1 files changed, 117 insertions, 0 deletions
diff --git a/src/blind-from-portable.c b/src/blind-from-portable.c
new file mode 100644
index 0000000..ccb902d
--- /dev/null
+++ b/src/blind-from-portable.c
@@ -0,0 +1,117 @@
+/* See LICENSE file for copyright and license details. */
+#include "stream.h"
+#include "util.h"
+
+#include <alloca.h>
+#include <math.h>
+#include <string.h>
+
+USAGE("[-s]")
+
+#define USING_BINARY32 0
+#define USING_BINARY64 0
+
+#define CONV(ITYPE, SITYPE, OTYPE, EXPONENT, HA2EXPONENT, FRACTION, SUFFIX)\
+	do {\
+		static int cache_i = 0;\
+		static ITYPE cache_in[] = {0, 0, 0, 0};\
+		static OTYPE cache_out[] = {0, 0, 0, 0};\
+		ITYPE exponent, fraction, signb;\
+		SITYPE sexponent;\
+		OTYPE ret, dexponent;\
+		if (portable == cache_in[cache_i]) {\
+			ret = cache_out[cache_i++];\
+			cache_i &= 3;\
+			return ret;\
+		}\
+		signb = portable >> (EXPONENT + FRACTION);\
+		exponent = (portable >> FRACTION) ^ (signb << EXPONENT);\
+		fraction = portable & (((ITYPE)1 << FRACTION) - 1);\
+		if (!exponent) {\
+			if (!fraction) {\
+				ret = (OTYPE)0.0;\
+			} else {\
+				sexponent = 1 - HA2EXPONENT - FRACTION;\
+				dexponent = (OTYPE)sexponent;\
+				ret = (ITYPE)fraction;\
+				ret *= pow##SUFFIX((OTYPE)2.0, dexponent);\
+			}\
+		} else if (exponent + 1 == (ITYPE)1 << EXPONENT) {\
+			ret = (OTYPE)(fraction ? NAN : INFINITY);\
+		} else {\
+			fraction |= (ITYPE)1 << FRACTION;\
+			sexponent = (SITYPE)exponent;\
+			sexponent -= HA2EXPONENT + FRACTION;\
+			dexponent = (OTYPE)sexponent;\
+			ret = (ITYPE)fraction;\
+			ret *= pow##SUFFIX((OTYPE)2.0, dexponent);\
+		}\
+		ret = signb ? -ret : ret;\
+		cache_out[cache_i++] = ret;\
+		cache_i &= 3;\
+		return ret;\
+	} while (0)
+
+#define PROCESS(ITYPE, OTYPE, BITS)\
+	do {\
+		size_t i, n;\
+		ITYPE *ibuf = (ITYPE *)(stream->buf);\
+		OTYPE *obuf = sizeof(ITYPE) == sizeof(OTYPE) ? (OTYPE *)(stream->buf)\
+			: alloca(sizeof(stream->buf) / sizeof(ITYPE) * sizeof(OTYPE));\
+		strict *= !USING_BINARY##BITS;\
+		if (!strict && sizeof(ITYPE) != sizeof(OTYPE))\
+			eprintf("-s is required on this machine\n");\
+		do {\
+			n = stream->ptr / sizeof(ITYPE);\
+			if (strict) {\
+				for (i = 0; i < n; i++)\
+					obuf[i] = conv_##OTYPE(le##BITS##toh(ibuf[i]));\
+			} else {\
+				for (i = 0; i < n; i++)\
+					obuf[i] = *(OTYPE *)&(ITYPE){le##BITS##toh(ibuf[i])};\
+			}\
+			ewriteall(STDOUT_FILENO, obuf, n * sizeof(OTYPE), "<stdout>");\
+			n *= sizeof(ITYPE);\
+			memmove(stream->buf, stream->buf + n, stream->ptr -= n);\
+		} while (eread_stream(stream, SIZE_MAX));\
+		if (stream->ptr)\
+			eprintf("%s: incomplete frame\n", stream->file);\
+	} while (0)
+
+static double conv_double(uint64_t portable) {CONV(uint64_t, int64_t, double, 11, 1023, 52,);}
+static float  conv_float (uint32_t portable) {CONV(uint32_t, int32_t, float, 8, 127, 23, f);}
+
+static void process_xyza (struct stream *stream, int strict) {PROCESS(uint64_t, double, 64);}
+static void process_xyzaf(struct stream *stream, int strict) {PROCESS(uint32_t, float, 32);}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	int strict = 0;
+	void (*process)(struct stream *stream, int strict);
+
+	ARGBEGIN {
+	case 's':
+		strict = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+	if (argc)
+		usage();
+
+	eopen_stream(&stream, NULL);
+
+	if (!strcmp(stream.pixfmt, "xyza"))
+		process = process_xyza;
+	else if (!strcmp(stream.pixfmt, "xyza f"))
+		process = process_xyzaf;
+	else
+		eprintf("pixel format %s is not supported\n", stream.pixfmt);
+
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+	process(&stream, strict);
+	return 0;
+}