update: journal entry week starting 10 February

docs/posts/2025/february/10.md

@@ -2,7 +2,7 @@
 title: First glimpse of Spring
 date:
   created: 2025-02-10
-  updated: 2025-02-15
+  updated: 2025-02-16
 authors:
   - practicalli
 categories:
@@ -14,18 +14,48 @@ tags:
 draft: false
 ---
 
-A sunny day at the end of the week inspired me to get out on my road bike, doing some [important bike maintenance](#cycling)
+A sunny day at the end of the week inspired me to get out on my road bike, once essential [bike maintenance](#cycling) was completed.
+
+Saturday Park Run was the first in over a year and it was very challenging.  My time was 39 minutes and 25 seconds, around 9 minutes slower than my personal best so there is a long road ahead to a reasonable fitness.
 
 April is the start of a new tax year in the UK so time for a [personal financial review](#finances).
 
-This weeks digital music organisation included [The Cranberries](https://en.wikipedia.org/wiki/The_Cranberries), an excellent Irish rock band.
+This weeks digital music organisation included [The Cranberries](https://en.wikipedia.org/wiki/The_Cranberries), an excellent Irish rock band. [The Mission](https://en.wikipedia.org/wiki/The_Mission_(band)) and [Fields Of The Nephilim](https://en.wikipedia.org/wiki/Fields_of_the_Nephilim) unleashed my inner Goth.
 
 ![Ribble Endurance SL Disc road bicycle](https://c02.purpledshub.com/uploads/sites/39/2019/05/DSC_6888-2827ed4-e1568023172553.jpg){loading=lazy}
 
 
 <!-- more -->
 
 
+## Digital Music
+
+ffmpeg is a versatile tool for converting audio and video formats and has a huge amount of options that I dont really want to keep looking up for common tasks.
+
+
+Using `*.{wav,flac,mp3,opus}` in the `for` expression will fail as it expects to find at least 1 file for each of the file name extensions listed in the collection, e.g. if none of the files end in `.wav` then the `for` expression will fail even if there are files with one of the other file name extensions.
+
+`*.(wav|flac|mp3|ogg)` uses the `Or` pattern (`|`) so will succeed if there is at least one file that contains one of the file name extensions, e.g. if there is a `.wav` file then the script succeeds even if the directory does not contain any of the other file name extensions.
+
+
+!!! EXAMPLE "Convert music file to Opus format"
+    ```shell
+    #!/usr/bin/zsh
+
+    # Convert audio files (.wav, .flac, .mp3) in current directory to Opus format
+    # zsh specific parsing of current directory
+    # `*.(wav|flac|mp3)` matches file name with any of the wav, flac or mp3 file extensions
+    #
+    # libopus uses variable bit rate by default - https://ffmpeg.org/ffmpeg-codecs.html#libopus-1
+    # 96 to 128k bit rate recommended for Music
+    # 128k variable bit rate encoding provides near transparent encoding
+
+    for x in *.(wav|flac|mp3|ogg) ; do
+      ffmpeg -i "$x" -b:a 96k -c:a libopus "${x:r}".opus
+    done
+    ```
+
+
 ## Finances
 
 Its that time of the year to review my tax position for the 2024-25 tax year.  I earned sufficient to pay tax in the highest band, so I am reviewing if I need to increase my personal pension contributions to offset the tax paid for the year.