如何使用 ffprobe 确定 webm 持续时间 [英] How to determine webm duration using ffprobe

问题描述

我的目标很简单，我有几个 webm 文件需要连接，但首先我需要确定它们的持续时间.

My goal is simple , I have several webm files need to be concated, but first I need to determine their durations.

webm 文件好像是作为流播放的，所以没有办法知道每个文件的长度.

It seems webm file are played as streams, so there is no way to tell the length of each file.

我一直在使用 ffprobe 来完成这项工作，但返回的持续时间为 N/A.我使用的命令是:

I have been using ffprobe to do the job ,but the duration returned is N/A.The command I use was:

ffprobe -i input.file -show_format | grep duration

谢谢.

ffprobe 的完整输出列表如下:

The complete output of ffprobe list below:

 ffprobe version 2.6.2 Copyright (c) 2007-2015 the FFmpeg developers
  built with Apple LLVM version 6.1.0 (clang-602.0.49) (based on LLVM 3.6.0svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.6.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-libtheora --enable-libvorbis --enable-libvpx --enable-vda
  libavutil      54. 20.100 / 54. 20.100
  libavcodec     56. 26.100 / 56. 26.100
  libavformat    56. 25.101 / 56. 25.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 11.102 /  5. 11.102
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, matroska,webm, from '231':
  Metadata:
    encoder         : GStreamer matroskamux version 1.5.91
    creation_time   : 2015-12-05 07:59:29
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0(eng): Video: vp8, yuv420p, 640x480, SAR 1:1 DAR 4:3, 14.99 fps, 14.99 tbr, 1k tbn, 1k tbc (default)
    Metadata:
      title           : Video
    Stream #0:1(eng): Audio: vorbis, 48000 Hz, stereo, fltp (default)
    Metadata:
      title           : Audio
duration=N/A

推荐答案

我遇到了一些不包含 Duration 和 Bitrate 的文件的相同问题，并找到了以下解决方案:

I faced the same issue with some files that does not contain the Duration nor Bitrate on it and found the following solution:

1- 重新打包文件:(请注意，这不会对文件进行转码，只会复制它们)

1- Repackage the files with: (Note that this won't transcode the files, just will copy them)

ffmpeg -i source.webm -vcodec copy -acodec copy new_source.webm

2- 从新的复制文件中获取持续时间:

2- Take the duration from the new copied file:

ffprobe new_source.webm | grep Duration

这篇关于如何使用 ffprobe 确定 webm 持续时间的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！