How to create silent .ogg audio file

后端 未结 2 1059
旧巷少年郎
旧巷少年郎 2021-01-18 04:12

In answer to the question \"How-to make a silent mp3 or wav-file\" on ubuntuforums.org FakeOutdoorsman provided the following recipe:

Another method b

2条回答
  •  心在旅途
    2021-01-18 04:54

    Silent audio

    That's an outdated method. You can now use the anullsrc filter instead, and it will work on any OS:

    ffmpeg -f lavfi -i anullsrc -t 5 -c:a libvorbis output.ogg
    
    • Default sample rate is 44100, and default channel layout is stereo. If you want something different you can do something like: anullsrc=r=48000:cl=mono (or use cl=1 for mono).

    • For Vorbis in general, avoid the native encoder vorbis if possible; libvorbis will provide a better output (although it doesn't really matter with a silent output).


    Other somewhat related examples

    Test tone

    An annoying tone or beeping tone can be made with sine filter. Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:

    ffmpeg -f lavfi -i sine=f=220:b=4:d=5 -c:a libvorbis output.oga
    

    Just black video

    Using the color filter.

    ffmpeg -f lavfi -i color=d=5 -c:v libtheora output.ogv
    
    • Default frame rate is 25 and default video size is 320x240. To change it: color=r=24:s=1280x720:d=5.

    • But who uses Theora anymore? A more modern alternative that likely fills its niche is VP8/VP9 + Vorbis in WebM: -c:v libvpx output.webm.

    Test pattern + 440 Hz tone

    Using testsrc and sine filters:

    ffmpeg -f lavfi -i testsrc -f lavfi -i sine -t 10 -c:v libtheora -c:a libvorbis \
    -q:v 5 -q:a 5 output.ogv
    
    • Change frame rate and video size the same way as shown above for the color filter.

    • See FFmpeg Filter Documentation: Video Sources for a list of many other video source filters such as smptehdbars.

    Also see

    • FFmpeg Wiki: A Brief Theora and Vorbis Encoding Guide
    • FFmpeg Codecs Documentation: libtheora
    • FFmpeg Codecs Documentation: libvorbis
    • ​Hydrogen Audio: Recommended Vorbis Encoder Settings
    • FFmpeg Wiki: VP8 Video in WebM Encoding Guide

提交回复
热议问题