[File] [PATCH] of Magdir/audio for encrypted Garmin Voice Processing Module (*.vpm)

[Jörg Jenderek]

Hello,

some days ago i run file command version 5.35 on Garmin Voice Processing
Module (*.vpm). Some are only described as "data".

Unfortunately there seems to exist at least 3 variants of Garmin VPM. In
one variant Garmin Voice Processing Module is stored in a container
format usually used for geographical cards. This IMG file format with
reference is handled by Magdir/map some days ago. The other format start
with magic "AUDIMG" and is already handled by Magdir/audio. This format
 for non text-to-speech (TTS) contain hundreds of WAV audios. For every
phrase like "turn left" a wav file is stored. This is visible by looking
fo and counting magic RIFF (handled by Magdir/riff). Some clever
programmers like "turboccc" recognize this and build their own audio
tools to manipulate VPM files. Apparently Garmin do not like this and
started to switch to an encrypted variant. This is visible when the VPM
file does not contain any human readable string any more. Luckily such
encrypted examples seem to start with the same byte sequence. This is
now expressed by additional magic lines in Magdir/audio like
 0 ubequad 0xa141190fecc8ced6 Garmin Voice Processing Module (encrypted)
 !:mime	audio/x-vpm-garmin
 !:ext	vpm
Unfortunately there does not exist any web site about the encrypted VPM
variant. But when you buy or download additional voices for the Garmin
navigation devices like DrNightmare, Elfred, Yeti, these VPM files are
encrypted. Garmin itself offer a software with name Voice Studio. This
tool lets you create custom voices for your navigation device and stores
the result as an encrypted VPM. So i add the product web site as URL.

After applying the above mentioned modifications by patch
file-5.35-audio-garmin.diff then all inspected examples are now
described by Magdir/audio like:

Deutsch__Marie.vpm:           Garmin Voice Processing Module (encrypted)
DrNightmare.vpm:              Garmin Voice Processing Module (encrypted)
Elfred.vpm:                   Garmin Voice Processing Module (encrypted)
English_British_James.vpm:    Garmin Voice Processing Module (encrypted)
English_British_Kate.vpm:     Garmin Voice Processing Module (encrypted)
TeamGarmin-DaveZabriskie.vpm: Garmin Voice Processing Module (encrypted)
test.vpm:                     Garmin Voice Processing Module (encrypted)
test2garmin.vpm:              Garmin Voice Processing Module (encrypted)
Turkce__Ipek.vpm:             Garmin Voice Processing Module (encrypted)
Yeti.vpm:                     Garmin Voice Processing Module (encrypted)

I hope my diff file can be applied in future version of file utility.

With best wishes
Jörg Jenderek
-- 
Jörg Jenderek




-------------- next part --------------
--- file-5.35/magic/Magdir/audio.old	2018-10-19 00:35:42 +0000
+++ file-5.35/magic/Magdir/audio	2019-01-03 03:43:44 +0000
@@ -779,4 +779,13 @@
 >>>>>>&-4	indirect	x	\b
 # 2 - ~ 131 WAV samples following same way
+#
+# Summary:	encrypted Garmin Voice Processing Module
+# From:		Joerg Jenderek
+# URL:		https://www.garmin.com/us/products/ontheroad/voicestudio
+# NOTE:		Encrypted variant used in voices like DrNightmare, Elfred, Yeti.
+#		There exist 2 other Garmin VPM formats
+0	ubequad		0xa141190fecc8ced6	Garmin Voice Processing Module (encrypted)
+!:mime	audio/x-vpm-garmin
+!:ext	vpm
 
 # From Martin Mueller Skarbiniks Pedersen