/// <summary>
/// The construct modify args.
/// </summary>
/// <param name="source">
/// The source.
/// </param>
/// <param name="output">
/// The output.
/// </param>
/// <param name="request">
/// The request.
/// </param>
/// <returns>
/// The System.String.
/// </returns>
protected override string ConstructModifyArgs(FileInfo source, FileInfo output, AudioUtilityRequest request)
{
string codec;
var ext = MediaTypes.CanonicaliseExtension(output.Extension);
switch (ext)
{
case MediaTypes.ExtWav:
codec = "pcm_s16le"; // pcm signed 16-bit little endian - compatible with CDDA
break;
case MediaTypes.ExtMp3:
codec = "libmp3lame";
break;
case MediaTypes.ExtOgg:
case MediaTypes.ExtOggAudio: // http://wiki.hydrogenaudio.org/index.php?title=Recommended_Ogg_Vorbis#Recommended_Encoder_Settings
codec = "libvorbis -q 7"; // ogg container vorbis encoder at quality level of 7
break;
case MediaTypes.ExtWebm:
case MediaTypes.ExtWebmAudio:
codec = "libvorbis -q 7"; // webm container vorbis encoder at quality level of 7
break;
default:
codec = "copy";
break;
}
var args = new StringBuilder()
.AppendFormat(ArgsOverwrite + ArgsSource, source.FullName);
if (request.TargetSampleRate.HasValue)
{
//args.AppendFormat(ArgsSampleRate, request.SampleRate.Value);
args.AppendFormat(" -af aresample={0} ", request.TargetSampleRate.Value);
}
if (request.MixDownToMono.HasValue && request.MixDownToMono.Value)
{
args.AppendFormat(ArgsChannelCount, 1);
}
if (request.Channels.NotNull())
{
// request.Channel starts at 1, ffmpeg starts at 0.
args.AppendFormat(ArgsMapChannel, request.Channels.Single() - 1);
}
FormatFfmpegOffsetArgs(request, args);
args.AppendFormat(ArgsCodecOutput, codec, output.FullName);
return(args.ToString());
}
