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• Time-weighting frames of an animation using FFMPEG [duplicate]

  12 mars 2020, par Rohan S Byrne

  I’m using ’ffmpeg’ to make an mp4 out of hundreds of individual frames, which are timeslices from an experiment I’ve run. My problem is that the time sampling is not regular. I would like to somehow ’weight’ the frames according to their time index so that the framerate is fast when the sampling rate was fast and slow when the sampling rate was slow.

  I know how to do this sort of operation when taking, for instance, a time average using numpy arrays. I have no idea how to do it with ffmpeg.

  Any tips ?

• Having issues with exporting video in FFMPEG [closed]

  3 avril 2024, par Jake

  I am developing an application that uses FFMPEG to take numerous videos and concatenate them into one file. The user has the ability to flip an individual video if they would like. From Landscape to portrait. The application works as planned and it produces one single file, with the orientation however the user set them.

  


  The problem is, when I take that file that FFMPEG generated and tray to convert or copy it using FFMPEG. It will create a video file of all of the video prior to the segment where the orientation has been flipped. The flipped video as well as all of the other videos after it, will not be in the video.

  


  Below are the parameters to export each individual video.

  


  parameters = "-y -i " + '"' + frames[0].VideoPath + '"' + " -filter_complex " + '"' + @"[0:v]trim=" + frames[0].TimeCode.TotalSeconds + @":" + frames[1].TimeCode.TotalSeconds +
            @", setpts=PTS-STARTPTS[trimedv0];[trimedv0]yadif," + orientation + @"setsar=1/1, eq=contrast=1:brightness=" + video.Brightness + @", drawtext=text=\'%{pts\:localtime\:" + ToUnixTimestamp(frames[0].FrameTime) +
            @"\:'" + CurrentDisplayDateFormat.DateOutputFormat + @"'}\'" + @":fontfile =\'Fonts/" + font.FirstOrDefault() + @"\':fontcolor=" + fontColor + ":x=" + DATEXOFF +
            ":y=" + DATEYOFF + " -th:fontsize=" + tempFont +
            @":box=1:boxcolor=" + boxColor + @"@" + opacity + @", drawtext=text=\'%{pts\:localtime\:" + ToUnixTimestamp(frames[0].FrameTime) + @"\:'" + CurrentDisplayDateFormat.TimeOutputFormat + @"'}\'" + @":fontfile =\'Fonts/" + font.FirstOrDefault() + @"\':fontcolor=" + fontColor +
            ":x=" + TIMEXOFF + ":y=" + TIMEYOFF +
            " -th:fontsize=" + tempFont + @":box=1:boxcolor=" + boxColor + @"@" + opacity + ", " + fadeString + " -sn " + mapVar + " -progress - -nostats -an -c:v libx264 -b:v " + video.BitRate + " -preset ultrafast -profile:v baseline -level 3.0 " +
            @"-pix_fmt yuv420p -f mpegts " + vidPath + @"\v" + outputFile.ToString() + ".MP4";


  


  Below are the parameters to concatenate all of the videos :

  


  string parameters = "-y -probesize 100M -analyzeduration 100M -i concat:" + '"' + concatString + '"' + @" -c:v copy " + '"' + ExportOptions.CompleteDestinationPath + '"';


  


  Any ideas of what is going on and hopefully a solution ?

  


• Is there any way to set the overall bitrate of a video file in ffmpeg ?

  11 août 2021, par Rahul sivagnanam

  From what I understand, the overall bitrate of a file is a sum of the bitrate of all streams(video and audio) and the container bitrate. Ffmpeg provides option to set video bitrate and audio bitrate individually using -b:v and -b:a flags.

  


  Can we set a bitrate for the whole file using ffmpeg and let it calculate the individual stream bitrates on its own ?