John Lundsten wrote:
> I'm getting some strange readings from these 3 files
> Nnoc T0000002.WAV
> Nnoc T0000012.WAV
> Ppip T0000021.WAV
>
> The EBU chunk viewer refuses to open the files
> EDL Convert doesn't recognise the bext chunk or the sample rate
> Widget Pro sees the sample rate as 44.1k.
> Fostex BWF Manager, Total Commander, Adobe Audition, Sony Vegas Pro & Sou=
nd
> devices Wave Agent see the sample rate as =3D250k
>
> Now whilst 48k is the "assumed" sample rate of a BWF other sample rates a=
re
> allowed. But 250k being way higher than most apps would expect (& DAW's t=
o
> play) I can imagine they will not have programmed for this possibility.
Yep, 250 kHz is really a very uncommon sample rate for these applications a=
nd one cannot expect that every audio software is able to intrepret it corr=
ectly.
> Using "Nnoc T0000002.WAV"
> The timestamp is read as:--
> BwavWriter =3D 00:01:02:10.2 ( not clear to me what sub second units ar=
e
> being used here, ceratainly there is no FPS setting)
This would be the correct reading. According to the BWF specification (http=
://www.ebu.ch/CMSimages/fr/tec_doc_t3285_tcm7-10544.pdf), the bext chunk co=
ntains a 64 bit integer number ('TimeReference') that represents the sample=
count since midnight. In my RECORDER software however, this number represe=
nts (for practical reasons) the number of samples since the start of the pr=
ogram. So, the assoicated internal 64 bit counter is incremented at a rate =
of 250 kHz, which means that its resolution is 0.000004 s (=3D 4 ns).
Regards,
Raimund
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