#if !defined(_FX_JPEG_TURBO_) | |
/* | |
* jdpostct.c | |
* | |
* 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 the decompression postprocessing controller. | |
* This controller manages the upsampling, color conversion, and color | |
* quantization/reduction steps; specifically, it controls the buffering | |
* between upsample/color conversion and color quantization/reduction. | |
* | |
* If no color quantization/reduction is required, then this module has no | |
* work to do, and it just hands off to the upsample/color conversion code. | |
* An integrated upsample/convert/quantize process would replace this module | |
* entirely. | |
*/ | |
#define JPEG_INTERNALS | |
#include "jinclude.h" | |
#include "jpeglib.h" | |
/* Private buffer controller object */ | |
typedef struct { | |
struct jpeg_d_post_controller pub; /* public fields */ | |
/* Color quantization source buffer: this holds output data from | |
* the upsample/color conversion step to be passed to the quantizer. | |
* For two-pass color quantization, we need a full-image buffer; | |
* for one-pass operation, a strip buffer is sufficient. | |
*/ | |
jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */ | |
JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */ | |
JDIMENSION strip_height; /* buffer size in rows */ | |
/* for two-pass mode only: */ | |
JDIMENSION starting_row; /* row # of first row in current strip */ | |
JDIMENSION next_row; /* index of next row to fill/empty in strip */ | |
} my_post_controller; | |
typedef my_post_controller * my_post_ptr; | |
/* Forward declarations */ | |
METHODDEF(void) post_process_1pass | |
JPP((j_decompress_ptr cinfo, | |
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
JDIMENSION in_row_groups_avail, | |
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
JDIMENSION out_rows_avail)); | |
#ifdef QUANT_2PASS_SUPPORTED | |
METHODDEF(void) post_process_prepass | |
JPP((j_decompress_ptr cinfo, | |
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
JDIMENSION in_row_groups_avail, | |
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
JDIMENSION out_rows_avail)); | |
METHODDEF(void) post_process_2pass | |
JPP((j_decompress_ptr cinfo, | |
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
JDIMENSION in_row_groups_avail, | |
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
JDIMENSION out_rows_avail)); | |
#endif | |
/* | |
* Initialize for a processing pass. | |
*/ | |
METHODDEF(void) | |
start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode) | |
{ | |
my_post_ptr post = (my_post_ptr) cinfo->post; | |
switch (pass_mode) { | |
case JBUF_PASS_THRU: | |
if (cinfo->quantize_colors) { | |
/* Single-pass processing with color quantization. */ | |
post->pub.post_process_data = post_process_1pass; | |
/* We could be doing buffered-image output before starting a 2-pass | |
* color quantization; in that case, jinit_d_post_controller did not | |
* allocate a strip buffer. Use the virtual-array buffer as workspace. | |
*/ | |
if (post->buffer == NULL) { | |
post->buffer = (*cinfo->mem->access_virt_sarray) | |
((j_common_ptr) cinfo, post->whole_image, | |
(JDIMENSION) 0, post->strip_height, TRUE); | |
} | |
} else { | |
/* For single-pass processing without color quantization, | |
* I have no work to do; just call the upsampler directly. | |
*/ | |
post->pub.post_process_data = cinfo->upsample->upsample; | |
} | |
break; | |
#ifdef QUANT_2PASS_SUPPORTED | |
case JBUF_SAVE_AND_PASS: | |
/* First pass of 2-pass quantization */ | |
if (post->whole_image == NULL) | |
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
post->pub.post_process_data = post_process_prepass; | |
break; | |
case JBUF_CRANK_DEST: | |
/* Second pass of 2-pass quantization */ | |
if (post->whole_image == NULL) | |
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
post->pub.post_process_data = post_process_2pass; | |
break; | |
#endif /* QUANT_2PASS_SUPPORTED */ | |
default: | |
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
break; | |
} | |
post->starting_row = post->next_row = 0; | |
} | |
/* | |
* Process some data in the one-pass (strip buffer) case. | |
* This is used for color precision reduction as well as one-pass quantization. | |
*/ | |
METHODDEF(void) | |
post_process_1pass (j_decompress_ptr cinfo, | |
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
JDIMENSION in_row_groups_avail, | |
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
JDIMENSION out_rows_avail) | |
{ | |
my_post_ptr post = (my_post_ptr) cinfo->post; | |
JDIMENSION num_rows, max_rows; | |
/* Fill the buffer, but not more than what we can dump out in one go. */ | |
/* Note we rely on the upsampler to detect bottom of image. */ | |
max_rows = out_rows_avail - *out_row_ctr; | |
if (max_rows > post->strip_height) | |
max_rows = post->strip_height; | |
num_rows = 0; | |
(*cinfo->upsample->upsample) (cinfo, | |
input_buf, in_row_group_ctr, in_row_groups_avail, | |
post->buffer, &num_rows, max_rows); | |
/* Quantize and emit data. */ | |
(*cinfo->cquantize->color_quantize) (cinfo, | |
post->buffer, output_buf + *out_row_ctr, (int) num_rows); | |
*out_row_ctr += num_rows; | |
} | |
#ifdef QUANT_2PASS_SUPPORTED | |
/* | |
* Process some data in the first pass of 2-pass quantization. | |
*/ | |
METHODDEF(void) | |
post_process_prepass (j_decompress_ptr cinfo, | |
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
JDIMENSION in_row_groups_avail, | |
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
JDIMENSION out_rows_avail) | |
{ | |
my_post_ptr post = (my_post_ptr) cinfo->post; | |
JDIMENSION old_next_row, num_rows; | |
/* Reposition virtual buffer if at start of strip. */ | |
if (post->next_row == 0) { | |
post->buffer = (*cinfo->mem->access_virt_sarray) | |
((j_common_ptr) cinfo, post->whole_image, | |
post->starting_row, post->strip_height, TRUE); | |
} | |
/* Upsample some data (up to a strip height's worth). */ | |
old_next_row = post->next_row; | |
(*cinfo->upsample->upsample) (cinfo, | |
input_buf, in_row_group_ctr, in_row_groups_avail, | |
post->buffer, &post->next_row, post->strip_height); | |
/* Allow quantizer to scan new data. No data is emitted, */ | |
/* but we advance out_row_ctr so outer loop can tell when we're done. */ | |
if (post->next_row > old_next_row) { | |
num_rows = post->next_row - old_next_row; | |
(*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row, | |
(JSAMPARRAY) NULL, (int) num_rows); | |
*out_row_ctr += num_rows; | |
} | |
/* Advance if we filled the strip. */ | |
if (post->next_row >= post->strip_height) { | |
post->starting_row += post->strip_height; | |
post->next_row = 0; | |
} | |
} | |
/* | |
* Process some data in the second pass of 2-pass quantization. | |
*/ | |
METHODDEF(void) | |
post_process_2pass (j_decompress_ptr cinfo, | |
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, | |
JDIMENSION in_row_groups_avail, | |
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, | |
JDIMENSION out_rows_avail) | |
{ | |
my_post_ptr post = (my_post_ptr) cinfo->post; | |
JDIMENSION num_rows, max_rows; | |
/* Reposition virtual buffer if at start of strip. */ | |
if (post->next_row == 0) { | |
post->buffer = (*cinfo->mem->access_virt_sarray) | |
((j_common_ptr) cinfo, post->whole_image, | |
post->starting_row, post->strip_height, FALSE); | |
} | |
/* Determine number of rows to emit. */ | |
num_rows = post->strip_height - post->next_row; /* available in strip */ | |
max_rows = out_rows_avail - *out_row_ctr; /* available in output area */ | |
if (num_rows > max_rows) | |
num_rows = max_rows; | |
/* We have to check bottom of image here, can't depend on upsampler. */ | |
max_rows = cinfo->output_height - post->starting_row; | |
if (num_rows > max_rows) | |
num_rows = max_rows; | |
/* Quantize and emit data. */ | |
(*cinfo->cquantize->color_quantize) (cinfo, | |
post->buffer + post->next_row, output_buf + *out_row_ctr, | |
(int) num_rows); | |
*out_row_ctr += num_rows; | |
/* Advance if we filled the strip. */ | |
post->next_row += num_rows; | |
if (post->next_row >= post->strip_height) { | |
post->starting_row += post->strip_height; | |
post->next_row = 0; | |
} | |
} | |
#endif /* QUANT_2PASS_SUPPORTED */ | |
/* | |
* Initialize postprocessing controller. | |
*/ | |
GLOBAL(void) | |
jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer) | |
{ | |
my_post_ptr post; | |
post = (my_post_ptr) | |
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
SIZEOF(my_post_controller)); | |
cinfo->post = (struct jpeg_d_post_controller *) post; | |
post->pub.start_pass = start_pass_dpost; | |
post->whole_image = NULL; /* flag for no virtual arrays */ | |
post->buffer = NULL; /* flag for no strip buffer */ | |
/* Create the quantization buffer, if needed */ | |
if (cinfo->quantize_colors) { | |
/* The buffer strip height is max_v_samp_factor, which is typically | |
* an efficient number of rows for upsampling to return. | |
* (In the presence of output rescaling, we might want to be smarter?) | |
*/ | |
post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor; | |
if (need_full_buffer) { | |
/* Two-pass color quantization: need full-image storage. */ | |
/* We round up the number of rows to a multiple of the strip height. */ | |
#ifdef QUANT_2PASS_SUPPORTED | |
post->whole_image = (*cinfo->mem->request_virt_sarray) | |
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE, | |
cinfo->output_width * cinfo->out_color_components, | |
(JDIMENSION) jround_up((long) cinfo->output_height, | |
(long) post->strip_height), | |
post->strip_height); | |
#else | |
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
#endif /* QUANT_2PASS_SUPPORTED */ | |
} else { | |
/* One-pass color quantization: just make a strip buffer. */ | |
post->buffer = (*cinfo->mem->alloc_sarray) | |
((j_common_ptr) cinfo, JPOOL_IMAGE, | |
cinfo->output_width * cinfo->out_color_components, | |
post->strip_height); | |
} | |
} | |
} | |
#endif //_FX_JPEG_TURBO_ |