X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/f228da9594290408ee03ffddbd01eadefbf06f1d..HEAD:/src/lbximg.c

diff --git a/src/lbximg.c b/src/lbximg.c
index 50dff07..f997506 100644
--- a/src/lbximg.c
+++ b/src/lbximg.c
@@ -1,7 +1,7 @@
 /*
  *  2ooM: The Master of Orion II Reverse Engineering Project
- *  Simple command-line tool to convert an LBX image to a set of PNGs.
- *  Copyright (C) 2006-2008 Nick Bowler
+ *  Simple command-line tool to convert an LBX image to other formats.
+ *  Copyright © 2006-2011, 2013-2014, 2021 Nick Bowler
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -16,44 +16,70 @@
  *  You should have received a copy of the GNU General Public License
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#define _GNU_SOURCE
 #include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #include <string.h>
 #include <limits.h>
+#include <stdint.h>
 #include <assert.h>
 #include <getopt.h>
 #include <errno.h>
 
-#include <png.h>
+#include "help.h"
 
 #include "tools.h"
 #include "image.h"
+#include "error.h"
 #include "lbx.h"
 
+#include "imgoutput.h"
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
 /* Global flags */
 static int verbose = 0;
 static char *outname = "out";
 static int usepalette = 1;
 
-static void printusage(void)
+#include "imgopts.h"
+static const char sopts[] = SOPT_STRING;
+static const struct option lopts[] = { LOPTS_INITIALIZER, {0} };
+
+static void print_usage(FILE *f)
 {
-	puts("usage: lbximg [-i|-d] [-v] [-p palette_file] [-O override_file]"
-	                  " [-f path]");
-	puts("              [frameno ...]");
+	const char *progname = tool_invocation();
+
+	fprintf(f, "Usage: %s [options] [-i|-d] [frame ...]\n", progname);
+	if (f != stdout)
+		fprintf(f, "Try %s --help for more information.\n", progname);
 }
 
-static void printhelp(void)
+static void print_help(void)
 {
-	printusage();
-	puts("For now, see the man page for detailed help.");
-}
+	const struct option *opt;
 
-static const char *progname;
-#define errmsg(fmt, ...) (\
-	fprintf(stderr, "%s: " fmt, progname, __VA_ARGS__)\
-)
+	print_usage(stdout);
+
+	putchar('\n');
+	puts("Options:");
+	for (opt = lopts; opt->name; opt++) {
+		struct lopt_help help;
+		int w;
+
+		if (!lopt_get_help(opt, &help))
+			continue;
+
+		help_print_option(opt, help.arg, help.desc, 20);
+	}
+	putchar('\n');
+
+	puts("For more information, see the lbximg(1) man page.");
+	putchar('\n');
+
+	printf("Report bugs to <%s>.\n", PACKAGE_BUGREPORT);
+}
 
 enum {
 	MODE_NONE,
@@ -61,20 +87,76 @@ enum {
 	MODE_IDENT,
 };
 
-int parserange(struct lbx_imginfo *info, char *str, unsigned char *bits)
+static const struct img_format {
+	img_output_func *output;
+	char name[4];
+	bool enabled;
+} formats[] = {
+#if HAVE_LIBPNG
+	{ img_output_png, "png", 1 },
+#endif
+	{ img_output_pam, "pam", 1 },
+	{ img_output_ppm, "ppm", 1 },
+	{ img_output_pbm, "pbm", 1 },
+};
+
+static int lookup_format(const char *fmt)
+{
+	for (size_t i = 0; i < sizeof formats / sizeof formats[0]; i++) {
+		assert(!formats[i].name[sizeof formats[i].name - 1]);
+
+		if (!fmt && formats[i].enabled)
+			return i;
+
+		if (strcmp(formats[i].name, fmt))
+			continue;
+
+		if (!formats[i].enabled) {
+			tool_err(-1, "%s support disabled at build time", fmt);
+			return -1;
+		}
+
+		return i;
+	}
+
+	tool_err(-1, "unknown format %s", fmt);
+	return -1;
+}
+
+bool img_is_masked(unsigned char *mask, unsigned width, unsigned height)
+{
+	unsigned long npixels = (unsigned long) width * height;
+	unsigned long mask_sz = npixels / CHAR_BIT + (npixels % CHAR_BIT != 0);
+
+	for (unsigned long i = 0; i < mask_sz; i++) {
+		if (i+1 < mask_sz) {
+			if (mask[i] != (unsigned char)-1)
+				return true;
+		} else {
+			unsigned char test = (1u << npixels % CHAR_BIT) - 1;
+
+			if ((mask[i] & test) != test)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+int parserange(unsigned frames, char *str, unsigned char *bits)
 {
 	unsigned long start, end;
 	unsigned int i;
 	char *endptr;
 
 	start = strtoul(str, &endptr, 0);
-	if (start >= info->nframes) {
-		errmsg("frame %lu out of range.\n", start);
+	if (start >= frames) {
+		tool_err(-1, "frame %lu out of range.", start);
 		return -1;
 	}
 
 	if (endptr == str) {
-		errmsg("invalid frame range: %s.\n", str);
+		tool_err(-1, "invalid frame range: %s.", str);
 		return -1;
 	}
 
@@ -84,21 +166,21 @@ int parserange(struct lbx_imginfo *info, char *str, unsigned char *bits)
 		break;
 	case '-':
 		end = strtoul(endptr+1, &endptr, 0);
-		if (end >= info->nframes) {
-			errmsg("frame %lu out of range.\n", end);
+		if (end >= frames) {
+			tool_err(-1, "frame %lu out of range.", end);
 			return -1;
 		}
 
 		if (endptr == str)
-			end = info->nframes - 1;
+			end = frames - 1;
 		break;
 	default:
-		errmsg("invalid frame range: %s.\n", str);
+		tool_err(-1, "invalid frame range: %s.", str);
 		return -1;
 	}
 
 	if (end < start) {
-		errmsg("invalid frame range: %s.\n", str);
+		tool_err(-1, "invalid frame range: %s.", str);
 		return -1;
 	}
 
@@ -109,287 +191,281 @@ int parserange(struct lbx_imginfo *info, char *str, unsigned char *bits)
 	return 0;
 }
 
-static int ismasked(unsigned char **mask, unsigned width, unsigned height)
-{
-	unsigned y, x;
-	for (y = 0; y < height; y++) {
-		for (x = 0; x < width; x++) {
-			if (mask[y][x] == 0) return 1;
-		}
-	}
-
-	return 0;
-}
-
-int outpng(unsigned int frameno,
-           unsigned char **framedata, unsigned char **mask,
-           unsigned int width, unsigned int height,
-           struct lbx_colour palette[static 256])
+static int output(unsigned int frameno, const struct img_format *fmt,
+                  unsigned char *pixels, unsigned char *pixel_mask,
+                  unsigned int width, unsigned int height,
+                  struct lbx_colour *palette)
 {
 	char name[strlen(outname) + sizeof ".65535.png"];
-	unsigned char *row;
-	unsigned int x, y;
 	FILE *of;
+	int rc;
 
-	png_structp png;
-	png_infop   info;
-
+	assert(fmt->output != NULL);
 	assert(frameno < 65536);
-	snprintf(name, sizeof name, "%s.%03d.png", outname, frameno);
-
-	row = malloc(4 * width);
-	if (!row) {
-		errmsg("failed to allocate row buffer: %s\n", strerror(errno));
-		return -1;
-	}
+	snprintf(name, sizeof name, "%s.%03d.%s", outname, frameno, fmt->name);
 
 	of = fopen(name, "wb");
 	if (!of) {
-		errmsg("failed to open %s: %s.\n", name, strerror(errno));
-		free(row);
+		tool_err(0, "failed to open %s", name);
 		return -1;
 	}
 
-	png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-	if (!png) {
-		errmsg("failed to init libpng.\n", 0);
-		goto err;
+	rc = fmt->output(of, name, width, height, pixels, pixel_mask, palette);
+	if (rc < 0) {
+		fclose(of);
+		return -1;
 	}
 
-	info = png_create_info_struct(png);
-	if (!info) {
-		errmsg("failed to init libpng.\n", 0);
-		png_destroy_write_struct(&png, NULL);
-		goto err;
+	if (fclose(of) == EOF) {
+		tool_err(0, "error writing %s", name);
+		return -1;
 	}
 
-	if (setjmp(png_jmpbuf(png))) {
-		free(row);
-		png_destroy_write_struct(&png, &info);
-		goto err;
-	}
+	if (verbose)
+		printf("wrote %s\n", name);
 
-	png_init_io(png, of);
+	return 0;
+}
 
-	if (!ismasked(mask, width, height)) {
-		/*
-		 * This case is easy; we can just feed the palette and pixel
-		 * data to libpng and let it do its magic.
-		 */
+static int loadoverride(FILE *f, struct lbx_colour *palette)
+{
+	struct lbx_image *img;
+	int rc, ret = 0;
 
-		png_set_IHDR(png, info, width, height, 8,
-		             PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
-			     PNG_COMPRESSION_TYPE_DEFAULT,
-			     PNG_FILTER_TYPE_DEFAULT);
-		
-		png_set_PLTE(png, info, (png_colorp)palette, 256);
-		png_set_rows(png, info, framedata);
-		png_write_png(png, info, PNG_TRANSFORM_IDENTITY, NULL);
-	} else {
-		/*
-		 * Unfortunately, LBX doesn't translate nicely to PNG here.
-		 * LBX has a 256 colour palette _plus_ transparency.
-		 * We'll form an RGBA PNG to deal with this.
-		 */
-
-		png_set_IHDR(png, info, width, height, 8,
-		             PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
-		             PNG_COMPRESSION_TYPE_DEFAULT,
-		             PNG_FILTER_TYPE_DEFAULT);
-	
-		png_write_info(png, info);
-	
-		for (y = 0; y < height; y++) {
-			for (x = 0; x < width; x++) {
-				row[4*x+0] = palette[framedata[y][x]].red;
-				row[4*x+1] = palette[framedata[y][x]].green;
-				row[4*x+2] = palette[framedata[y][x]].blue;
-				row[4*x+3] = (mask[y][x]) ? -1 : 0;
-			}
-	
-			png_write_row(png, row);
-		}
-	
-		png_write_end(png, NULL);
+	img = lbx_img_open(f, &lbx_default_fops, NULL);
+	if (!img) {
+		tool_err(-1, "failed to open override image: %s", lbx_errmsg());
+		return -1;
 	}
 
-	png_destroy_write_struct(&png, &info);
-	fclose(of);
-
-	if (verbose)
-		printf("wrote %s\n", name);
-
-	return 0;
+	rc = lbx_img_getpalette(img, palette);
+	if (rc < 0) {
+		tool_err(-1, "error reading override palette: %s", lbx_errmsg());
+		ret = -1;
+	} else if (rc == 0) {
+		tool_err(-1, "override image has no palette.");
+		ret = -1;
+	}
 
-err:
-	fclose(of);
-	remove(name);
-	free(row);
-	return -1;
+	lbx_img_close(img);
+	return ret;
 }
 
-static int loadoverride(FILE *f, struct lbx_colour palette[static 256])
+static int loadpalette(struct lbx_image *img, FILE *palf, FILE *override,
+                       struct lbx_colour *palette)
 {
-	LBX_IMG *overimg = lbximg_fopen(f);
-	struct lbx_imginfo info;
+	int rc, ret = -1;
 
-	if (!overimg) {
-		errmsg("failed to open override image: %s\n", lbx_strerror());
-		return -1;
+	/* Default the palette to a wonderful pink. */
+	for (unsigned i = 0; i < 256; i++) {
+		palette[i] = (struct lbx_colour){0x3f, 0x00, 0x3f};
 	}
-	lbximg_getinfo(overimg, &info);
 
-	if (!info.palettesz) {
-		errmsg("override image has no palette.\n", 0);
-		lbximg_close(overimg);
-		return -1;
+	/* Read the external palette, if any. */
+	if (palf) {
+		rc = lbx_img_loadpalette(palf, &lbx_default_fops, palette);
+		if (rc < 0) {
+			tool_err(-1, "error reading external palette: %s", lbx_errmsg());
+			return -1;
+		}
+
+		ret = 0;
 	}
 
-	if (lbximg_getpalette(overimg, palette) == -1) {
-		errmsg("error reading override palette: %s\n", lbx_strerror());
-		lbximg_close(overimg);
+	/* Read the embedded palette */
+	rc = lbx_img_getpalette(img, palette);
+	if (rc < 0) {
+		tool_err(-1, "error reading embedded palette: %s", lbx_errmsg());
 		return -1;
+	} else if (rc > 0) {
+		ret = 0;
 	}
 
-	lbximg_close(overimg);
-	return 0;
+	/* Read the override palette, if any. */
+	if (override) {
+		rc = loadoverride(override, palette);
+		if (rc < 0)
+			return -1;
+		ret = 0;
+	}
+
+	/* If we literally have no palette data at all, may as well fail. */
+	if (ret < 0)
+		tool_err(-1, "no palette available.");
+	return ret;
 }
 
-static int loadpalette(LBX_IMG *img, struct lbx_imginfo *info,
-                       FILE *palf, FILE *override,
-                       struct lbx_colour palette[static 256])
+/* Return true iff a divides b. */
+static bool divides(unsigned a, unsigned b)
 {
-	int i;
+	if (b == 0)
+		return true;
+	if (a == 0)
+		return false;
 
-	/* In no-palette mode, use palette indices for colour. */
-	if (!usepalette) {
-		for (i = 0; i < 256; i++) {
-			palette[i] = (struct lbx_colour){i,i,i};
-		}
+	return b % a == 0;
+}
 
-		return 0;
-	}
+/* Set n bits starting from offset in the bitmap. */
+static void
+set_bits(unsigned char *bitmap, unsigned long offset, unsigned long n)
+{
+	if (offset % CHAR_BIT) {
+		bitmap[offset/CHAR_BIT] |= (n >= CHAR_BIT ? -1u : (1u << n) - 1)
+	                          << offset%CHAR_BIT;
 
-	/* For sanity. */
-	if (!palf && !info->palettesz && !override) {
-		errmsg("no palette available.\n", 0);
-		return -1;
+		n -= MIN(n, CHAR_BIT - offset%CHAR_BIT);
+		offset += CHAR_BIT - offset%CHAR_BIT;
 	}
 
-	/* Default the palette to a wonderful pink. */
-	for (i = 0; i < 256; i++) {
-		palette[i] = (struct lbx_colour){0xff, 0x00, 0xff};
+	if (n > CHAR_BIT) {
+		memset(&bitmap[offset/CHAR_BIT], -1, n/CHAR_BIT);
+
+		offset += n - n%CHAR_BIT;
+		n %= CHAR_BIT;
 	}
 
-	/* Read the external palette, if any. */
-	if (palf && lbximg_loadpalette(palf, palette) == -1) {
-		errmsg("error reading external palette: %s\n", lbx_strerror());
-		return -1;
+	if (n) {
+		bitmap[offset/CHAR_BIT] |= (1u << n) - 1;
 	}
+}
+
+static int decode_frame(struct lbx_image *img, unsigned n,
+                        unsigned char *pixels, unsigned char *pixel_mask)
+{
+	unsigned x, y;
+	long rc;
 
-	/* Read the embedded palette, if any. */
-	if (info->palettesz && lbximg_getpalette(img, palette) == -1) {
-		errmsg("error reading embedded palette: %s\n", lbx_strerror());
+	rc = lbx_img_seek(img, n);
+	if (rc < 0) {
+		tool_err(-1, "frame %u: invalid frame: %s\n", n, lbx_errmsg());
 		return -1;
 	}
 
-	/* Read the override palette, if any. */
-	if (override && loadoverride(override, palette) == -1) {
-		return -1;
+	while ((rc = lbx_img_read_row_header(img, &x, &y)) != 0) {
+		unsigned long offset;
+
+		if (rc < 0) {
+			tool_err(-1, "frame %u: invalid row: %s", n, lbx_errmsg());
+			return -1;
+		}
+
+		offset = (unsigned long) y * img->width + x;
+		rc = lbx_img_read_row_data(img, pixels+offset);
+		if (rc < 0) {
+			tool_err(-1, "frame %u: error reading row: %s\n", n, lbx_errmsg());
+			return -1;
+		}
+
+		set_bits(pixel_mask, offset, rc);
 	}
 
 	return 0;
 }
 
-int decode(LBX_IMG *img, FILE *palf, FILE *override, char **argv)
+static int
+decode(struct lbx_image *img, FILE *palf, FILE *override, int fmt, char **argv)
 {
-	unsigned char *framebits;
+	unsigned char *pixels = NULL, *pixel_mask = NULL, *framebits = NULL;
 	struct lbx_colour palette[256];
-	struct lbx_imginfo info;
+	int rc, ret = EXIT_FAILURE;
 	int extracted = 0;
 	unsigned int i;
+	size_t npixels, mask_sz;
+
+	assert(fmt >= 0 && fmt < sizeof formats / sizeof formats[0]);
 
-	lbximg_getinfo(img, &info);
+	npixels = img->width;
+	if (img->height && npixels >= (size_t)-1 / img->height) {
+		tool_err(-1, "image too large");
+		goto err;
+	}
+	npixels *= img->height;
+
+	/* Ensure there is at least 1 byte to allocate */
+	if (npixels == 0)
+		npixels = 1;
 
-	framebits = malloc(info.nframes / CHAR_BIT + 1);
+	framebits = calloc(1, img->frames / CHAR_BIT + 1);
 	if (!framebits) {
-		return EXIT_FAILURE;
+		tool_err(0, "failed to allocate memory");
+		goto err;
+	}
+
+	pixels = calloc(img->width, img->height);
+	if (!pixels) {
+		tool_err(0, "failed to allocate memory");
+		goto err;
+	}
+
+	mask_sz = npixels / CHAR_BIT + (npixels % CHAR_BIT != 0);
+	pixel_mask = malloc(mask_sz);
+	if (!pixel_mask) {
+		tool_err(0, "failed to allocate memory");
+		goto err;
 	}
 
 	/* Figure out what images we're extracting. */
 	if (!argv[0]) {
 		/* extract all images by default. */
-		memset(framebits, -1, info.nframes / CHAR_BIT + 1);
+		memset(framebits, -1, img->frames / CHAR_BIT + 1);
 	} else {
 		for (i = 0; argv[i]; i++) {
-			parserange(&info, argv[i], framebits);
+			parserange(img->frames, argv[i], framebits);
 		}
 	}
 
-	if (loadpalette(img, &info, palf, override, palette) == -1) {
-		goto err;
+	if (usepalette) {
+		if (loadpalette(img, palf, override, palette) == -1) {
+			ret = EXIT_FAILURE;
+			goto err;
+		}
 	}
 
 	/* Extract the images, in order. */
-	for (i = 0; i < info.nframes; i++) {
-		unsigned char **data;
-		unsigned char **mask;
-
-		if (!(framebits[i / CHAR_BIT] & (1 << (i % CHAR_BIT))))
-			continue;
-
-		data = lbximg_getframe(img, i);
-		if (!data) {
-			errmsg("error in frame %u: %s\n", i, lbx_strerror());
-			continue;
+	ret = EXIT_SUCCESS;
+	for (i = 0; i < img->frames; i++) {
+		if (divides(img->chunk, i))
+			memset(pixel_mask, 0, mask_sz);
+
+		rc = decode_frame(img, i, pixels, pixel_mask);
+		if (rc < 0) {
+			ret = EXIT_FAILURE;
+			goto err;
 		}
 
-		mask = lbximg_getmask(img);
+		if (framebits[i / CHAR_BIT] & (1u << (i % CHAR_BIT))) {
+			rc = output(i, &formats[fmt], pixels, pixel_mask,
+			            img->width, img->height,
+				    usepalette ? palette : NULL);
 
-		if (!outpng(i, data, mask, info.width, info.height, palette)) {
-			extracted = 1;
+			if (rc == 0) {
+				extracted = 1;
+			}
 		}
 	}
 
 	if (!extracted) {
-		errmsg("no frames extracted.\n", 0);
-		goto err;
+		tool_err(-1, "no frames extracted.");
+		ret = EXIT_FAILURE;
 	}
-
-	free(framebits);
-	return EXIT_SUCCESS;
 err:
+	free(pixels);
+	free(pixel_mask);
 	free(framebits);
-	return EXIT_FAILURE;
+	return ret;
 }
 
 int main(int argc, char **argv)
 {
-	int mode = MODE_NONE;
-	FILE *inf = stdin, *palf = NULL, *overf = NULL;
-	const char *name = "stdin";
-	LBX_IMG *img;
-	int opt;
-
-	static const char *sopts = "idvf:p:O:V";
-	static const struct option lopts[] = {
-		{ "ident",    0, NULL, 'i' },
-		{ "decode",   0, NULL, 'd' },
-		{ "verbose",  0, NULL, 'v' },
-		{ "file",     1, NULL, 'f' },
-		{ "palette",  1, NULL, 'p' },
-		{ "override", 1, NULL, 'p' },
-
-		{ "version",  0, NULL, 'V' },
-		{ "usage",    0, NULL, 'U' },
-		{ "help",     0, NULL, 'H' },
-
-		{ "nopalette", 0, &usepalette, 0 },
-
-		{ 0 }
-	};
-
-	progname = "lbximg"; /* argv[0]; */
+	int mode = MODE_NONE, fmt, opt, rc = EXIT_FAILURE;
+	struct lbx_pipe_state stdin_handle = { .f = stdin };
+	const char *file = NULL, *fmtstring = NULL;
+	const char *ext_palette = NULL, *ovr_palette = NULL;
+	FILE *palf = NULL, *overf = NULL;
+	struct lbx_image *img;
+
+	tool_init("lbximg", argc, argv);
 	while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {
 		switch(opt) {
 		case 'i':
@@ -401,79 +477,97 @@ int main(int argc, char **argv)
 		case 'v':
 			verbose = 1;
 			break;
+		case 'F':
+			fmtstring = optarg;
+			break;
 		case 'f':
-			if (strcmp(optarg, "-") == 0)
-				break;
-
-			name = strrchr(optarg, '/');
-			name = name ? name+1 : optarg;
-
-			inf = fopen(optarg, "rb");
-			if (!inf) {
-				errmsg("failed to open %s: %m\n", optarg);
-				return EXIT_FAILURE;
-			}
+			file = optarg;
+			break;
+		case 'n':
+			usepalette = 0;
 			break;
 		case 'p':
-			palf = fopen(optarg, "rb");
-			if (!palf) {
-				errmsg("failed to open %s: %m\n", optarg);
-				return EXIT_FAILURE;
-			}
+			ext_palette = optarg;
 
 			break;
 		case 'O':
-			overf = fopen(optarg, "rb");
-			if (!overf) {
-				errmsg("failed to open %s: %m\n", optarg);
-				return EXIT_FAILURE;
-			}
+			ovr_palette = optarg;
+			break;
+		case LOPT_OUTPUT_PREFIX:
+			outname = optarg;
 			break;
 		case 'V':
-			puts(VERSION_BOILERPLATE("lbximg"));
-			return EXIT_SUCCESS;
-		case 'U':
-			printusage();
+			tool_version();
 			return EXIT_SUCCESS;
 		case 'H':
-			printhelp();
+			print_help();
 			return EXIT_SUCCESS;
-		case '?':
-		case ':':
+		default:
 			return EXIT_FAILURE;
 		}
 	}
 
 	if (mode == MODE_NONE) {
-		errmsg("you must specify a mode.\n", 0);
+		tool_err(-1, "you must specify a mode.");
 		return EXIT_FAILURE;
 	}
 
-	img = lbximg_fopen(inf);
+	fmt = lookup_format(fmtstring);
+	if (fmt < 0)
+		return EXIT_FAILURE;
+
+	if (file)
+		img = lbx_img_fopen(file);
+	else
+		img = lbx_img_open(&stdin_handle, &lbx_pipe_fops, NULL);
+
 	if (!img) {
-		errmsg("failed to open image: %s.\n", lbx_strerror());
+		tool_err(-1, "failed to open image: %s.", lbx_errmsg());
+		return EXIT_FAILURE;
+	}
+
+	if (ext_palette && !(palf = fopen(ext_palette, "rb"))) {
+		tool_err(0, "failed to open %s", optarg);
+		return EXIT_FAILURE;
+	}
+
+	if (ovr_palette && !(overf = fopen(ovr_palette, "rb"))) {
+		tool_err(0, "failed to open %s", optarg);
 		return EXIT_FAILURE;
 	}
 
 	if (verbose || mode == MODE_IDENT) {
-		struct lbx_imginfo info;
-		lbximg_getinfo(img, &info);
+		int palette_count;
+
+		if (!file)
+			file = "stdin";
 
-		printf("%s is %ux%u LBX image, %u frame(s)%s%s\n",
-		       name, info.width, info.height, info.nframes,
-		       info.palettesz ? ", embedded palette" : "",
-		       info.looping   ? ", loops" : "");
+		palette_count = lbx_img_getpalette(img, NULL);
+		if (palette_count < 0) {
+			tool_err(-1, "error reading image: %s", lbx_errmsg());
+			return EXIT_FAILURE;
+		}
+
+		printf("%s is %hux%hu LBX image, %hhu frame(s)%s%s%s\n",
+		       file, img->width, img->height, img->frames,
+		       palette_count ? ", embedded palette" : "",
+		       img->chunk    ? ", chunked" : "",
+		       img->leadin+1 < img->frames ? ", loops" : "");
 	}
 
 	switch (mode) {
+	case MODE_IDENT:
+		rc = 0;
+		break;
 	case MODE_DECODE:
-		if (decode(img, palf, overf, &argv[optind])) {
-			lbximg_close(img);
-			return EXIT_FAILURE;
-		}
+		rc = decode(img, palf, overf, fmt, &argv[optind]);
 		break;
 	}
 
-	lbximg_close(img);
-	return EXIT_SUCCESS;
+	lbx_img_close(img);
+	if (palf)
+		fclose(palf);
+	if (overf)
+		fclose(overf);
+	return rc;
 }