From 07422debb9a69a2dfb3059bef80d096774f87adb Mon Sep 17 00:00:00 2001
From: Daniel <790119+DanTheMan827@users.noreply.github.com>
Date: Fri, 27 Feb 2026 21:05:58 +0000
Subject: [PATCH] feat(downloads): add lossless container option

This uses ffmpeg to ensure that the downloaded lossless audio is in the desired container format.
---
 index.html      | 11 +++++++++++
 js/api.js       | 40 +++++++++++++++++++++++++++++++++++++++-
 js/downloads.js | 40 +++++++++++++++++++++++++++++++++++++++-
 js/settings.js  | 10 ++++++++++
 js/storage.js   | 14 ++++++++++++++
 5 files changed, 113 insertions(+), 2 deletions(-)

diff --git a/index.html b/index.html
index 6a3b5c8..9506106 100644
--- a/index.html
+++ b/index.html
@@ -4316,6 +4316,17 @@
                                         <option value="LOW">AAC 96kbps</option>
                                     </select>
                                 </div>
+                                <div class="setting-item">
+                                    <div class="info">
+                                        <span class="label">Lossless Container</span>
+                                        <span class="description">Container format for lossless downloads</span>
+                                    </div>
+                                    <select id="lossless-container-setting">
+                                        <option value="flac">FLAC</option>
+                                        <option value="alac">Apple Lossless</option>
+                                        <option value="nochange">Don't change</option>
+                                    </select>
+                                </div>
                                 <div class="setting-item">
                                     <div class="info">
                                         <span class="label">Cover Art Size</span>
diff --git a/js/api.js b/js/api.js
index ce18fdc..5355a9a 100644
--- a/js/api.js
+++ b/js/api.js
@@ -6,11 +6,12 @@ import {
     isTrackUnavailable,
     getExtensionFromBlob,
 } from './utils.js';
-import { trackDateSettings } from './storage.js';
+import { trackDateSettings, losslessContainerSettings } from './storage.js';
 import { APICache } from './cache.js';
 import { addMetadataToAudio } from './metadata.js';
 import { DashDownloader } from './dash-downloader.js';
 import { encodeToMp3, MP3EncodingError } from './mp3-encoder.js';
+import { ffmpeg } from './ffmpeg.js';
 
 export const DASH_MANIFEST_UNAVAILABLE_CODE = 'DASH_MANIFEST_UNAVAILABLE';
 const TIDAL_V2_TOKEN = 'txNoH4kkV41MfH25';
@@ -1208,6 +1209,43 @@ export class LosslessAPI {
                 }
             }
 
+            if (quality.endsWith('LOSSLESS')) {
+                try {
+                    switch (losslessContainerSettings.getContainer()) {
+                        case 'flac':
+                            if ((await getExtensionFromBlob(blob)) != 'flac') {
+                                blob = await ffmpeg(
+                                    blob,
+                                    { args: ['-c:a', 'flac'] },
+                                    'output.flac',
+                                    'audio/flac',
+                                    onProgress,
+                                    options.signal
+                                );
+                            }
+                            break;
+                        case 'alac':
+                            blob = await ffmpeg(
+                                blob,
+                                { args: ['-c:a', 'alac'] },
+                                'output.m4a',
+                                'audio/m4a',
+                                onProgress,
+                                options.signal
+                            );
+                            break;
+                        default:
+                            break;
+                    }
+                } catch (error) {
+                    if (error?.name === 'AbortError') {
+                        throw error;
+                    }
+
+                    console.error('Lossless container conversion failed:', error);
+                }
+            }
+
             // Add metadata if track information is provided
             if (track) {
                 if (onProgress) {
diff --git a/js/downloads.js b/js/downloads.js
index 594481f..616e5f8 100644
--- a/js/downloads.js
+++ b/js/downloads.js
@@ -11,11 +11,12 @@ import {
     getExtensionFromBlob,
     escapeHtml,
 } from './utils.js';
-import { lyricsSettings, bulkDownloadSettings, playlistSettings } from './storage.js';
+import { lyricsSettings, bulkDownloadSettings, losslessContainerSettings, playlistSettings } from './storage.js';
 import { addMetadataToAudio } from './metadata.js';
 import { DashDownloader } from './dash-downloader.js';
 import { generateM3U, generateM3U8, generateCUE, generateNFO, generateJSON } from './playlist-generator.js';
 import { encodeToMp3 } from './mp3-encoder.js';
+import { ffmpeg } from './ffmpeg.js';
 
 const downloadTasks = new Map();
 const bulkDownloadTasks = new Map();
@@ -350,6 +351,43 @@ async function downloadTrackBlob(track, quality, api, lyricsManager = null, sign
         blob = await encodeToMp3(blob, () => undefined, signal);
     }
 
+    if (quality.endsWith('LOSSLESS')) {
+        try {
+            switch (losslessContainerSettings.getContainer()) {
+                case 'flac':
+                    if ((await getExtensionFromBlob(blob)) != 'flac') {
+                        blob = await ffmpeg(
+                            blob,
+                            { args: ['-c:a', 'flac'] },
+                            'output.flac',
+                            'audio/flac',
+                            () => undefined,
+                            signal
+                        );
+                    }
+                    break;
+                case 'alac':
+                    blob = await ffmpeg(
+                        blob,
+                        { args: ['-c:a', 'alac'] },
+                        'output.m4a',
+                        'audio/m4a',
+                        () => undefined,
+                        signal
+                    );
+                    break;
+                default:
+                    break;
+            }
+        } catch (error) {
+            if (error?.name === 'AbortError') {
+                throw error;
+            }
+
+            console.error('Lossless container conversion failed:', error);
+        }
+    }
+
     // Detect actual format from blob signature BEFORE adding metadata
     const extension = await getExtensionFromBlob(blob);
 
diff --git a/js/settings.js b/js/settings.js
index dd310ff..514fe4f 100644
--- a/js/settings.js
+++ b/js/settings.js
@@ -11,6 +11,7 @@ import {
     replayGainSettings,
     smoothScrollingSettings,
     downloadQualitySettings,
+    losslessContainerSettings,
     coverArtSizeSettings,
     qualityBadgeSettings,
     trackDateSettings,
@@ -805,6 +806,15 @@ export function initializeSettings(scrobbler, player, api, ui) {
         });
     }
 
+    const losslessContainerSetting = document.getElementById('lossless-container-setting');
+    if (losslessContainerSetting) {
+        losslessContainerSetting.value = losslessContainerSettings.getContainer();
+
+        losslessContainerSetting.addEventListener('change', (e) => {
+            losslessContainerSettings.setContainer(e.target.value);
+        });
+    }
+
     // Cover Art Size setting
     const coverArtSizeSetting = document.getElementById('cover-art-size-setting');
     if (coverArtSizeSetting) {
diff --git a/js/storage.js b/js/storage.js
index a152638..7a6027d 100644
--- a/js/storage.js
+++ b/js/storage.js
@@ -533,6 +533,20 @@ export const downloadQualitySettings = {
     },
 };
 
+export const losslessContainerSettings = {
+    STORAGE_KEY: 'lossless-container',
+    getContainer() {
+        try {
+            return localStorage.getItem(this.STORAGE_KEY) || 'flac';
+        } catch {
+            return 'flac';
+        }
+    },
+    setContainer(container) {
+        localStorage.setItem(this.STORAGE_KEY, container);
+    },
+};
+
 export const coverArtSizeSettings = {
     STORAGE_KEY: 'cover-art-size',
     getSize() {