[ExtractAudio] Rescale --audio-quality correctly

Authored by: CrypticSignal, pukkandan

4 files changed, 28 insertions, 17 deletions

diff --git a/yt_dlp/__init__.py b/yt_dlp/__init__.py
index 84628bf45..0070d50a8 100644
--- a/yt_dlp/__init__.py
+++ b/yt_dlp/__init__.py
@@ -29,6 +29,8 @@ from .utils import (
     error_to_compat_str,
     ExistingVideoReached,
     expand_path,
+    float_or_none,
+    int_or_none,
     match_filter_func,
     MaxDownloadsReached,
     parse_duration,
@@ -230,7 +232,7 @@ def _real_main(argv=None):
             parser.error('invalid audio format specified')
     if opts.audioquality:
         opts.audioquality = opts.audioquality.strip('k').strip('K')
-        if not opts.audioquality.isdigit():
+        if int_or_none(float_or_none(opts.audioquality)) is None:  # int_or_none prevents inf, nan
             parser.error('invalid audio quality specified')
     if opts.recodevideo is not None:
         opts.recodevideo = opts.recodevideo.replace(' ', '')
diff --git a/yt_dlp/options.py b/yt_dlp/options.py
index a3a6c74b3..bd9fdd37b 100644
--- a/yt_dlp/options.py
+++ b/yt_dlp/options.py
@@ -1215,7 +1215,7 @@ def parseOpts(overrideArguments=None):
     postproc.add_option(
         '--audio-quality', metavar='QUALITY',
         dest='audioquality', default='5',
-        help='Specify ffmpeg audio quality, insert a value between 0 (better) and 9 (worse) for VBR or a specific bitrate like 128K (default %default)')
+        help='Specify ffmpeg audio quality, insert a value between 0 (best) and 10 (worst) for VBR or a specific bitrate like 128K (default %default)')
     postproc.add_option(
         '--remux-video',
         metavar='FORMAT', dest='remuxvideo', default=None,
diff --git a/yt_dlp/postprocessor/ffmpeg.py b/yt_dlp/postprocessor/ffmpeg.py
index b7fcc569b..96f7be6ff 100644
--- a/yt_dlp/postprocessor/ffmpeg.py
+++ b/yt_dlp/postprocessor/ffmpeg.py
@@ -371,9 +371,29 @@ class FFmpegExtractAudioPP(FFmpegPostProcessor):
     def __init__(self, downloader=None, preferredcodec=None, preferredquality=None, nopostoverwrites=False):
         FFmpegPostProcessor.__init__(self, downloader)
         self._preferredcodec = preferredcodec or 'best'
-        self._preferredquality = preferredquality
+        self._preferredquality = float_or_none(preferredquality)
         self._nopostoverwrites = nopostoverwrites
 
+    def _quality_args(self, codec):
+        if self._preferredquality is None:
+            return []
+        elif self._preferredquality > 10:
+            return ['-b:a', f'{self._preferredquality}k']
+
+        limits = {
+            'libmp3lame': (10, 0),
+            'aac': (0.1, 11),
+            'vorbis': (0, 10),
+            'opus': None,  # doesn't support -q:a
+            'wav': None,
+            'flac': None,
+        }[codec]
+        if not limits:
+            return []
+
+        q = limits[1] + (limits[0] - limits[1]) * (self._preferredquality / 10)
+        return ['-q:a', f'{q}']
+
     def run_ffmpeg(self, path, out_path, codec, more_opts):
         if codec is None:
             acodec_opts = []
@@ -417,23 +437,12 @@ class FFmpegExtractAudioPP(FFmpegPostProcessor):
                 # MP3 otherwise.
                 acodec = 'libmp3lame'
                 extension = 'mp3'
-                more_opts = []
-                if self._preferredquality is not None:
-                    if int(self._preferredquality) < 10:
-                        more_opts += ['-q:a', self._preferredquality]
-                    else:
-                        more_opts += ['-b:a', self._preferredquality + 'k']
+                more_opts = self._quality_args(acodec)
         else:
             # We convert the audio (lossy if codec is lossy)
             acodec = ACODECS[self._preferredcodec]
             extension = self._preferredcodec
-            more_opts = []
-            if self._preferredquality is not None:
-                # The opus codec doesn't support the -aq option
-                if int(self._preferredquality) < 10 and extension != 'opus':
-                    more_opts += ['-q:a', self._preferredquality]
-                else:
-                    more_opts += ['-b:a', self._preferredquality + 'k']
+            more_opts = self._quality_args(acodec)
             if self._preferredcodec == 'aac':
                 more_opts += ['-f', 'adts']
             if self._preferredcodec == 'm4a':
diff --git a/yt_dlp/utils.py b/yt_dlp/utils.py
index 2953909fc..62f83c9ce 100644
--- a/yt_dlp/utils.py
+++ b/yt_dlp/utils.py
@@ -3871,7 +3871,7 @@ def int_or_none(v, scale=1, default=None, get_attr=None, invscale=1):
         return default
     try:
         return int(v) * invscale // scale
-    except (ValueError, TypeError):
+    except (ValueError, TypeError, OverflowError):
         return default