mg_jpg.c

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/*******************************************************************************
 * Copyright © 2014 The DTVKit Open Software Foundation Ltd (www.dtvkit.org)
 * Copyright © 2008 Ocean Blue Software Ltd
 *
 * This file is part of a DTVKit Software Component
 * You are permitted to copy, modify or distribute this file subject to the terms
 * of the DTVKit 1.0 Licence which can be found in licence.txt or at www.dtvkit.org
 * 
 * THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
 * EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * If you or your organisation is not a member of DTVKit then you have access
 * to this source code outside of the terms of the licence agreement
 * and you are expected to delete this and any associated files immediately.
 * Further information on DTVKit, membership and terms can be found at www.dtvkit.org
 *******************************************************************************/
/*---includes for this file--------------------------------------------------*/
#include "decoder.h"

/* compiler library header files */
#include <stdlib.h>
#include <string.h>  /* memset */
#include <stdio.h>
#include <setjmp.h>  /* setjmp OPTIONAL? */

/* this contains modified source from third party file: jdatasrc.c
 * The reason we have this here is because we want "different source manager"
 * in case customer has their own jpeg library.
 *
 * The following copyright was in that file:
 *
 * Copyright (C) 1994-1996, Thomas G. Lane.
 * This file is part of the Independent JPEG Group's software.
 * For conditions of distribution and use, see the accompanying README file.
 *
 * This file contains decompression data source routines for the case of
 * reading JPEG data from a file (or any stdio stream).  While these routines
 * are sufficient for most applications, some will want to use a different
 * source manager.
 * IMPORTANT: we assume that fread() will correctly transcribe an array of
 * UINT8s from 8-bit-wide elements on external storage.  If char is wider
 * than 8 bits on your machine, you may need to do some tweaking.
 */
#include <jpeglib.h>
#include <jerror.h>

/* OBS header files */
#include "glue_memory.h"
#include "mg_ctxt.h"
#include "osd_utils.h"
#include "glue_assert.h"

/*---constant definitions for this file--------------------------------------*/

#define INPUT_BUF_SIZE  4096  /* choose an efficiently fread'able size */

#define GetColourIndex(r, g, b, a) \
   OSD_FindNearestColourIndex((a << 24) | (r << 16) | (g << 8) | b )

/*---local typedef structs for this file-------------------------------------*/

typedef struct smyfile
{
   unsigned char *data;
   unsigned int posn;
   unsigned int left;
} myfile_t;

struct my_error_mgr
{
   struct jpeg_error_mgr pub;
   jmp_buf setjmp_buffer;
};

typedef struct my_error_mgr *my_error_ptr;

/* Expanded data source object for stdio input */

typedef struct
{
   struct jpeg_source_mgr pub; /* public fields */

   myfile_t *infile;     /* source stream */
   UINT8 *buffer;      /* start of buffer */
   boolean start_of_file;  /* have we gotten any data yet? */
} my_source_mgr;

typedef my_source_mgr *my_src_ptr;

/*---local function definitions----------------------------------------------*/


static void my_error_exit( j_common_ptr cinfo )
{
   /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
   my_error_ptr myerr = (my_error_ptr) cinfo->err;

   /* Always display the message. */
   /* We could postpone this until after returning, if we chose. */
   (*cinfo->err->output_message)(cinfo);

   /* Return control to the setjmp point */
   longjmp(myerr->setjmp_buffer, 1);
}

#if JPEG_LIB_VERSION == 62
/* pseudo_fread is called from the jpeg lib - see file "jinclude.h" line 87 */
size_t pseudo_fread( void *buf, size_t size, size_t count, FILE *file )
{
   assert(0);
   return 0;
}

#endif

/*
 * Initialize source --- called by jpeg_read_header
 * before any data is actually read.
 */

METHODDEF(void)
init_source(j_decompress_ptr cinfo)
{
   my_src_ptr src = (my_src_ptr) cinfo->src;

   /* We reset the empty-input-file flag for each image,
    * but we don't clear the input buffer.
    * This is correct behavior for reading a series of images from one source.
    */
   src->start_of_file = TRUE;
}

/*
 * Fill the input buffer --- called whenever buffer is emptied.
 *
 * In typical applications, this should read fresh data into the buffer
 * (ignoring the current state of next_input_byte & bytes_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been reloaded.  It is not necessary to
 * fill the buffer entirely, only to obtain at least one more byte.
 *
 * There is no such thing as an EOF return.  If the end of the file has been
 * reached, the routine has a choice of ERREXIT() or inserting fake data into
 * the buffer.  In most cases, generating a warning message and inserting a
 * fake EOI marker is the best course of action --- this will allow the
 * decompressor to output however much of the image is there.  However,
 * the resulting error message is misleading if the real problem is an empty
 * input file, so we handle that case specially.
 *
 * In applications that need to be able to suspend compression due to input
 * not being available yet, a FALSE return indicates that no more data can be
 * obtained right now, but more may be forthcoming later.  In this situation,
 * the decompressor will return to its caller (with an indication of the
 * number of scanlines it has read, if any).  The application should resume
 * decompression after it has loaded more data into the input buffer.  Note
 * that there are substantial restrictions on the use of suspension --- see
 * the documentation.
 *
 * When suspending, the decompressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point must be rescanned after resumption, so move it to
 * the front of the buffer rather than discarding it.
 */

METHODDEF(boolean)
fill_input_buffer(j_decompress_ptr cinfo)
{
   my_src_ptr src = (my_src_ptr) cinfo->src;
   myfile_t *pseudo_file = src->infile;
   size_t nbytes = INPUT_BUF_SIZE;

   if (pseudo_file->left < INPUT_BUF_SIZE)
   {
      nbytes = pseudo_file->left;
      if (nbytes == 0)
      {
         if (src->start_of_file)
         { /* Treat empty input file as fatal error */
            ERREXIT(cinfo, JERR_INPUT_EMPTY);
         }
         WARNMS(cinfo, JWRN_JPEG_EOF);
         /* Insert a fake EOI marker */
         src->buffer[0] = (UINT8) 0xFF;
         src->buffer[1] = (UINT8) JPEG_EOI;
         nbytes = 2;
      }
   }
   memcpy( src->buffer, pseudo_file->data + pseudo_file->posn, nbytes );
   pseudo_file->posn += nbytes;
   pseudo_file->left -= nbytes;

   src->pub.next_input_byte = src->buffer;
   src->pub.bytes_in_buffer = nbytes;
   src->start_of_file = FALSE;

   return TRUE;
}


/*
 * Skip data --- used to skip over a potentially large amount of
 * uninteresting data (such as an APPn marker).
 *
 * Writers of suspendable-input applications must note that skip_input_data
 * is not granted the right to give a suspension return.  If the skip extends
 * beyond the data currently in the buffer, the buffer can be marked empty so
 * that the next read will cause a fill_input_buffer call that can suspend.
 * Arranging for additional bytes to be discarded before reloading the input
 * buffer is the application writer's problem.
 */

METHODDEF(void)
skip_input_data(j_decompress_ptr cinfo, long num_bytes)
{
   my_src_ptr src = (my_src_ptr) cinfo->src;

   /* Just a dumb implementation for now.  Could use fseek() except
    * it doesn't work on pipes.  Not clear that being smart is worth
    * any trouble anyway --- large skips are infrequent.
    */
   if (num_bytes > 0)
   {
      while (num_bytes > (long) src->pub.bytes_in_buffer)
      {
         num_bytes -= (long) src->pub.bytes_in_buffer;
         (void) fill_input_buffer(cinfo);
         /* note we assume that fill_input_buffer will never return FALSE,
          * so suspension need not be handled.
          */
      }
      src->pub.next_input_byte += (size_t) num_bytes;
      src->pub.bytes_in_buffer -= (size_t) num_bytes;
   }
}


/*
 * An additional method that can be provided by data source modules is the
 * resync_to_restart method for error recovery in the presence of RST markers.
 * For the moment, this source module just uses the default resync method
 * provided by the JPEG library.  That method assumes that no backtracking
 * is possible.
 */


/*
 * Terminate source --- called by jpeg_finish_decompress
 * after all data has been read.  Often a no-op.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */

METHODDEF(void)
term_source(j_decompress_ptr cinfo)
{
   /* no work necessary here */
}


/*
 * Prepare for input from a stdio stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing decompression.
 */

METHODDEF(void)
jobs_stdio_src(j_decompress_ptr cinfo, myfile_t * infile)
{
   my_src_ptr src;

   /* The source object and input buffer are made permanent so that a series
    * of JPEG images can be read from the same file by calling jpeg_stdio_src
    * only before the first one.  (If we discarded the buffer at the end of
    * one image, we'd likely lose the start of the next one.)
    * This makes it unsafe to use this manager and a different source
    * manager serially with the same JPEG object.  Caveat programmer.
    */
   if (cinfo->src == NULL)    /* first time for this JPEG object? */
   {
      cinfo->src = (struct jpeg_source_mgr *)
         (*cinfo->mem->alloc_small)((j_common_ptr) cinfo, JPOOL_PERMANENT,
            sizeof(my_source_mgr));
      src = (my_src_ptr) cinfo->src;
      src->buffer = (UINT8 *)
         (*cinfo->mem->alloc_small)((j_common_ptr) cinfo, JPOOL_PERMANENT,
            INPUT_BUF_SIZE * sizeof(UINT8));
   }

   src = (my_src_ptr) cinfo->src;
   src->pub.init_source = init_source;
   src->pub.fill_input_buffer = fill_input_buffer;
   src->pub.skip_input_data = skip_input_data;
   src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
   src->pub.term_source = term_source;
   src->infile = infile;
   src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
   src->pub.next_input_byte = NULL; /* until buffer loaded */
}

/*---global function definitions---------------------------------------------*/

S_IMAGE* DEC_DecodeJpg( U8BIT *data, U32BIT len )
{
   S_IMAGE *j_bmp = 0;
   myfile_t pseudo_file;
   struct jpeg_decompress_struct cinfo;
   struct my_error_mgr jerr;
   U8BIT density_unit;
   U8BIT *row_ptr;
   U16BIT r_bytes;

   if (len > 0)
   {
      pseudo_file.data = data;
      pseudo_file.posn = 0;
      pseudo_file.left = len;
      cinfo.err = jpeg_std_error(&jerr.pub);
      jerr.pub.error_exit = my_error_exit;
      if (setjmp(jerr.setjmp_buffer))
      {
         /* If we get here, the JPEG code has signaled an error.
          * We need to clean up the JPEG object, close the input file, and return.
          */
         jpeg_destroy_decompress(&cinfo);
         OSD_MemFree(j_bmp);
         j_bmp = 0;
      }
      else
      {
         jpeg_create_decompress(&cinfo);
         jobs_stdio_src( &cinfo, &pseudo_file );
         (void)jpeg_read_header(&cinfo, TRUE);

         /* jpeg_calc_output_dimensions() */
         cinfo.out_color_space = JCS_RGB;

         (void)jpeg_start_decompress(&cinfo);
         assert(cinfo.output_components == 3);

         IF_COL_DEPTH( COLOUR_FORMAT_PALETTE )
         {
            #ifdef OSD_8_BIT
            j_bmp = (S_IMAGE *) OSD_MemAlloc(sizeof(S_IMAGE));
            if (j_bmp)
            {
               U8BIT *s_buff = OSD_MemAlloc( cinfo.output_width * cinfo.output_height );
               if (s_buff)
               {
                  r_bytes = cinfo.output_width * cinfo.output_components;
                  row_ptr = OSD_MemAlloc( r_bytes );
                  if (row_ptr)
                  {
                     U16BIT r_ndx;
                     j_bmp->col_buff = s_buff;
                     j_bmp->width = cinfo.output_width;
                     j_bmp->height = cinfo.output_height;

                     /* For 8-bit, we don't support HD resolutions, so consider all to be SD */
                     j_bmp->y_resolution = SD_METRIC_RESOLUTION;

                     j_bmp->pix_bytes = 1;
                     j_bmp->opaque = COMPLETELY_OPAQUE;
                     while (cinfo.output_scanline < cinfo.output_height)
                     {
                        (void)jpeg_read_scanlines( &cinfo, &row_ptr, 1 );
                        for (r_ndx = 0; r_ndx != r_bytes; r_ndx += cinfo.output_components)
                        {
                           *s_buff++ = GetColourIndex(row_ptr[r_ndx], row_ptr[r_ndx + 1], row_ptr[r_ndx + 2], 0xff);
                        }
                     }
                     OSD_MemFree(row_ptr);
                  }
                  else
                  {
                     OSD_MemFree(s_buff);
                     OSD_MemFree(j_bmp);
                     j_bmp = 0;
                     /*using a warning so that process continues (error will abort)*/
                     WARNMS1(&cinfo, JERR_OUT_OF_MEMORY, 0);
                  }
               }
               else
               {
                  OSD_MemFree(j_bmp);
                  j_bmp = 0;
               }
            }
            #endif /* OSD_8_BIT */
         }
         ELSE
         {
            #if defined(OSD_16_BIT) || defined(OSD_31_BIT) || defined(OSD_32_BIT)
            /* HD true colour */
            r_bytes = cinfo.output_width * cinfo.output_components;

            j_bmp = (S_IMAGE *) OSD_MemAlloc(sizeof(S_IMAGE));
            if (j_bmp)
            {
               U32BIT resolution;
               if (!cinfo.saw_JFIF_marker)
               {
                  resolution = SD_METRIC_RESOLUTION;
               }
               else
               {
                  density_unit = cinfo.density_unit;
                  if ((cinfo.Y_density != cinfo.X_density) ||
                      (density_unit < 1) || (density_unit > 2))
                  {
                     /* Force this to be SD resolution */
                     density_unit = 0;
                  }

                  resolution = cinfo.Y_density;

                  if (density_unit == 1)
                  {
                     /* density in dots/inch */
                     resolution = (resolution * 5000 + 63) / 127;
                  }
                  else if (density_unit == 2)
                  {
                     /* density in dots/cm */
                     switch (cinfo.Y_density)
                     {
                        case 53: resolution = 5315; break;
                        case 35: resolution = 3543; break;
                        case 28: resolution = 2835; break;
                        default: resolution = resolution * 100;
                     }
                  }
                  else
                  {
                     /* SD resolution */
                     resolution = SD_METRIC_RESOLUTION;
                  }
               }
               if (resolution)
               {
                  row_ptr = OSD_MemAlloc( r_bytes * cinfo.output_height );
                  if (!row_ptr)
                  {
                     OSD_MemFree(j_bmp);
                     j_bmp = 0;
                     /*using a warning so that process continues (error will abort)*/
                     WARNMS1(&cinfo, JERR_OUT_OF_MEMORY, 0);
                  }
                  else
                  {
                     j_bmp->y_resolution = (U16BIT)resolution;
                     j_bmp->width = cinfo.output_width;
                     j_bmp->height = cinfo.output_height;
                     j_bmp->col_buff = row_ptr;
                     j_bmp->pix_bytes = 3;
                     j_bmp->opaque = COMPLETELY_OPAQUE;
                     while (cinfo.output_scanline < cinfo.output_height)
                     {
                        (void)jpeg_read_scanlines( &cinfo, &row_ptr, 1 );
                        row_ptr += r_bytes;
                     }
                  }
               }
            }
            #endif /* OSD_16_BIT || OSD_32_BIT */
         }
         (void)jpeg_finish_decompress(&cinfo);
         jpeg_destroy_decompress(&cinfo);
      }
   }
   return j_bmp;
}

void DEC_FreeJpg( S_IMAGE *data )
{
   OSD_MemFree(data->col_buff);
   OSD_MemFree(data);
}