextFill(j_decompress_ptr cinfo) {

  // we shouldn't get here.

  ERREXIT(cinfo, JERR_FILE_READ);

  return FALSE;

}

static void ContextSkip(j_decompress_ptr cinfo, long jump_size) {

  JPEGReadContext* const ctx = (JPEGReadContext*)cinfo->src;

  size_t jump = (size_t)jump_size;

  if (jump > ctx->pub.bytes_in_buffer) {  // Don't overflow the buffer.

    jump = ctx->pub.bytes_in_buffer;

  }

  ctx->pub.bytes_in_buffer -= jump;

  ctx->pub.next_input_byte += jump;

}

static void ContextTerm(j_decompress_ptr cinfo) {

  (void)cinfo;

}

static void ContextSetup(volatile struct jpeg_decompress_struct* const cinfo,

                         JPEGReadContext* const ctx) {

  cinfo->src = (struct jpeg_source_mgr*)ctx;

  ctx->pub.init_source = ContextInit;

  ctx->pub.fill_input_buffer = ContextFill;

  ctx->pub.skip_input_data = ContextSkip;

  ctx->pub.resync_to_restart = jpeg_resync_to_restart;

  ctx->pub.term_source = ContextTerm;

  ctx->pub.bytes_in_buffer = 0;

  ctx->pub.next_input_byte = NULL;

}

int ReadJPEG(const uint8_t* const data, size_t data_size,

             WebPPicture* const pic, int keep_alpha,

             Metadata* const metadata) {

  volatile int ok = 0;

  int width, height;

  int64_t stride;

  volatile struct jpeg_decompress_struct dinfo;

  struct my_error_mgr jerr;

  uint8_t* volatile rgb = NULL;

  JSAMPROW buffer[1];

  JPEGReadContext ctx;

  if (data == NULL || data_size == 0 || pic == NULL) return 0;

  (void)keep_alpha;

  memset(&ctx, 0, sizeof(ctx));

  ctx.data = data;

  ctx.data_size = data_size;

  memset((j_decompress_ptr)&dinfo, 0, sizeof(dinfo));   // for setjmp sanity

  dinfo.err = jpeg_std_error(&jerr.pub);

  jerr.pub.error_exit = my_error_exit;

  if (setjmp(jerr.setjmp_buffer)) {

 Error:

    MetadataFree(metadata);

    jpeg_destroy_decompress((j_decompress_ptr)&dinfo);

    goto End;

  }

  jpeg_create_decompress((j_decompress_ptr)&dinfo);

  ContextSetup(&dinfo, &ctx;;

  if (metadata != NULL) SaveMetadataMarkers((j_decompress_ptr)&dinfo);

  jpeg_read_header((j_decompress_ptr)&dinfo, TRUE);

  dinfo.out_color_space = JCS_RGB;

  dinfo.do_fancy_upsampling = TRUE;

  jpeg_start_decompress((j_decompress_ptr)&dinfo);

  if (dinfo.output_components != 3) {

    goto Error;

  }

  width = dinfo.output_width;

  height = dinfo.output_height;

  stride = (int64_t)dinfo.output_width * dinfo.output_components * sizeof(*rgb);

  if (stride != (int)stride ||

      !ImgIoUtilCheckSizeArgumentsOverflow(stride, height)) {

    goto Error;

  }

  rgb = (uint8_t*)malloc((size_t)stride * height);

  if (rgb == NULL) {

    goto Error;

  }

  buffer[0] = (JSAMPLE*)rgb;

  while (dinfo.output_scanline < dinfo.output_height) {

    if (jpeg_read_scanlines((j_decompress_ptr)&dinfo, buffer, 1) != 1) {

      goto Error;

    }

    buffer[0] += stride;

  }

  if (metadata != NULL) {

    ok = ExtractMetadataFromJPEG((j_decompress_ptr)&dinfo, metadata);

    if (!ok) {

      fprintf(stderr, "Error extracting JPEG metadata!\n");

      goto Error;

    }

  }

  jpeg_finish_decompress((j_decompress_ptr)&dinfo);

  jpeg_destroy_decompress((j_decompress_ptr)&dinfo);

  // WebP conversion.

  pic->width = width;

  pic->height = height;

  ok = WebPPictureImportRGB(pic, rgb, (int)stride);

  if (!ok) goto Error;

 End:

  free(rgb);

  return ok;

}

#else  // !WEBP_HAVE_JPEG

int ReadJPEG(const uint8_t* const data, size_t data_size,

             struct WebPPicture* const pic, int keep_alpha,

             struct Metadata* const metadata) {

  (void)data;

  (void)data_size;

  (void)pic;

  (void)keep_alpha;

  (void)metadata;

  fprintf(stderr, "JPEG support not compiled. Please install the libjpeg "

          "development package before building.\n");

  return 0;

}

#endif  // WEBP_HAVE_JPEG

// -----------------------------------------------------------------------------