diff options
| -rw-r--r-- | v4l2-hdmi-example/CHANGELOG | 1 | ||||
| -rw-r--r-- | v4l2-hdmi-example/README | 12 | ||||
| -rw-r--r-- | v4l2-hdmi-example/main.c | 259 |
3 files changed, 272 insertions, 0 deletions
diff --git a/v4l2-hdmi-example/CHANGELOG b/v4l2-hdmi-example/CHANGELOG new file mode 100644 index 0000000..673729c --- /dev/null +++ b/v4l2-hdmi-example/CHANGELOG @@ -0,0 +1 @@ +Version 0.1 diff --git a/v4l2-hdmi-example/README b/v4l2-hdmi-example/README new file mode 100644 index 0000000..52e67ad --- /dev/null +++ b/v4l2-hdmi-example/README @@ -0,0 +1,12 @@ + +Compilation: + +arm-linux-gnueabi-gcc main.c -o tvdemo -Ikernel/usr/include/ -std=gnu99 -lm -O2 + +Command line example + +./tvdemo /dev/video10 720 480 0 0 + +TODO: + +Add Makefile diff --git a/v4l2-hdmi-example/main.c b/v4l2-hdmi-example/main.c new file mode 100644 index 0000000..32308a1 --- /dev/null +++ b/v4l2-hdmi-example/main.c @@ -0,0 +1,259 @@ +#include <errno.h> +#include <fcntl.h> +#include <linux/videodev2.h> +#include <math.h> +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> + +#define ERRSTR strerror(errno) + +#define BYE_ON(cond, ...) \ +do { \ + if (cond) { \ + int errsv = errno; \ + fprintf(stderr, "ERROR(%s:%d) : ", \ + __FILE__, __LINE__); \ + errno = errsv; \ + fprintf(stderr, __VA_ARGS__); \ + abort(); \ + } \ +} while(0) + +#define BUFFER_CNT 3 + +struct buffer { + int index; + void *data; + size_t size; + size_t width; + size_t height; + + /* buffer state */ + double t; +}; + +struct setup { + char *path; + int width; + int height; + int xoffset; + int yoffset; +}; + +struct context { + int fd; + struct buffer *buffer; + size_t buffer_cnt; +}; + +int parse_args(struct setup *setup, int argc, char *argv[]); + +int showtime(struct context *ctx); + +int main(int argc, char *argv[]) +{ + int ret; + + struct setup setup; + ret = parse_args(&setup, argc, argv); + BYE_ON(ret, "syntax error\n"); + + int fd; + fd = open(argv[1], O_RDWR); + BYE_ON(fd < 0, "open failed: %s\n", ERRSTR); + + /* configure desired image size */ + struct v4l2_format fmt; + fmt.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + fmt.fmt.pix.width = setup.width; + fmt.fmt.pix.height = setup.height; + /* format is hardcoded: draw procedures work only in 32-bit mode */ + fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_BGR32; + + ret = ioctl(fd, VIDIOC_S_FMT, &fmt); + BYE_ON(ret < 0, "VIDIOC_S_FMT failed: %s\n", ERRSTR); + + /* update format struct to values adjusted by a driver */ + ret = ioctl(fd, VIDIOC_G_FMT, &fmt); + BYE_ON(ret < 0, "VIDIOC_G_FMT failed: %s\n", ERRSTR); + + /* allocate buffers */ + struct v4l2_requestbuffers rqbufs; + rqbufs.count = BUFFER_CNT; + rqbufs.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + rqbufs.memory = V4L2_MEMORY_MMAP; + + ret = ioctl(fd, VIDIOC_REQBUFS, &rqbufs); + BYE_ON(ret < 0, "VIDIOC_REQBUFS failed: %s\n", ERRSTR); + BYE_ON(rqbufs.count < BUFFER_CNT, "failed to get %d buffers\n", + BUFFER_CNT); + + struct buffer buffer[BUFFER_CNT]; + /* size_t size = 4 * setup.width * setup.height; */ + + /* buffers initalization */ + for (int i = 0; i < BUFFER_CNT; ++i) { + struct v4l2_plane plane; + struct v4l2_buffer buf; + buf.index = i; + buf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + buf.memory = V4L2_MEMORY_MMAP; + buf.m.planes = &plane; + buf.length = 1; + /* get buffer properties from a driver */ + ret = ioctl(fd, VIDIOC_QUERYBUF, &buf); + BYE_ON(ret < 0, "VIDIOC_QUERYBUF for buffer %d failed: %s\n", + buf.index, ERRSTR); + + buffer[i].index = i; + /* mmap buffer to user space */ + buffer[i].data = mmap(NULL, plane.length, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, plane.m.mem_offset); + BYE_ON(buffer[i].data == MAP_FAILED, "mmap failed: %s\n", + ERRSTR); + buffer[i].size = plane.length; + buffer[i].width = fmt.fmt.pix.width; + buffer[i].height = fmt.fmt.pix.height; + /* fill buffer with black */ + for (size_t j = 0; 4 * j < buffer[i].size; ++j) + ((uint32_t*)buffer[i].data)[j] = 0xff000000; + } + + /* crop output area on display */ + struct v4l2_crop crop; + crop.type = V4L2_BUF_TYPE_VIDEO_OUTPUT; + crop.c.left = setup.xoffset; + crop.c.top = setup.yoffset; + crop.c.width = setup.width; + crop.c.height = setup.height; + ret = ioctl(fd, VIDIOC_S_CROP, &crop); + BYE_ON(ret < 0, "VIDIOC_S_CROP failed: %s\n", ERRSTR); + + struct context context; + context.fd = fd; + context.buffer = buffer; + context.buffer_cnt = BUFFER_CNT; + /* It's show-time !!! */ + showtime(&context); + + return 0; +} + +int parse_args(struct setup *setup, int argc, char *argv[]) +{ + setup->path = argv[1]; + setup->width = atoi(argv[2]); + setup->height = atoi(argv[3]); + setup->xoffset = atoi(argv[4]); + setup->yoffset = atoi(argv[5]); + return 0; +} + +double gettime(void); +void buffer_fill(struct buffer *buf, double t); +int queue(int fd, int index); +int dequeue(int fd, int *index); + +int showtime(struct context *ctx) +{ + double t; + + /* fill and pass all buffers to the driver */ + for (int i = 0; i < ctx->buffer_cnt; ++i) { + t = gettime(); + buffer_fill(&ctx->buffer[i], t); + queue(ctx->fd, i); + } + fprintf(stderr, "start\n"); + /* start streaming */ + int ret, type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + ret = ioctl(ctx->fd, VIDIOC_STREAMON, &type); + BYE_ON(ret, "VIDIOC_STREAMON failed: %s\n", ERRSTR); + + int index; + /* main loop, every dequeued buffer is refilled and enqueued again */ + while (dequeue(ctx->fd, &index) == 0) { + t = gettime(); + buffer_fill(&ctx->buffer[index], t); + queue(ctx->fd, index); + } + return 0; +} + +double gettime(void) +{ + struct timeval tv; + gettimeofday(&tv, NULL); + double t = tv.tv_sec + 1e-6 * tv.tv_usec; + return t; +} + +void draw_rect(struct buffer *buf, struct v4l2_rect *r, uint32_t v) +{ + uint32_t *ptr = buf->data; + ptr += buf->width * r->top + r->left; + for (int i = 0; i < r->height; ++i) { + for (int j = 0; j < r->width; ++j) + ptr[j] = v; + ptr += buf->width; + } +} + +void prepare_rect(struct buffer *buf, struct v4l2_rect *r, double t) +{ + r->left = 0.8 * buf->width * (0.5 + 0.5 * sin(t)); + r->top = 0.8 * buf->height * (0.5 + 0.5 * sin(1.41 * t)); + r->width = 0.2 * buf->width; + r->height = 0.2 * buf->height; +} + +void buffer_fill(struct buffer *buf, double t) +{ + struct v4l2_rect r; + prepare_rect(buf, &r, buf->t); + draw_rect(buf, &r, 0xff000000); + prepare_rect(buf, &r, t); + int R, G, B; + R = 125 + 125 * sin(3 * t); + G = 125 + 125 * sin(4 * t); + B = 125 + 125 * sin(5 * t); + draw_rect(buf, &r, (R << 0) | (G << 8) | (B << 16) | (0xff << 24)); + buf->t = t; +} + +int queue(int fd, int index) +{ + struct v4l2_buffer buf; + struct v4l2_plane plane; + memset(&buf, 0, sizeof buf); + memset(&plane, 0, sizeof plane); + buf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + buf.index = index; + buf.memory = V4L2_MEMORY_MMAP; + buf.m.planes = &plane; + buf.length = 1; + int ret; + ret = ioctl(fd, VIDIOC_QBUF, &buf); + BYE_ON(ret, "VIDIOC_QBUF(index = %d) failed: %s\n", + index, ERRSTR); + return 0; +} + +int dequeue(int fd, int *index) +{ + int ret; + struct v4l2_buffer buf; + memset(&buf, 0, sizeof buf); + buf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + buf.memory = V4L2_MEMORY_MMAP; + ret = ioctl(fd, VIDIOC_DQBUF, &buf); + BYE_ON(ret, "VIDIOC_DQBUF failed: %s\n", ERRSTR); + *index = buf.index; + return 0; +} |