🚀 go-pugleaf

BIG Thanks Julio. I'll post the results,
Peter

"Julio Farias" <jfariasXXXX@uolsinectis.com.ar> wrote in message
news:i37kj0p6hhugruv89p0kktsk85d9ippn7u@4ax.com...
> On Mon, 30 Aug 2004 13:49:15 +1000, "Peter P" <pp1@comrad.com.au>
> wrote:
>
> >I would appreciate any assistance with explanation of where the time and
> >date stamp of Digital Video (DV) AVI files is placed (in either Type 1 or
> >Type 2 DV files). I have checked on MSDN for explanation but cannot find
(or
> >determine) where the stamp(s) are kept in the file.
> >
> What I'm going to tell you is in part the result of intensive search
> in the net -with no much success, as you've probably seen by yourself-
> and own experimentation. This means that in no way will I give general
> advice, but simply tell what I've found.
>
> All what follows refers to Type-1 DV AVI files. As you know this is
> the format -headers apart- in which the stream is natively stored on
> DV tape.
>
> The DV stream is organized into 80-byte so-called DIF blocks; 150 of
> them form a DIF sequence; an NTSC frame comprises 10 sequences (120000
> bytes), a PAL one 12 (144000 bytes).
> Each DIF sequence has 135 proper video blocks (image data), 9
> interleaved audio blocks, the remaining 6 being:
> 1 header block
> 2 subcode blocks, where timecode resides
> 3 VAUX blocks, where date/time is recorded, besides other data
>
> To reach the subcode and VAUX blocks I first look for 'data chunks'
> (terminology from MS "AVI RIFF File Reference"). In DV these are
> identified by a '##dc' FOURCC; in my D8 streams it's normally '00dc'.
> (Any decent hex editor will do the task)
>
> Eight bytes past the beginning of the FOURCC, the header block starts,
> identified by '1Fh'. 80 bytes beyond, the first subcode block begins
> with '3Fh'. Here you can find the recording timecode in the '13h'
> field with the format 'frame-second-minute-hour' (you have to subtract
> 40h, 80h, 80h and C0h respectively to get them in decimal values -BCD
> really)
>
> The VAUX blocks start with a '5Xh' identifier. I've seen written
> somewhere that it should be '5Fh', but my SONY produces other
> identifiers -always starting with 5. Here you'll go for the '62h' and
> '63h' fields, to find
>
> 62h: 'FF'-day-month-year (subtract C0h, E0h for day, month)
>
> 63h: 'FF'-second-minute-hour (treat as in timecode)
>
> Other fields in the VAUX give recording data -aperture, etc- I guess
> but have no yet experimented with them.
>
> Hope this helps. I'd recommend you to give a look at the 'libdv' free
> code. It's easily found through Google and can give interesting info
> to the curious.
>
> Julio