[MPlayer-dev-eng] i need help - transformation matrix

[Fabian Franz]

Am Montag, 26. August 2002 23:43 schrieb Arpi:
> Hi,
>
> > > >  63 22 44 90  4 81  6 31 86 58 36 11 68 39 73 53
> > > >  69 57 18 88 34 71  1 23 46 94 54 27 75 50 30  7
> > > >  70 92 20 74 10 37 85 13 56 41 87 65  2 59 24 47
> > > >  79 93 29 89 52 15 26 95 40 17  9 45 60 76 62  0
> > > >  64 43 66 83 12 16 32 21 72 14 35 28 61 80 78 48
> > > >  77  5 82 67 84 38  8 42 19 51  3 91 33 49 25 55
> >
> > i have only 2 .rm files using 'sipr' audio, but they are same bitrate and
> > so same buffersize.
>
> hmm i've found one using 0x140 byte packets instead of 0x128.
> after running the nibble-level 'cracker tool' :) i've got that it uses 40
> nibbles (20 bytes) long sub-packets, and wonder: 0x140*2/40 == 16
> and, it has 6 rows just like the 0x128 samples.
> ie, it uses 16*6 sub-packets in teh transformation.
> let's see the matrix it uses:
>
>  63 22 44 90  4 81  6 31 86 58 36 11 68 39 73 53
>  69 57 18 88 34 71  1 23 46 94 54 27 75 50 30  7
>  70 92 20 74 10 37 85 13 56 41 87 65  2 59 24 47
>  79 93 29 89 52 15 26 95 40 17  9 45 60 76 62  0
>  64 43 66 83 12 16 32 21 72 14 35 28 61 80 78 48
>  77  5 82 67 84 38  8 42 19 51  3 91 33 49 25 55
>
> yes! it seems to be the same used by 0x128 variant.
> so, even if they change buffer size, the number of sub-packets is constant
> 16 per row and they seems to stick to 6 rows per group.
>
> at least for tehse 3 samples... i need much more samples :(

I found some using google: one with 16 Kbps Bitrate:

www.tekupu.com/sound/autahi-vox

(rename to .ra)

http://www.nv.doe.gov/news&pubs/photos&films/0800021/plumbbob/plumbbob1_hi.rm

(video, but audio-stream is sipr (only audio-codec loaded))

and so on by just searching google with:

audio sipr

cu

Fabian
>
> and probably this matrix is some hardcoded thing not generated by algo or
> any logic, so we have to crack all possible variants and store it.
> until now i have only this one, but the number of rows is a parameter in
> teh header and it can be other than 6, at least the fileformat seems to
> allow that.
>
>
> A'rpi / Astral & ESP-team