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videoffmpegframe-rateffmpeg-php
dazzafact
dazzafact

Reputation: 2860

FFmpeg - Calculating with Framerate?

I have to cut my video exactly. This video could have 25fps or 30fps (i dont know). is there a Variable in ffmpeg for the framerate so i could calculate on which frame i had to Cut? I only have the seconds of my video. something like this (for example 80sec video):

vf "fade=in:0:12,fade=out:(80*r):12"

-vf "fade=in:0:12,fade=out:2500:12"

Upvotes: 1

Views: 1174

Answers (2)

Joshua D. Boyd
Joshua D. Boyd

Reputation: 4856

You can specify the fade in start time and duration time in addition to start frame and frame duration.

-vf "fade=in:st=0.0:d=0.5,fade=out:st=75.5:d=0.5"

Upvotes: 1

Scott Stensland
Scott Stensland

Reputation: 28285

ffmpeg comes installed with 

ffprobe

which shows stats of given media file ... here is an example

ffprobe "The Fourth Phase of Water - Dr. Gerald Pollack at TEDxGuelphU-i-T7tCMUDXU.mp4"

... here is output of above command

ffprobe version N-86279-gac8dfcbd89 Copyright (c) 2007-2017 the FFmpeg developers
  built with gcc 6.3.0 (Ubuntu 6.3.0-12ubuntu2) 20170406
  configuration: 
  libavutil      55. 63.100 / 55. 63.100
  libavcodec     57. 96.101 / 57. 96.101
  libavformat    57. 72.101 / 57. 72.101
  libavdevice    57.  7.100 / 57.  7.100
  libavfilter     6. 90.100 /  6. 90.100
  libswscale      4.  7.101 /  4.  7.101
  libswresample   2.  8.100 /  2.  8.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'The Fourth Phase of Water - Dr. Gerald Pollack at TEDxGuelphU-i-T7tCMUDXU.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2016-08-25T12:06:13.000000Z
  Duration: 00:24:14.34, start: 0.000000, bitrate: 923 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720, 794 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc (default)
    Metadata:
      creation_time   : 2016-08-25T12:06:13.000000Z
      handler_name    : ISO Media file produced by Google Inc.
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 125 kb/s (default)
    Metadata:
      creation_time   : 2016-08-25T12:06:13.000000Z
      handler_name    : ISO Media file produced by Google Inc.

so now you have both total time and fps so you can calculate total number of frames or just use time to cut your video

Upvotes: 1

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