2 files changed, 83 insertions, 15 deletions
diff --git a/app/dl_formats.py b/app/dl_formats.py
new file mode 100644
index 0000000..d0af344
--- /dev/null
+++ b/app/dl_formats.py
@@ -0,0 +1,80 @@
+def get_format(format: str, quality: str) -> str:
+    """
+    Returns format for download
+
+    Args:
+      format (str): format selected
+      quality (str): quality selected
+
+    Raises:
+      Exception: unknown quality, unknown format
+
+    Returns:
+      dl_format: Formatted download string
+    """
+    final_fmt = ""
+
+    if format.startswith("custom:"):
+        final_fmt = format[7:]
+    else:
+        final_fmt = _get_final_fmt(format, quality)
+
+    return final_fmt
+
+
+def get_opts(format: str, quality: str, ytdl_opts: dict) -> dict:
+    """
+    Returns extra download options
+    Mostly postprocessing options
+
+    Args:
+      format (str): format selected
+      quality (str): quality of format selected (needed for some formats)
+      ytdl_opts (dict): current options selected
+
+    Returns:
+      ytdl_opts: Extra options
+    """
+    if "postprocessors" not in ytdl_opts:
+        ytdl_opts["postprocessors"] = []
+
+    if format == "mp3":
+        extra_args = {}
+        if quality != "best":
+            extra_args = {"preferredquality": quality}
+        ytdl_opts["postprocessors"].append(
+            {"key": "FFmpegExtractAudio", "preferredcodec": "mp3", **extra_args},
+        )
+
+    return ytdl_opts
+
+
+def _get_final_fmt(format: str, quality: str) -> str:
+    vfmt, afmt, vres = "", "", ""
+
+    if format in ("mp4", "any"):
+        # video {res} {vfmt} + audio {afmt} {res} {vfmt}
+        if format == "mp4":
+            vfmt, afmt = "[ext=mp4]", "[ext=m4a]"
+
+        if quality == "audio":
+            final_fmt = "bestaudio/best"
+        else:
+            if quality in ("best", "audio"):
+                vres = ""
+            elif quality in ("1440", "1080", "720", "480"):
+                vres = f"[height<={quality}]"
+            else:
+                raise Exception(f"Unknown quality {quality}")
+            combo = vres + vfmt
+            final_fmt = f"bestvideo{combo}+bestaudio{afmt}/best{combo}"
+    elif format == "mp3":
+        if quality == "best" or quality in ("128", "192", "320"):
+            final_fmt = "bestaudio/best"
+            # Audio quality needs to be set post-download, set in opts
+        else:
+            raise Exception(f"Unknown quality {quality}")
+    else:
+        raise Exception(f"Unkown format {format}")
+
+    return final_fmt
diff --git a/app/ytdl.py b/app/ytdl.py
index a14855d..688744b 100644
--- a/app/ytdl.py
+++ b/app/ytdl.py
@@ -4,6 +4,7 @@ from collections import OrderedDict
 import asyncio
 import multiprocessing
 import logging
+from dl_formats import get_format, get_opts
 
 log = logging.getLogger('ytdl')
 
@@ -36,21 +37,8 @@ class Download:
     def __init__(self, download_dir, output_template, quality, format, ytdl_opts, info):
         self.download_dir = download_dir
         self.output_template = output_template
-        vfmt, afmt = '', ''
-        if format == 'mp4':
-            vfmt, afmt = '[ext=mp4]', '[ext=m4a]'
-        if quality == 'best':
-            self.format = f'bestvideo{vfmt}+bestaudio{afmt}/best{vfmt}'
-        elif quality in ('1440p', '1080p', '720p', '480p'):
-            res = quality[:-1]
-            self.format = f'bestvideo[height<={res}]{vfmt}+bestaudio{afmt}/best[height<={res}]{vfmt}'
-        elif quality == 'audio':
-            self.format = f'bestaudio{afmt}'
-        elif quality.startswith('custom:'):
-            self.format = quality[7:]
-        else:
-            raise Exception(f'unknown quality {quality}')
-        self.ytdl_opts = ytdl_opts
+        self.format = get_format(format, quality)
+        self.ytdl_opts = get_opts(format, quality, ytdl_opts)
         self.info = info
         self.canceled = False
         self.tmpfilename = None