我运行命令
"%~dp0bin\ffmpeg.exe" -rtbufsize 2G -f gdigrab -framerate 1/3 -draw_mouse 0 -i desktop -f dshow -i audio="Stereo Mix (Realtek High Defini" -ac 1 -c:v libx264 -preset ultrafast -crf 0 -movflags +faststart -c:a libopus -b:a 24k -y "output.mkv"
10〜100帧后得到以下结果。
[dshow @ 0000000000576280] real-time buffer [Stereo Mix (Realtek High Defini] [audio input] too full or near too full (72% of size: 3041280 [rtbufsize parameter])! frame dropped!
frame= 7 fps=0.4 q=0.0 size= 1kB time=00:00:00.47 bitrate= 14.3kbits/
frame= 7 fps=0.4 q=0.0 size= 1kB time=00:00:00.47 bitrate= 14.3kbits/
frame= 7 fps=0.4 q=0.0 size= 1kB time=00:00:00.47 bitrate= 14.3kbits/
frame= 7 fps=0.4 q=0.0 size= 1kB time=00:00:00.47 bitrate= 14.3kbits/
[dshow @ 0000000000576280] real-time buffer [Stereo Mix (Realtek High Defini] [audio input] too full or near too full (81% of size: 3041280 [rtbufsize parameter])! frame dropped!
因此，问题是：具有源立体声，16位，48KHz的音频输入如何使ffmpeg无法在i5 CPU中捕获音频？视频捕获很好，它是h.264。
ffmpeg的版本是：
ffmpeg version N-94125-gd33414d2ad Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 9.1.1 (GCC) 20190621
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
libavutil 56. 29.100 / 56. 29.100
libavcodec 58. 53.100 / 58. 53.100
libavformat 58. 28.101 / 58. 28.101
libavdevice 58. 7.100 / 58. 7.100
libavfilter 7. 55.100 / 7. 55.100
libswscale 5. 4.101 / 5. 4.101
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100