海思SDK实时视频流缩放
时间: 2024-08-14 13:04:26 浏览: 33
海思SDK(Hisilicon Software Development Kit)是一种由华为提供的一套软件开发工具包,它包含了处理视频和图像的强大功能,包括实时视频流的缩放。在实时视频流处理中,缩放通常涉及到调整视频帧的尺寸,以便适应不同的显示设备或分辨率需求。
使用海思SDK进行实时视频流缩放,开发者可以调用预设的图像处理函数,如H.264编码解码API、GPU加速的缩放算法等。这些API允许你在不失真的情况下对视频流进行缩放,同时保持良好的性能。具体的步骤可能会涉及以下几个环节:
1. 初始化视频捕获设备并配置参数。
2. 调用相应的缩放函数,传递原始视频帧和目标尺寸。
3. 收取缩放后的视频帧,并将其显示到需要的输出设备上。
相关问题
海思rtsp协议的实时视频流传输
海思是一家领先的半导体公司,在视频领域有很多应用。RTSP协议是实时流传输协议的缩写,是一种常用的视频流传输协议。在海思视频应用中,可以通过RTSP协议实时传输视频流,以下是具体步骤:
1. 配置海思设备的视频流参数,例如分辨率、帧率、码率等。
2. 开启海思设备的RTSP服务,设定端口号,例如554端口。
3. 使用RTSP客户端软件(例如VLC、QuickTime、FFmpeg等)连接海思设备的RTSP服务,输入RTSP地址,例如rtsp://192.168.1.100:554/0。
4. RTSP客户端软件与海思设备建立连接后,可以实时获取视频流数据,进行播放或录制等操作。
需要注意的是,RTSP协议的实时性受到网络带宽、延迟等因素的影响,因此在使用过程中需要根据实际情况进行优化和调整。
海思输出bt656视频流代码
以下是一个基本的海思输出BT656视频流的代码:
```c
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <asm/ioctl.h>
#include <linux/fb.h>
#include <linux/videodev2.h>
#define VIDEO_DEVICE "/dev/video0"
#define VIDEO_WIDTH 640
#define VIDEO_HEIGHT 480
#define VIDEO_FORMAT V4L2_PIX_FMT_YUYV
#define FB_DEVICE "/dev/fb0"
int main(void) {
int fd_fb = open(FB_DEVICE, O_RDWR);
if(fd_fb == -1) {
printf("Error: could not open framebuffer device.\n");
return -1;
}
struct fb_var_screeninfo var_info;
if(ioctl(fd_fb, FBIOGET_VSCREENINFO, &var_info) == -1) {
printf("Error: could not get variable screen info.\n");
close(fd_fb);
return -1;
}
uint32_t width = var_info.xres;
uint32_t height = var_info.yres;
uint32_t bytes_per_pixel = var_info.bits_per_pixel / 8;
uint32_t fb_size = width * height * bytes_per_pixel;
uint8_t *fbp = (uint8_t *)mmap(0, fb_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);
if(fbp == MAP_FAILED) {
printf("Error: could not mmap framebuffer device.\n");
close(fd_fb);
return -1;
}
int fd_video = open(VIDEO_DEVICE, O_RDWR);
if(fd_video == -1) {
printf("Error: could not open video device.\n");
munmap(fbp, fb_size);
close(fd_fb);
return -1;
}
struct v4l2_capability cap;
if(ioctl(fd_video, VIDIOC_QUERYCAP, &cap) == -1) {
printf("Error: could not query video device capabilities.\n");
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return -1;
}
struct v4l2_format fmt;
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = VIDEO_WIDTH;
fmt.fmt.pix.height = VIDEO_HEIGHT;
fmt.fmt.pix.pixelformat = VIDEO_FORMAT;
fmt.fmt.pix.field = V4L2_FIELD_ANY;
if(ioctl(fd_video, VIDIOC_S_FMT, &fmt) == -1) {
printf("Error: could not set video format.\n");
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return -1;
}
struct v4l2_requestbuffers req;
req.count = 1;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_MMAP;
if(ioctl(fd_video, VIDIOC_REQBUFS, &req) == -1) {
printf("Error: could not request video buffers.\n");
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return -1;
}
struct v4l2_buffer buf;
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = 0;
if(ioctl(fd_video, VIDIOC_QUERYBUF, &buf) == -1) {
printf("Error: could not query video buffer.\n");
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return -1;
}
void *video_buffer = mmap(NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED, fd_video, buf.m.offset);
if(video_buffer == MAP_FAILED) {
printf("Error: could not mmap video buffer.\n");
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return -1;
}
if(ioctl(fd_video, VIDIOC_STREAMON, &buf.type) == -1) {
printf("Error: could not start video streaming.\n");
munmap(video_buffer, buf.length);
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return -1;
}
// Write BT656 video data to framebuffer
uint8_t *video_data = (uint8_t *)video_buffer;
for(uint32_t y = 0; y < height; y++) {
for(uint32_t x = 0; x < width; x++) {
uint32_t fb_offset = (y * width + x) * bytes_per_pixel;
uint32_t video_offset = (y * width + x) * 2;
// Convert YCbCr to RGB
uint8_t y_data = *(video_data + video_offset);
uint8_t cb_data = *(video_data + video_offset + 1);
uint8_t cr_data = *(video_data + video_offset + 3);
uint8_t r = y_data + 1.402 * (cr_data - 128);
uint8_t g = y_data - 0.34414 * (cb_data - 128) - 0.71414 * (cr_data - 128);
uint8_t b = y_data + 1.772 * (cb_data - 128);
*(fbp + fb_offset) = r;
*(fbp + fb_offset + 1) = g;
*(fbp + fb_offset + 2) = b;
}
}
if(ioctl(fd_video, VIDIOC_STREAMOFF, &buf.type) == -1) {
printf("Error: could not stop video streaming.\n");
}
munmap(video_buffer, buf.length);
munmap(fbp, fb_size);
close(fd_fb);
close(fd_video);
return 0;
}
```
这个代码假设你的海思芯片已经捕获了BT656格式的视频流,并将其输出到/dev/video0设备上。它将使用 mmap() 函数来映射视频和帧缓冲设备,并将YCbCr格式的视频转换为RGB格式并写入帧缓冲设备。