/// <summary>
/// Generates a visualisation of an audio stream using the 'showfreqs' filter
/// </summary>
/// <param name="inputPath">Path to the input file containing the audio stream to visualise</param>
/// <param name="outputPath">Path to output the visualised audio stream to</param>
/// <param name="size">The Size of the outputted video stream</param>
/// <param name="pixelFormat">The output pixel format (default is yuv420p)</param>
/// <param name="mode">The visualisation mode (default is bar)</param>
/// <param name="amplitudeScale">The frequency scale (default is lin)</param>
/// <param name="frequencyScale">The amplitude scale (default is log)</param>
/// <returns>IConversion object</returns>
public async Task <IConversion> VisualiseAudio(string inputPath, string outputPath, VideoSize size,
PixelFormat pixelFormat = PixelFormat.yuv420p,
VisualisationMode mode = VisualisationMode.bar,
AmplitudeScale amplitudeScale = AmplitudeScale.lin,
FrequencyScale frequencyScale = FrequencyScale.log)
{
return(await Task.FromResult(Conversion.VisualiseAudio(inputPath, outputPath, size, pixelFormat, mode, amplitudeScale, frequencyScale)));
}
private void Update(EvaluationContext context)
{
var t = (float)EvaluationContext.BeatTime * SpeedFactor.GetValue(context);
//var value = Value.GetValue(context);
var amplitude = Amplitude.GetValue(context);
var period = Period.GetValue(context);
var offset = Offset.GetValue(context);
var phase = Phase.GetValue(context);
var amplitudeScale = AmplitudeScale.GetValue(context);
Result.Value = new System.Numerics.Vector2(
(float)Math.Sin(t / period.X + phase.X) * amplitude.X * amplitudeScale + offset.X,
(float)Math.Sin(t / period.Y + phase.Y) * amplitude.Y * amplitudeScale + offset.Y
);
}
public static IConversion VisualiseAudio(string inputPath, string outputPath, VideoSize size,
PixelFormat pixelFormat = PixelFormat.yuv420p,
VisualisationMode mode = VisualisationMode.bar,
AmplitudeScale amplitudeScale = AmplitudeScale.lin,
FrequencyScale frequencyScale = FrequencyScale.log)
{
IMediaInfo inputInfo = FFmpeg.GetMediaInfo(inputPath).GetAwaiter().GetResult();
IAudioStream audioStream = inputInfo.AudioStreams.FirstOrDefault();
IVideoStream videoStream = inputInfo.VideoStreams.FirstOrDefault();
string filter = $"\"[0:a]showfreqs=mode={mode}:fscale={frequencyScale}:ascale={amplitudeScale},format={pixelFormat},scale={size.ToFFmpegFormat()} [v]\"";
return(New()
.AddStream(audioStream)
.AddParameter($"-filter_complex {filter}")
.AddParameter("-map [v]")
.SetFrameRate(videoStream != null ? videoStream.Framerate : 30) // Pin framerate at the original rate or 30 fps to stop dropped or duplicated frames
.SetOutput(outputPath));
}
private void Update(EvaluationContext context)
{
var t = OverrideTime.IsConnected
? OverrideTime.GetValue(context)
: (float)context.LocalFxTime * SpeedFactor.GetValue(context);
//var value = Value.GetValue(context);
var amplitude = Amplitude.GetValue(context);
var period = Period.GetValue(context);
var offset = Offset.GetValue(context);
var phase = Phase.GetValue(context);
var amplitudeScale = AmplitudeScale.GetValue(context);
Result.Value = new Vector3(
(float)Math.Sin(t / period.X + phase.X) * amplitude.X * amplitudeScale + offset.X,
(float)Math.Sin(t / period.Y + phase.Y) * amplitude.Y * amplitudeScale + offset.Y,
(float)Math.Sin(t / period.Z + phase.Z) * amplitude.Z * amplitudeScale + offset.Z
);
}
public async Task VisualiseAudioTest(VideoSize size, PixelFormat pixelFormat, VisualisationMode mode, AmplitudeScale amplitudeScale, FrequencyScale frequencyScale)
{
string output = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + FileExtensions.Mp4);
IMediaInfo info = await FFmpeg.GetMediaInfo(Resources.MkvWithAudio);
IAudioStream audioStream = info.AudioStreams.First()?.SetCodec(AudioCodec.aac);
IConversionResult conversionResult = await(await FFmpeg.Conversions.FromSnippet.VisualiseAudio(Resources.Mp4WithAudio, output, size, pixelFormat, mode, amplitudeScale, frequencyScale))
.Start();
IMediaInfo resultFile = await FFmpeg.GetMediaInfo(output);
// The resulting streams are 4 seconds longer than the original
Assert.Equal(resultFile.VideoStreams.First().Duration, audioStream.Duration + TimeSpan.FromSeconds(4));
Assert.Equal(resultFile.AudioStreams.First().Duration, audioStream.Duration + TimeSpan.FromSeconds(4));
Assert.Equal(1920, resultFile.VideoStreams.First().Width);
Assert.Equal(1080, resultFile.VideoStreams.First().Height);
}
