From fd03f074a9b95d45e3eaf1d1167616b7cd9a00db Mon Sep 17 00:00:00 2001
From: WorldObservationLog <wolc@duck.com>
Date: Sat, 18 May 2024 17:22:45 +0800
Subject: [PATCH] fix: MP4Box encapsulation error

---
 src/mp4.py | 18 +++++++++++++++++-
 src/rip.py |  5 +++--
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/mp4.py b/src/mp4.py
index c881e02..b2650f5 100644
--- a/src/mp4.py
+++ b/src/mp4.py
@@ -156,7 +156,7 @@ def encapsulate(song_info: SongInfo, decrypted_media: bytes, atmos_convent: bool
                 f.write(str(nhml_xml))
             subprocess.run(f"gpac -i {nhml_name.absolute()} nhmlr -o {song_name.absolute()}",
                            stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
-    subprocess.run(f'mp4box -ipod {song_name.absolute()}',
+    subprocess.run(f'mp4box -brand "M4A " -ab "M4A " -ab "mp42" {song_name.absolute()}',
                    stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
     with open(song_name.absolute(), "rb") as f:
         final_song = f.read()
@@ -188,3 +188,19 @@ def write_metadata(song: bytes, metadata: SongMetadata, embed_metadata: list[str
         embed_song = f.read()
     tmp_dir.cleanup()
     return embed_song
+
+
+# There are suspected errors in M4A files encapsulated by MP4Box and GPAC,
+# causing some applications to be unable to correctly process Metadata (such as Android.media, Salt Music)
+# Using FFMPEG re-encapsulating solves this problem
+def fix_encapsulate(song: bytes) -> bytes:
+    tmp_dir = TemporaryDirectory()
+    name = uuid.uuid4().hex
+    song_name = Path(tmp_dir.name) / Path(f"{name}.m4a")
+    new_song_name = Path(tmp_dir.name) / Path(f"{name}_fixed.m4a")
+    with open(song_name.absolute(), "wb") as f:
+        f.write(song)
+    subprocess.run(["ffmpeg", "-y", "-i", song_name.absolute(), "-fflags", "+bitexact", "-c:a", "copy", "-c:v", "copy",
+                    new_song_name.absolute()], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    with open(new_song_name.absolute(), "rb") as f:
+        return f.read()
diff --git a/src/rip.py b/src/rip.py
index 6a2e9c3..32245f0 100644
--- a/src/rip.py
+++ b/src/rip.py
@@ -11,7 +11,7 @@ from src.adb import Device
 from src.decrypt import decrypt
 from src.metadata import SongMetadata
 from src.models import PlaylistInfo
-from src.mp4 import extract_media, extract_song, encapsulate, write_metadata
+from src.mp4 import extract_media, extract_song, encapsulate, write_metadata, fix_encapsulate
 from src.save import save
 from src.types import GlobalAuthParams, Codec
 from src.url import Song, Album, URLType, Artist, Playlist
@@ -73,7 +73,8 @@ async def rip_song(song: Song, auth_params: GlobalAuthParams, codec: str, config
         decrypted_song = await decrypt(song_info, keys, song_data, device)
         song = encapsulate(song_info, decrypted_song, config.download.atmosConventToM4a)
         if not if_raw_atmos(codec, config.download.atmosConventToM4a):
-            song = write_metadata(song, song_metadata, config.metadata.embedMetadata, config.download.coverFormat)
+            metadata_song = write_metadata(song, song_metadata, config.metadata.embedMetadata, config.download.coverFormat)
+            song = fix_encapsulate(metadata_song)
         filename = save(song, codec, song_metadata, config.download, playlist)
         logger.info(f"Song {song_metadata.artist} - {song_metadata.title} saved!")
         if config.download.afterDownloaded: