如何在 Linux 上通过命令行识别视频格式
如果您想知道从某处下载的视频文件使用什么视频/音频编解码器，您可以播放视频本身。大多数媒体播放器软件（例如 VLC 或 MPlayer）可以显示正在播放的视频文件的属性。但是，有一些命令行实用程序可以让您快速确定视频属性。
在本教程中，我将描述如何在 Linux 上从命令行检查视频格式。
方法一：exiftool
确定视频属性的第一种方法是使用 exiftool，它是一个综合媒体元数据查看器和编辑器。使用exiftool，您可以轻松查找给定视频文件的元数据。
$ exiftool input.mp4
ExifTool Version Number : 8.60
File Name : input.mp4
Directory : .
File Size : 168 MB
File Modification Date/Time : 2012:05:15 11:19:04-04:00
File Permissions : rw-rw-r--
File Type : MP4
MIME Type : video/mp4
Major Brand : MP4 v2 [ISO 14496-14]
Minor Version : 0.0.0
Compatible Brands : isom, mp42
Movie Header Version : 0
Create Date : 2012:05:14 15:18:50
Modify Date : 2012:05:14 15:18:50
Time Scale : 600
Duration : 0:56:32
Preferred Rate : 1
Preferred Volume : 100.00%
Preview Time : 0 s
Preview Duration : 0 s
Poster Time : 0 s
Selection Time : 0 s
Selection Duration : 0 s
Current Time : 0 s
Next Track ID : 3
Track Header Version : 0
Track Create Date : 0000:00:00 00:00:00
Track Modify Date : 2012:05:14 15:18:51
Track ID : 1
Track Duration : 0:56:32
Track Layer : 0
Track Volume : 0.00%
Image Width : 960
Image Height : 720
Graphics Mode : srcCopy
Op Color : 0 0 0
Compressor ID : avc1
Source Image Width : 960
Source Image Height : 720
X Resolution : 72
Y Resolution : 72
Bit Depth : 24
Video Frame Rate : 6
Matrix Structure : 1 0 0 0 1 0 0 0 1
Media Header Version : 0
Media Create Date : 2012:05:14 15:18:51
Media Modify Date : 2012:05:14 15:18:51
Media Time Scale : 44100
Media Duration : 0:56:32
Media Language Code : und
Handler Description : IsoMedia File Produced by Google, 5-11-2011
Balance : 0
Audio Format : mp4a
Audio Channels : 2
Audio Bits Per Sample : 16
Audio Sample Rate : 44100
Handler Type : Metadata
Handler Vendor ID : Apple
Movie Data Size : 175021210
Avg Bitrate : 413 kbps
Image Size : 960x720
Rotation : 0
方法二：tovid
另一种识别视频格式的方法是使用tovid命令行工具，这是一个用于创建DVD的命令行工具。该工具还可以识别视频格式。
前面提到的 ExifTool 的一个问题是该工具访问的元数据可能不准确，有时甚至会产生误导。与 ExifTool 不同，tovid 实际上探测输入视频文件（通过使用 MPlayer）以获得准确的帧速率和视频速率。
要在 Ubuntu 或 Linux Mint 上安装 tovid：
$ sudo apt-get install tovid
要在其他 Linux 发行版上安装 tovid，您可以从源代码安装它。
要使用 tovid 查找视频属性，请按如下方式运行它。
$ tovid id input.mp4
Read options from /home/dev/.tovid/tovid.ini:
--------------------------------
tovid id
Identify video files
Version 0.33
http://tovid.wikia.com
--------------------------------
Analyzing file: 'input.mp4'...
=========================================================
File: input.mp4
Width: 960 pixels
Height: 720 pixels
Aspect ratio: 1.33:1
Frames: 20357
Duration: 00:56:32 hours/mins/secs
Framerate: 6.000 frames per second
Video format: H264
Video bitrate: 288536 bits per second
---------------------------
Audio track 1 (Stream 0.1, AID 0):
---------------------------
Codec: aac
Bitrate: 124000 bits per second
Sampling rate: 44100 Hz
=========================================================
Audio is compliant with the following formats:
Not compliant with (S)VCD or DVD
Video is compliant with the following formats:
Not compliant with (S)VCD or DVD
This video does not seem to be compliant with (S)VCD or DVD
standards. If you burn it to a video disc, it may not work.
=========================================================
方法三：mplayer
您还可以直接从命令行使用 mplayer 来获取有关视频的信息。
$ mplayer -vo null -ao null -identify -frames 0 input.mp4
MPlayer svn r34540 (Ubuntu), built with gcc-4.7 (C) 2000-2012 MPlayer Team
Playing input.mp4.
libavformat version 53.21.0 (external)
Mismatching header version 53.19.0
libavformat file format detected.
ID_VIDEO_ID=0
[lavf] stream 0: video (h264), -vid 0
ID_AUDIO_ID=0
[lavf] stream 1: audio (aac), -aid 0, -alang und
VIDEO: [H264] 960x720 24bpp 6.000 fps 288.5 kbps (35.2 kbyte/s)
Clip info:
major_brand: mp42
ID_CLIP_INFO_NAME0=major_brand
ID_CLIP_INFO_VALUE0=mp42
minor_version: 0
ID_CLIP_INFO_NAME1=minor_version
ID_CLIP_INFO_VALUE1=0
compatible_brands: isommp42
ID_CLIP_INFO_NAME2=compatible_brands
ID_CLIP_INFO_VALUE2=isommp42
creation_time: 2012-05-14 15:18:50
ID_CLIP_INFO_NAME3=creation_time
ID_CLIP_INFO_VALUE3=2012-05-14 15:18:50
ID_CLIP_INFO_N=4
Load subtitles in ./
ID_FILENAME=input.mp4
ID_DEMUXER=lavfpref
ID_VIDEO_FORMAT=H264
ID_VIDEO_BITRATE=288536
ID_VIDEO_WIDTH=960
ID_VIDEO_HEIGHT=720
ID_VIDEO_FPS=6.000
ID_VIDEO_ASPECT=0.0000
ID_AUDIO_FORMAT=MP4A
ID_AUDIO_BITRATE=124144
ID_AUDIO_RATE=44100
ID_AUDIO_NCH=2
ID_START_TIME=0.00
ID_LENGTH=3392.85
ID_SEEKABLE=1
ID_CHAPTERS=0
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 53.35.0 (external)
Mismatching header version 53.32.2
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
==========================================================================
ID_VIDEO_CODEC=ffh264
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 44100 Hz, 2 ch, s16le, 124.1 kbit/8.80% (ratio: 15518->176400)
ID_AUDIO_BITRATE=124144
ID_AUDIO_RATE=44100
ID_AUDIO_NCH=2
Selected audio codec: [ffaac] afm: ffmpeg (FFmpeg AAC (MPEG-2/MPEG-4 Audio))
==========================================================================
AO: [null] 44100Hz 2ch s16le (2 bytes per sample)
ID_AUDIO_CODEC=ffaac
方法四：ffmpeg
如果您的系统上安装了 FFmpeg，则可以使用 FFmpeg 从命令行检查视频编解码器信息，如下所示。
$ ffmpeg -i input.mp4
ffmpeg -i storm.mp4
ffmpeg version 0.8.6-6:0.8.6-0ubuntu0.12.10.1, Copyright (c) 2000-2013 the Libav developers
built on Apr 2 2013 17:02:16 with gcc 4.7.2
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'storm.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: isommp42
creation_time : 2012-05-14 15:18:50
Duration: 00:56:32.85, start: 0.000000, bitrate: 414 kb/s
Stream #0.0(und): Video: h264 (High), yuv420p, 960x720, 288 kb/s, 6 fps, 6 tbr, 12 tbn, 12 tbc
Metadata:
creation_time : 1970-01-01 00:00:00
Stream #0.1(und): Audio: aac, 44100 Hz, stereo, s16, 124 kb/s
Metadata:
creation_time : 2012-05-14 15:18:51