exportvideo.nb

ExportVideo[prefix_, framerate_, frames_] := Module[{
   digits =  Ceiling @ Log10 @ Length @ frames
   },
  (* create directory (OK if already exist, 
  prints error and continues *)
  CreateDirectory[prefix];
  (* export each frame as a png with an enumerated filename, 
  padded with zeroes *)
  Table[
   Export[
    StringJoin[prefix, "/", StringPadLeft[ToString[x], digits, "0"], 
     ".png"],
    frames[[x]]
    ],
   {x, Length@frames}
   ];
  (* concatenate the series of png images in order, 
  encoded with yuv420p and libx264 for most compatibility *)
  RunProcess[{
    "ffmpeg",
    "-f", "image2",
    "-framerate", ToString @ framerate,
    "-i", StringJoin[prefix, "/%", ToString @ digits, "d.png"],
    "-pix_fmt", "yuv420p",
    "-c:v", "libx264",
     "-movflags", "+faststart",
    "-filter:v", "crop='floor(in_w/2)*2:floor(in_h/2)*2'",
    StringJoin[prefix, "/", prefix, ".mp4"]
    }];
  (* create a pallete.png from the mp4 for the next step in gif \
creation *)
  RunProcess[{
    "ffmpeg",
    "-i", StringJoin[prefix, "/",  prefix, ".mp4"],
    "-filter_complex", "[0:v] palettegen",
    StringJoin[prefix, "/palette.png"]
    }];
  (* create a gif going back over the original images, 
  but now using the color palette produced from the mp4 *)
  RunProcess[{
    "ffmpeg",
    "-f", "image2",
    "-framerate", ToString @framerate,
    "-i", StringJoin[prefix, "/%",  ToString @ digits, "d.png"],
    "-i", StringJoin[prefix, "/palette.png"],
    "-filter_complex", "[0:v][1:v] paletteuse",
    StringJoin[prefix, "/", prefix, ".gif"]
    }]
  ]