| /* |
| * jwrjfif.c |
| * |
| * Copyright (C) 1991, 1992, 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 routines to write standard JPEG file headers/markers. |
| * The file format created is a raw JPEG data stream with (optionally) an |
| * APP0 marker per the JFIF spec. This will handle baseline and |
| * JFIF-convention JPEG files, although there is currently no provision |
| * for inserting a thumbnail image in the JFIF header. |
| * |
| * These routines may need modification for non-Unix environments or |
| * specialized applications. As they stand, they assume output to |
| * an ordinary stdio stream. However, the changes to write to something |
| * else are localized in the macros appearing just below. |
| * |
| * These routines are invoked via the methods write_file_header, |
| * write_scan_header, write_jpeg_data, write_scan_trailer, and |
| * write_file_trailer. |
| */ |
| |
| #include "jinclude.h" |
| |
| #ifdef JFIF_SUPPORTED |
| |
| |
| /* |
| * To output to something other than a stdio stream, you'd need to redefine |
| * these macros. |
| */ |
| |
| /* Write a single byte */ |
| #define emit_byte(cinfo,x) putc((x), cinfo->output_file) |
| |
| /* Write some bytes from a (char *) buffer */ |
| #define WRITE_BYTES(cinfo,dataptr,datacount) \ |
| { if (JFWRITE(cinfo->output_file, dataptr, datacount) \ |
| != (size_t) (datacount)) \ |
| ERREXIT(cinfo->emethods, "Output file write error"); } |
| |
| /* Clean up and verify successful output */ |
| #define CHECK_OUTPUT(cinfo) \ |
| { fflush(cinfo->output_file); \ |
| if (ferror(cinfo->output_file)) \ |
| ERREXIT(cinfo->emethods, "Output file write error"); } |
| |
| |
| /* End of stdio-specific code. */ |
| |
| |
| typedef enum { /* JPEG marker codes */ |
| M_SOF0 = 0xc0, |
| M_SOF1 = 0xc1, |
| M_SOF2 = 0xc2, |
| M_SOF3 = 0xc3, |
| |
| M_SOF5 = 0xc5, |
| M_SOF6 = 0xc6, |
| M_SOF7 = 0xc7, |
| |
| M_JPG = 0xc8, |
| M_SOF9 = 0xc9, |
| M_SOF10 = 0xca, |
| M_SOF11 = 0xcb, |
| |
| M_SOF13 = 0xcd, |
| M_SOF14 = 0xce, |
| M_SOF15 = 0xcf, |
| |
| M_DHT = 0xc4, |
| |
| M_DAC = 0xcc, |
| |
| M_RST0 = 0xd0, |
| M_RST1 = 0xd1, |
| M_RST2 = 0xd2, |
| M_RST3 = 0xd3, |
| M_RST4 = 0xd4, |
| M_RST5 = 0xd5, |
| M_RST6 = 0xd6, |
| M_RST7 = 0xd7, |
| |
| M_SOI = 0xd8, |
| M_EOI = 0xd9, |
| M_SOS = 0xda, |
| M_DQT = 0xdb, |
| M_DNL = 0xdc, |
| M_DRI = 0xdd, |
| M_DHP = 0xde, |
| M_EXP = 0xdf, |
| |
| M_APP0 = 0xe0, |
| M_APP15 = 0xef, |
| |
| M_JPG0 = 0xf0, |
| M_JPG13 = 0xfd, |
| M_COM = 0xfe, |
| |
| M_TEM = 0x01, |
| |
| M_ERROR = 0x100 |
| } JPEG_MARKER; |
| |
| |
| LOCAL void |
| emit_marker (compress_info_ptr cinfo, JPEG_MARKER mark) |
| /* Emit a marker code */ |
| { |
| emit_byte(cinfo, 0xFF); |
| emit_byte(cinfo, mark); |
| } |
| |
| |
| LOCAL void |
| emit_2bytes (compress_info_ptr cinfo, int value) |
| /* Emit a 2-byte integer; these are always MSB first in JPEG files */ |
| { |
| emit_byte(cinfo, (value >> 8) & 0xFF); |
| emit_byte(cinfo, value & 0xFF); |
| } |
| |
| |
| LOCAL int |
| emit_dqt (compress_info_ptr cinfo, int index) |
| /* Emit a DQT marker */ |
| /* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */ |
| { |
| QUANT_TBL_PTR data = cinfo->quant_tbl_ptrs[index]; |
| int prec = 0; |
| int i; |
| |
| for (i = 0; i < DCTSIZE2; i++) { |
| if (data[i] > 255) |
| prec = 1; |
| } |
| |
| emit_marker(cinfo, M_DQT); |
| |
| emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2); |
| |
| emit_byte(cinfo, index + (prec<<4)); |
| |
| for (i = 0; i < DCTSIZE2; i++) { |
| if (prec) |
| emit_byte(cinfo, data[i] >> 8); |
| emit_byte(cinfo, data[i] & 0xFF); |
| } |
| |
| return prec; |
| } |
| |
| |
| LOCAL void |
| emit_dht (compress_info_ptr cinfo, int index, boolean is_ac) |
| /* Emit a DHT marker */ |
| { |
| HUFF_TBL * htbl; |
| int length, i; |
| |
| if (is_ac) { |
| htbl = cinfo->ac_huff_tbl_ptrs[index]; |
| index += 0x10; /* output index has AC bit set */ |
| } else { |
| htbl = cinfo->dc_huff_tbl_ptrs[index]; |
| } |
| |
| if (htbl == NULL) |
| ERREXIT1(cinfo->emethods, "Huffman table 0x%02x was not defined", index); |
| |
| if (! htbl->sent_table) { |
| emit_marker(cinfo, M_DHT); |
| |
| length = 0; |
| for (i = 1; i <= 16; i++) |
| length += htbl->bits[i]; |
| |
| emit_2bytes(cinfo, length + 2 + 1 + 16); |
| emit_byte(cinfo, index); |
| |
| for (i = 1; i <= 16; i++) |
| emit_byte(cinfo, htbl->bits[i]); |
| |
| for (i = 0; i < length; i++) |
| emit_byte(cinfo, htbl->huffval[i]); |
| |
| htbl->sent_table = TRUE; |
| } |
| } |
| |
| |
| LOCAL void |
| emit_dac (compress_info_ptr cinfo) |
| /* Emit a DAC marker */ |
| /* Since the useful info is so small, we want to emit all the tables in */ |
| /* one DAC marker. Therefore this routine does its own scan of the table. */ |
| { |
| char dc_in_use[NUM_ARITH_TBLS]; |
| char ac_in_use[NUM_ARITH_TBLS]; |
| int length, i; |
| |
| for (i = 0; i < NUM_ARITH_TBLS; i++) |
| dc_in_use[i] = ac_in_use[i] = 0; |
| |
| for (i = 0; i < cinfo->num_components; i++) { |
| dc_in_use[cinfo->comp_info[i].dc_tbl_no] = 1; |
| ac_in_use[cinfo->comp_info[i].ac_tbl_no] = 1; |
| } |
| |
| length = 0; |
| for (i = 0; i < NUM_ARITH_TBLS; i++) |
| length += dc_in_use[i] + ac_in_use[i]; |
| |
| emit_marker(cinfo, M_DAC); |
| |
| emit_2bytes(cinfo, length*2 + 2); |
| |
| for (i = 0; i < NUM_ARITH_TBLS; i++) { |
| if (dc_in_use[i]) { |
| emit_byte(cinfo, i); |
| emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4)); |
| } |
| if (ac_in_use[i]) { |
| emit_byte(cinfo, i + 0x10); |
| emit_byte(cinfo, cinfo->arith_ac_K[i]); |
| } |
| } |
| } |
| |
| |
| LOCAL void |
| emit_dri (compress_info_ptr cinfo) |
| /* Emit a DRI marker */ |
| { |
| emit_marker(cinfo, M_DRI); |
| |
| emit_2bytes(cinfo, 4); /* fixed length */ |
| |
| emit_2bytes(cinfo, (int) cinfo->restart_interval); |
| } |
| |
| |
| LOCAL void |
| emit_sof (compress_info_ptr cinfo, JPEG_MARKER code) |
| /* Emit a SOF marker */ |
| { |
| int i; |
| |
| emit_marker(cinfo, code); |
| |
| emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */ |
| |
| if (cinfo->image_height > 65535L || cinfo->image_width > 65535L) |
| ERREXIT(cinfo->emethods, "Maximum image dimension for JFIF is 65535 pixels"); |
| |
| emit_byte(cinfo, cinfo->data_precision); |
| emit_2bytes(cinfo, (int) cinfo->image_height); |
| emit_2bytes(cinfo, (int) cinfo->image_width); |
| |
| emit_byte(cinfo, cinfo->num_components); |
| |
| for (i = 0; i < cinfo->num_components; i++) { |
| emit_byte(cinfo, cinfo->comp_info[i].component_id); |
| emit_byte(cinfo, (cinfo->comp_info[i].h_samp_factor << 4) |
| + cinfo->comp_info[i].v_samp_factor); |
| emit_byte(cinfo, cinfo->comp_info[i].quant_tbl_no); |
| } |
| } |
| |
| |
| LOCAL void |
| emit_sos (compress_info_ptr cinfo) |
| /* Emit a SOS marker */ |
| { |
| int i; |
| |
| emit_marker(cinfo, M_SOS); |
| |
| emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */ |
| |
| emit_byte(cinfo, cinfo->comps_in_scan); |
| |
| for (i = 0; i < cinfo->comps_in_scan; i++) { |
| emit_byte(cinfo, cinfo->cur_comp_info[i]->component_id); |
| emit_byte(cinfo, (cinfo->cur_comp_info[i]->dc_tbl_no << 4) |
| + cinfo->cur_comp_info[i]->ac_tbl_no); |
| } |
| |
| emit_byte(cinfo, 0); /* Spectral selection start */ |
| emit_byte(cinfo, DCTSIZE2-1); /* Spectral selection end */ |
| emit_byte(cinfo, 0); /* Successive approximation */ |
| } |
| |
| |
| LOCAL void |
| emit_jfif_app0 (compress_info_ptr cinfo) |
| /* Emit a JFIF-compliant APP0 marker */ |
| { |
| /* |
| * Length of APP0 block (2 bytes) |
| * Block ID (4 bytes - ASCII "JFIF") |
| * Zero byte (1 byte to terminate the ID string) |
| * Version Major, Minor (2 bytes - 0x01, 0x01) |
| * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm) |
| * Xdpu (2 bytes - dots per unit horizontal) |
| * Ydpu (2 bytes - dots per unit vertical) |
| * Thumbnail X size (1 byte) |
| * Thumbnail Y size (1 byte) |
| */ |
| |
| emit_marker(cinfo, M_APP0); |
| |
| emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */ |
| |
| emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */ |
| emit_byte(cinfo, 0x46); |
| emit_byte(cinfo, 0x49); |
| emit_byte(cinfo, 0x46); |
| emit_byte(cinfo, 0); |
| emit_byte(cinfo, 1); /* Major version */ |
| emit_byte(cinfo, 1); /* Minor version */ |
| emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */ |
| emit_2bytes(cinfo, (int) cinfo->X_density); |
| emit_2bytes(cinfo, (int) cinfo->Y_density); |
| emit_byte(cinfo, 0); /* No thumbnail image */ |
| emit_byte(cinfo, 0); |
| } |
| |
| |
| /* |
| * Write the file header. |
| */ |
| |
| |
| METHODDEF void |
| write_file_header (compress_info_ptr cinfo) |
| { |
| char qt_in_use[NUM_QUANT_TBLS]; |
| int i, prec; |
| boolean is_baseline; |
| |
| emit_marker(cinfo, M_SOI); /* first the SOI */ |
| |
| if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */ |
| emit_jfif_app0(cinfo); |
| |
| /* Emit DQT for each quantization table. */ |
| /* Note that doing it here means we can't adjust the QTs on-the-fly. */ |
| /* If we did want to do that, we'd have a problem with checking precision */ |
| /* for the is_baseline determination. */ |
| |
| for (i = 0; i < NUM_QUANT_TBLS; i++) |
| qt_in_use[i] = 0; |
| |
| for (i = 0; i < cinfo->num_components; i++) |
| qt_in_use[cinfo->comp_info[i].quant_tbl_no] = 1; |
| |
| prec = 0; |
| for (i = 0; i < NUM_QUANT_TBLS; i++) { |
| if (qt_in_use[i]) |
| prec += emit_dqt(cinfo, i); |
| } |
| /* now prec is nonzero iff there are any 16-bit quant tables. */ |
| |
| /* Check for a non-baseline specification. */ |
| /* Note we assume that Huffman table numbers won't be changed later. */ |
| is_baseline = TRUE; |
| if (cinfo->arith_code || (cinfo->data_precision != 8)) |
| is_baseline = FALSE; |
| for (i = 0; i < cinfo->num_components; i++) { |
| if (cinfo->comp_info[i].dc_tbl_no > 1 || cinfo->comp_info[i].ac_tbl_no > 1) |
| is_baseline = FALSE; |
| } |
| if (prec && is_baseline) { |
| is_baseline = FALSE; |
| /* If it's baseline except for quantizer size, warn the user */ |
| TRACEMS(cinfo->emethods, 0, |
| "Caution: quantization tables are too coarse for baseline JPEG"); |
| } |
| |
| |
| /* Emit the proper SOF marker */ |
| if (cinfo->arith_code) |
| emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */ |
| else if (is_baseline) |
| emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */ |
| else |
| emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */ |
| } |
| |
| |
| /* |
| * Write the start of a scan (everything through the SOS marker). |
| */ |
| |
| METHODDEF void |
| write_scan_header (compress_info_ptr cinfo) |
| { |
| int i; |
| |
| if (cinfo->arith_code) { |
| /* Emit arith conditioning info. We will have some duplication |
| * if the file has multiple scans, but it's so small it's hardly |
| * worth worrying about. |
| */ |
| emit_dac(cinfo); |
| } else { |
| /* Emit Huffman tables. Note that emit_dht takes care of |
| * suppressing duplicate tables. |
| */ |
| for (i = 0; i < cinfo->comps_in_scan; i++) { |
| emit_dht(cinfo, cinfo->cur_comp_info[i]->dc_tbl_no, FALSE); |
| emit_dht(cinfo, cinfo->cur_comp_info[i]->ac_tbl_no, TRUE); |
| } |
| } |
| |
| /* Emit DRI if required --- note that DRI value could change for each scan. |
| * If it doesn't, a tiny amount of space is wasted in multiple-scan files. |
| * We assume DRI will never be nonzero for one scan and zero for a later one. |
| */ |
| if (cinfo->restart_interval) |
| emit_dri(cinfo); |
| |
| emit_sos(cinfo); |
| } |
| |
| |
| /* |
| * Write some bytes of compressed data within a scan. |
| */ |
| |
| METHODDEF void |
| write_jpeg_data (compress_info_ptr cinfo, char *dataptr, int datacount) |
| { |
| WRITE_BYTES(cinfo, dataptr, datacount); |
| } |
| |
| |
| /* |
| * Finish up after a compressed scan (series of write_jpeg_data calls). |
| */ |
| |
| METHODDEF void |
| write_scan_trailer (compress_info_ptr cinfo) |
| { |
| /* no work needed in this format */ |
| } |
| |
| |
| /* |
| * Finish up at the end of the file. |
| */ |
| |
| METHODDEF void |
| write_file_trailer (compress_info_ptr cinfo) |
| { |
| emit_marker(cinfo, M_EOI); |
| /* Make sure we wrote the output file OK */ |
| CHECK_OUTPUT(cinfo); |
| } |
| |
| |
| /* |
| * The method selection routine for standard JPEG header writing. |
| * This should be called from c_ui_method_selection if appropriate. |
| */ |
| |
| GLOBAL void |
| jselwjfif (compress_info_ptr cinfo) |
| { |
| cinfo->methods->write_file_header = write_file_header; |
| cinfo->methods->write_scan_header = write_scan_header; |
| cinfo->methods->write_jpeg_data = write_jpeg_data; |
| cinfo->methods->write_scan_trailer = write_scan_trailer; |
| cinfo->methods->write_file_trailer = write_file_trailer; |
| } |
| |
| #endif /* JFIF_SUPPORTED */ |