ffmpeg – Page 2 – 业余语言练习

x11grab

#Linux系统下录屏 #ffplay -window_title monitor -f x11grab\ -video_size 200:100 -i :0.0+800,25 \ -vf “drawbox=x=30:y=0.5:w=50:h=20:color=ff0000:t=1,\ scale=300×300” -left 880 -top 1 ffmpeg -f x11grab -framerate 30 -video_size 200:100 \ -i :0.0+800,25 \ -vf “setpts=(RTCTIME-RTCSTART)/(TB*1000000),\ drawbox=x=30:y=0.5:w=50:h=20:color=#FF0000” \ -f mp4 wubi.mp4 && exit 先用ffplay播放,体验录制区域,再用ffmpeg真正录制屏幕。

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transpose

transpose参数说明 (1)=90CpimterClockwise and Vertical Flip(default),逆时针旋转90°后垂直翻转。 (2)1=90Clockwise,顺时针旋转90° (3)2=90CounterClockwise,逆时针旋转90° (4)3=90Clockwise,顺时针旋转90°后垂直翻转。 ffmpeg –help filter=transpose ffmpeg -i IMG_0001.jpg -vf “transpose=1,transpose=1” \ -f image2 IMG_0001_0-r180.jpg && exit

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使用Python和OpenCV来捕获图像

sudo apt-get install libopencv-dev python3-opencv cat python3-opencv ——————————— import cv2 # 指定摄像头索引,0通常是内置摄像头,1是外接USB摄像头(如果有多个摄像头) cap = cv2.VideoCapture(2) # 检查摄像头是否成功打开 if not cap.isOpened(): print(“无法打开摄像头”) exit() # 捕获一帧图像 ret, frame = cap.read() # 如果帧被正确捕获,ret是True if ret: cv2.imwrite(‘captured_image.jpg’, frame) # 保存图像到文件 print(“图像已保存”) else: print(“无法捕获图像”) # 释放摄像头资源 cap.release() cv2.destroyAllWindows() ——————————— python3 python3-opencv

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linux usb摄像头采集图像

sudo apt-get update sudo apt-get install v4l-utils root135@root135:~$ v4l2-ctl –list-devices Lenovo EasyCamera: Lenovo EasyC (usb-0000:00:14.0-4): /dev/video0 /dev/video1 /dev/media0 2K USB Camera: 2K USB Camera (usb-0000:00:1a.0-1.2.3): /dev/video2 /dev/video3 /dev/media1

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ffmpeg-drawtext

#ffplay -i 35-0-0.jpg -vf “crop=240:190:1072:0” #ffplay -i a0.jpg \ # -vf “drawtext=fontfile=/usr/share/fonts/songhei.ttf:fontcolor=ffffff:fontsize=460:x=1565:y=-40:text=’■'” \ #ffmpeg -i a0.jpg -vframes:v 1 \ # -vf “drawtext=fontfile=/usr/share/fonts/songhei.ttf:fontcolor=ffffff:fontsize=460:x=1565:y=-40:text=’■'” \ # -f image2 38-0.jpg && #ffmpeg -i a1.jpg -vframes:v 1 \ # -vf “drawtext=fontfile=/usr/share/fonts/songhei.ttf:fontcolor=ffffff:fontsize=460:x=1565:y=-40:text=’■'” \ # -f image2 38-1.jpg && #ffmpeg -i a2.jpg -vframes:v 1 \ # -vf “drawtext=fontfile=/usr/share/fonts/songhei.ttf:fontcolor=ffffff:fontsize=460:x=1565:y=-40:text=’■'” \ # -f… Continue reading ffmpeg-drawtext

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