Add vu-rewrite-head

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

1 files changed, 127 insertions, 0 deletions

diff --git a/src/vu-rewrite-head.c b/src/vu-rewrite-head.c
new file mode 100644
index 0000000..e7663c8
--- /dev/null
+++ b/src/vu-rewrite-head.c
@@ -0,0 +1,127 @@
+/* See LICENSE file for copyright and license details. */
+#include "stream.h"
+#include "util.h"
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+
+USAGE("[-h] file [(frames | 'auto') [(width | 'same') (height | 'same') [format | 'same']]]")
+
+static void
+rewrite(struct stream *stream, int frames_auto)
+{
+	char head[3 * sizeof(size_t) + 4 + sizeof(stream->pixfmt) + 6];
+	ssize_t headlen;
+	size_t frame_size, frame_count, length;
+	struct stat st;
+	char *data;
+
+	echeck_frame_size(stream->width, stream->height, stream->pixel_size, 0, stream->file);
+	frame_size = stream->width * stream->height * stream->pixel_size;
+
+	if (fstat(stream->fd, &st))
+		eprintf("fstat %s:", stream->file);
+	if (!S_ISREG(st.st_mode))
+		eprintf("%s: not a regular file\n", stream->file);
+
+	frame_count = (size_t)(st.st_size) / frame_size;
+	if (frame_count * frame_size != (size_t)(st.st_size))
+		eprintf("%s: given the select width and height, "
+			"the file has an incomplete frame\n", stream->file);
+	if (frames_auto)
+		stream->frames = frame_count;
+	else if (stream->frames != frame_count)
+		eprintf("%s: frame count mismatch\n", stream->file);
+
+	sprintf(head, "%zu %zu %zu %s\n%cuivf%zn",
+		stream->frames, stream->width, stream->height, stream->pixfmt, 0, &headlen);
+
+	length = stream->frames * frame_size;
+	if (length > (size_t)SSIZE_MAX || headlen > (size_t)SSIZE_MAX - length)
+		eprintf("%s: video is too long\n", stream->file);
+
+	if (headlen > stream->headlen)
+		if (ftruncate(stream->fd, length + headlen))
+			eprintf("ftruncate %s:", stream->file);
+
+	data = mmap(0, length + (size_t)headlen, PROT_READ | PROT_WRITE, MAP_PRIVATE, stream->fd, 0);
+	if (headlen != stream->headlen)
+		memmove(data + headlen, data + stream->headlen, length);
+	memcpy(data, head, (size_t)headlen);
+	munmap(data, length + (size_t)headlen);
+
+	if (headlen < stream->headlen)
+		if (ftruncate(stream->fd, length + headlen))
+			eprintf("ftruncate %s:", stream->file);
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	int headless = 0, frames_auto = 0;
+
+	ARGBEGIN {
+	case 'h':
+		headless = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+
+	if (headless) {
+		if (argc != 5)
+			eprintf("all positional arguments are mandatory unless -h is used\n");
+	} else if (argc != 1 || argc != 2 || argc != 4 || argc != 5) {
+		usage();
+	}
+
+
+	memset(&stream, 0, sizeof(stream));
+	stream.file = argv[0];
+	stream.fd = eopen(stream.file, O_RDWR);
+	if (!headless)
+		einit_stream(&stream);
+
+
+	if (argc < 2 || !strcmp(argv[1], "auto"))
+		frames_auto = 1;
+	else
+		stream.frames = etozu_arg("the frame count", argv[1], 0, SIZE_MAX);
+
+	if (argc < 4);
+	else if (strcmp(argv[2], "same"))
+		stream.width = etozu_arg("the width",  argv[2], 1, SIZE_MAX);
+	else if (headless)
+		eprintf("cannot use both 'same' and -h\n");
+
+	if (argc < 4);
+	else if (strcmp(argv[3], "same"))
+		stream.height = etozu_arg("the height", argv[3], 1, SIZE_MAX);
+	else if (headless)
+		eprintf("cannot use both 'same' and -h\n");
+
+	if (argc < 5);
+	else if (strcmp(argv[4], "same")) {
+		if (strlen(argv[4]) >= sizeof(stream.pixfmt))
+			eprintf("choosen pixel format is unsupported\n");
+		strcpy(stream.pixfmt, argv[5]);
+		if (set_pixel_size(&stream))
+			eprintf("choosen pixel format is unsupported\n");
+	} else if (headless) {
+		eprintf("cannot use both 'same' and -h\n");
+	} else if (argc > 1) {
+		usage();
+	}
+
+
+	rewrite(&stream, frames_auto);
+	close(stream.fd);
+	return 0;
+}