| /* |
| * jctrans.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1995-1998, Thomas G. Lane. |
| * Modified 2000-2009 by Guido Vollbeding. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 2020, 2022, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * file. |
| * |
| * This file contains library routines for transcoding compression, |
| * that is, writing raw DCT coefficient arrays to an output JPEG file. |
| * The routines in jcapimin.c will also be needed by a transcoder. |
| */ |
| |
| #define JPEG_INTERNALS |
| #include "jinclude.h" |
| #include "jpeglib.h" |
| #include "jpegapicomp.h" |
| |
| |
| /* Forward declarations */ |
| LOCAL(void) transencode_master_selection(j_compress_ptr cinfo, |
| jvirt_barray_ptr *coef_arrays); |
| LOCAL(void) transencode_coef_controller(j_compress_ptr cinfo, |
| jvirt_barray_ptr *coef_arrays); |
| |
| |
| /* |
| * Compression initialization for writing raw-coefficient data. |
| * Before calling this, all parameters and a data destination must be set up. |
| * Call jpeg_finish_compress() to actually write the data. |
| * |
| * The number of passed virtual arrays must match cinfo->num_components. |
| * Note that the virtual arrays need not be filled or even realized at |
| * the time write_coefficients is called; indeed, if the virtual arrays |
| * were requested from this compression object's memory manager, they |
| * typically will be realized during this routine and filled afterwards. |
| */ |
| |
| GLOBAL(void) |
| jpeg_write_coefficients(j_compress_ptr cinfo, jvirt_barray_ptr *coef_arrays) |
| { |
| if (cinfo->master->lossless) |
| ERREXIT(cinfo, JERR_NOTIMPL); |
| |
| if (cinfo->global_state != CSTATE_START) |
| ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); |
| /* Mark all tables to be written */ |
| jpeg_suppress_tables(cinfo, FALSE); |
| /* (Re)initialize error mgr and destination modules */ |
| (*cinfo->err->reset_error_mgr) ((j_common_ptr)cinfo); |
| (*cinfo->dest->init_destination) (cinfo); |
| /* Perform master selection of active modules */ |
| transencode_master_selection(cinfo, coef_arrays); |
| /* Wait for jpeg_finish_compress() call */ |
| cinfo->next_scanline = 0; /* so jpeg_write_marker works */ |
| cinfo->global_state = CSTATE_WRCOEFS; |
| } |
| |
| |
| /* |
| * Initialize the compression object with default parameters, |
| * then copy from the source object all parameters needed for lossless |
| * transcoding. Parameters that can be varied without loss (such as |
| * scan script and Huffman optimization) are left in their default states. |
| */ |
| |
| GLOBAL(void) |
| jpeg_copy_critical_parameters(j_decompress_ptr srcinfo, j_compress_ptr dstinfo) |
| { |
| JQUANT_TBL **qtblptr; |
| jpeg_component_info *incomp, *outcomp; |
| JQUANT_TBL *c_quant, *slot_quant; |
| int tblno, ci, coefi; |
| |
| if (srcinfo->master->lossless) |
| ERREXIT(dstinfo, JERR_NOTIMPL); |
| |
| /* Safety check to ensure start_compress not called yet. */ |
| if (dstinfo->global_state != CSTATE_START) |
| ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state); |
| /* Copy fundamental image dimensions */ |
| dstinfo->image_width = srcinfo->image_width; |
| dstinfo->image_height = srcinfo->image_height; |
| dstinfo->input_components = srcinfo->num_components; |
| dstinfo->in_color_space = srcinfo->jpeg_color_space; |
| #if JPEG_LIB_VERSION >= 70 |
| dstinfo->jpeg_width = srcinfo->output_width; |
| dstinfo->jpeg_height = srcinfo->output_height; |
| dstinfo->min_DCT_h_scaled_size = srcinfo->min_DCT_h_scaled_size; |
| dstinfo->min_DCT_v_scaled_size = srcinfo->min_DCT_v_scaled_size; |
| #endif |
| /* Initialize all parameters to default values */ |
| jpeg_set_defaults(dstinfo); |
| /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB. |
| * Fix it to get the right header markers for the image colorspace. |
| */ |
| jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space); |
| dstinfo->data_precision = srcinfo->data_precision; |
| dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling; |
| /* Copy the source's quantization tables. */ |
| for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) { |
| if (srcinfo->quant_tbl_ptrs[tblno] != NULL) { |
| qtblptr = &dstinfo->quant_tbl_ptrs[tblno]; |
| if (*qtblptr == NULL) |
| *qtblptr = jpeg_alloc_quant_table((j_common_ptr)dstinfo); |
| memcpy((*qtblptr)->quantval, srcinfo->quant_tbl_ptrs[tblno]->quantval, |
| sizeof((*qtblptr)->quantval)); |
| (*qtblptr)->sent_table = FALSE; |
| } |
| } |
| /* Copy the source's per-component info. |
| * Note we assume jpeg_set_defaults has allocated the dest comp_info array. |
| */ |
| dstinfo->num_components = srcinfo->num_components; |
| if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS) |
| ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components, |
| MAX_COMPONENTS); |
| for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info; |
| ci < dstinfo->num_components; ci++, incomp++, outcomp++) { |
| outcomp->component_id = incomp->component_id; |
| outcomp->h_samp_factor = incomp->h_samp_factor; |
| outcomp->v_samp_factor = incomp->v_samp_factor; |
| outcomp->quant_tbl_no = incomp->quant_tbl_no; |
| /* Make sure saved quantization table for component matches the qtable |
| * slot. If not, the input file re-used this qtable slot. |
| * IJG encoder currently cannot duplicate this. |
| */ |
| tblno = outcomp->quant_tbl_no; |
| if (tblno < 0 || tblno >= NUM_QUANT_TBLS || |
| srcinfo->quant_tbl_ptrs[tblno] == NULL) |
| ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno); |
| slot_quant = srcinfo->quant_tbl_ptrs[tblno]; |
| c_quant = incomp->quant_table; |
| if (c_quant != NULL) { |
| for (coefi = 0; coefi < DCTSIZE2; coefi++) { |
| if (c_quant->quantval[coefi] != slot_quant->quantval[coefi]) |
| ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno); |
| } |
| } |
| /* Note: we do not copy the source's Huffman table assignments; |
| * instead we rely on jpeg_set_colorspace to have made a suitable choice. |
| */ |
| } |
| /* Also copy JFIF version and resolution information, if available. |
| * Strictly speaking this isn't "critical" info, but it's nearly |
| * always appropriate to copy it if available. In particular, |
| * if the application chooses to copy JFIF 1.02 extension markers from |
| * the source file, we need to copy the version to make sure we don't |
| * emit a file that has 1.02 extensions but a claimed version of 1.01. |
| * We will *not*, however, copy version info from mislabeled "2.01" files. |
| */ |
| if (srcinfo->saw_JFIF_marker) { |
| if (srcinfo->JFIF_major_version == 1) { |
| dstinfo->JFIF_major_version = srcinfo->JFIF_major_version; |
| dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version; |
| } |
| dstinfo->density_unit = srcinfo->density_unit; |
| dstinfo->X_density = srcinfo->X_density; |
| dstinfo->Y_density = srcinfo->Y_density; |
| } |
| } |
| |
| |
| /* |
| * Master selection of compression modules for transcoding. |
| * This substitutes for jcinit.c's initialization of the full compressor. |
| */ |
| |
| LOCAL(void) |
| transencode_master_selection(j_compress_ptr cinfo, |
| jvirt_barray_ptr *coef_arrays) |
| { |
| /* Although we don't actually use input_components for transcoding, |
| * jcmaster.c's initial_setup will complain if input_components is 0. |
| */ |
| cinfo->input_components = 1; |
| /* Initialize master control (includes parameter checking/processing) */ |
| jinit_c_master_control(cinfo, TRUE /* transcode only */); |
| |
| /* Entropy encoding: either Huffman or arithmetic coding. */ |
| if (cinfo->arith_code) { |
| #ifdef C_ARITH_CODING_SUPPORTED |
| jinit_arith_encoder(cinfo); |
| #else |
| ERREXIT(cinfo, JERR_ARITH_NOTIMPL); |
| #endif |
| } else { |
| if (cinfo->progressive_mode) { |
| #ifdef C_PROGRESSIVE_SUPPORTED |
| jinit_phuff_encoder(cinfo); |
| #else |
| ERREXIT(cinfo, JERR_NOT_COMPILED); |
| #endif |
| } else |
| jinit_huff_encoder(cinfo); |
| } |
| |
| /* We need a special coefficient buffer controller. */ |
| transencode_coef_controller(cinfo, coef_arrays); |
| |
| jinit_marker_writer(cinfo); |
| |
| /* We can now tell the memory manager to allocate virtual arrays. */ |
| (*cinfo->mem->realize_virt_arrays) ((j_common_ptr)cinfo); |
| |
| /* Write the datastream header (SOI, JFIF) immediately. |
| * Frame and scan headers are postponed till later. |
| * This lets application insert special markers after the SOI. |
| */ |
| (*cinfo->marker->write_file_header) (cinfo); |
| } |
| |
| |
| /* |
| * The rest of this file is a special implementation of the coefficient |
| * buffer controller. This is similar to jccoefct.c, but it handles only |
| * output from presupplied virtual arrays. Furthermore, we generate any |
| * dummy padding blocks on-the-fly rather than expecting them to be present |
| * in the arrays. |
| */ |
| |
| /* Private buffer controller object */ |
| |
| typedef struct { |
| struct jpeg_c_coef_controller pub; /* public fields */ |
| |
| JDIMENSION iMCU_row_num; /* iMCU row # within image */ |
| JDIMENSION mcu_ctr; /* counts MCUs processed in current row */ |
| int MCU_vert_offset; /* counts MCU rows within iMCU row */ |
| int MCU_rows_per_iMCU_row; /* number of such rows needed */ |
| |
| /* Virtual block array for each component. */ |
| jvirt_barray_ptr *whole_image; |
| |
| /* Workspace for constructing dummy blocks at right/bottom edges. */ |
| JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU]; |
| } my_coef_controller; |
| |
| typedef my_coef_controller *my_coef_ptr; |
| |
| |
| LOCAL(void) |
| start_iMCU_row(j_compress_ptr cinfo) |
| /* Reset within-iMCU-row counters for a new row */ |
| { |
| my_coef_ptr coef = (my_coef_ptr)cinfo->coef; |
| |
| /* In an interleaved scan, an MCU row is the same as an iMCU row. |
| * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows. |
| * But at the bottom of the image, process only what's left. |
| */ |
| if (cinfo->comps_in_scan > 1) { |
| coef->MCU_rows_per_iMCU_row = 1; |
| } else { |
| if (coef->iMCU_row_num < (cinfo->total_iMCU_rows - 1)) |
| coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor; |
| else |
| coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height; |
| } |
| |
| coef->mcu_ctr = 0; |
| coef->MCU_vert_offset = 0; |
| } |
| |
| |
| /* |
| * Initialize for a processing pass. |
| */ |
| |
| METHODDEF(void) |
| start_pass_coef(j_compress_ptr cinfo, J_BUF_MODE pass_mode) |
| { |
| my_coef_ptr coef = (my_coef_ptr)cinfo->coef; |
| |
| if (pass_mode != JBUF_CRANK_DEST) |
| ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); |
| |
| coef->iMCU_row_num = 0; |
| start_iMCU_row(cinfo); |
| } |
| |
| |
| /* |
| * Process some data. |
| * We process the equivalent of one fully interleaved MCU row ("iMCU" row) |
| * per call, ie, v_samp_factor block rows for each component in the scan. |
| * The data is obtained from the virtual arrays and fed to the entropy coder. |
| * Returns TRUE if the iMCU row is completed, FALSE if suspended. |
| * |
| * NB: input_buf is ignored; it is likely to be a NULL pointer. |
| */ |
| |
| METHODDEF(boolean) |
| compress_output(j_compress_ptr cinfo, JSAMPIMAGE input_buf) |
| { |
| my_coef_ptr coef = (my_coef_ptr)cinfo->coef; |
| JDIMENSION MCU_col_num; /* index of current MCU within row */ |
| JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1; |
| JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1; |
| int blkn, ci, xindex, yindex, yoffset, blockcnt; |
| JDIMENSION start_col; |
| JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN]; |
| JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU]; |
| JBLOCKROW buffer_ptr; |
| jpeg_component_info *compptr; |
| |
| /* Align the virtual buffers for the components used in this scan. */ |
| for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| compptr = cinfo->cur_comp_info[ci]; |
| buffer[ci] = (*cinfo->mem->access_virt_barray) |
| ((j_common_ptr)cinfo, coef->whole_image[compptr->component_index], |
| coef->iMCU_row_num * compptr->v_samp_factor, |
| (JDIMENSION)compptr->v_samp_factor, FALSE); |
| } |
| |
| /* Loop to process one whole iMCU row */ |
| for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row; |
| yoffset++) { |
| for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row; |
| MCU_col_num++) { |
| /* Construct list of pointers to DCT blocks belonging to this MCU */ |
| blkn = 0; /* index of current DCT block within MCU */ |
| for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| compptr = cinfo->cur_comp_info[ci]; |
| start_col = MCU_col_num * compptr->MCU_width; |
| blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width : |
| compptr->last_col_width; |
| for (yindex = 0; yindex < compptr->MCU_height; yindex++) { |
| if (coef->iMCU_row_num < last_iMCU_row || |
| yindex + yoffset < compptr->last_row_height) { |
| /* Fill in pointers to real blocks in this row */ |
| buffer_ptr = buffer[ci][yindex + yoffset] + start_col; |
| for (xindex = 0; xindex < blockcnt; xindex++) |
| MCU_buffer[blkn++] = buffer_ptr++; |
| } else { |
| /* At bottom of image, need a whole row of dummy blocks */ |
| xindex = 0; |
| } |
| /* Fill in any dummy blocks needed in this row. |
| * Dummy blocks are filled in the same way as in jccoefct.c: |
| * all zeroes in the AC entries, DC entries equal to previous |
| * block's DC value. The init routine has already zeroed the |
| * AC entries, so we need only set the DC entries correctly. |
| */ |
| for (; xindex < compptr->MCU_width; xindex++) { |
| MCU_buffer[blkn] = coef->dummy_buffer[blkn]; |
| MCU_buffer[blkn][0][0] = MCU_buffer[blkn - 1][0][0]; |
| blkn++; |
| } |
| } |
| } |
| /* Try to write the MCU. */ |
| if (!(*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) { |
| /* Suspension forced; update state counters and exit */ |
| coef->MCU_vert_offset = yoffset; |
| coef->mcu_ctr = MCU_col_num; |
| return FALSE; |
| } |
| } |
| /* Completed an MCU row, but perhaps not an iMCU row */ |
| coef->mcu_ctr = 0; |
| } |
| /* Completed the iMCU row, advance counters for next one */ |
| coef->iMCU_row_num++; |
| start_iMCU_row(cinfo); |
| return TRUE; |
| } |
| |
| |
| METHODDEF(boolean) |
| compress_output_12(j_compress_ptr cinfo, J12SAMPIMAGE input_buf) |
| { |
| return compress_output(cinfo, (JSAMPIMAGE)input_buf); |
| } |
| |
| |
| /* |
| * Initialize coefficient buffer controller. |
| * |
| * Each passed coefficient array must be the right size for that |
| * coefficient: width_in_blocks wide and height_in_blocks high, |
| * with unitheight at least v_samp_factor. |
| */ |
| |
| LOCAL(void) |
| transencode_coef_controller(j_compress_ptr cinfo, |
| jvirt_barray_ptr *coef_arrays) |
| { |
| my_coef_ptr coef; |
| JBLOCKROW buffer; |
| int i; |
| |
| coef = (my_coef_ptr) |
| (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| sizeof(my_coef_controller)); |
| cinfo->coef = (struct jpeg_c_coef_controller *)coef; |
| coef->pub.start_pass = start_pass_coef; |
| coef->pub.compress_data = compress_output; |
| coef->pub.compress_data_12 = compress_output_12; |
| |
| /* Save pointer to virtual arrays */ |
| coef->whole_image = coef_arrays; |
| |
| /* Allocate and pre-zero space for dummy DCT blocks. */ |
| buffer = (JBLOCKROW) |
| (*cinfo->mem->alloc_large) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
| C_MAX_BLOCKS_IN_MCU * sizeof(JBLOCK)); |
| jzero_far((void *)buffer, C_MAX_BLOCKS_IN_MCU * sizeof(JBLOCK)); |
| for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) { |
| coef->dummy_buffer[i] = buffer + i; |
| } |
| } |