1 files changed, 463 insertions, 0 deletions
diff --git a/filter/faxd.c b/filter/faxd.c
new file mode 100644
index 00000000..1b86c17b
--- /dev/null
+++ b/filter/faxd.c
@@ -0,0 +1,463 @@
+#include <fitz.h>
+
+#include "faxd.h"
+#include "faxc.h"
+
+enum
+{
+	SNORMAL,	/* neutral state, waiting for any code */
+	SMAKEUP,	/* got a 1d makeup code, waiting for terminating code */
+	SEOL,		/* at eol, needs output buffer space */
+	SH1, SH2	/* in H part 1 and 2 (both makeup and terminating codes) */
+};
+
+#define DEBUG 1
+
+#ifdef noDEBUG
+#define DPRINT(...) fprintf(stderr, __VA_ARGS__)
+#else
+#define DPRINT(...)
+#endif
+
+/* TODO: uncompressed */
+
+typedef struct fz_faxd_s fz_faxd;
+
+struct fz_faxd_s
+{
+	fz_filter super;
+	
+	int k;
+	int endofline;
+	int encodedbytealign;
+	int columns;
+	int rows;
+	int endofblock;
+	int blackis1;
+
+	int stride;
+	int ridx;
+
+	int bidx;
+	unsigned int word;
+
+	int stage, a, c, dim, eolc;
+	unsigned char *ref;
+	unsigned char *dst;
+};
+
+fz_error *
+fz_newfaxd(fz_filter **fp, fz_obj *params)
+{
+	fz_obj *obj;
+
+	FZ_NEWFILTER(fz_faxd, fax, faxd);
+
+	fax->ref = nil;
+	fax->dst = nil;
+
+	fax->k = 0;
+	fax->endofline = 0;
+	fax->encodedbytealign = 0;
+	fax->columns = 1728;
+	fax->rows = 0;
+	fax->endofblock = 1;
+	fax->blackis1 = 0;
+
+	obj = fz_dictgets(params, "K");
+	if (obj) fax->k = fz_toint(obj);
+
+	obj = fz_dictgets(params, "EndOfLine");
+	if (obj) fax->endofline = fz_tobool(obj);
+
+	obj = fz_dictgets(params, "EncodedByteAlign");
+	if (obj) fax->encodedbytealign = fz_tobool(obj);
+
+	obj = fz_dictgets(params, "Columns");
+	if (obj) fax->columns = fz_toint(obj);
+
+	obj = fz_dictgets(params, "Rows");
+	if (obj) fax->rows = fz_toint(obj);
+
+	obj = fz_dictgets(params, "EndOfBlock");
+	if (obj) fax->endofblock = fz_tobool(obj);
+
+	obj = fz_dictgets(params, "BlackIs1");
+	if (obj) fax->blackis1 = fz_tobool(obj);
+
+	fax->stride = ((fax->columns - 1) >> 3) + 1;
+	fax->ridx = 0;
+	fax->bidx = 32;
+	fax->word = 0;
+
+	fax->stage = SNORMAL;
+	fax->a = -1;
+	fax->c = 0;
+	fax->dim = fax->k < 0 ? 2 : 1;
+	fax->eolc = 0;
+
+	fax->ref = fz_malloc(fax->stride);
+	if (!fax->ref) { fz_free(fax); return fz_outofmem; }
+
+	fax->dst = fz_malloc(fax->stride);
+	if (!fax->dst) { fz_free(fax); fz_free(fax->ref); return fz_outofmem; }
+
+	memset(fax->ref, 0, fax->stride);
+	memset(fax->dst, 0, fax->stride);
+
+	DPRINT("FAXD k=%d eol=%d eba=%d cols=%d rows=%d eob=%d black1=%d stride=%d\n",
+		fax->k, fax->endofline, fax->encodedbytealign,
+		fax->columns, fax->rows, fax->endofblock, fax->blackis1,
+		fax->stride);
+
+	return nil;
+}
+
+void
+fz_freefaxd(fz_filter *p)
+{
+	fz_faxd *fax = (fz_faxd*) p;
+	fz_free(fax->ref);
+	fz_free(fax->dst);
+	fz_free(fax);
+}
+
+static inline void eatbits(fz_faxd *fax, int nbits)
+{
+	fax->word <<= nbits;
+	fax->bidx += nbits;
+}
+
+static inline fz_error * fillbits(fz_faxd *fax, fz_buffer *in)
+{
+	while (fax->bidx >= 8)
+	{
+		if (in->rp + 1 > in->wp)
+			return fz_ioneedin;
+		fax->bidx -= 8;
+		fax->word |= *in->rp << fax->bidx;
+		in->rp ++;
+	}
+	return nil;
+}
+
+static int
+getcode(fz_faxd *fax, const cfd_node *table, int initialbits)
+{
+	unsigned int word = fax->word;
+	int tidx = word >> (32 - initialbits);
+	int val = table[tidx].val;
+	int nbits = table[tidx].nbits;
+
+	if (nbits > initialbits)
+	{
+		int mask = (1 << (32 - initialbits)) - 1;
+		tidx = val + ((word & mask) >> (32 - nbits));
+		val = table[tidx].val;
+		nbits = initialbits + table[tidx].nbits;
+	}
+
+	eatbits(fax, nbits);
+
+	return val;
+}
+
+/* decode one 1d code */
+static fz_error *
+dec1d(fz_faxd *fax)
+{
+	int code;
+
+	if (fax->a == -1)
+		fax->a = 0;
+
+	if (fax->c)
+		code = getcode(fax, cf_black_decode, cfd_black_initial_bits);
+	else
+		code = getcode(fax, cf_white_decode, cfd_white_initial_bits);
+
+	DPRINT("%c %d\n", fax->c?'b':'w', code);
+
+	if (code == UNCOMPRESSED)
+		return fz_throw("ioerror: uncompressed data in faxd");
+
+	if (code < 0)
+		return fz_throw("ioerror: invalid 1d code in faxd");
+
+	if (fax->a + code > fax->columns)
+		return fz_throw("ioerror: invalid 1d data in faxd");
+
+	if (fax->c)
+		setbits(fax->dst, fax->a, fax->a + code);
+
+	fax->a += code;
+
+	if (code < 64)
+	{
+		fax->c = !fax->c;
+		fax->stage = SNORMAL;
+	}
+	else
+		fax->stage = SMAKEUP;
+
+	return nil;
+}
+
+/* decode one 2d code */
+static fz_error *
+dec2d(fz_faxd *fax)
+{
+	int code, b1, b2;
+
+	if (fax->stage == SH1 || fax->stage == SH2)
+	{
+		if (fax->a == -1)
+			fax->a = 0;
+
+		if (fax->c)
+			code = getcode(fax, cf_black_decode, cfd_black_initial_bits);
+		else
+			code = getcode(fax, cf_white_decode, cfd_white_initial_bits);
+
+		DPRINT("%c %d\n", fax->c ? 'b' : 'w', code);
+
+		if (code == UNCOMPRESSED)
+			return fz_throw("ioerror: uncompressed data in faxd");
+
+		if (code < 0)
+			return fz_throw("ioerror: invalid 2d code in faxd");
+
+		if (fax->a + code > fax->columns)
+			return fz_throw("ioerror: invalid 2d data in faxd");
+
+		if (fax->c)
+			setbits(fax->dst, fax->a, fax->a + code);
+
+		fax->a += code;
+
+		if (code < 64)
+		{
+			fax->c = !fax->c;
+			if (fax->stage == SH1)
+				fax->stage = SH2;
+			else if (fax->stage == SH2)
+				fax->stage = SNORMAL;
+		}
+
+		return nil;
+	}
+
+	code = getcode(fax, cf_2d_decode, cfd_2d_initial_bits);
+
+	switch (code)
+	{
+		case H:
+			fax->stage = SH1;
+			DPRINT("H\n");
+			break;
+
+		case P:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			b2 = findchanging(fax->ref, b1, fax->columns);
+			DPRINT("P\n");
+			if (fax->c) setbits(fax->dst, fax->a, b2);
+			fax->a = b2;
+			break;
+
+		case V0:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("V0\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1);
+			fax->a = b1;
+			fax->c = !fax->c;
+			break;
+
+		case VR1:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("VR1\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1 + 1);
+			fax->a = b1 + 1;
+			fax->c = !fax->c;
+			break;
+
+		case VR2:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("VR2\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1 + 2);
+			fax->a = b1 + 2;
+			fax->c = !fax->c;
+			break;
+
+		case VR3:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("VR3\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1 + 3);
+			fax->a = b1 + 3;
+			fax->c = !fax->c;
+			break;
+
+		case VL1:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("VL1\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1 - 1);
+			fax->a = b1 - 1;
+			fax->c = !fax->c;
+			break;
+
+		case VL2:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("VL2\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1 - 2);
+			fax->a = b1 - 2;
+			fax->c = !fax->c;
+			break;
+
+		case VL3:
+			b1 = findchangingcolor(fax->ref, fax->a, fax->columns, !fax->c);
+			DPRINT("VL3\n");
+			if (fax->c) setbits(fax->dst, fax->a, b1 - 3);
+			fax->a = b1 - 3;
+			fax->c = !fax->c;
+			break;
+
+		case UNCOMPRESSED:
+			return fz_throw("ioerror: uncompressed data in faxd");
+
+		case ERROR:
+			return fz_throw("ioerror: invalid 2d code in faxd");
+
+		default:
+			return fz_throw("ioerror: invalid 2d code in faxd (%d)", code);
+	}
+
+	return 0;
+}
+
+fz_error *
+fz_processfaxd(fz_filter *f, fz_buffer *in, fz_buffer *out)
+{
+	fz_faxd *fax = (fz_faxd*)f;
+	fz_error * err;
+	int i;
+
+	if (fax->stage == SEOL)
+		goto eol;
+
+loop:
+
+	if (fillbits(fax, in))
+	{
+		if (in->eof) {
+			if (fax->bidx > 31) {
+				if (fax->a > 0)
+					goto eol;
+				goto rtc;
+			}
+		}
+		else {
+			return fz_ioneedin;
+		}
+	}
+
+	if ((fax->word >> (32 - 12)) == 0)
+	{
+		eatbits(fax, 1);
+		goto loop;
+	}
+
+	if ((fax->word >> (32 - 12)) == 1)
+	{
+		DPRINT("EOL\n");
+		eatbits(fax, 12);
+		fax->eolc ++;
+
+		if (fax->k > 0) {
+			if ((fax->word >> (32 - 1)) == 1)
+				fax->dim = 1;
+			else
+				fax->dim = 2;
+			eatbits(fax, 1);
+			DPRINT("DIM %d\n", fax->dim);
+		}
+	}
+	else if (fax->dim == 1)
+	{
+		fax->eolc = 0;
+		err = dec1d(fax);
+		if (err) return err;
+
+	}
+	else if (fax->dim == 2)
+	{
+		fax->eolc = 0;
+		err = dec2d(fax);
+		if (err) return err;
+	}
+
+	/* no eol check after makeup codes nor in the middle of an H code */
+	if (fax->stage == SMAKEUP || fax->stage == SH1 || fax->stage == SH2)
+		goto loop;
+
+	/* check for eol conditions */
+	if (fax->eolc || fax->a >= fax->columns)
+	{
+		if (fax->a > 0)
+			goto eol;
+		if (fax->eolc == (fax->k < 0 ? 2 : 6))
+			goto rtc;
+	}
+
+	goto loop;
+
+eol:
+	fax->stage = SEOL;
+	if (out->wp + fax->stride > out->ep)
+		return fz_ioneedout;
+
+	if (fax->blackis1)
+		memcpy(out->wp, fax->dst, fax->stride);
+	else
+		for (i = 0; i < fax->stride; i++)
+			out->wp[i] = ~fax->dst[i];
+
+	memcpy(fax->ref, fax->dst, fax->stride);
+	memset(fax->dst, 0, fax->stride);
+	out->wp += fax->stride;
+
+	fax->stage = SNORMAL;
+	fax->c = 0;
+	fax->a = -1;
+	fax->ridx ++;
+
+	if (!fax->endofblock && fax->rows) {
+		if (fax->ridx >= fax->rows)
+			goto rtc;
+	}
+
+	/* we have not read dim from eol, make a guess */
+	if (fax->k > 0 && !fax->eolc)
+	{
+		if (fax->ridx % fax->k == 0)
+			fax->dim = 1;
+		else
+			fax->dim = 2;
+	}
+
+	DPRINT("%dd scanline %d\n", fax->dim, fax->ridx + 1);
+
+	/* if endofline & encodedbytealign, EOLs are *not* optional */
+	if (fax->encodedbytealign) {
+		if (fax->endofline)
+			eatbits(fax, (12 - fax->bidx) & 7);
+		else
+			eatbits(fax, (8 - fax->bidx) & 7);
+	}
+
+	goto loop;
+
+rtc:
+	DPRINT("RTC\n");
+	out->eof = 1;
+	return fz_iodone;
+}
+