Add blind-extract-alpha

Signed-off-by: Mattias Andrée <maandree@kth.se>

3 files changed, 70 insertions, 0 deletions

diff --git a/src/blind-extract-alpha.c b/src/blind-extract-alpha.c
new file mode 100644
index 0000000..ac27724
--- /dev/null
+++ b/src/blind-extract-alpha.c
@@ -0,0 +1,62 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("colour-file")
+
+#define PROCESS(TYPE, SUFFIX)\
+	static void\
+	process_##SUFFIX(struct stream *stream, int fd, const char *fname)\
+	{\
+		char buf[sizeof(stream->buf)];\
+		size_t i, n;\
+		TYPE a;\
+		do {\
+			n = stream->ptr / stream->pixel_size;\
+			for (i = 0; i < n; i++) {\
+				a = ((TYPE *)(stream->buf))[4 * i + 3];\
+				((TYPE *)(stream->buf))[4 * i + 3] = 1;\
+				((TYPE *)buf)[4 * i + 0] = a;\
+				((TYPE *)buf)[4 * i + 1] = a;\
+				((TYPE *)buf)[4 * i + 2] = a;\
+				((TYPE *)buf)[4 * i + 3] = 1;\
+			}\
+			n *= stream->pixel_size;\
+			ewriteall(fd, stream->buf, n, fname);\
+			ewriteall(STDOUT_FILENO, buf, n, "<stdout>");\
+			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);\
+	}
+
+PROCESS(double, lf)
+PROCESS(float, f)
+
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	int fd;
+	void (*process)(struct stream *stream, int fd, const char *fname);
+
+	UNOFLAGS(argc != 1);
+
+	eopen_stream(&stream, NULL);
+	fd = eopen(argv[0], O_WRONLY | O_CREAT | O_TRUNC, 0666);
+
+	if (!strcmp(stream.pixfmt, "xyza"))
+		process = process_lf;
+	else if (!strcmp(stream.pixfmt, "xyza f"))
+		process = process_f;
+	else
+		eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt);
+
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+	if (dprint_stream_head(fd, &stream) < 0)
+		eprintf("dprintf %s:", argv[0]);
+
+	process(&stream, fd, argv[0]);
+	return 0;
+}
diff --git a/src/stream.c b/src/stream.c
index 6c9dc72..c21d269 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -123,6 +123,13 @@ fprint_stream_head(FILE *fp, struct stream *stream)
 }
 
 
+int
+dprint_stream_head(int fd, struct stream *stream)
+{
+	return DPRINTF_HEAD(fd, stream->frames, stream->width, stream->height, stream->pixfmt);
+}
+
+
 size_t
 enread_stream(int status, struct stream *stream, size_t n)
 {
diff --git a/src/stream.h b/src/stream.h
index d15ce8d..8733f43 100644
--- a/src/stream.h
+++ b/src/stream.h
@@ -88,6 +88,7 @@ void enopen_stream(int status, struct stream *stream, const char *file);
 int set_pixel_size(struct stream *stream);
 void enset_pixel_size(int status, struct stream *stream);
 void fprint_stream_head(FILE *fp, struct stream *stream);
+int dprint_stream_head(int fd, struct stream *stream);
 size_t enread_stream(int status, struct stream *stream, size_t n);
 void eninf_check_fd(int status, int fd, const char *file);
 void encheck_dimensions(int status, const struct stream *stream, enum dimension dimensions, const char *prefix);