Expect Python to be already in PATH (#114)

* Expect python to already be in PATH

* Expect python to be in PATH

* Fix special handlling of conversion on windows

* Some cleaning

* Update docs

core/convert.py

@@ -2,6 +2,16 @@ import subprocess
 import os
 
 
+"""
+What are the differences and similarities between ffmpeg, libav, and avconv?
+https://stackoverflow.com/questions/9477115
+ffmeg encoders high to lower quality
+libopus > libvorbis >= libfdk_aac > aac > libmp3lame
+libfdk_aac due to copyrights needs to be compiled by end user
+on MacOS brew install ffmpeg --with-fdk-aac will do just that. Other OS?
+https://trac.ffmpeg.org/wiki/Encode/AAC
+"""
+
 def song(input_song, output_song, folder, avconv=False, verbose=False):
     """Do the audio format conversion."""
     if not input_song == output_song:
@@ -17,17 +27,12 @@ def song(input_song, output_song, folder, avconv=False, verbose=False):
 
 def convert_with_avconv(input_song, output_song, folder, verbose):
     """Convert the audio file using avconv."""
-    if os.name == 'nt':
-        avconv_path = '..\\Scripts\\avconv.exe'
-    else:
-        avconv_path = 'avconv'
-
     if verbose:
         level = 'debug'
     else:
         level = '0'
 
-    command = [avconv_path,
+    command = ['avconv',
                '-loglevel', level,
                '-i',        os.path.join(folder, input_song),
                '-ab',       '192k',
@@ -37,27 +42,11 @@ def convert_with_avconv(input_song, output_song, folder, verbose):
 
 
 def convert_with_ffmpeg(input_song, output_song, folder, verbose):
-    """Convert the audio file using FFMpeg.
-
-    What are the differences and similarities between ffmpeg, libav, and avconv?
-    https://stackoverflow.com/questions/9477115
-    ffmeg encoders high to lower quality
-    libopus > libvorbis >= libfdk_aac > aac > libmp3lame
-    libfdk_aac due to copyrights needs to be compiled by end user
-    on MacOS brew install ffmpeg --with-fdk-aac will do just that. Other OS?
-    https://trac.ffmpeg.org/wiki/Encode/AAC
-    """
-
-    if os.name == "nt":
-        ffmpeg_pre = '..\\Scripts\\ffmpeg.exe '
-    else:
-        ffmpeg_pre = 'ffmpeg '
-
-    ffmpeg_pre += '-y '
+    """Convert the audio file using FFmpeg."""
+    ffmpeg_pre = 'ffmpeg -y '
     if not verbose:
         ffmpeg_pre += '-hide_banner -nostats -v panic '
 
-    ffmpeg_params = ''
     input_ext = input_song.split('.')[-1]
     output_ext = output_song.split('.')[-1]