使用ffmpeg将webm转换为wav

Question

我已在Python中成功使用ffmpeg将mp3-文件转换为wav，因此我可以将其发布到Google Speech-To-Text。现在我对webm文件有相同的情况，而我拥有的旧功能不起作用。它应该将文件转换为wav并将其拆分为15秒的块。我可以从webm -file中执行此操作，还是需要先将其转换为其他格式？

我使用的功能：

def convert_and_split(filename):
    command = ['ffmpeg', '-i', filename, '-f', 'segment', '-segment_time', '15', '-c', 'copy', 'parts/out%09d.wav']
    subprocess.run(command,stdout=subprocess.PIPE,stdin=subprocess.PIPE)

编辑。忘记提及此功能目前对webm -files的作用。它产生一个wav文件out000000000.wav，该文件为空。在控制台中，我收到如下错误消息：

[segment @ 0x55970b22fe80] Opening 'parts/out000000000.wav' for writing
[wav @ 0x55970b1ffbc0] opus codec not supported in WAVE format
Could not write header for output file #0 (incorrect codec parameters ?): Function not implemented

编辑2。我认为我做对了，但想听听是否有更好的方法可以做到这一点。

首先，我将文件转换为单声道wav，然后将其拆分为大块。请随时指出任何错误或错误。

def convert_webm_to_wav(file):
    command = ['ffmpeg', '-i', file, '-acodec', 'pcm_s16le', '-ac', '1', '-ar', '16000', '/home/janip/openvidu_files/' + file.name[:-5] + '.wav']
    subprocess.run(command,stdout=subprocess.PIPE,stdin=subprocess.PIPE)

def split_audio(filename):
    command = ['ffmpeg', '-i', filename, '-f', 'segment', '-segment_time', '15', '-c', 'copy', '/home/janip/work/Holda/Nut_ideas/voice_chat_demos/openvidu-tutorials/openvidu-js-node/python_scripts/parts/out%09d.wav']
    subprocess.run(command,stdout=subprocess.PIPE,stdin=subprocess.PIPE)

Answer 1

ffmpeg -i ./big-buck-bunny_trailer.webm -c:a pcm_f32le ./out.wav

输出：

ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with Apple clang version 11.0.3 (clang-1103.0.32.59)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.3 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags=-fno-stack-check --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, matroska,webm, from './big-buck-bunny_trailer.webm':
  Metadata:
    encoder         : http://sourceforge.net/projects/yamka
    creation_time   : 2010-05-20T08:21:12.000000Z
  Duration: 00:00:32.48, start: 0.000000, bitrate: 533 kb/s
    Stream #0:0(eng): Video: vp8, yuv420p(progressive), 640x360, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
    Stream #0:1(eng): Audio: vorbis, 44100 Hz, mono, fltp (default)
Stream mapping:
  Stream #0:1 -> #0:0 (vorbis (native) -> pcm_f32le (native))
Press [q] to stop, [?] for help
Output #0, wav, to './out.wav':
  Metadata:
    ISFT            : Lavf58.29.100
    Stream #0:0(eng): Audio: pcm_f32le ([3][0][0][0] / 0x0003), 44100 Hz, mono, flt, 1411 kb/s (default)
    Metadata:
      encoder         : Lavc58.54.100 pcm_f32le
size=    5597kB time=00:00:32.50 bitrate=1410.7kbits/s speed= 625x
video:0kB audio:5597kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.001989%