jdapistd.c - third_party/libjpeg-turbo - Git at Google

 /*
  * jdapistd.c
  *
  * This file was part of the Independent JPEG Group's software:
  * Copyright (C) 1994-1996, Thomas G. Lane.
  * Modifications:
  * Copyright (C) 2010, D. R. Commander.
  * For conditions of distribution and use, see the accompanying README file.
  *
  * This file contains application interface code for the decompression half
  * of the JPEG library.  These are the "standard" API routines that are
  * used in the normal full-decompression case.  They are not used by a
  * transcoding-only application.  Note that if an application links in
  * jpeg_start_decompress, it will end up linking in the entire decompressor.
  * We thus must separate this file from jdapimin.c to avoid linking the
  * whole decompression library into a transcoder.
  */

 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
 #include "jpegcomp.h"


 /* Forward declarations */
 LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));


 /*
  * Decompression initialization.
  * jpeg_read_header must be completed before calling this.
  *
  * If a multipass operating mode was selected, this will do all but the
  * last pass, and thus may take a great deal of time.
  *
  * Returns FALSE if suspended.  The return value need be inspected only if
  * a suspending data source is used.
  */

 GLOBAL(boolean)
 jpeg_start_decompress (j_decompress_ptr cinfo)
 {
   if (cinfo->global_state == DSTATE_READY) {
     /* First call: initialize master control, select active modules */
     jinit_master_decompress(cinfo);
     if (cinfo->buffered_image) {
       /* No more work here; expecting jpeg_start_output next */
       cinfo->global_state = DSTATE_BUFIMAGE;
       return TRUE;
     }
     cinfo->global_state = DSTATE_PRELOAD;
   }
   if (cinfo->global_state == DSTATE_PRELOAD) {
     /* If file has multiple scans, absorb them all into the coef buffer */
     if (cinfo->inputctl->has_multiple_scans) {
 #ifdef D_MULTISCAN_FILES_SUPPORTED
       for (;;) {
 	int retcode;
 	/* Call progress monitor hook if present */
 	if (cinfo->progress != NULL)
 	  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
 	/* Absorb some more input */
 	retcode = (*cinfo->inputctl->consume_input) (cinfo);
 	if (retcode == JPEG_SUSPENDED)
 	  return FALSE;
 	if (retcode == JPEG_REACHED_EOI)
 	  break;
 	/* Advance progress counter if appropriate */
 	if (cinfo->progress != NULL &&
 	    (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
 	  if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
 	    /* jdmaster underestimated number of scans; ratchet up one scan */
 	    cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
 	  }
 	}
       }
 #else
       ERREXIT(cinfo, JERR_NOT_COMPILED);
 #endif /* D_MULTISCAN_FILES_SUPPORTED */
     }
     cinfo->output_scan_number = cinfo->input_scan_number;
   } else if (cinfo->global_state != DSTATE_PRESCAN)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   /* Perform any dummy output passes, and set up for the final pass */
   return output_pass_setup(cinfo);
 }


 /*
  * Set up for an output pass, and perform any dummy pass(es) needed.
  * Common subroutine for jpeg_start_decompress and jpeg_start_output.
  * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
  * Exit: If done, returns TRUE and sets global_state for proper output mode.
  *       If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
  */

 LOCAL(boolean)
 output_pass_setup (j_decompress_ptr cinfo)
 {
   if (cinfo->global_state != DSTATE_PRESCAN) {
     /* First call: do pass setup */
     (*cinfo->master->prepare_for_output_pass) (cinfo);
     cinfo->output_scanline = 0;
     cinfo->global_state = DSTATE_PRESCAN;
   }
   /* Loop over any required dummy passes */
   while (cinfo->master->is_dummy_pass) {
 #ifdef QUANT_2PASS_SUPPORTED
     /* Crank through the dummy pass */
     while (cinfo->output_scanline < cinfo->output_height) {
       JDIMENSION last_scanline;
       /* Call progress monitor hook if present */
       if (cinfo->progress != NULL) {
 	cinfo->progress->pass_counter = (long) cinfo->output_scanline;
 	cinfo->progress->pass_limit = (long) cinfo->output_height;
 	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
       }
       /* Process some data */
       last_scanline = cinfo->output_scanline;
       (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
 				    &cinfo->output_scanline, (JDIMENSION) 0);
       if (cinfo->output_scanline == last_scanline)
 	return FALSE;		/* No progress made, must suspend */
     }
     /* Finish up dummy pass, and set up for another one */
     (*cinfo->master->finish_output_pass) (cinfo);
     (*cinfo->master->prepare_for_output_pass) (cinfo);
     cinfo->output_scanline = 0;
 #else
     ERREXIT(cinfo, JERR_NOT_COMPILED);
 #endif /* QUANT_2PASS_SUPPORTED */
   }
   /* Ready for application to drive output pass through
    * jpeg_read_scanlines or jpeg_read_raw_data.
    */
   cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
   return TRUE;
 }


 /*
  * Read some scanlines of data from the JPEG decompressor.
  *
  * The return value will be the number of lines actually read.
  * This may be less than the number requested in several cases,
  * including bottom of image, data source suspension, and operating
  * modes that emit multiple scanlines at a time.
  *
  * Note: we warn about excess calls to jpeg_read_scanlines() since
  * this likely signals an application programmer error.  However,
  * an oversize buffer (max_lines > scanlines remaining) is not an error.
  */

 GLOBAL(JDIMENSION)
 jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
 		     JDIMENSION max_lines)
 {
   JDIMENSION row_ctr;

   if (cinfo->global_state != DSTATE_SCANNING)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   if (cinfo->output_scanline >= cinfo->output_height) {
     WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
     return 0;
   }

   /* Call progress monitor hook if present */
   if (cinfo->progress != NULL) {
     cinfo->progress->pass_counter = (long) cinfo->output_scanline;
     cinfo->progress->pass_limit = (long) cinfo->output_height;
     (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
   }

   /* Process some data */
   row_ctr = 0;
   (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
   cinfo->output_scanline += row_ctr;
   return row_ctr;
 }


 /*
  * Alternate entry point to read raw data.
  * Processes exactly one iMCU row per call, unless suspended.
  */

 GLOBAL(JDIMENSION)
 jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
 		    JDIMENSION max_lines)
 {
   JDIMENSION lines_per_iMCU_row;

   if (cinfo->global_state != DSTATE_RAW_OK)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   if (cinfo->output_scanline >= cinfo->output_height) {
     WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
     return 0;
   }

   /* Call progress monitor hook if present */
   if (cinfo->progress != NULL) {
     cinfo->progress->pass_counter = (long) cinfo->output_scanline;
     cinfo->progress->pass_limit = (long) cinfo->output_height;
     (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
   }

   /* Verify that at least one iMCU row can be returned. */
   lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->_min_DCT_scaled_size;
   if (max_lines < lines_per_iMCU_row)
     ERREXIT(cinfo, JERR_BUFFER_SIZE);

   /* Decompress directly into user's buffer. */
   if (! (*cinfo->coef->decompress_data) (cinfo, data))
     return 0;			/* suspension forced, can do nothing more */

   /* OK, we processed one iMCU row. */
   cinfo->output_scanline += lines_per_iMCU_row;
   return lines_per_iMCU_row;
 }


 /* Additional entry points for buffered-image mode. */

 #ifdef D_MULTISCAN_FILES_SUPPORTED

 /*
  * Initialize for an output pass in buffered-image mode.
  */

 GLOBAL(boolean)
 jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
 {
   if (cinfo->global_state != DSTATE_BUFIMAGE &&
       cinfo->global_state != DSTATE_PRESCAN)
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   /* Limit scan number to valid range */
   if (scan_number <= 0)
     scan_number = 1;
   if (cinfo->inputctl->eoi_reached &&
       scan_number > cinfo->input_scan_number)
     scan_number = cinfo->input_scan_number;
   cinfo->output_scan_number = scan_number;
   /* Perform any dummy output passes, and set up for the real pass */
   return output_pass_setup(cinfo);
 }


 /*
  * Finish up after an output pass in buffered-image mode.
  *
  * Returns FALSE if suspended.  The return value need be inspected only if
  * a suspending data source is used.
  */

 GLOBAL(boolean)
 jpeg_finish_output (j_decompress_ptr cinfo)
 {
   if ((cinfo->global_state == DSTATE_SCANNING ||
        cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
     /* Terminate this pass. */
     /* We do not require the whole pass to have been completed. */
     (*cinfo->master->finish_output_pass) (cinfo);
     cinfo->global_state = DSTATE_BUFPOST;
   } else if (cinfo->global_state != DSTATE_BUFPOST) {
     /* BUFPOST = repeat call after a suspension, anything else is error */
     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
   }
   /* Read markers looking for SOS or EOI */
   while (cinfo->input_scan_number <= cinfo->output_scan_number &&
 	 ! cinfo->inputctl->eoi_reached) {
     if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
       return FALSE;		/* Suspend, come back later */
   }
   cinfo->global_state = DSTATE_BUFIMAGE;
   return TRUE;
 }

 #endif /* D_MULTISCAN_FILES_SUPPORTED */
	/*
	* jdapistd.c
	*
	* This file was part of the Independent JPEG Group's software:
	* Copyright (C) 1994-1996, Thomas G. Lane.
	* Modifications:
	* Copyright (C) 2010, D. R. Commander.
	* For conditions of distribution and use, see the accompanying README file.
	*
	* This file contains application interface code for the decompression half
	* of the JPEG library. These are the "standard" API routines that are
	* used in the normal full-decompression case. They are not used by a
	* transcoding-only application. Note that if an application links in
	* jpeg_start_decompress, it will end up linking in the entire decompressor.
	* We thus must separate this file from jdapimin.c to avoid linking the
	* whole decompression library into a transcoder.
	*/

	#define JPEG_INTERNALS
	#include "jinclude.h"
	#include "jpeglib.h"
	#include "jpegcomp.h"


	/* Forward declarations */
	LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));


	/*
	* Decompression initialization.
	* jpeg_read_header must be completed before calling this.
	*
	* If a multipass operating mode was selected, this will do all but the
	* last pass, and thus may take a great deal of time.
	*
	* Returns FALSE if suspended. The return value need be inspected only if
	* a suspending data source is used.
	*/

	GLOBAL(boolean)
	jpeg_start_decompress (j_decompress_ptr cinfo)
	{
	if (cinfo->global_state == DSTATE_READY) {
	/* First call: initialize master control, select active modules */
	jinit_master_decompress(cinfo);
	if (cinfo->buffered_image) {
	/* No more work here; expecting jpeg_start_output next */
	cinfo->global_state = DSTATE_BUFIMAGE;
	return TRUE;
	}
	cinfo->global_state = DSTATE_PRELOAD;
	}
	if (cinfo->global_state == DSTATE_PRELOAD) {
	/* If file has multiple scans, absorb them all into the coef buffer */
	if (cinfo->inputctl->has_multiple_scans) {
	#ifdef D_MULTISCAN_FILES_SUPPORTED
	for (;;) {
	int retcode;
	/* Call progress monitor hook if present */
	if (cinfo->progress != NULL)
	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
	/* Absorb some more input */
	retcode = (*cinfo->inputctl->consume_input) (cinfo);
	if (retcode == JPEG_SUSPENDED)
	return FALSE;
	if (retcode == JPEG_REACHED_EOI)
	break;
	/* Advance progress counter if appropriate */
	if (cinfo->progress != NULL &&
	(retcode == JPEG_ROW_COMPLETED \|\| retcode == JPEG_REACHED_SOS)) {
	if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
	/* jdmaster underestimated number of scans; ratchet up one scan */
	cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
	}
	}
	}
	#else
	ERREXIT(cinfo, JERR_NOT_COMPILED);
	#endif /* D_MULTISCAN_FILES_SUPPORTED */
	}
	cinfo->output_scan_number = cinfo->input_scan_number;
	} else if (cinfo->global_state != DSTATE_PRESCAN)
	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
	/* Perform any dummy output passes, and set up for the final pass */
	return output_pass_setup(cinfo);
	}


	/*
	* Set up for an output pass, and perform any dummy pass(es) needed.
	* Common subroutine for jpeg_start_decompress and jpeg_start_output.
	* Entry: global_state = DSTATE_PRESCAN only if previously suspended.
	* Exit: If done, returns TRUE and sets global_state for proper output mode.
	* If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
	*/

	LOCAL(boolean)
	output_pass_setup (j_decompress_ptr cinfo)
	{
	if (cinfo->global_state != DSTATE_PRESCAN) {
	/* First call: do pass setup */
	(*cinfo->master->prepare_for_output_pass) (cinfo);
	cinfo->output_scanline = 0;
	cinfo->global_state = DSTATE_PRESCAN;
	}
	/* Loop over any required dummy passes */
	while (cinfo->master->is_dummy_pass) {
	#ifdef QUANT_2PASS_SUPPORTED
	/* Crank through the dummy pass */
	while (cinfo->output_scanline < cinfo->output_height) {
	JDIMENSION last_scanline;
	/* Call progress monitor hook if present */
	if (cinfo->progress != NULL) {
	cinfo->progress->pass_counter = (long) cinfo->output_scanline;
	cinfo->progress->pass_limit = (long) cinfo->output_height;
	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
	}
	/* Process some data */
	last_scanline = cinfo->output_scanline;
	(*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
	&cinfo->output_scanline, (JDIMENSION) 0);
	if (cinfo->output_scanline == last_scanline)
	return FALSE; /* No progress made, must suspend */
	}
	/* Finish up dummy pass, and set up for another one */
	(*cinfo->master->finish_output_pass) (cinfo);
	(*cinfo->master->prepare_for_output_pass) (cinfo);
	cinfo->output_scanline = 0;
	#else
	ERREXIT(cinfo, JERR_NOT_COMPILED);
	#endif /* QUANT_2PASS_SUPPORTED */
	}
	/* Ready for application to drive output pass through
	* jpeg_read_scanlines or jpeg_read_raw_data.
	*/
	cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
	return TRUE;
	}


	/*
	* Read some scanlines of data from the JPEG decompressor.
	*
	* The return value will be the number of lines actually read.
	* This may be less than the number requested in several cases,
	* including bottom of image, data source suspension, and operating
	* modes that emit multiple scanlines at a time.
	*
	* Note: we warn about excess calls to jpeg_read_scanlines() since
	* this likely signals an application programmer error. However,
	* an oversize buffer (max_lines > scanlines remaining) is not an error.
	*/

	GLOBAL(JDIMENSION)
	jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
	JDIMENSION max_lines)
	{
	JDIMENSION row_ctr;

	if (cinfo->global_state != DSTATE_SCANNING)
	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
	if (cinfo->output_scanline >= cinfo->output_height) {
	WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
	return 0;
	}

	/* Call progress monitor hook if present */
	if (cinfo->progress != NULL) {
	cinfo->progress->pass_counter = (long) cinfo->output_scanline;
	cinfo->progress->pass_limit = (long) cinfo->output_height;
	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
	}

	/* Process some data */
	row_ctr = 0;
	(*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
	cinfo->output_scanline += row_ctr;
	return row_ctr;
	}


	/*
	* Alternate entry point to read raw data.
	* Processes exactly one iMCU row per call, unless suspended.
	*/

	GLOBAL(JDIMENSION)
	jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
	JDIMENSION max_lines)
	{
	JDIMENSION lines_per_iMCU_row;

	if (cinfo->global_state != DSTATE_RAW_OK)
	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
	if (cinfo->output_scanline >= cinfo->output_height) {
	WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
	return 0;
	}

	/* Call progress monitor hook if present */
	if (cinfo->progress != NULL) {
	cinfo->progress->pass_counter = (long) cinfo->output_scanline;
	cinfo->progress->pass_limit = (long) cinfo->output_height;
	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
	}

	/* Verify that at least one iMCU row can be returned. */
	lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->_min_DCT_scaled_size;
	if (max_lines < lines_per_iMCU_row)
	ERREXIT(cinfo, JERR_BUFFER_SIZE);

	/* Decompress directly into user's buffer. */
	if (! (*cinfo->coef->decompress_data) (cinfo, data))
	return 0; /* suspension forced, can do nothing more */

	/* OK, we processed one iMCU row. */
	cinfo->output_scanline += lines_per_iMCU_row;
	return lines_per_iMCU_row;
	}


	/* Additional entry points for buffered-image mode. */

	#ifdef D_MULTISCAN_FILES_SUPPORTED

	/*
	* Initialize for an output pass in buffered-image mode.
	*/

	GLOBAL(boolean)
	jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
	{
	if (cinfo->global_state != DSTATE_BUFIMAGE &&
	cinfo->global_state != DSTATE_PRESCAN)
	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
	/* Limit scan number to valid range */
	if (scan_number <= 0)
	scan_number = 1;
	if (cinfo->inputctl->eoi_reached &&
	scan_number > cinfo->input_scan_number)
	scan_number = cinfo->input_scan_number;
	cinfo->output_scan_number = scan_number;
	/* Perform any dummy output passes, and set up for the real pass */
	return output_pass_setup(cinfo);
	}


	/*
	* Finish up after an output pass in buffered-image mode.
	*
	* Returns FALSE if suspended. The return value need be inspected only if
	* a suspending data source is used.
	*/

	GLOBAL(boolean)
	jpeg_finish_output (j_decompress_ptr cinfo)
	{
	if ((cinfo->global_state == DSTATE_SCANNING \|\|
	cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
	/* Terminate this pass. */
	/* We do not require the whole pass to have been completed. */
	(*cinfo->master->finish_output_pass) (cinfo);
	cinfo->global_state = DSTATE_BUFPOST;
	} else if (cinfo->global_state != DSTATE_BUFPOST) {
	/* BUFPOST = repeat call after a suspension, anything else is error */
	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
	}
	/* Read markers looking for SOS or EOI */
	while (cinfo->input_scan_number <= cinfo->output_scan_number &&
	! cinfo->inputctl->eoi_reached) {
	if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
	return FALSE; /* Suspend, come back later */
	}
	cinfo->global_state = DSTATE_BUFIMAGE;
	return TRUE;
	}

	#endif /* D_MULTISCAN_FILES_SUPPORTED */