uvc_with_csc.py 程序为前篇文章《02-Media-7-uvc.py 使用软件解码的USB摄像头(UVC)捕获视频并显示的程序》的姊妹篇，区别在于：uvc_with_csc.py使用了硬件解码。

UVC.start(cvt = True) #cvt 是否将snapshot获取的图像硬件解码为NV12格式

使用3.5寸液晶显示屏的源代码：

import time, os, urandom, sys, gc

from media.display import *
from media.media import *
from media.uvc import *

from nonai2d import CSC

DISPLAY_WIDTH = ALIGN_UP(800, 16)
DISPLAY_HEIGHT = 480

#DISPLAY_WIDTH = ALIGN_UP(1920, 16)
#DISPLAY_HEIGHT = 1080


csc = CSC(0, CSC.PIXEL_FORMAT_RGB_565)

# use lcd as display output
Display.init(Display.ST7701, width = DISPLAY_WIDTH, height = DISPLAY_HEIGHT, to_ide = True)
#Display.init(Display.LT9611, width = DISPLAY_WIDTH, height = DISPLAY_HEIGHT, to_ide = True)
# init media manager
MediaManager.init()

while True:
    plugin, dev = UVC.probe()
    if plugin:
        print(f"detect USB Camera {dev}")
        break
    time.sleep_ms(100)

for i, mode in enumerate(UVC.list_video_mode()):
    print(f"模式{i}: {mode.width}x{mode.height} {mode.format}@{mode.fps}fps")

mode = UVC.video_mode(640, 480, UVC.FORMAT_MJPEG, 30)
#mode = UVC.video_mode(1920, 1080, UVC.FORMAT_MJPEG, 30)

succ, mode = UVC.select_video_mode(mode)
print(f"select mode success: {succ}, mode: {mode}")

UVC.start(cvt = True)#cvt 是否将snapshot获取的图像硬件解码为NV12格式

clock = time.clock()

while True:
    clock.tick()

    img = None
    while img is None:
        try:
            img = UVC.snapshot()
        except:
            print("drop frame")
            continue

    img = csc.convert(img)
    Display.show_image(img)
    img.__del__()
    gc.collect()

    print(f"fps: {clock.fps()}")

# deinit display
Display.deinit()
csc.destroy()
UVC.stop()
time.sleep_ms(100)
# release media buffer
MediaManager.deinit()

使用HDMI外接高清显示屏的接口示例程序：

import time, os, urandom, sys, gc

from media.display import *
from media.media import *
from media.uvc import *

from nonai2d import CSC

#DISPLAY_WIDTH = ALIGN_UP(800, 16)
#DISPLAY_HEIGHT = 480

DISPLAY_WIDTH = ALIGN_UP(1920, 16)
DISPLAY_HEIGHT = 1080


csc = CSC(0, CSC.PIXEL_FORMAT_RGB_565)

# use lcd as display output
#Display.init(Display.ST7701, width = DISPLAY_WIDTH, height = DISPLAY_HEIGHT, to_ide = True)
Display.init(Display.LT9611, width = DISPLAY_WIDTH, height = DISPLAY_HEIGHT, to_ide = True)
# init media manager
MediaManager.init()

while True:
    plugin, dev = UVC.probe()
    if plugin:
        print(f"detect USB Camera {dev}")
        break
    time.sleep_ms(100)

for i, mode in enumerate(UVC.list_video_mode()):
    print(f"模式{i}: {mode.width}x{mode.height} {mode.format}@{mode.fps}fps")

#mode = UVC.video_mode(640, 480, UVC.FORMAT_MJPEG, 30)
mode = UVC.video_mode(1920, 1080, UVC.FORMAT_MJPEG, 30)

succ, mode = UVC.select_video_mode(mode)
print(f"select mode success: {succ}, mode: {mode}")

UVC.start(cvt = True)#cvt 是否将snapshot获取的图像硬件解码为NV12格式

clock = time.clock()

while True:
    clock.tick()

    img = None
    while img is None:
        try:
            img = UVC.snapshot()
        except:
            print("drop frame")
            continue

    img = csc.convert(img)
    Display.show_image(img)
    img.__del__()
    gc.collect()

    print(f"fps: {clock.fps()}")

# deinit display
Display.deinit()
csc.destroy()
UVC.stop()
time.sleep_ms(100)
# release media buffer
MediaManager.deinit()