获取视频属性

用ffprobe获取视频分辨率 宽度和高度

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

举例：

  1. # ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 course_1608_video_normalWatermark_477w360h.mp4
  2. 480x360

查看视频基本信息

通过：

  1. ffmpeg -i xxx.mp4

即可看到mp4视频的信息，其中包括了字幕的信息：

  1.     Stream #0:2(zho): Subtitle: mov_text (tx3g / 0x67337874), 1280x108, 0 kb/s (default)
  2.     Metadata:
  3.       creation_time   : 2018-10-13T03:27:31.000000Z
  4.       handler_name    : SubtitleHandler

其中：

  • Stream #0:2：字幕也是一个stream流，index是0:2
  • zho：(应该)表示是中文
  • mov_text：后来才听说，好像指的是Apple Mov Text格式的？

举例1

  1. ➜  ffmpeg_edit_subtitle ffmpeg -i CTT_Folge_01_CH_Subs_DefaultZhcnButNotShow.mp4
  2. ffmpeg version 3.4.2 Copyright (c) 2000-2018 the FFmpeg developers
  3.   built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
  4.   configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --disable-jack --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  5.   libavutil      55. 78.100 / 55. 78.100
  6.   libavcodec     57.107.100 / 57.107.100
  7.   libavformat    57. 83.100 / 57. 83.100
  8.   libavdevice    57. 10.100 / 57. 10.100
  9.   libavfilter     6.107.100 /  6.107.100
  10.   libavresample   3.  7.  0 /  3.  7.  0
  11.   libswscale      4.  8.100 /  4.  8.100
  12.   libswresample   2.  9.100 /  2.  9.100
  13.   libpostproc    54.  7.100 / 54.  7.100
  14. Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'CTT_Folge_01_CH_Subs_DefaultZhcnButNotShow.mp4':
  15.   Metadata:
  16.     major_brand     : mp42
  17.     minor_version   : 512
  18.     compatible_brands: isomiso2avc1mp41
  19.     creation_time   : 2018-10-13T03:27:31.000000Z
  20.     encoder         : HandBrake 1.1.2 2018090500
  21.   Duration: 00:26:52.03, start: -0.001333, bitrate: 1762 kb/s
  22.     Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720 [SAR 1:1 DAR 16:9], 1599 kb/s, 25 fps, 25 tbr, 90k tbn, 180k tbc (default)
  23.     Metadata:
  24.       creation_time   : 2018-10-13T03:27:31.000000Z
  25.       handler_name    : VideoHandler
  26.     Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 157 kb/s (default)
  27.     Metadata:
  28.       creation_time   : 2018-10-13T03:27:31.000000Z
  29.       handler_name    : Stereo
  30.     Stream #0:2(zho): Subtitle: mov_text (tx3g / 0x67337874), 1280x108, 0 kb/s (default)
  31.     Metadata:
  32.       creation_time   : 2018-10-13T03:27:31.000000Z
  33.       handler_name    : SubtitleHandler
  34. At least one output file must be specified

看到字幕了：Stream #0:2(zho)

zho应该是中文

且显示已经是default了，即默认是中文字幕（而不是之前的英文字幕）

举例2

  1. ffmpeg -i 1xx-我来保证你们的安全.mp4
  2. ffmpeg version 3.4.2 Copyright (c) 2000-2018 the FFmpeg developers
  3.   built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
  4.   configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --disable-jack --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  5.   libavutil      55. 78.100 / 55. 78.100
  6.   libavcodec     57.107.100 / 57.107.100
  7.   libavformat    57. 83.100 / 57. 83.100
  8.   libavdevice    57. 10.100 / 57. 10.100
  9.   libavfilter     6.107.100 /  6.107.100
  10.   libavresample   3.  7.  0 /  3.  7.  0
  11.   libswscale      4.  8.100 /  4.  8.100
  12.   libswresample   2.  9.100 /  2.  9.100
  13.   libpostproc    54.  7.100 / 54.  7.100
  14. Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1xxx-我来保证你们的安全.mp4':
  15.   Metadata:
  16.     major_brand     : isom
  17.     minor_version   : 0
  18.     compatible_brands: isomiso2avc1
  19.     creation_time   : 2018-01-28T05:46:37.000000Z
  20.   Duration: 00:01:26.24, start: 0.000000, bitrate: 606 kb/s
  21.     Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 541 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
  22.     Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 62 kb/s (default)
  23.     Metadata:
  24.       creation_time   : 2018-01-28T05:46:35.000000Z
  25. At least one output file must be specified

中并没有Subtitle的信息

-> 看来这个视频本身就不包含独立的字幕

-> 没法用ffmpeg去提取字幕了