How to determine webm duration using ffprobe
My goal is simple , I have several webm files need to be concated, but first I need to determine their durations.
It seems webm file are played as streams, so there is no way to tell the length of each file.
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
thanks.
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
Answer
I faced the same issue with some files that does not contain the Duration nor Bitrate on it and found the following solution:
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- Take the duration from the new copied file:
ffprobe new_source.webm | grep Duration