- audio - conversion to opus

Author: devgopher

3dParty/FileSignatures

@@ -15,7 +15,7 @@ public UniversalConvertorTests()
         }
 
         [Test()]
-        public void ConvertMp3ToMp3Test()
+        public void ConvertMp3ToOpusTest()
         {
             if (!File.Exists("voice.mp3"))
                 Assert.Fail("no voice.mp3!");

Botticelli.Audio.Tests/UniversalConvertorTests.cs

@@ -3,7 +3,7 @@
     public class AudioInfo
     {
         public AudioFormat AudioFormat { get; set; }
-        public int Bitrate => BitsPerSample * SampleRate;
+        public int Bitrate { get; set; }
         public int BitsPerSample { get; set; }
         public int SampleRate { get; set; }
         public int Channels { get; set; }

Botticelli.Audio/AudioInfo.cs

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="FFMpegCore" Version="5.1.0" />
     <PackageReference Include="NAudio" Version="2.2.1" />
     <PackageReference Include="NAudio.Lame" Version="2.1.0" />
     <PackageReference Include="NAudio.Vorbis" Version="1.5.0" />

Botticelli.Audio/Botticelli.Audio.csproj

@@ -1,4 +1,8 @@
-using NAudio.Lame;
+using FFMpegCore;
+using FFMpegCore.Enums;
+using FFMpegCore.Exceptions;
+using FFMpegCore.Pipes;
+using NAudio.Lame;
 using NAudio.Vorbis;
 using NAudio.Wave;
 
@@ -12,60 +16,64 @@ public class UniversalConvertor : IConvertor
 
     public byte[] Convert(Stream input, AudioInfo targetParams)
     {
-        var srcParams = _analyzer.Analyze(input);
-
-        //if (targetParams.AudioFormat == AudioFormat.Opus)
-        //    return ProcessByStreamEncoder<OpusEncoder, OpusAudioEncoderConfiguration>(input, srcParams);
-        //if (targetParams.AudioFormat == AudioFormat.M4a || targetParams.AudioFormat == AudioFormat.Aac)
-        //    return ProcessByStreamEncoder<AACEncoder, AacAudioEncoderConfiguration>(input, srcParams);
+        if (targetParams.AudioFormat is AudioFormat.M4a or AudioFormat.Aac or AudioFormat.Opus)
+            return ProcessByStreamEncoder(input, targetParams);
 
+        var srcParams = _analyzer.Analyze(input);
 
         using var resultStream = new MemoryStream();
         using var srcStream = GetSourceWaveStream(input, srcParams);
         using var tgtStream = GetTargetWaveStream(srcStream, targetParams);
-        var result = tgtStream.ToArray();
-        return result;
-    }
-
-    //private static byte[] ProcessByStreamEncoder<TEnc, TConfig>(Stream input, AudioInfo srcParams)
-    //where TEnc : IAudioEncoderBase, new()
-    //where TConfig : AudioEncoderConfiguration, new()
-    //{
-    //    using var enc = new TEnc();
-
-    //    InitStreamEncoder<TEnc, TConfig>(srcParams, enc);
-
-    //    using var sr = new BinaryReader(input);
 
-    //    var bytes = sr.ReadBytes((int)input.Length);
-    //    enc.Transform(new MediaBuffer<byte>(bytes));
-
-    //    return enc.OutputQueue?.LastOrDefault()?.Buffer?.Array;
-    //}
+        return tgtStream.ToArray();
+    }
 
-    //private static void InitStreamEncoder<TEnc, TConfig>(AudioInfo srcParams, TEnc enc)
-    //    where TEnc : IAudioEncoderBase, new()
-    //    where TConfig : AudioEncoderConfiguration, new()
-    //{
-    //    enc.Init(new TConfig()
-    //    {
-    //        Channels = srcParams.Channels,
-    //        Samplerate = srcParams.SampleRate,
-    //        BitsPerSample = srcParams.BitsPerSample,
-    //        Bitrate = srcParams.Bitrate
-    //    });
-    //}
+    private static byte[] ProcessByStreamEncoder(Stream input, AudioInfo tgtParams)
+    {
+        try
+        {
+            var codec = string.Empty;
+            input.Seek(0, SeekOrigin.Begin);
+
+            switch (tgtParams.AudioFormat)
+            {
+                case AudioFormat.Ogg:
+                    codec = "ogg";
+                    break;
+                case AudioFormat.Aac:
+                case AudioFormat.M4a:
+                    codec = "aac";
+                    break;
+                case AudioFormat.Opus:
+                    codec = "opus";
+                    break;
+                case AudioFormat.Unknown:
+                default:
+                    throw new ArgumentOutOfRangeException();
+            }
+
+            using var output = new MemoryStream();
+            FFMpegArguments
+                .FromPipeInput(new StreamPipeSource(input))
+                .OutputToPipe(new StreamPipeSink(output), options => options
+                    .ForceFormat(codec)
+                    .WithAudioBitrate(AudioQuality.Low))
+                .ProcessSynchronously();
+            
+            return output.ToArray();
+        }
+        catch (IOException ex)
+        {
+            return Array.Empty<byte>();
+        }
+    }
 
     private WaveStream GetSourceWaveStream(Stream input, AudioInfo srcParams)
     {
         return srcParams.AudioFormat switch
         {
             AudioFormat.Mp3     => new Mp3FileReader(input),
             AudioFormat.Ogg     => new VorbisWaveReader(input),
-            //AudioFormat.Wav     => new WaveFileReader(input),
-            //AudioFormat.Aac     => new WaveFileReader(input),
-            //AudioFormat.M4a     => new WaveFileReader(input),
-            //AudioFormat.Unknown => new WaveFileReader(input),
             _                   => new WaveFileReader(input)
         };
     }
@@ -77,7 +85,7 @@ private MemoryStream GetTargetWaveStream(WaveStream input, AudioInfo srcParams)
 
         Stream writerStream = srcParams.AudioFormat switch
         {
-            AudioFormat.Mp3     => new LameMP3FileWriter(ms, input.WaveFormat, LAMEPreset.MEDIUM_FAST),
+            AudioFormat.Mp3     => new LameMP3FileWriter(ms, input.WaveFormat, LAMEPreset.ABR_16),
             //AudioFormat.Wav     => new WavFileWriter(input),
             //AudioFormat.Aac     => new WavFileWriter(input),
             //AudioFormat.M4a     => new WavFileWriter(input),