1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/libjpeg/jdpostct.c	Sat Feb 01 19:58:19 2014 +0200
     1.3 @@ -0,0 +1,290 @@
     1.4 +/*
     1.5 + * jdpostct.c
     1.6 + *
     1.7 + * Copyright (C) 1994-1996, Thomas G. Lane.
     1.8 + * This file is part of the Independent JPEG Group's software.
     1.9 + * For conditions of distribution and use, see the accompanying README file.
    1.10 + *
    1.11 + * This file contains the decompression postprocessing controller.
    1.12 + * This controller manages the upsampling, color conversion, and color
    1.13 + * quantization/reduction steps; specifically, it controls the buffering
    1.14 + * between upsample/color conversion and color quantization/reduction.
    1.15 + *
    1.16 + * If no color quantization/reduction is required, then this module has no
    1.17 + * work to do, and it just hands off to the upsample/color conversion code.
    1.18 + * An integrated upsample/convert/quantize process would replace this module
    1.19 + * entirely.
    1.20 + */
    1.21 +
    1.22 +#define JPEG_INTERNALS
    1.23 +#include "jinclude.h"
    1.24 +#include "jpeglib.h"
    1.25 +
    1.26 +
    1.27 +/* Private buffer controller object */
    1.28 +
    1.29 +typedef struct {
    1.30 +  struct jpeg_d_post_controller pub; /* public fields */
    1.31 +
    1.32 +  /* Color quantization source buffer: this holds output data from
    1.33 +   * the upsample/color conversion step to be passed to the quantizer.
    1.34 +   * For two-pass color quantization, we need a full-image buffer;
    1.35 +   * for one-pass operation, a strip buffer is sufficient.
    1.36 +   */
    1.37 +  jvirt_sarray_ptr whole_image;	/* virtual array, or NULL if one-pass */
    1.38 +  JSAMPARRAY buffer;		/* strip buffer, or current strip of virtual */
    1.39 +  JDIMENSION strip_height;	/* buffer size in rows */
    1.40 +  /* for two-pass mode only: */
    1.41 +  JDIMENSION starting_row;	/* row # of first row in current strip */
    1.42 +  JDIMENSION next_row;		/* index of next row to fill/empty in strip */
    1.43 +} my_post_controller;
    1.44 +
    1.45 +typedef my_post_controller * my_post_ptr;
    1.46 +
    1.47 +
    1.48 +/* Forward declarations */
    1.49 +METHODDEF(void) post_process_1pass
    1.50 +	JPP((j_decompress_ptr cinfo,
    1.51 +	     JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
    1.52 +	     JDIMENSION in_row_groups_avail,
    1.53 +	     JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
    1.54 +	     JDIMENSION out_rows_avail));
    1.55 +#ifdef QUANT_2PASS_SUPPORTED
    1.56 +METHODDEF(void) post_process_prepass
    1.57 +	JPP((j_decompress_ptr cinfo,
    1.58 +	     JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
    1.59 +	     JDIMENSION in_row_groups_avail,
    1.60 +	     JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
    1.61 +	     JDIMENSION out_rows_avail));
    1.62 +METHODDEF(void) post_process_2pass
    1.63 +	JPP((j_decompress_ptr cinfo,
    1.64 +	     JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
    1.65 +	     JDIMENSION in_row_groups_avail,
    1.66 +	     JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
    1.67 +	     JDIMENSION out_rows_avail));
    1.68 +#endif
    1.69 +
    1.70 +
    1.71 +/*
    1.72 + * Initialize for a processing pass.
    1.73 + */
    1.74 +
    1.75 +METHODDEF(void)
    1.76 +start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
    1.77 +{
    1.78 +  my_post_ptr post = (my_post_ptr) cinfo->post;
    1.79 +
    1.80 +  switch (pass_mode) {
    1.81 +  case JBUF_PASS_THRU:
    1.82 +    if (cinfo->quantize_colors) {
    1.83 +      /* Single-pass processing with color quantization. */
    1.84 +      post->pub.post_process_data = post_process_1pass;
    1.85 +      /* We could be doing buffered-image output before starting a 2-pass
    1.86 +       * color quantization; in that case, jinit_d_post_controller did not
    1.87 +       * allocate a strip buffer.  Use the virtual-array buffer as workspace.
    1.88 +       */
    1.89 +      if (post->buffer == NULL) {
    1.90 +	post->buffer = (*cinfo->mem->access_virt_sarray)
    1.91 +	  ((j_common_ptr) cinfo, post->whole_image,
    1.92 +	   (JDIMENSION) 0, post->strip_height, TRUE);
    1.93 +      }
    1.94 +    } else {
    1.95 +      /* For single-pass processing without color quantization,
    1.96 +       * I have no work to do; just call the upsampler directly.
    1.97 +       */
    1.98 +      post->pub.post_process_data = cinfo->upsample->upsample;
    1.99 +    }
   1.100 +    break;
   1.101 +#ifdef QUANT_2PASS_SUPPORTED
   1.102 +  case JBUF_SAVE_AND_PASS:
   1.103 +    /* First pass of 2-pass quantization */
   1.104 +    if (post->whole_image == NULL)
   1.105 +      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
   1.106 +    post->pub.post_process_data = post_process_prepass;
   1.107 +    break;
   1.108 +  case JBUF_CRANK_DEST:
   1.109 +    /* Second pass of 2-pass quantization */
   1.110 +    if (post->whole_image == NULL)
   1.111 +      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
   1.112 +    post->pub.post_process_data = post_process_2pass;
   1.113 +    break;
   1.114 +#endif /* QUANT_2PASS_SUPPORTED */
   1.115 +  default:
   1.116 +    ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
   1.117 +    break;
   1.118 +  }
   1.119 +  post->starting_row = post->next_row = 0;
   1.120 +}
   1.121 +
   1.122 +
   1.123 +/*
   1.124 + * Process some data in the one-pass (strip buffer) case.
   1.125 + * This is used for color precision reduction as well as one-pass quantization.
   1.126 + */
   1.127 +
   1.128 +METHODDEF(void)
   1.129 +post_process_1pass (j_decompress_ptr cinfo,
   1.130 +		    JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
   1.131 +		    JDIMENSION in_row_groups_avail,
   1.132 +		    JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
   1.133 +		    JDIMENSION out_rows_avail)
   1.134 +{
   1.135 +  my_post_ptr post = (my_post_ptr) cinfo->post;
   1.136 +  JDIMENSION num_rows, max_rows;
   1.137 +
   1.138 +  /* Fill the buffer, but not more than what we can dump out in one go. */
   1.139 +  /* Note we rely on the upsampler to detect bottom of image. */
   1.140 +  max_rows = out_rows_avail - *out_row_ctr;
   1.141 +  if (max_rows > post->strip_height)
   1.142 +    max_rows = post->strip_height;
   1.143 +  num_rows = 0;
   1.144 +  (*cinfo->upsample->upsample) (cinfo,
   1.145 +		input_buf, in_row_group_ctr, in_row_groups_avail,
   1.146 +		post->buffer, &num_rows, max_rows);
   1.147 +  /* Quantize and emit data. */
   1.148 +  (*cinfo->cquantize->color_quantize) (cinfo,
   1.149 +		post->buffer, output_buf + *out_row_ctr, (int) num_rows);
   1.150 +  *out_row_ctr += num_rows;
   1.151 +}
   1.152 +
   1.153 +
   1.154 +#ifdef QUANT_2PASS_SUPPORTED
   1.155 +
   1.156 +/*
   1.157 + * Process some data in the first pass of 2-pass quantization.
   1.158 + */
   1.159 +
   1.160 +METHODDEF(void)
   1.161 +post_process_prepass (j_decompress_ptr cinfo,
   1.162 +		      JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
   1.163 +		      JDIMENSION in_row_groups_avail,
   1.164 +		      JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
   1.165 +		      JDIMENSION out_rows_avail)
   1.166 +{
   1.167 +  my_post_ptr post = (my_post_ptr) cinfo->post;
   1.168 +  JDIMENSION old_next_row, num_rows;
   1.169 +
   1.170 +  /* Reposition virtual buffer if at start of strip. */
   1.171 +  if (post->next_row == 0) {
   1.172 +    post->buffer = (*cinfo->mem->access_virt_sarray)
   1.173 +	((j_common_ptr) cinfo, post->whole_image,
   1.174 +	 post->starting_row, post->strip_height, TRUE);
   1.175 +  }
   1.176 +
   1.177 +  /* Upsample some data (up to a strip height's worth). */
   1.178 +  old_next_row = post->next_row;
   1.179 +  (*cinfo->upsample->upsample) (cinfo,
   1.180 +		input_buf, in_row_group_ctr, in_row_groups_avail,
   1.181 +		post->buffer, &post->next_row, post->strip_height);
   1.182 +
   1.183 +  /* Allow quantizer to scan new data.  No data is emitted, */
   1.184 +  /* but we advance out_row_ctr so outer loop can tell when we're done. */
   1.185 +  if (post->next_row > old_next_row) {
   1.186 +    num_rows = post->next_row - old_next_row;
   1.187 +    (*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
   1.188 +					 (JSAMPARRAY) NULL, (int) num_rows);
   1.189 +    *out_row_ctr += num_rows;
   1.190 +  }
   1.191 +
   1.192 +  /* Advance if we filled the strip. */
   1.193 +  if (post->next_row >= post->strip_height) {
   1.194 +    post->starting_row += post->strip_height;
   1.195 +    post->next_row = 0;
   1.196 +  }
   1.197 +}
   1.198 +
   1.199 +
   1.200 +/*
   1.201 + * Process some data in the second pass of 2-pass quantization.
   1.202 + */
   1.203 +
   1.204 +METHODDEF(void)
   1.205 +post_process_2pass (j_decompress_ptr cinfo,
   1.206 +		    JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
   1.207 +		    JDIMENSION in_row_groups_avail,
   1.208 +		    JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
   1.209 +		    JDIMENSION out_rows_avail)
   1.210 +{
   1.211 +  my_post_ptr post = (my_post_ptr) cinfo->post;
   1.212 +  JDIMENSION num_rows, max_rows;
   1.213 +
   1.214 +  /* Reposition virtual buffer if at start of strip. */
   1.215 +  if (post->next_row == 0) {
   1.216 +    post->buffer = (*cinfo->mem->access_virt_sarray)
   1.217 +	((j_common_ptr) cinfo, post->whole_image,
   1.218 +	 post->starting_row, post->strip_height, FALSE);
   1.219 +  }
   1.220 +
   1.221 +  /* Determine number of rows to emit. */
   1.222 +  num_rows = post->strip_height - post->next_row; /* available in strip */
   1.223 +  max_rows = out_rows_avail - *out_row_ctr; /* available in output area */
   1.224 +  if (num_rows > max_rows)
   1.225 +    num_rows = max_rows;
   1.226 +  /* We have to check bottom of image here, can't depend on upsampler. */
   1.227 +  max_rows = cinfo->output_height - post->starting_row;
   1.228 +  if (num_rows > max_rows)
   1.229 +    num_rows = max_rows;
   1.230 +
   1.231 +  /* Quantize and emit data. */
   1.232 +  (*cinfo->cquantize->color_quantize) (cinfo,
   1.233 +		post->buffer + post->next_row, output_buf + *out_row_ctr,
   1.234 +		(int) num_rows);
   1.235 +  *out_row_ctr += num_rows;
   1.236 +
   1.237 +  /* Advance if we filled the strip. */
   1.238 +  post->next_row += num_rows;
   1.239 +  if (post->next_row >= post->strip_height) {
   1.240 +    post->starting_row += post->strip_height;
   1.241 +    post->next_row = 0;
   1.242 +  }
   1.243 +}
   1.244 +
   1.245 +#endif /* QUANT_2PASS_SUPPORTED */
   1.246 +
   1.247 +
   1.248 +/*
   1.249 + * Initialize postprocessing controller.
   1.250 + */
   1.251 +
   1.252 +GLOBAL(void)
   1.253 +jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
   1.254 +{
   1.255 +  my_post_ptr post;
   1.256 +
   1.257 +  post = (my_post_ptr)
   1.258 +    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
   1.259 +				SIZEOF(my_post_controller));
   1.260 +  cinfo->post = (struct jpeg_d_post_controller *) post;
   1.261 +  post->pub.start_pass = start_pass_dpost;
   1.262 +  post->whole_image = NULL;	/* flag for no virtual arrays */
   1.263 +  post->buffer = NULL;		/* flag for no strip buffer */
   1.264 +
   1.265 +  /* Create the quantization buffer, if needed */
   1.266 +  if (cinfo->quantize_colors) {
   1.267 +    /* The buffer strip height is max_v_samp_factor, which is typically
   1.268 +     * an efficient number of rows for upsampling to return.
   1.269 +     * (In the presence of output rescaling, we might want to be smarter?)
   1.270 +     */
   1.271 +    post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
   1.272 +    if (need_full_buffer) {
   1.273 +      /* Two-pass color quantization: need full-image storage. */
   1.274 +      /* We round up the number of rows to a multiple of the strip height. */
   1.275 +#ifdef QUANT_2PASS_SUPPORTED
   1.276 +      post->whole_image = (*cinfo->mem->request_virt_sarray)
   1.277 +	((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
   1.278 +	 cinfo->output_width * cinfo->out_color_components,
   1.279 +	 (JDIMENSION) jround_up((long) cinfo->output_height,
   1.280 +				(long) post->strip_height),
   1.281 +	 post->strip_height);
   1.282 +#else
   1.283 +      ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
   1.284 +#endif /* QUANT_2PASS_SUPPORTED */
   1.285 +    } else {
   1.286 +      /* One-pass color quantization: just make a strip buffer. */
   1.287 +      post->buffer = (*cinfo->mem->alloc_sarray)
   1.288 +	((j_common_ptr) cinfo, JPOOL_IMAGE,
   1.289 +	 cinfo->output_width * cinfo->out_color_components,
   1.290 +	 post->strip_height);
   1.291 +    }
   1.292 +  }
   1.293 +}