Use ffprobe (part of FFmpeg toolkit)

example:

ffprobe -v quiet -print_format json -show_format -show_streams ~/Movies/big_buck_bunny_720p_5mb.mp4

output:

{    "streams": [        {            "index": 0,            "codec_name": "h264",            "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",            "profile": "Main",            "codec_type": "video",            "codec_time_base": "1/50",            "codec_tag_string": "avc1",            "codec_tag": "0x31637661",            "width": 1280,            "height": 720,            "coded_width": 1280,            "coded_height": 720,            "has_b_frames": 0,            "sample_aspect_ratio": "1:1",            "display_aspect_ratio": "16:9",            "pix_fmt": "yuv420p",            "level": 31,            "chroma_location": "left",            "refs": 1,            "is_avc": "1",            "nal_length_size": "4",            "r_frame_rate": "25/1",            "avg_frame_rate": "25/1",            "time_base": "1/12800",            "start_pts": 0,            "start_time": "0.000000",            "duration_ts": 378368,            "duration": "29.560000",            "bit_rate": "1032960",            "bits_per_raw_sample": "8",            "nb_frames": "739",            "disposition": {                "default": 1,                "dub": 0,                "original": 0,                "comment": 0,                "lyrics": 0,                "karaoke": 0,                "forced": 0,                "hearing_impaired": 0,                "visual_impaired": 0,                "clean_effects": 0,                "attached_pic": 0            },            "tags": {                "creation_time": "1970-01-01 00:00:00",                "language": "und",                "handler_name": "VideoHandler"            }        },        {            "index": 1,            "codec_name": "aac",            "codec_long_name": "AAC (Advanced Audio Coding)",            "profile": "LC",            "codec_type": "audio",            "codec_time_base": "1/48000",            "codec_tag_string": "mp4a",            "codec_tag": "0x6134706d",            "sample_fmt": "fltp",            "sample_rate": "48000",            "channels": 6,            "channel_layout": "5.1",            "bits_per_sample": 0,            "r_frame_rate": "0/0",            "avg_frame_rate": "0/0",            "time_base": "1/48000",            "start_pts": 0,            "start_time": "0.000000",            "duration_ts": 1419264,            "duration": "29.568000",            "bit_rate": "383960",            "max_bit_rate": "416704",            "nb_frames": "1386",            "disposition": {                "default": 1,                "dub": 0,                "original": 0,                "comment": 0,                "lyrics": 0,                "karaoke": 0,                "forced": 0,                "hearing_impaired": 0,                "visual_impaired": 0,                "clean_effects": 0,                "attached_pic": 0            },            "tags": {                "creation_time": "1970-01-01 00:00:00",                "language": "und",                "handler_name": "SoundHandler"            }        }    ],    "format": {        "filename": "/Users/farsheed/Movies/big_buck_bunny_720p_5mb.mp4",        "nb_streams": 2,        "nb_programs": 0,        "format_name": "mov,mp4,m4a,3gp,3g2,mj2",        "format_long_name": "QuickTime / MOV",        "start_time": "0.000000",        "duration": "29.568000",        "size": "5253880",        "bit_rate": "1421504",        "probe_score": 100,        "tags": {            "major_brand": "isom",            "minor_version": "512",            "compatible_brands": "isomiso2avc1mp41",            "creation_time": "1970-01-01 00:00:00",            "encoder": "Lavf53.24.2"        }    }}

See documentation for more info.

Use ffprobe:

ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 input.mp4

Example output:

1280x720

See FFprobe Documentation and FFmpeg Wiki: FFprobe Tips for more info.

Using exiftool

run the command

exiftool VIDEOFILE

The output you get is similar to this:

ExifTool Version Number         : 9.76File Name                       : gource2.mkvDirectory                       : .File Size                       : 2010 MBFile Modification Date/Time     : 2015:01:07 14:16:22-06:00File Access Date/Time           : 2015:01:07 14:16:22-06:00File Inode Change Date/Time     : 2015:01:07 14:16:22-06:00File Permissions                : rw-rw-r--File Type                       : MKVMIME Type                       : video/x-matroskaEBML Version                    : 1EBML Read Version               : 1Doc Type                        : matroskaDoc Type Version                : 4Doc Type Read Version           : 2Timecode Scale                  : 1 msMuxing App                      : libebml v1.3.0 + libmatroska v1.4.1Writing App                     : mkvmerge v7.4.0 ('Circles') 64bit built on Dec 17 2014 11:31:10Duration                        : 2:35:09Date/Time Original              : 2015:01:07 20:14:22ZVideo Codec ID                  : V_MPEG4/ISO/AVCVideo Frame Rate                : 60Track Language                  : undImage Width                     : 1280Image Height                    : 1024Display Width                   : 1280Display Height                  : 1024Track Number                    : 2Track Type                      : AudioAudio Codec ID                  : A_DTSDefault Duration                : 10.666666 msAudio Sample Rate               : 48000Audio Channels                  : 6Image Size                      : 1280x1024

Using ffmpeg/ffprobe

run the command

ffprobe VIDEOFILE

alternatively:

ffmpeg -i VIDEOFILE

The output you get is similar to this:

ffprobe version 2.1.6 Copyright (c) 2007-2014 the FFmpeg developers  built on Nov 29 2014 12:07:56 with gcc 4.8.3 (GCC) 20140911 (Red Hat 4.8.3-7)  configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-frei0r --enable-gnutls --enable-libass --enable-libcdio --enable-libcelt --enable-libdc1394 --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopencv --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect  libavutil      52. 48.101 / 52. 48.101  libavcodec     55. 39.101 / 55. 39.101  libavformat    55. 19.104 / 55. 19.104  libavdevice    55.  5.100 / 55.  5.100  libavfilter     3. 90.100 /  3. 90.100  libavresample   1.  1.  0 /  1.  1.  0  libswscale      2.  5.101 /  2.  5.101  libswresample   0. 17.104 /  0. 17.104  libpostproc    52.  3.100 / 52.  3.100Input #0, matroska,webm, from 'gource2.mkv':  Metadata:    creation_time   : 2015-01-07 20:14:22  Duration: 02:35:09.70, start: 0.000000, bitrate: 1811 kb/s    Stream #0:0: Video: h264 (Constrained Baseline), yuv420p, 1280x1024, SAR 1:1 DAR 5:4, 60 fps, 60 tbr, 1k tbn, 120 tbc (default)    Stream #0:1(eng): Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536 kb/s (default)

Using mplayer

run the command

mplayer -really-quiet -ao null -vo null -identify -frames 0 VIDEOFILE

The output you get is similar to this:

ID_VIDEO_ID=0ID_AUDIO_ID=0ID_AID_0_LANG=engID_CLIP_INFO_NAME0=creation_timeID_CLIP_INFO_VALUE0=2015-01-07 20:14:22ID_CLIP_INFO_N=1ID_FILENAME=gource2.mkvID_DEMUXER=lavfprefID_VIDEO_FORMAT=H264ID_VIDEO_BITRATE=0ID_VIDEO_WIDTH=1280ID_VIDEO_HEIGHT=1024ID_VIDEO_FPS=60.000ID_VIDEO_ASPECT=0.0000ID_AUDIO_FORMAT=8193ID_AUDIO_BITRATE=1536000ID_AUDIO_RATE=48000ID_AUDIO_NCH=6ID_START_TIME=0.00ID_LENGTH=9309.70ID_SEEKABLE=1ID_CHAPTERS=0ID_VIDEO_CODEC=ffh264ID_AUDIO_BITRATE=1536000ID_AUDIO_RATE=48000ID_AUDIO_NCH=6ID_AUDIO_CODEC=ffdcaID_EXIT=EOF

Using mediainfo

run the command

mediainfo VIDEOFILE

The output you get is similar to this:

GeneralUnique ID                                : 311795358270161665158539797930749663166 (0xEA919A09196F0CAEF4E1B4FEB72B17BE)Complete name                            : gource2.mkvFormat                                   : MatroskaFormat version                           : Version 4 / Version 2File size                                : 1.96 GiBDuration                                 : 2h 35mnOverall bit rate                         : 1 811 KbpsEncoded date                             : UTC 2015-01-07 20:14:22Writing application                      : mkvmerge v7.4.0 ('Circles') 64bit built on Dec 17 2014 11:31:10Writing library                          : libebml v1.3.0 + libmatroska v1.4.1VideoID                                       : 1Format                                   : AVCFormat/Info                              : Advanced Video CodecFormat profile                           : Baseline@L4.2Format settings, CABAC                   : NoFormat settings, ReFrames                : 1 frameCodec ID                                 : V_MPEG4/ISO/AVCBit rate                                 : 266 KbpsWidth                                    : 1 280 pixelsHeight                                   : 1 024 pixelsDisplay aspect ratio                     : 5:4Frame rate mode                          : VariableColor space                              : YUVChroma subsampling                       : 4:2:0Bit depth                                : 8 bitsScan type                                : ProgressiveWriting library                          : x264 core 138 r2363 c628e3bEncoding settings                        : cabac=0 / ref=1 / deblock=0:1:1 / analyse=0:0 / me=dia / subme=0 / psy=1 / psy_rd=0.40:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=0 / keyint=250 / keyint_min=25 / scenecut=0 / intra_refresh=0 / rc=crf / mbtree=0 / crf=22.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=0Default                                  : YesForced                                   : NoAudioID                                       : 2Format                                   : DTSFormat/Info                              : Digital Theater SystemsMode                                     : 16Format settings, Endianness              : BigCodec ID                                 : A_DTSDuration                                 : 2h 35mnBit rate mode                            : ConstantBit rate                                 : 1 509 KbpsChannel(s)                               : 6 channelsChannel positions                        : Front: L C R, Side: L R, LFESampling rate                            : 48.0 KHzBit depth                                : 24 bitsCompression mode                         : LossyStream size                              : 1.64 GiB (83%)Language                                 : EnglishDefault                                  : YesForced                                   : No

time summary

exiftool    real    0m0.089s    user    0m0.081s    sys     0m0.008smplayer    real    0m0.050s    user    0m0.034s    sys     0m0.017sffprobe/ffmpeg    real    0m0.017s    user    0m0.011s    sys     0m0.007smediainfo    real    0m0.029s    user    0m0.025s    sys     0m0.004s

YMMV, but ffprobe is the fastest followed by mediainfo then mplayer and finally exiftool

ffprobe < mediainfo < mplayer < exiftool