流式传输实时视频时更改文本

Question

我有一个使用 picamera 和覆盆子派进行实时流式传输的脚本，我想更改亮度并使用"camera.annotate_text"在屏幕上显示其值，但我得到的是一个静态数字，如何在屏幕上显示当前的亮度值？

from time import sleep
import keyboard
import sys
camera = PiCamera()
camera.brightness =50
def increase():
    was_pressed = False
    while True:
        if keyboard.is_pressed('1'):
            if not was_pressed:
                if camera.brightness<100 :
                    camera.brightness += 5
                    was_pressed= True
        elif keyboard.is_pressed('3'):
            if not was_pressed:
                if camera.brightness>0 :
                    camera.brightness -= 5
                    was_pressed= True
        elif keyboard.is_pressed('m'):
            if not was_pressed:
                sys.exit()                                      
        else:
            was_pressed = False
try:
    while True:
        camera.start_preview()
        camera.annotate_text='B:%i'%camera.brightness
        increase()
    sleep(1000)
except KeyboardInterrupt:
    camera.stop_preview()

Answer 1

我现在无法测试它，但它应该只是一个循环，或者至少你应该在第一个循环中使用camera.annotate_text

import keyboard
import sys
camera = PiCamera()
camera.brightness = 50
def increase():
    was_pressed = False
    while True:
        if keyboard.is_pressed('1'):
            if not was_pressed:
                if camera.brightness<100 :
                    camera.brightness += 5
                    was_pressed= True
        elif keyboard.is_pressed('3'):
            if not was_pressed:
                if camera.brightness>0 :
                    camera.brightness -= 5
                    was_pressed= True
        elif keyboard.is_pressed('m'):
            if not was_pressed:
                sys.exit()                                      
        else:
            was_pressed = False
        camera.annotate_text='B:%i'%camera.brightness
try:
    camera.start_preview()
    increase()
except KeyboardInterrupt:
    camera.stop_preview()