No sound if youtube-dl -f webm/bestvideo+bestaudio

[megapro17]

When downloading from youtube, if using
youtube-dl -f webm/bestvideo+bestaudio - completely no sound
In opposition, if using youtube-dl -f mp4/bestvideo+bestaudio sound exists

I have found some workaround, if type youtube-dl -f bestvideo[ext=webm]+bestaudio it downloads normally with sound, but I still sure this is some bug exists.

[dstftw]

> py -2.7 .\youtube_dl\__main__.py  BaW_jenozKc -f webm/bestvideo+bestaudio
[youtube] BaW_jenozKc: Downloading webpage
[youtube] BaW_jenozKc: Downloading video info webpage
[download] Destination: youtube-dl test video ''_-BaW_jenozKc.webm
[download] 100% of 181.60KiB in 00:01

> ffmpeg.exe -i '.\youtube-dl test video ''''_-BaW_jenozKc.webm'
ffmpeg version N-85653-gb4330a0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 6.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  libavutil      55. 61.100 / 55. 61.100
  libavcodec     57. 93.100 / 57. 93.100
  libavformat    57. 72.101 / 57. 72.101
  libavdevice    57.  7.100 / 57.  7.100
  libavfilter     6. 87.100 /  6. 87.100
  libswscale      4.  7.101 /  4.  7.101
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
Input #0, matroska,webm, from '.\youtube-dl test video ''_-BaW_jenozKc.webm':
  Metadata:
    encoder         : google
  Duration: 00:00:09.93, start: 0.000000, bitrate: 149 kb/s
    Stream #0:0(eng): Video: vp8, yuv420p(progressive), 640x360, SAR 1:1 DAR 16:9, 1k fps, 30 tbr, 1k tbn, 1k tbc (default)
    Stream #0:1: Audio: vorbis, 44100 Hz, stereo, fltp (default)
At least one output file must be specified

Stream #0:1: Audio: vorbis, 44100 Hz, stereo, fltp (default)

[megapro17]

Wow, wow. Why you instantly closed this issue?
Try with newer opus included video.