Revert "fix #40: 音频导出过程中的&first修正，消除WAV转MP3导致的延迟"

This reverts commit cfdd2c9

Author: Starrah

MaiChartManager/Controllers/Music/MusicTransferController.cs

@@ -8,8 +8,9 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.VisualBasic.FileIO;
 using NAudio.Lame;
-using NAudio.Wave;
+using SimaiSharp;
 using Vanara.Windows.Forms;
+using Xabe.FFmpeg;
 using FolderBrowserDialog = System.Windows.Forms.FolderBrowserDialog;
 
 namespace MaiChartManager.Controllers.Music;
@@ -548,26 +549,13 @@ public async Task ExportAsMaidata(int id, string assetDir, bool ignoreVideo = fa
         await using var zipStream = HttpContext.Response.BodyWriter.AsStream();
         using var zipArchive = new ZipArchive(zipStream, ZipArchiveMode.Create, leaveOpen: true);
 
-        // 计算由于WAV转MP3导致的音频开头增加的空白段的长度，以便稍后通过&first参数给予修正。
-        // 具体的情况和原理，详见https://github.com/MuNET-OSS/MaiChartManager/issues/40
-        var wavPath = await AudioConvert.GetCachedWavPath(GetAudioCandidateIds(music));
-        if (wavPath is null)
-        {
-            var message = BuildAudioResolveErrorMessage(music);
-            logger.LogError("{message}", message);
-            throw new FileNotFoundException(message);
-        }
-        using var wavReader = new WaveFileReader(wavPath);
-        // 根据上面issue中的结论，wav转mp3引起的开头空白段的长度为1728采样点
-        var audioDelay = 1728 / (double)wavReader.WaveFormat.SampleRate;
-        
         Ma2Parser parser = new();
         var simaiFile = new StringBuilder();
 
         simaiFile.AppendLine($"&title={music.Name}");
         simaiFile.AppendLine($"&artist={music.Artist}");
         simaiFile.AppendLine($"&wholebpm={music.Bpm}");
-        simaiFile.AppendLine($"&first={audioDelay:0.####}");
+        simaiFile.AppendLine("&first=0.0333");
         simaiFile.AppendLine($"&shortid={music.Id}");
         simaiFile.AppendLine($"&genreid={music.GenreId}");
         var genre = StaticSettings.GenreList.FirstOrDefault(it => it.Id == music.GenreId);
@@ -646,10 +634,16 @@ public async Task ExportAsMaidata(int id, string assetDir, bool ignoreVideo = fa
             Comment = version?.GenreName,
             AlbumArt = img,
         };
+        var wavPath = await AudioConvert.GetCachedWavPath(GetAudioCandidateIds(music));
+        if (wavPath is null)
+        {
+            var message = BuildAudioResolveErrorMessage(music);
+            logger.LogError("{message}", message);
+            throw new FileNotFoundException(message);
+        }
 
-        AudioConvert.ConvertWavToMp3Stream(wavReader, soundStream, tag);
+        AudioConvert.ConvertWavPathToMp3Stream(wavPath, soundStream, tag);
         soundStream.Close();
-        wavReader.Close();
 
         if (!ignoreVideo && StaticSettings.MovieDataMap.TryGetValue(music.NonDxId, out var movieUsmPath))
         {

MaiChartManager/Utils/AudioConvert.cs

@@ -77,11 +77,6 @@ public static async Task<string> GetCachedWavPath(string acbPath, string awbPath
     public static void ConvertWavPathToMp3Stream(string wavPath, Stream mp3Stream, ID3TagData? tagData = null)
     {
         using var reader = new WaveFileReader(wavPath);
-        ConvertWavToMp3Stream(reader, mp3Stream, tagData);
-    }
-    
-    public static void ConvertWavToMp3Stream(WaveFileReader reader, Stream mp3Stream, ID3TagData? tagData = null)
-    {
         using var writer = new LameMP3FileWriter(mp3Stream, reader.WaveFormat, 256, tagData);
         reader.CopyTo(writer);
     }