python 请问这两种字符串格式有什么区别

方法1 .通过以下代码可以正常工作

record_cmd='ffmpeg  -f dshow -i video=\"{0}\" -f dshow -i audio=\"{1}\" -vcodec libxvid -acodec aac  -s 1920x1080 d:\\mycamera1.mkv'.format("HIK 1080P Camera","麦克风 (HIK 1080P Camera-Audio)")
fun=subprocess.Popen(record_cmd)

方法2 ，输入设备更换为变量后就会提示错误，请帮忙分析到底错在什么地方。字符串转码为encode('UTF8')或GBK也会出现另外的问题

CAMERA_DEVICE = "HIK 1080P Camera"
AUDIO_DEVICE="麦克风 (HIK 1080P Camera-Audio) "
record_cmd='ffmpeg  -f dshow -i video=\"{0}\" -f dshow -i audio=\"{1}\" -vcodec libxvid -acodec aac -s 1920x1080 d:\\mycamera1.mkv'.format(CAMERA_DEVICE,AUDIO_DEVICE)
fun=subprocess.Popen(record_cmd)

错误信息：

dshow @ 00000153c161fc80] Could not find audio only device with name [楹﹀厠椋?(HIK 1080P Camera-Audio) ] among source devices of type audio.[dshow @ 00000153c161fc80] Searching for audio device within video devices for 楹﹀厠椋?(HIK 1080P Camera-Audio)
[dshow @ 00000153c161fc80] Could not find audio only device with name [楹﹀厠椋?(HIK 1080P Camera-Audio) ] among source devices of type video.audio=楹﹀厠椋?(HIK 1080P Camera-Audio) : I/O error