v4l2-source: Add V4L2 source class

The v4l2_source class is an implementation of the video_source class
that uses a V4L2 capture device to provide video.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 201 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index c69bc94..f3d7208 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ OBJS		:= \
 			stream.o \
 			uvc.o \
 			v4l2.o \
+			v4l2-source.o \
 			video-buffers.o \
 			video-source.o
 
diff --git a/v4l2-source.c b/v4l2-source.c
new file mode 100644
index 0000000..7eced6a
--- /dev/null
+++ b/v4l2-source.c
@@ -0,0 +1,180 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * V4L2 video source
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "events.h"
+#include "tools.h"
+#include "v4l2.h"
+#include "v4l2-source.h"
+#include "video-buffers.h"
+
+struct v4l2_source {
+	struct video_source src;
+
+	struct v4l2_device *vdev;
+};
+
+#define to_v4l2_source(s) container_of(s, struct v4l2_source, src)
+
+static void v4l2_source_video_process(void *d)
+{
+	struct v4l2_source *src = d;
+	struct video_buffer buf;
+	int ret;
+
+	ret = v4l2_dequeue_buffer(src->vdev, &buf);
+	if (ret < 0)
+		return;
+
+	src->src.handler(src->src.handler_data, &src->src, &buf);
+}
+
+static void v4l2_source_destroy(struct video_source *s)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	v4l2_close(src->vdev);
+	free(src);
+}
+
+static int v4l2_source_set_format(struct video_source *s,
+				  struct v4l2_pix_format *fmt)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	return v4l2_set_format(src->vdev, fmt);
+}
+
+static int v4l2_source_alloc_buffers(struct video_source *s, unsigned int nbufs)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	return v4l2_alloc_buffers(src->vdev, V4L2_MEMORY_MMAP, nbufs);
+}
+
+static int v4l2_source_export_buffers(struct video_source *s,
+				      struct video_buffer_set **bufs)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+	struct video_buffer_set *buffers;
+	unsigned int i;
+	int ret;
+
+	ret = v4l2_export_buffers(src->vdev);
+	if (ret < 0)
+		return ret;
+
+	buffers = video_buffer_set_new(src->vdev->buffers.nbufs);
+	if (!buffers)
+		return -ENOMEM;
+
+	for (i = 0; i < src->vdev->buffers.nbufs; ++i) {
+		struct video_buffer *buffer = &src->vdev->buffers.buffers[i];
+
+		buffers->buffers[i].size = buffer->size;
+		buffers->buffers[i].dmabuf = buffer->dmabuf;
+	}
+
+	*bufs = buffers;
+	return 0;
+}
+
+static int v4l2_source_free_buffers(struct video_source *s)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	return v4l2_free_buffers(src->vdev);
+}
+
+static int v4l2_source_stream_on(struct video_source *s)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+	unsigned int i;
+	int ret;
+
+	/* Queue all buffers. */
+	for (i = 0; i < src->vdev->buffers.nbufs; ++i) {
+		struct video_buffer buf = {
+			.index = i,
+			.size = src->vdev->buffers.buffers[i].size,
+			.dmabuf = src->vdev->buffers.buffers[i].dmabuf,
+		};
+
+		ret = v4l2_queue_buffer(src->vdev, &buf);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = v4l2_stream_on(src->vdev);
+	if (ret < 0)
+		return ret;
+
+	events_watch_fd(src->src.events, src->vdev->fd, EVENT_READ,
+			v4l2_source_video_process, src);
+
+	return 0;
+}
+
+static int v4l2_source_stream_off(struct video_source *s)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	events_unwatch_fd(src->src.events, src->vdev->fd, EVENT_READ);
+
+	return v4l2_stream_off(src->vdev);
+}
+
+static int v4l2_source_queue_buffer(struct video_source *s,
+				    struct video_buffer *buf)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	return v4l2_queue_buffer(src->vdev, buf);
+}
+
+static const struct video_source_ops v4l2_source_ops = {
+	.destroy = v4l2_source_destroy,
+	.set_format = v4l2_source_set_format,
+	.alloc_buffers = v4l2_source_alloc_buffers,
+	.export_buffers = v4l2_source_export_buffers,
+	.free_buffers = v4l2_source_free_buffers,
+	.stream_on = v4l2_source_stream_on,
+	.stream_off = v4l2_source_stream_off,
+	.queue_buffer = v4l2_source_queue_buffer,
+};
+
+struct video_source *v4l2_video_source_create(const char *devname)
+{
+	struct v4l2_source *src;
+
+	src = malloc(sizeof *src);
+	if (!src)
+		return NULL;
+
+	memset(src, 0, sizeof *src);
+	src->src.ops = &v4l2_source_ops;
+
+	src->vdev = v4l2_open(devname);
+	if (!src->vdev) {
+		free(src);
+		return NULL;
+	}
+
+	return &src->src;
+}
+
+void v4l2_video_source_init(struct video_source *s, struct events *events)
+{
+	struct v4l2_source *src = to_v4l2_source(s);
+
+	src->src.events = events;
+}
diff --git a/v4l2-source.h b/v4l2-source.h
new file mode 100644
index 0000000..53e28d6
--- /dev/null
+++ b/v4l2-source.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * V4L2 video source
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+#ifndef __V4L2_VIDEO_SOURCE_H__
+#define __V4L2_VIDEO_SOURCE_H__
+
+#include "video-source.h"
+
+struct events;
+struct video_source;
+
+struct video_source *v4l2_video_source_create(const char *devname);
+void v4l2_video_source_init(struct video_source *src, struct events *events);
+
+#endif /* __VIDEO_SOURCE_H__ */