我想使用FFMpeg从我的网络摄像头捕获单个图像，但以下命令返回错误。有什么想法吗？
ffmpeg -f dshow -i video="Integrated Webcam" -t 1 –r 25 c:\temp\image%d.jpg
以下是命令行窗口中的文本。
C:\Users\User\Downloads\FFMPeg\ffmpeg-20150915-git-8e92462-win64-static\bin>f
fmpeg -f dshow -i video="Integrated Webcam" -t 1 -r 25 c:\temp\image%d.jpg
ffmpeg version N-75287-g8e92462 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.9.3 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --
enable-libdcadec --enable-libfreetype --enable-libgme --enable-libgsm --enable-l
ibilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --en
able-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --ena
ble-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc
--enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enabl
e-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-lzma --ena
ble-decklink --enable-zlib
libavutil 55. 2.100 / 55. 2.100
libavcodec 57. 1.100 / 57. 1.100
libavformat 57. 0.100 / 57. 0.100
libavdevice 57. 0.100 / 57. 0.100
libavfilter 6. 3.100 / 6. 3.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.100 / 2. 0.100
libpostproc 54. 0.100 / 54. 0.100
Input #0, dshow, from 'video=Integrated Webcam':
Duration: N/A, start: 417955.980000, bitrate: N/A
Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 640x480, 30 tbr,
10000k tbn, 30 tbc
[NULL @ 000000000304a5e0] Unable to find a suitable output format for 'ΓÇôr'
ΓÇôr: Invalid argument