Skip compression of atrac3 wave files

src/redux/actions.ts

@@ -450,10 +450,9 @@ async function getTrackNameFromMediaTags(file: File, titleFormat: TitleFormatTyp
     }
 }
 
-export function convertAndUpload(files: File[], format: UploadFormat, titleFormat: TitleFormatType) {
+export function convertAndUpload(files: File[], requestedFormat: UploadFormat, titleFormat: TitleFormatType) {
     return async function(dispatch: AppDispatch, getState: () => RootState) {
         const { audioExportService, netmdService } = serviceRegistry;
-        const wireformat = WireformatDict[format];
 
         await netmdService?.stop();
         dispatch(batchActions([uploadDialogActions.setVisible(true), uploadDialogActions.setCancelUpload(false)]));
@@ -498,7 +497,7 @@ export function convertAndUpload(files: File[], format: UploadFormat, titleForma
         };
 
         let conversionIterator = async function*(files: File[]) {
-            let converted: Promise<{ file: File; data: ArrayBuffer }>[] = [];
+            let converted: Promise<{ file: File; data: ArrayBuffer; format: Wireformat }>[] = [];
 
             let i = 0;
             function convertNext() {
@@ -518,11 +517,12 @@ export function convertAndUpload(files: File[], format: UploadFormat, titleForma
                 converted.push(
                     new Promise(async (resolve, reject) => {
                         let data: ArrayBuffer;
+                        let format: Wireformat;
                         try {
                             await audioExportService!.prepare(f);
-                            data = await audioExportService!.export({ format });
+                            ({ data, format } = await audioExportService!.export({ requestedFormat }));
                             convertNext();
-                            resolve({ file: f, data: data });
+                            resolve({ file: f, data: data, format: format });
                         } catch (err) {
                             error = err;
                             errorMessage = `${f.name}: Unsupported or unrecognized format`;
@@ -553,7 +553,7 @@ export function convertAndUpload(files: File[], format: UploadFormat, titleForma
                 break;
             }
 
-            const { file, data } = item;
+            const { file, data, format } = item;
 
             let title = file.name;
             try {
@@ -577,7 +577,7 @@ export function convertAndUpload(files: File[], format: UploadFormat, titleForma
             updateTrack();
             updateProgressCallback({ written: 0, encrypted: 0, total: 100 });
             try {
-                await netmdService?.upload(halfWidthTitle, fullWidthTitle, data, wireformat, updateProgressCallback);
+                await netmdService?.upload(halfWidthTitle, fullWidthTitle, data, format, updateProgressCallback);
             } catch (err) {
                 error = err;
                 errorMessage = `${file.name}: Error uploading to device. There might not be enough space left.`;

src/services/audio-export.ts

@@ -1,6 +1,8 @@
 import { createWorker, setLogging } from '@ffmpeg/ffmpeg';
 import { AtracdencProcess } from './atracdenc-worker';
-import { getPublicPathFor } from '../utils';
+import { getAtrac3Info, getPublicPathFor } from '../utils';
+import { Wireformat } from 'netmd-js';
+import { WireformatDict } from '../redux/actions';
 const AtracdencWorker = require('worker-loader!./atracdenc-worker'); // eslint-disable-line import/no-webpack-loader-syntax
 
 interface LogPayload {
@@ -10,7 +12,7 @@ interface LogPayload {
 
 export interface AudioExportService {
     init(): Promise<void>;
-    export(params: { format: string }): Promise<ArrayBuffer>;
+    export(params: { requestedFormat: 'SP' | 'LP2' | 'LP4' }): Promise<{ data: ArrayBuffer; format: Wireformat }>;
     info(): Promise<{ format: string | null; input: string | null }>;
     prepare(file: File): Promise<void>;
 }
@@ -21,12 +23,14 @@ export class FFMpegAudioExportService implements AudioExportService {
     public loglines: { action: string; message: string }[] = [];
     public inFileName: string = ``;
     public outFileNameNoExt: string = ``;
+    public inFile?: File;
 
     async init() {
         setLogging(true);
     }
 
     async prepare(file: File) {
+        this.inFile = file;
         this.loglines = [];
         this.ffmpegProcess = createWorker({
             logger: (payload: LogPayload) => {
@@ -79,33 +83,45 @@ export class FFMpegAudioExportService implements AudioExportService {
         return { format, input };
     }
 
-    async export({ format }: { format: string }) {
+    async export({ requestedFormat }: { requestedFormat: 'SP' | 'LP2' | 'LP4' | 'LP105' }) {
         let result: ArrayBuffer;
-        if (format === `SP`) {
+        let format: Wireformat;
+        const atrac3Info = await getAtrac3Info(this.inFile!);
+        if (atrac3Info) {
+            format = WireformatDict[atrac3Info.mode];
+            result = (await this.inFile!.arrayBuffer()).slice(atrac3Info.dataOffset);
+        } else if (requestedFormat === `SP`) {
             const outFileName = `${this.outFileNameNoExt}.raw`;
             await this.ffmpegProcess.transcode(this.inFileName, outFileName, '-ac 2 -ar 44100 -f s16be');
             let { data } = await this.ffmpegProcess.read(outFileName);
             result = data.buffer;
+            format = Wireformat.pcm;
         } else {
             const outFileName = `${this.outFileNameNoExt}.wav`;
             await this.ffmpegProcess.transcode(this.inFileName, outFileName, '-f wav -ar 44100 -ac 2');
             let { data } = await this.ffmpegProcess.read(outFileName);
             let bitrate: string = `0`;
-            switch (format) {
+            switch (requestedFormat) {
                 case `LP2`:
                     bitrate = `128`;
+                    format = Wireformat.lp2;
                     break;
                 case `LP105`:
                     bitrate = `102`;
+                    format = Wireformat.l105kbps;
                     break;
                 case `LP4`:
                     bitrate = `64`;
+                    format = Wireformat.lp4;
                     break;
             }
             result = await this.atracdencProcess!.encode(data.buffer, bitrate);
         }
         this.ffmpegProcess.worker.terminate();
         this.atracdencProcess!.terminate();
-        return result;
+        return {
+            data: result,
+            format,
+        };
     }
 }

src/utils.ts

@@ -472,4 +472,79 @@ export function askNotificationPermission(): Promise<NotificationPermission> {
     }
 }
 
+export async function getAtrac3Info(file: File) {
+    // see: http://soundfile.sapp.org/doc/WaveFormat/
+    // and: https://www.fatalerrors.org/a/detailed-explanation-of-wav-file-format.html
+
+    const fileData = await file.arrayBuffer();
+    if (fileData.byteLength < 44) {
+        return null;
+    }
+
+    const riffDescriptor = new Uint32Array(fileData.slice(0, 12));
+    if (riffDescriptor[0] !== 0x46464952 || riffDescriptor[2] !== 0x45564157) {
+        // 'RIFF' && 'WAVE'
+        return null;
+    }
+
+    // WAVE format
+    const waveDescriptor = new Uint32Array(fileData.slice(12, 20));
+    if (waveDescriptor[0] !== 0x20746d66) {
+        return false;
+    }
+
+    const audioFormatAndChanneld = new Uint16Array(fileData.slice(20, 24));
+    if (audioFormatAndChanneld[0] !== 0x270 || audioFormatAndChanneld[1] !== 2) {
+        // 'atrac3' && 2 channels
+        return null;
+    }
+
+    const sampleRateAndByteRate = new Uint32Array(fileData.slice(24, 32));
+    if (sampleRateAndByteRate[0] !== 44100) {
+        // Sample rate
+        return null;
+    }
+    const byteRate = sampleRateAndByteRate[1];
+
+    let mode: 'LP2' | 'LP105' | 'LP4' | null = null;
+    if (byteRate > 16000) {
+        mode = 'LP2';
+    } else if (byteRate > 13000) {
+        mode = 'LP105';
+    } else if (byteRate > 8000) {
+        mode = 'LP4';
+    } else {
+        mode = null;
+    }
+
+    if (mode === null) {
+        return null;
+    }
+
+    const waveBlockEndOffset = new Uint16Array(fileData.slice(36, 38));
+
+    let dataOffset = -1;
+
+    const nextBlockStartOffset = waveBlockEndOffset[0] + 38;
+    const nextBlockEndOffset = nextBlockStartOffset + 8;
+    const nextBlock = new Uint32Array(fileData.slice(nextBlockStartOffset, nextBlockEndOffset));
+    if (nextBlock[0] === 0x61746164) {
+        // data
+        dataOffset = nextBlockEndOffset;
+    } else if (nextBlock[0] === 0x74636166) {
+        // fact
+        const dataBlockLength = 8;
+        dataOffset = nextBlockEndOffset + nextBlock[1] + dataBlockLength;
+    }
+
+    if (dataOffset === -1) {
+        return null;
+    }
+
+    return {
+        mode,
+        dataOffset,
+    };
+}
+
 declare let process: any;