cdba: add image capture support

Add support for capturing an image from the server and saving it on the
client with a new command, ^A i.

Signed-off-by: Rayyan Ansari <[email protected]>

camera.c

@@ -0,0 +1,272 @@
+/*
+ * Copyright (c) 2024, Linaro Ltd.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <linux/videodev2.h>
+
+#include <jpeglib.h>
+
+#include "camera.h"
+#include "device.h"
+
+static int camera_init_device(const char *dev_name, int *fd_ref, char **driver_ref)
+{
+	*fd_ref = open(dev_name, O_RDWR);
+	if (*fd_ref < 0)
+	{
+		fprintf(stderr, "Couldn't open device: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	struct v4l2_capability cap;
+
+	if (ioctl(*fd_ref, VIDIOC_QUERYCAP, &cap) < 0)
+	{
+		fprintf(stderr, "Couldn't query device capabilities: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	*driver_ref = strdup((char *)cap.driver);
+
+	return 0;
+}
+
+static int camera_configure_format(const int fd, int *width_ref, int *height_ref, uint32_t *format_ref)
+{
+	struct v4l2_format fmt = {0};
+	fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+
+	if (ioctl(fd, VIDIOC_G_FMT, &fmt) < 0)
+	{
+		fprintf(stderr, "Couldn't get format: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	struct v4l2_frmsizeenum frame_size = {0};
+	fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
+	frame_size.pixel_format = fmt.fmt.pix.pixelformat;
+
+	if (ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &frame_size) < 0)
+	{
+		fprintf(stderr, "Couldn't get frame size: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	fmt.fmt.pix.width = frame_size.discrete.width;
+	fmt.fmt.pix.height = frame_size.discrete.height;
+
+	if (ioctl(fd, VIDIOC_S_FMT, &fmt) < 0)
+	{
+		fprintf(stderr, "Couldn't set format: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	*width_ref = fmt.fmt.pix.width;
+	*height_ref = fmt.fmt.pix.height;
+	*format_ref = fmt.fmt.pix.pixelformat;
+
+	return 0;
+}
+
+static int camera_request_buffer(const int fd)
+{
+	struct v4l2_requestbuffers reqbuf = {0};
+	reqbuf.count = 1;
+	reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	reqbuf.memory = V4L2_MEMORY_MMAP;
+
+	if (ioctl(fd, VIDIOC_REQBUFS, &reqbuf) < 0)
+	{
+		fprintf(stderr, "Couldn't request buffer: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int camera_query_buffer(const int fd, uint8_t **buf_ref, struct v4l2_buffer *buf_info_ref)
+{
+	buf_info_ref->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	buf_info_ref->memory = V4L2_MEMORY_MMAP;
+	buf_info_ref->index = 0;
+
+	if (ioctl(fd, VIDIOC_QUERYBUF, buf_info_ref) < 0)
+	{
+		fprintf(stderr, "Couldn't query buffer: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	*buf_ref = mmap(NULL, buf_info_ref->length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, buf_info_ref->m.offset);
+	if (buf_ref == MAP_FAILED)
+	{
+		fprintf(stderr, "Couldn't map buffer: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int camera_capture_frame(const int fd, struct v4l2_buffer *buf_info)
+{
+	if (ioctl(fd, VIDIOC_QBUF, buf_info))
+	{
+		fprintf(stderr, "Couldn't queue buffer: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+	enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	if (ioctl(fd, VIDIOC_STREAMON, &type) < 0)
+	{
+		fprintf(stderr, "Couldn't start streaming: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+	if (ioctl(fd, VIDIOC_DQBUF, buf_info) < 0)
+	{
+		fprintf(stderr, "Couldn't dequeue buffer: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+	if (ioctl(fd, VIDIOC_STREAMOFF, &type) < 0)
+	{
+		fprintf(stderr, "Couldn't stop streaming: %s (%d)\n", strerror(errno), errno);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int camera_yuyv_to_jpeg(uint8_t **jpeg_ref, unsigned long *size_ref, const uint8_t *yuyv, const int width, const int height)
+{
+	struct jpeg_compress_struct cinfo;
+	struct jpeg_error_mgr jerr;
+
+	JSAMPROW row_pointer[1];
+
+	cinfo.err = jpeg_std_error(&jerr);
+	jpeg_create_compress(&cinfo);
+
+	jpeg_mem_dest(&cinfo, jpeg_ref, size_ref);
+
+	cinfo.image_width = width;
+	cinfo.image_height = height;
+	cinfo.input_components = 3;
+	cinfo.in_color_space = JCS_YCbCr;
+
+	jpeg_set_defaults(&cinfo);
+	jpeg_set_quality(&cinfo, 100, TRUE);
+
+	jpeg_start_compress(&cinfo, TRUE);
+
+	uint8_t* row_buffer = (uint8_t*)malloc(width * 3 * sizeof(uint8_t));
+	if (!row_buffer)
+	{
+		fprintf(stderr, "Memory allocation failed\n");
+		jpeg_destroy_compress(&cinfo);
+		return -1;
+	}
+
+	while (cinfo.next_scanline < height)
+	{
+		const uint32_t offset = cinfo.next_scanline * width * 2;
+		for (uint32_t i = 0, j = 0; i < width * 2; i += 4, j += 6)
+		{
+			row_buffer[j + 0] = yuyv[offset + i + 0];
+			row_buffer[j + 1] = yuyv[offset + i + 1];
+			row_buffer[j + 2] = yuyv[offset + i + 3];
+			row_buffer[j + 3] = yuyv[offset + i + 2];
+			row_buffer[j + 4] = yuyv[offset + i + 1];
+			row_buffer[j + 5] = yuyv[offset + i + 3];
+		}
+		row_pointer[0] = row_buffer;
+		jpeg_write_scanlines(&cinfo, row_pointer, 1);
+	}
+
+	jpeg_finish_compress(&cinfo);
+	jpeg_destroy_compress(&cinfo);
+
+	free(row_buffer);
+
+	return 0;
+}
+
+int camera_capture_jpeg(uint8_t **buffer_ref, unsigned long *size_ref, const char *video_device)
+{
+	int fd = -1;
+	uint8_t *raw_buffer = NULL;
+
+	int ret = 0;
+	char *driver_str = NULL;
+
+	int width, height = 0;
+	uint32_t format = 0;
+
+	struct v4l2_buffer buf_info = {0};
+
+	uint8_t *jpeg = NULL;
+
+	ret = camera_init_device(video_device, &fd, &driver_str);
+	if (ret < 0)
+	{
+		goto cleanup;
+	}
+
+	ret = camera_configure_format(fd, &width, &height, &format);
+	if (ret < 0)
+	{
+		goto cleanup;
+	}
+
+	fprintf(stderr, "Driver: %s, Resolution: %dx%d, Format: %c%c%c%c\n", driver_str, width, height,
+		(char)((format >> 0) & 0xFF), (char)((format >> 8) & 0xFF), (char)((format >> 16) & 0xFF), (char)((format >> 24) & 0xFF));
+	free(driver_str);
+
+	ret = camera_request_buffer(fd);
+	if (ret < 0)
+	{
+		goto cleanup;
+	}
+
+	ret = camera_query_buffer(fd, &raw_buffer, &buf_info);
+	if (ret < 0)
+	{
+		goto cleanup;
+	}
+
+	camera_capture_frame(fd, &buf_info);
+
+	switch (format)
+	{
+		case V4L2_PIX_FMT_YUYV:
+			camera_yuyv_to_jpeg(&jpeg, size_ref, raw_buffer, width, height);
+			break;
+
+		default:
+			fprintf(stderr, "Unsupported format\n");
+			ret = -1;
+			goto cleanup;
+	}
+
+	*buffer_ref = jpeg;
+
+cleanup:
+	if (fd >= 0)
+	{
+		close(fd);
+	}
+	if (raw_buffer != NULL)
+	{
+		munmap(raw_buffer, buf_info.length);
+	}
+
+	return ret;
+}

camera.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2024, Linaro Ltd.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef __CAMERA_H__
+#define __CAMERA_H__
+
+#include <stdint.h>
+
+int camera_capture_jpeg(uint8_t **buffer_ref, unsigned long *size_ref, const char *video_device);
+
+#endif // __CAMERA_H__

cdba-server.c

@@ -14,6 +14,10 @@
 #include <unistd.h>
 #include <syslog.h>
 
+#ifndef CDBA_CAMERA_DISABLED
+#include "camera.h"
+#endif // CDBA_CAMERA_DISABLED
+
 #include "cdba-server.h"
 #include "circ_buf.h"
 #include "device.h"
@@ -99,6 +103,50 @@ static void msg_fastboot_continue(void)
 	cdba_send(MSG_FASTBOOT_CONTINUE);
 }
 
+#ifdef CDBA_CAMERA_DISABLED
+static void capture_image(struct device *device)
+{
+	fprintf(stderr, "Camera support is not built into the server\n");
+}
+#else
+static void capture_image(struct device *device)
+{
+	uint8_t *jpeg = NULL;
+	size_t size = 0;
+
+	if (!device->video_device)
+	{
+		fprintf(stderr, "video_device not specified!\n");
+		return;
+	}
+
+	int ret = camera_capture_jpeg(&jpeg, &size, device->video_device);
+	if (ret < 0)
+	{
+		fprintf(stderr, "Failed to capture image\n");
+		return;
+	}
+
+	const size_t chunk_size = 1024;
+	size_t remaining_size = size;
+	const uint8_t *ptr = jpeg;
+
+	while (remaining_size > 0) {
+		size_t send_size = remaining_size > chunk_size ? chunk_size : remaining_size;
+
+		cdba_send_buf(MSG_CAPTURE_IMAGE, send_size, ptr);
+
+		ptr += send_size;
+		remaining_size -= send_size;
+	}
+
+	// Empty message to indicate end of image
+	cdba_send_buf(MSG_CAPTURE_IMAGE, 0, NULL);
+
+	free(jpeg);
+}
+#endif // CDBA_CAMERA_DISABLED
+
 void cdba_send_buf(int type, size_t len, const void *buf)
 {
 	struct msg msg = {
@@ -185,6 +233,9 @@ static int handle_stdin(int fd, void *buf)
 		case MSG_FASTBOOT_CONTINUE:
 			msg_fastboot_continue();
 			break;
+		case MSG_CAPTURE_IMAGE:
+			capture_image(selected_device);
+			break;
 		default:
 			fprintf(stderr, "unk %d len %d\n", msg->type, msg->len);
 			exit(1);