Howto: How to load music and audio books on hörbert’s memory card under Linux. You do not need the Hörbert software.
What you need
With’ sox’ and simple file commands you can fill the card yourself. You can usually install’ sox’ with the package manager of your distribution.
The file system
Memory card format
The memory card must be formatted in FAT32 format. Our memory cards are delivered in this format. According to the specification, a maximum of 32GB cards can be formatted with FAT32.
Folder structure and files on the memory card
The root directory of the card must contain folders with the names 0 to 8. This contains your audio files 0. WAV 1. WAV 2. WAV etc. The file names determine the playlist order and start with 0. WAV (decimal number zero).
As long as you always convert the files yourself and copy them to the hörbert’s memory card, you don’t have to worry about the file hoerbert.xml. This file is only used by the hörbert software for Mac and Windows. If it is not available, the hörbert software can create it itself. However, it is better not to delete the file, because even if it is not up to date, hoerbert.xml keeps the disk space free if it is to be updated at some point.
The audio file format
Converting your audio files
The audio files must be in WAV format with 32 KHz sample rate, 16 bit, mono. With the tool ‘sox’ you can use the following command line for the conversion. Which files your ‘sox’ program can read depends on the compiled options.
sox –buffer 131072 –multi-threaded –no-glob inputFileName –clobber -r 32000 -b 16 -e signed-integer –no-glob outputFilename.WAV remix – gain -n -1.5 bass +1 loudness -1 pad 0 0 dither
Why not copy files directly?
Why can’t you copy mp3 files directly to the memory card?
It’s easy: so you don’t have to change batteries as often. The decoding of mp3 files requires more processing power than hörbert’s playback format. Some mp3 decoder chips even require more power than hörbert needs altogether. If you don’t have enough space, you can buy a larger memory card once for little money, but you will have to change batteries or rechargeable batteries less often over the entire period of use. hörbert gets a little bit ‘greener’ by this trick!