ref: e8388c3697d0cd52a7d2108c4940cd5a610a30c2
parent: 8294be64e7ba4985568fd9dea2a897ffd49afe35
author: robs <robs>
date: Mon Jul 2 13:57:47 EDT 2007
Added workaround info for dodgy vox files
--- a/soxformat.7
+++ b/soxformat.7
@@ -523,6 +523,15 @@
.B .vox (also with \-t sndfile)
A headerless file of Dialogic/OKI ADPCM audio data commonly comes with the
extension .vox. This ADPCM data has 12-bit precision packed into only 4-bits.
+.SP
+Note: some early Dialogic hardware does not always reset the ADPCM
+encoder at the start of each vox file. This can result in clipping
+and/or DC offset problems when it comes to decoding the audio. Whilst
+little can be done about the clipping, a DC offset can be removed by
+passing the decoded audio through a high-pass filter, e.g.:
+.EX
+ sox input.vox output.au highpass 10
+.EE
.TP
.B .w64 (libsndfile)
Sonic Foundry's 64-bit RIFF/WAV format.