1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
#+title: Recursive Command-Line FLAC to Opus Conversion
#+date: 2022-07-30
#+description: Learn how to convert all FLAC files to Opus, including recursive files in subdirectories.
#+filetags: :linux:
* Converting FLAC to OPUS
I am currently rebuilding my music library from scratch so that I can
effectively archive all the music I own in the
[[https://en.wikipedia.org/wiki/FLAC][FLAC file format]], a lossless
audio codec.
However, streaming FLAC files outside the home can be difficult due to
the size of the files, especially if you're using a weak connection.
So, in order to archive the music in a lossless format and still be able
to stream it easily, I opted to create a copy of my FLAC files in the
[[https://en.wikipedia.org/wiki/Opus_(audio_format)][Opus audio codec]].
This allows me to archive a quality, lossless version of the music and
then point my streaming service to the smaller, stream-ready version.
** Dependencies
The process I follow utilizes the =opus-tools= package in Ubuntu. Before
proceeding, install the package:
#+begin_src sh
sudo apt install opus-tools
#+end_src
If you want to use a different conversion method, such as =ffmpeg= or
=avconv=, simply install that package instead.
** Conversion Process
The script I'm using is stored in my home directory, but feel free to
create it wherever you want. It does not need to be in the same
directory as your music files.
#+begin_src sh
cd ~ && nano transform.sh
#+end_src
Once you have your new bash script opened in an editor, go ahead and
paste the following logic into the script.
You *MUST* edit the following variables in order for it to work:
- =source=: The source directory where your FLAC files are stored.
- =dest=: The destination directory where you want the resulting Opus
files to be stored.
You *MAY* want to edit the following variables to suit your needs:
- =filename=: If you are converting to a file format other than Opus,
you'll need to edit this so that your resulting files have the correct
filename extension.
- =reldir=: This variable can be edited to strip out more leading
directories in the file path. As you'll see later, I ignore this for
now and simply clean it up afterward.
- =opusenc=: This is the actual conversion process. You may want to edit
the bitrate to suit your needs. I set mine at 128 but some prefer 160
or higher.
#+begin_src sh
#!/bin/bash
## - The IFS takes care of spaces in file and dirnames
## - your folders may vary
## - what you mount to the folders does not matter
## - in RELDIR, the f5 most likely MUST be edited,
## since its responsible, how many leading directories
## will be removed from the directory structure in order
## to append that exact path to the outfile
## - the commented echos are still in place in order to give
## you the variables for testing, before running.
IFS=$'\n'
## the paths given here contain the directory structure that I want to keep
## source=/mnt/music/archives/ARTIST/ALBUM/FLACFILE.flac
## local=/mnt/music/library/ARTIST/ALBUM/OPUSFILE.opus
source=/mnt/music/archives
dest=/mnt/music/library
for i in $(find $source -type f -iname '*.flac' );
do
## SET VARIABLES for PATHS and FILENAMES
fullfile=$i
filename="${i##*/}"
filename="${filename%.*}.opus"
fulldir=$(dirname "${i}")
reldir="$(echo $fulldir | cut -d'/' -f5-)"
reldir=${reldir//flac}
outdir="$dest/$reldir"
outfile="$outdir/$filename"
# is that working?
# outfile='$local/""$(echo $(dirname "${i}") | cut -d'/' -f5-)"//flac"/"${i##*/}"'
# echo 'output file: ' "$outfile"
## SHOW ME THE CONTENTS of the VARIABLES
# echo 'File found:' "$i"
# echo 'Relative dir: ' "$reldir"
# echo 'directory will be created: ' "$outdir"
# echo 'Filename: ' "$filename"
# echo 'FileExt: ' "$extension"
# echo 'output file: ' "$outfile"
echo "\n\n"
## CREATE Output Folders
mkdir -p "$outdir"
## RUN
# ffmpeg and avconv are alternative options if opusenc isn't adequate
opusenc --vbr --bitrate 128 --date "$DATE" \
--title "$TITLE" --artist "$ARTIST" --album "$ALBUM" --genre "$GENRE" \
--comment "ALBUMARTIST=$ALBUMARTIST" --comment "DISCNUMBER=$DISCNUMBER" \
--comment "TRACKNUMBER=$TRACKNUMBER" --comment "TRACKTOTAL=$TRACKTOTAL" \
--comment "LYRICS=$LYRICS" "$fullfile" "$outfile"
## just for testing
# sleep 1
done
#+end_src
Once you're done, simply save the file and exit your editor. Don't
forget to enable execution of the script:
#+begin_src sh
chmod +x transform.sh
#+end_src
Finally, you may now run the script:
#+begin_src sh
./transform.sh
#+end_src
If you used =opusenc=, you'll see the conversions happen within the
terminal as it progresses. You will also see variables printed if you
uncommented any of the bash script's comments.
** Cleanup
As I noted above, I didn't customize my =reldir= variable in the script,
which caused my output directory to be =/mnt/music/library/archives=
instead of =/mnt/music/library=. So, I moved the output up one level and
deleted the accidental directory.
#+begin_src sh
cd /mnt/music/library
mv archives/** .
rm -rf archives
#+end_src
** Check the Resulting Size
If you want to see what kind of file size savings you've gained, you can
always use the =du= command to check:
#+begin_src sh
cd /mnt/music
du -h --max-depth=1 .
#+end_src
In my case, my small library went from 78GB to 6.3GB!
#+begin_src txt
78G ./archives
6.3G ./library
#+end_src
|
