pnm_dec.c

DIGITAL IMAGERY is pervasive in our world today. Consequently, standards for the efficient represen

	int_fast64_t v;
	int depth;
	int type;
	int c;
	int n;

	ret = -1;

#if 0
	numcmpts = jas_image_numcmpts(image);
#endif
	fmt = pnm_fmt(hdr->magic);
	type = pnm_type(hdr->magic);
	depth = pnm_maxvaltodepth(hdr->maxval);

	data[0] = 0;
	data[1] = 0;
	data[2] = 0;
	for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
		if (!(data[cmptno] = jas_matrix_create(1, hdr->width))) {
			goto done;
		}
	}

	for (y = 0; y < hdr->height; ++y) {
		if (type == PNM_TYPE_PBM) {
			if (fmt == PNM_FMT_BIN) {
				for (x = 0; x < hdr->width;) {
					if ((c = jas_stream_getc(in)) == EOF) {
						goto done;
					}
					n = 8;
					while (n > 0 && x < hdr->width) {
						jas_matrix_set(data[0], 0, x, 1 - ((c >> 7) & 1));
						c <<= 1;
						--n;
						++x;
					}
				}
			} else {
				for (x = 0; x < hdr->width; ++x) {
					int uv;
					if (pnm_getbitstr(in, &uv)) {
						goto done;
					}
					jas_matrix_set(data[0], 0, x, 1 - uv);
				}
			}
		} else {
			for (x = 0; x < hdr->width; ++x) {
				for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
					if (fmt == PNM_FMT_BIN) {
						/* The sample data is in binary format. */
						if (hdr->sgnd) {
							/* The sample data is signed. */
							int_fast32_t sv;
							if (pnm_getsint(in, depth, &sv)) {
								if (!pnm_allowtrunc) {
									goto done;
								}
								sv = 0;
							}
							v = sv;
						} else {
							/* The sample data is unsigned. */
							uint_fast32_t uv;
							if (pnm_getuint(in, depth, &uv)) {
								if (!pnm_allowtrunc) {
									goto done;
								}
								uv = 0;
							}
							v = uv;
						}
					} else {
						/* The sample data is in text format. */
						if (hdr->sgnd) {
							/* The sample data is signed. */
							int_fast32_t sv;
							if (pnm_getsintstr(in, &sv)) {
								if (!pnm_allowtrunc) {
									goto done;
								}
								sv = 0;
							}
							v = sv;
						} else {
							/* The sample data is unsigned. */
							uint_fast32_t uv;
							if (pnm_getuintstr(in, &uv)) {
								if (!pnm_allowtrunc) {
									goto done;
								}
								uv = 0;
							}
							v = uv;
						}
					}
					jas_matrix_set(data[cmptno], 0, x, v);
				}
			}
		}
		for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
			if (jas_image_writecmpt(image, cmptno, 0, y, hdr->width, 1,
			  data[cmptno])) {
				goto done;
			}
		}
	}

	ret = 0;

done:

	for (cmptno = 0; cmptno < hdr->numcmpts; ++cmptno) {
		if (data[cmptno]) {
			jas_matrix_destroy(data[cmptno]);
		}
	}

	return ret;
}

/******************************************************************************\
* Miscellaneous functions.
\******************************************************************************/

static int pnm_getsint(jas_stream_t *in, int wordsize, int_fast32_t *val)
{
	uint_fast32_t tmpval;

	if (pnm_getuint(in, wordsize, &tmpval)) {
		return -1;
	}
	if (val) {
		assert((tmpval & (1 << (wordsize - 1))) == 0);
		*val = tmpval;
	}

	return 0;
}

static int pnm_getuint(jas_stream_t *in, int wordsize, uint_fast32_t *val)
{
	uint_fast32_t tmpval;
	int c;
	int n;

	tmpval = 0;
	n = (wordsize + 7) / 8;
	while (--n >= 0) {
		if ((c = jas_stream_getc(in)) == EOF) {
			return -1;
		}
		tmpval = (tmpval << 8) | c;
	}
	tmpval &= (((uint_fast64_t) 1) << wordsize) - 1;
	if (val) {
		*val = tmpval;
	}

	return 0;
}

static int pnm_getbitstr(jas_stream_t *in, int *val)
{
	int c;
	int_fast32_t v;
	for (;;) {
		if ((c = pnm_getc(in)) == EOF) {
			return -1;
		}
		if (c == '#') {
			for (;;) {
				if ((c = pnm_getc(in)) == EOF) {
					return -1;
				}
				if (c == '\n') {
					break;
				}
			}
		} else if (c == '0' || c == '1') {
			v = c - '0';
			break;
		}
	}
	if (val) {
		*val = v;
	}
	return 0;
}

static int pnm_getuintstr(jas_stream_t *in, uint_fast32_t *val)
{
	uint_fast32_t v;
	int c;

	/* Discard any leading whitespace. */
	do {
		if ((c = pnm_getc(in)) == EOF) {
			return -1;
		}
	} while (isspace(c));

	/* Parse the number. */
	v = 0;
	while (isdigit(c)) {
		v = 10 * v + c - '0';
		if ((c = pnm_getc(in)) < 0) {
			return -1;
		}
	}

	/* The number must be followed by whitespace. */
	if (!isspace(c)) {
		return -1;
	}

	if (val) {
		*val = v;
	}
	return 0;
}

static int pnm_getsintstr(jas_stream_t *in, int_fast32_t *val)
{
	int c;
	int s;
	int_fast32_t v;

	/* Discard any leading whitespace. */
	do {
		if ((c = pnm_getc(in)) == EOF) {
			return -1;
		}
	} while (isspace(c));

	/* Get the number, allowing for a negative sign. */
	s = 1;
	if (c == '-') {
		s = -1;
		if ((c = pnm_getc(in)) == EOF) {
			return -1;
		}
	} else if (c == '+') {
		if ((c = pnm_getc(in)) == EOF) {
			return -1;
		}
	}
	v = 0;
	while (isdigit(c)) {
		v = 10 * v + c - '0';
		if ((c = pnm_getc(in)) < 0) {
			return -1;
		}
	}

	/* The number must be followed by whitespace. */
	if (!isspace(c)) {
		return -1;
	}

	if (val) {
		*val = (s >= 0) ? v : (-v);
	}

	return 0;
}

static int pnm_getc(jas_stream_t *in)
{
	int c;
	for (;;) {
		if ((c = jas_stream_getc(in)) == EOF) {
			return -1;
		}
		if (c != '#') {
			return c;
		}
		do {
			if ((c = jas_stream_getc(in)) == EOF) {
				return -1;
			}
		} while (c != '\n' && c != '\r');
	}
}

static int pnm_getint16(jas_stream_t *in, int *val)
{
	int v;
	int c;

	if ((c = jas_stream_getc(in)) == EOF) {
		return -1;
	}
	v = c & 0xff;
	if ((c = jas_stream_getc(in)) == EOF) {
		return -1;
	}
	v = (v << 8) | (c & 0xff);
	*val = v;

	return 0;
}