nuclear@26: /*
nuclear@26:  * jctrans.c
nuclear@26:  *
nuclear@26:  * Copyright (C) 1995-1998, Thomas G. Lane.
nuclear@26:  * This file is part of the Independent JPEG Group's software.
nuclear@26:  * For conditions of distribution and use, see the accompanying README file.
nuclear@26:  *
nuclear@26:  * This file contains library routines for transcoding compression,
nuclear@26:  * that is, writing raw DCT coefficient arrays to an output JPEG file.
nuclear@26:  * The routines in jcapimin.c will also be needed by a transcoder.
nuclear@26:  */
nuclear@26: 
nuclear@26: #define JPEG_INTERNALS
nuclear@26: #include "jinclude.h"
nuclear@26: #include "jpeglib.h"
nuclear@26: 
nuclear@26: 
nuclear@26: /* Forward declarations */
nuclear@26: LOCAL(void) transencode_master_selection
nuclear@26: 	JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
nuclear@26: LOCAL(void) transencode_coef_controller
nuclear@26: 	JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * Compression initialization for writing raw-coefficient data.
nuclear@26:  * Before calling this, all parameters and a data destination must be set up.
nuclear@26:  * Call jpeg_finish_compress() to actually write the data.
nuclear@26:  *
nuclear@26:  * The number of passed virtual arrays must match cinfo->num_components.
nuclear@26:  * Note that the virtual arrays need not be filled or even realized at
nuclear@26:  * the time write_coefficients is called; indeed, if the virtual arrays
nuclear@26:  * were requested from this compression object's memory manager, they
nuclear@26:  * typically will be realized during this routine and filled afterwards.
nuclear@26:  */
nuclear@26: 
nuclear@26: GLOBAL(void)
nuclear@26: jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)
nuclear@26: {
nuclear@26:   if (cinfo->global_state != CSTATE_START)
nuclear@26:     ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
nuclear@26:   /* Mark all tables to be written */
nuclear@26:   jpeg_suppress_tables(cinfo, FALSE);
nuclear@26:   /* (Re)initialize error mgr and destination modules */
nuclear@26:   (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
nuclear@26:   (*cinfo->dest->init_destination) (cinfo);
nuclear@26:   /* Perform master selection of active modules */
nuclear@26:   transencode_master_selection(cinfo, coef_arrays);
nuclear@26:   /* Wait for jpeg_finish_compress() call */
nuclear@26:   cinfo->next_scanline = 0;	/* so jpeg_write_marker works */
nuclear@26:   cinfo->global_state = CSTATE_WRCOEFS;
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * Initialize the compression object with default parameters,
nuclear@26:  * then copy from the source object all parameters needed for lossless
nuclear@26:  * transcoding.  Parameters that can be varied without loss (such as
nuclear@26:  * scan script and Huffman optimization) are left in their default states.
nuclear@26:  */
nuclear@26: 
nuclear@26: GLOBAL(void)
nuclear@26: jpeg_copy_critical_parameters (j_decompress_ptr srcinfo,
nuclear@26: 			       j_compress_ptr dstinfo)
nuclear@26: {
nuclear@26:   JQUANT_TBL ** qtblptr;
nuclear@26:   jpeg_component_info *incomp, *outcomp;
nuclear@26:   JQUANT_TBL *c_quant, *slot_quant;
nuclear@26:   int tblno, ci, coefi;
nuclear@26: 
nuclear@26:   /* Safety check to ensure start_compress not called yet. */
nuclear@26:   if (dstinfo->global_state != CSTATE_START)
nuclear@26:     ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state);
nuclear@26:   /* Copy fundamental image dimensions */
nuclear@26:   dstinfo->image_width = srcinfo->image_width;
nuclear@26:   dstinfo->image_height = srcinfo->image_height;
nuclear@26:   dstinfo->input_components = srcinfo->num_components;
nuclear@26:   dstinfo->in_color_space = srcinfo->jpeg_color_space;
nuclear@26:   /* Initialize all parameters to default values */
nuclear@26:   jpeg_set_defaults(dstinfo);
nuclear@26:   /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
nuclear@26:    * Fix it to get the right header markers for the image colorspace.
nuclear@26:    */
nuclear@26:   jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space);
nuclear@26:   dstinfo->data_precision = srcinfo->data_precision;
nuclear@26:   dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
nuclear@26:   /* Copy the source's quantization tables. */
nuclear@26:   for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
nuclear@26:     if (srcinfo->quant_tbl_ptrs[tblno] != NULL) {
nuclear@26:       qtblptr = & dstinfo->quant_tbl_ptrs[tblno];
nuclear@26:       if (*qtblptr == NULL)
nuclear@26: 	*qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo);
nuclear@26:       MEMCOPY((*qtblptr)->quantval,
nuclear@26: 	      srcinfo->quant_tbl_ptrs[tblno]->quantval,
nuclear@26: 	      SIZEOF((*qtblptr)->quantval));
nuclear@26:       (*qtblptr)->sent_table = FALSE;
nuclear@26:     }
nuclear@26:   }
nuclear@26:   /* Copy the source's per-component info.
nuclear@26:    * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
nuclear@26:    */
nuclear@26:   dstinfo->num_components = srcinfo->num_components;
nuclear@26:   if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS)
nuclear@26:     ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
nuclear@26: 	     MAX_COMPONENTS);
nuclear@26:   for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
nuclear@26:        ci < dstinfo->num_components; ci++, incomp++, outcomp++) {
nuclear@26:     outcomp->component_id = incomp->component_id;
nuclear@26:     outcomp->h_samp_factor = incomp->h_samp_factor;
nuclear@26:     outcomp->v_samp_factor = incomp->v_samp_factor;
nuclear@26:     outcomp->quant_tbl_no = incomp->quant_tbl_no;
nuclear@26:     /* Make sure saved quantization table for component matches the qtable
nuclear@26:      * slot.  If not, the input file re-used this qtable slot.
nuclear@26:      * IJG encoder currently cannot duplicate this.
nuclear@26:      */
nuclear@26:     tblno = outcomp->quant_tbl_no;
nuclear@26:     if (tblno < 0 || tblno >= NUM_QUANT_TBLS ||
nuclear@26: 	srcinfo->quant_tbl_ptrs[tblno] == NULL)
nuclear@26:       ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno);
nuclear@26:     slot_quant = srcinfo->quant_tbl_ptrs[tblno];
nuclear@26:     c_quant = incomp->quant_table;
nuclear@26:     if (c_quant != NULL) {
nuclear@26:       for (coefi = 0; coefi < DCTSIZE2; coefi++) {
nuclear@26: 	if (c_quant->quantval[coefi] != slot_quant->quantval[coefi])
nuclear@26: 	  ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno);
nuclear@26:       }
nuclear@26:     }
nuclear@26:     /* Note: we do not copy the source's Huffman table assignments;
nuclear@26:      * instead we rely on jpeg_set_colorspace to have made a suitable choice.
nuclear@26:      */
nuclear@26:   }
nuclear@26:   /* Also copy JFIF version and resolution information, if available.
nuclear@26:    * Strictly speaking this isn't "critical" info, but it's nearly
nuclear@26:    * always appropriate to copy it if available.  In particular,
nuclear@26:    * if the application chooses to copy JFIF 1.02 extension markers from
nuclear@26:    * the source file, we need to copy the version to make sure we don't
nuclear@26:    * emit a file that has 1.02 extensions but a claimed version of 1.01.
nuclear@26:    * We will *not*, however, copy version info from mislabeled "2.01" files.
nuclear@26:    */
nuclear@26:   if (srcinfo->saw_JFIF_marker) {
nuclear@26:     if (srcinfo->JFIF_major_version == 1) {
nuclear@26:       dstinfo->JFIF_major_version = srcinfo->JFIF_major_version;
nuclear@26:       dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version;
nuclear@26:     }
nuclear@26:     dstinfo->density_unit = srcinfo->density_unit;
nuclear@26:     dstinfo->X_density = srcinfo->X_density;
nuclear@26:     dstinfo->Y_density = srcinfo->Y_density;
nuclear@26:   }
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * Master selection of compression modules for transcoding.
nuclear@26:  * This substitutes for jcinit.c's initialization of the full compressor.
nuclear@26:  */
nuclear@26: 
nuclear@26: LOCAL(void)
nuclear@26: transencode_master_selection (j_compress_ptr cinfo,
nuclear@26: 			      jvirt_barray_ptr * coef_arrays)
nuclear@26: {
nuclear@26:   /* Although we don't actually use input_components for transcoding,
nuclear@26:    * jcmaster.c's initial_setup will complain if input_components is 0.
nuclear@26:    */
nuclear@26:   cinfo->input_components = 1;
nuclear@26:   /* Initialize master control (includes parameter checking/processing) */
nuclear@26:   jinit_c_master_control(cinfo, TRUE /* transcode only */);
nuclear@26: 
nuclear@26:   /* Entropy encoding: either Huffman or arithmetic coding. */
nuclear@26:   if (cinfo->arith_code) {
nuclear@26:     ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
nuclear@26:   } else {
nuclear@26:     if (cinfo->progressive_mode) {
nuclear@26: #ifdef C_PROGRESSIVE_SUPPORTED
nuclear@26:       jinit_phuff_encoder(cinfo);
nuclear@26: #else
nuclear@26:       ERREXIT(cinfo, JERR_NOT_COMPILED);
nuclear@26: #endif
nuclear@26:     } else
nuclear@26:       jinit_huff_encoder(cinfo);
nuclear@26:   }
nuclear@26: 
nuclear@26:   /* We need a special coefficient buffer controller. */
nuclear@26:   transencode_coef_controller(cinfo, coef_arrays);
nuclear@26: 
nuclear@26:   jinit_marker_writer(cinfo);
nuclear@26: 
nuclear@26:   /* We can now tell the memory manager to allocate virtual arrays. */
nuclear@26:   (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
nuclear@26: 
nuclear@26:   /* Write the datastream header (SOI, JFIF) immediately.
nuclear@26:    * Frame and scan headers are postponed till later.
nuclear@26:    * This lets application insert special markers after the SOI.
nuclear@26:    */
nuclear@26:   (*cinfo->marker->write_file_header) (cinfo);
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * The rest of this file is a special implementation of the coefficient
nuclear@26:  * buffer controller.  This is similar to jccoefct.c, but it handles only
nuclear@26:  * output from presupplied virtual arrays.  Furthermore, we generate any
nuclear@26:  * dummy padding blocks on-the-fly rather than expecting them to be present
nuclear@26:  * in the arrays.
nuclear@26:  */
nuclear@26: 
nuclear@26: /* Private buffer controller object */
nuclear@26: 
nuclear@26: typedef struct {
nuclear@26:   struct jpeg_c_coef_controller pub; /* public fields */
nuclear@26: 
nuclear@26:   JDIMENSION iMCU_row_num;	/* iMCU row # within image */
nuclear@26:   JDIMENSION mcu_ctr;		/* counts MCUs processed in current row */
nuclear@26:   int MCU_vert_offset;		/* counts MCU rows within iMCU row */
nuclear@26:   int MCU_rows_per_iMCU_row;	/* number of such rows needed */
nuclear@26: 
nuclear@26:   /* Virtual block array for each component. */
nuclear@26:   jvirt_barray_ptr * whole_image;
nuclear@26: 
nuclear@26:   /* Workspace for constructing dummy blocks at right/bottom edges. */
nuclear@26:   JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU];
nuclear@26: } my_coef_controller;
nuclear@26: 
nuclear@26: typedef my_coef_controller * my_coef_ptr;
nuclear@26: 
nuclear@26: 
nuclear@26: LOCAL(void)
nuclear@26: start_iMCU_row (j_compress_ptr cinfo)
nuclear@26: /* Reset within-iMCU-row counters for a new row */
nuclear@26: {
nuclear@26:   my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
nuclear@26: 
nuclear@26:   /* In an interleaved scan, an MCU row is the same as an iMCU row.
nuclear@26:    * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
nuclear@26:    * But at the bottom of the image, process only what's left.
nuclear@26:    */
nuclear@26:   if (cinfo->comps_in_scan > 1) {
nuclear@26:     coef->MCU_rows_per_iMCU_row = 1;
nuclear@26:   } else {
nuclear@26:     if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1))
nuclear@26:       coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
nuclear@26:     else
nuclear@26:       coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
nuclear@26:   }
nuclear@26: 
nuclear@26:   coef->mcu_ctr = 0;
nuclear@26:   coef->MCU_vert_offset = 0;
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * Initialize for a processing pass.
nuclear@26:  */
nuclear@26: 
nuclear@26: METHODDEF(void)
nuclear@26: start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
nuclear@26: {
nuclear@26:   my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
nuclear@26: 
nuclear@26:   if (pass_mode != JBUF_CRANK_DEST)
nuclear@26:     ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
nuclear@26: 
nuclear@26:   coef->iMCU_row_num = 0;
nuclear@26:   start_iMCU_row(cinfo);
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * Process some data.
nuclear@26:  * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
nuclear@26:  * per call, ie, v_samp_factor block rows for each component in the scan.
nuclear@26:  * The data is obtained from the virtual arrays and fed to the entropy coder.
nuclear@26:  * Returns TRUE if the iMCU row is completed, FALSE if suspended.
nuclear@26:  *
nuclear@26:  * NB: input_buf is ignored; it is likely to be a NULL pointer.
nuclear@26:  */
nuclear@26: 
nuclear@26: METHODDEF(boolean)
nuclear@26: compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
nuclear@26: {
nuclear@26:   my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
nuclear@26:   JDIMENSION MCU_col_num;	/* index of current MCU within row */
nuclear@26:   JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
nuclear@26:   JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
nuclear@26:   int blkn, ci, xindex, yindex, yoffset, blockcnt;
nuclear@26:   JDIMENSION start_col;
nuclear@26:   JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
nuclear@26:   JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
nuclear@26:   JBLOCKROW buffer_ptr;
nuclear@26:   jpeg_component_info *compptr;
nuclear@26: 
nuclear@26:   /* Align the virtual buffers for the components used in this scan. */
nuclear@26:   for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
nuclear@26:     compptr = cinfo->cur_comp_info[ci];
nuclear@26:     buffer[ci] = (*cinfo->mem->access_virt_barray)
nuclear@26:       ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
nuclear@26:        coef->iMCU_row_num * compptr->v_samp_factor,
nuclear@26:        (JDIMENSION) compptr->v_samp_factor, FALSE);
nuclear@26:   }
nuclear@26: 
nuclear@26:   /* Loop to process one whole iMCU row */
nuclear@26:   for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
nuclear@26:        yoffset++) {
nuclear@26:     for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
nuclear@26: 	 MCU_col_num++) {
nuclear@26:       /* Construct list of pointers to DCT blocks belonging to this MCU */
nuclear@26:       blkn = 0;			/* index of current DCT block within MCU */
nuclear@26:       for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
nuclear@26: 	compptr = cinfo->cur_comp_info[ci];
nuclear@26: 	start_col = MCU_col_num * compptr->MCU_width;
nuclear@26: 	blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
nuclear@26: 						: compptr->last_col_width;
nuclear@26: 	for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
nuclear@26: 	  if (coef->iMCU_row_num < last_iMCU_row ||
nuclear@26: 	      yindex+yoffset < compptr->last_row_height) {
nuclear@26: 	    /* Fill in pointers to real blocks in this row */
nuclear@26: 	    buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
nuclear@26: 	    for (xindex = 0; xindex < blockcnt; xindex++)
nuclear@26: 	      MCU_buffer[blkn++] = buffer_ptr++;
nuclear@26: 	  } else {
nuclear@26: 	    /* At bottom of image, need a whole row of dummy blocks */
nuclear@26: 	    xindex = 0;
nuclear@26: 	  }
nuclear@26: 	  /* Fill in any dummy blocks needed in this row.
nuclear@26: 	   * Dummy blocks are filled in the same way as in jccoefct.c:
nuclear@26: 	   * all zeroes in the AC entries, DC entries equal to previous
nuclear@26: 	   * block's DC value.  The init routine has already zeroed the
nuclear@26: 	   * AC entries, so we need only set the DC entries correctly.
nuclear@26: 	   */
nuclear@26: 	  for (; xindex < compptr->MCU_width; xindex++) {
nuclear@26: 	    MCU_buffer[blkn] = coef->dummy_buffer[blkn];
nuclear@26: 	    MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0];
nuclear@26: 	    blkn++;
nuclear@26: 	  }
nuclear@26: 	}
nuclear@26:       }
nuclear@26:       /* Try to write the MCU. */
nuclear@26:       if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) {
nuclear@26: 	/* Suspension forced; update state counters and exit */
nuclear@26: 	coef->MCU_vert_offset = yoffset;
nuclear@26: 	coef->mcu_ctr = MCU_col_num;
nuclear@26: 	return FALSE;
nuclear@26:       }
nuclear@26:     }
nuclear@26:     /* Completed an MCU row, but perhaps not an iMCU row */
nuclear@26:     coef->mcu_ctr = 0;
nuclear@26:   }
nuclear@26:   /* Completed the iMCU row, advance counters for next one */
nuclear@26:   coef->iMCU_row_num++;
nuclear@26:   start_iMCU_row(cinfo);
nuclear@26:   return TRUE;
nuclear@26: }
nuclear@26: 
nuclear@26: 
nuclear@26: /*
nuclear@26:  * Initialize coefficient buffer controller.
nuclear@26:  *
nuclear@26:  * Each passed coefficient array must be the right size for that
nuclear@26:  * coefficient: width_in_blocks wide and height_in_blocks high,
nuclear@26:  * with unitheight at least v_samp_factor.
nuclear@26:  */
nuclear@26: 
nuclear@26: LOCAL(void)
nuclear@26: transencode_coef_controller (j_compress_ptr cinfo,
nuclear@26: 			     jvirt_barray_ptr * coef_arrays)
nuclear@26: {
nuclear@26:   my_coef_ptr coef;
nuclear@26:   JBLOCKROW buffer;
nuclear@26:   int i;
nuclear@26: 
nuclear@26:   coef = (my_coef_ptr)
nuclear@26:     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@26: 				SIZEOF(my_coef_controller));
nuclear@26:   cinfo->coef = (struct jpeg_c_coef_controller *) coef;
nuclear@26:   coef->pub.start_pass = start_pass_coef;
nuclear@26:   coef->pub.compress_data = compress_output;
nuclear@26: 
nuclear@26:   /* Save pointer to virtual arrays */
nuclear@26:   coef->whole_image = coef_arrays;
nuclear@26: 
nuclear@26:   /* Allocate and pre-zero space for dummy DCT blocks. */
nuclear@26:   buffer = (JBLOCKROW)
nuclear@26:     (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@26: 				C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
nuclear@26:   jzero_far((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
nuclear@26:   for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) {
nuclear@26:     coef->dummy_buffer[i] = buffer + i;
nuclear@26:   }
nuclear@26: }