public string GetFFmpegArgs()
{
StringBuilder args = new StringBuilder();
// Input file path
args.Append($"-i \"{InputFilePath}\" ");
// Video codec
switch (VideoCodec)
{
case ConverterVideoCodecs.x264: // https://trac.ffmpeg.org/wiki/Encode/H.264
args.Append($"-c:v libx264 -preset medium -crf {VideoQuality.Clamp(0, 51)} ");
args.Append("-pix_fmt yuv420p -movflags +faststart "); // For browser support
break;
case ConverterVideoCodecs.x265: // https://trac.ffmpeg.org/wiki/Encode/H.265
args.Append($"-c:v libx265 -preset medium -crf {VideoQuality.Clamp(0, 51)} ");
break;
case ConverterVideoCodecs.vp8: // https://trac.ffmpeg.org/wiki/Encode/VP8
args.Append($"-c:v libvpx -crf {VideoQuality.Clamp(0, 63)} -b:v 0 ");
break;
case ConverterVideoCodecs.vp9: // https://trac.ffmpeg.org/wiki/Encode/VP9
args.Append($"-c:v libvpx-vp9 -crf {VideoQuality.Clamp(0, 63)} -b:v 0 ");
break;
case ConverterVideoCodecs.xvid: // https://trac.ffmpeg.org/wiki/Encode/MPEG-4
args.Append($"-c:v libxvid -q:v {VideoQuality.Clamp(1, 31)} ");
break;
case ConverterVideoCodecs.gif: // https://ffmpeg.org/ffmpeg-filters.html#palettegen-1
args.Append("-lavfi \"palettegen=stats_mode=full[palette],[0:v][palette]paletteuse=dither=sierra2_4a\" ");
break;
case ConverterVideoCodecs.webp: // https://www.ffmpeg.org/ffmpeg-codecs.html#libwebp
args.Append("-c:v libwebp -lossless 0 -preset default -loop 0 ");
break;
case ConverterVideoCodecs.apng:
args.Append("-f apng -plays 0 ");
break;
}
// Audio codec
switch (VideoCodec)
{
case ConverterVideoCodecs.x264: // https://trac.ffmpeg.org/wiki/Encode/AAC
case ConverterVideoCodecs.x265:
args.Append("-c:a aac -b:a 128k ");
break;
case ConverterVideoCodecs.vp8: // https://trac.ffmpeg.org/wiki/TheoraVorbisEncodingGuide
case ConverterVideoCodecs.vp9:
args.Append("-c:a libvorbis -q:a 3 ");
break;
case ConverterVideoCodecs.xvid: // https://trac.ffmpeg.org/wiki/Encode/MP3
args.Append("-c:a libmp3lame -q:a 4 ");
break;
}
// Output file path
args.Append($"-y \"{OutputFilePath}\"");
return(args.ToString());
}