pnm_enc.c

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

	/* Initialize the header. */
	if (enc->numcmpts == 1) {
		hdr.magic = encopts.bin ? PNM_MAGIC_BINPGM : PNM_MAGIC_TXTPGM;
	} else if (enc->numcmpts == 3) {
		hdr.magic = encopts.bin ? PNM_MAGIC_BINPPM : PNM_MAGIC_TXTPPM;
	} else {
		return -1;
	}
	hdr.width = width;
	hdr.height = height;
	hdr.maxval = (1 << prec) - 1;
	hdr.sgnd = sgnd;

	/* Write the header. */
	if (pnm_puthdr(out, &hdr)) {
		return -1;
	}

	/* Write the image data. */
	if (pnm_putdata(out, &hdr, image, enc->numcmpts, enc->cmpts)) {
		return -1;
	}

	/* Flush the output stream. */
	if (jas_stream_flush(out)) {
		return -1;
	}

	return 0;
}

/******************************************************************************\
* Code for parsing options.
\******************************************************************************/

/* Parse the encoder options string. */
static int pnm_parseencopts(char *optstr, pnm_encopts_t *encopts)
{
	jas_tvparser_t *tvp;
	int ret;

	tvp = 0;

	/* Initialize default values for encoder options. */
	encopts->bin = true;

	/* Create the tag-value parser. */
	if (!(tvp = jas_tvparser_create(optstr ? optstr : ""))) {
		goto error;
	}

	/* Get tag-value pairs, and process as necessary. */
	while (!(ret = jas_tvparser_next(tvp))) {
		switch (jas_taginfo_nonull(jas_taginfos_lookup(pnm_opttab,
		  jas_tvparser_gettag(tvp)))->id) {
		case OPT_TEXT:
			encopts->bin = false;
			break;
		default:
			fprintf(stderr, "warning: ignoring invalid option %s\n",
			  jas_tvparser_gettag(tvp));
			break;
		}	
	}
	if (ret < 0) {
		goto error;
	}

	/* Destroy the tag-value parser. */
	jas_tvparser_destroy(tvp);

	return 0;

error:
	if (tvp) {
		jas_tvparser_destroy(tvp);
	}
	return -1;
}

/******************************************************************************\
* Function for writing header.
\******************************************************************************/

/* Write the header. */
static int pnm_puthdr(jas_stream_t *out, pnm_hdr_t *hdr)
{
	int_fast32_t maxval;

	if (pnm_putuint16(out, hdr->magic)) {
		return -1;
	}
	if (hdr->sgnd) {
		maxval = -hdr->maxval;
	} else {
		maxval = hdr->maxval;
	}
	jas_stream_printf(out, "\n%lu %lu\n%ld\n", (unsigned long) hdr->width,
	  (unsigned long) hdr->height, (long) maxval);
	if (jas_stream_error(out)) {
		return -1;
	}
	return 0;
}

/******************************************************************************\
* Functions for processing the sample data.
\******************************************************************************/

/* Write the image sample data. */
static int pnm_putdata(jas_stream_t *out, pnm_hdr_t *hdr, jas_image_t *image, int numcmpts, int *cmpts)
{
	int ret;
	int cmptno;
	int x;
	int y;
	jas_matrix_t *data[3];
	int fmt;
	jas_seqent_t *d[3];
	jas_seqent_t v;
	int minval;
	int linelen;
	int n;
	char buf[256];
	int depth;

	ret = -1;
	fmt = pnm_fmt(hdr->magic);
	minval = -((int) hdr->maxval + 1);
	depth = pnm_maxvaltodepth(hdr->maxval);

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

	for (y = 0; y < hdr->height; ++y) {
		for (cmptno = 0; cmptno < numcmpts; ++cmptno) {
			if (jas_image_readcmpt(image, cmpts[cmptno], 0, y, hdr->width, 1,
			  data[cmptno])) {
				goto done;
			}
			d[cmptno] = jas_matrix_getref(data[cmptno], 0, 0);
		}
		linelen = 0;
		for (x = 0; x < hdr->width; ++x) {
			for (cmptno = 0; cmptno < numcmpts; ++cmptno) {
				v = *d[cmptno];
				if (v < minval) {
					v = minval;
				}
				if (v > ((int) hdr->maxval)) {
					v = hdr->maxval;
				}
				if (fmt == PNM_FMT_BIN) {
					if (hdr->sgnd) {
						int_fast32_t sv;
						sv = v;
						if (pnm_putsint(out, depth, &sv)) {
							goto done;
						}
					} else {
						uint_fast32_t uv;
						uv = v;
						if (pnm_putuint(out, depth, &uv)) {
							goto done;
						}
					}
				} else {
					n = sprintf(buf, "%s%ld", ((!(!x && !cmptno)) ? " " : ""),
					  (long) v);
					if (linelen > 0 && linelen + n > PNM_MAXLINELEN) {
						jas_stream_printf(out, "\n");
						linelen = 0;
					}
					jas_stream_printf(out, "%s", buf);
					linelen += n;
				}
				++d[cmptno];
			}
		}
		if (fmt != PNM_FMT_BIN) {
			jas_stream_printf(out, "\n");
			linelen = 0;
		}
		if (jas_stream_error(out)) {
			goto done;
		}
	}

	ret = 0;

done:

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

	return ret;
}

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

static int pnm_putsint(jas_stream_t *out, int wordsize, int_fast32_t *val)
{
	uint_fast32_t tmpval;
	tmpval = (*val < 0) ?
	  ((~(JAS_CAST(uint_fast32_t, -(*val)) + 1)) & PNM_ONES(wordsize)) :
	  JAS_CAST(uint_fast32_t, (*val));
	return pnm_putuint(out, wordsize, &tmpval);
}

static int pnm_putuint(jas_stream_t *out, int wordsize, uint_fast32_t *val)
{
	int n;
	uint_fast32_t tmpval;
	int c;

	n = (wordsize + 7) / 8;
	tmpval &= PNM_ONES(8 * n);
	tmpval = (*val) << (8 * (4 - n));
	while (--n >= 0) {
		c = (tmpval >> 24) & 0xff;
		if (jas_stream_putc(out, c) == EOF) {
			return -1;
		}
		tmpval = (tmpval << 8) & 0xffffffff;
	}
	return 0;
}

/* Write a 16-bit unsigned integer to a stream. */
static int pnm_putuint16(jas_stream_t *out, uint_fast16_t val)
{
	if (jas_stream_putc(out, (unsigned char)(val >> 8)) == EOF ||
	  jas_stream_putc(out, (unsigned char)(val & 0xff)) == EOF) {
		return -1;
	}
	return 0;
}