Pure M2F2 Audio discs ? Is that a thing ?

[IsoBuster]

I have a question with many unknowns and I may even be totally barking up the wrong tree.

I have been going through old image files for which I had no solution nor explanation when I received them. From time to time I look into old things again to see if I can make sense of them now. While doing this I found 2 very similar image files that came from different sources. It's only now that I saw the similarities and it peaked my interest.

One of the sources claimed the disc was an audio disc that was used by an airline company as background music. The other source mentioned CD-i, which is why I'm posting this question here.

For your information:
The discs / image files don't contain audio tracks, I'm fairly sure of that.
They don't appear to feature any file system ! No CD-i (from ISO9660 derived) file system.
ALL sectors appear to be M2F2 and the 'real' data starts at sector 4350. Before that it's all zeroes.
PS. LBA 4350 is exactly at the 1 minute mark if every sector contains 1/75th of a second (like for Audio tracks).

Does this format ring any bells ?
Or was it perhaps something very specific / custom made for a big company ?

If it sounds familiar, any information may help me try to understand what I'm looking at.
If audio, what is the sampling rate etc. ? Or perhaps it's mpeg (even though on the surface it doesn't look like it to me).

FYI, I include sector 4350 of both image files here. Raw. So, 2352 bytes: 12 sync bytes, 4 header bytes, 8 subheader bytes followed by the data.

Code: Select all

LBA: 4.350

0000 : 00 FF FF FF FF FF FF FF  FF FF FF 00 01 00 00 02   ................
0010 : 00 00 64 03 00 00 64 03  1A 1A 1A 1A 1A 1A 1A 1A   ..d...d.........
0020 : 1A 1A 1A 1A 1A 1A 1A 1A  33 44 33 43 CD BB CC BC   ........3D3C....
0030 : 33 43 34 43 CC BC CB BC  33 43 44 33 CC BC BB CC   3C4C....3CD3....
0040 : 43 44 44 43 BC BB BC CC  44 44 34 34 CC CC DB CB   CDDC....DD44....
0050 : 33 33 24 34 CC CC CB CB  33 33 34 43 CC CC CB BC   33$4....334C....
0060 : 43 33 34 34 BC CC CC CB  33 33 33 34 CC CC CC CB   C344....3334....
0070 : 33 34 34 34 CC CB DB CB  43 34 23 34 BC CB CC DC   3444....C4#4....
0080 : 43 44 33 33 BC CB CC CC  43 33 34 33 BC CD CC CC   CD33....C343....
0090 : 43 42 43 34 BC BC BC CB  1A 1A 1A 1A 1A 1A 1A 1A   CBC4............
00A0 : 1A 1A 1A 1A 1A 1A 1A 1A  34 43 33 34 CB BC CC CB   ........4C34....
00B0 : 34 33 34 34 DB CC CB CC  24 44 34 43 DC CB CB BC   4344....$D4C....
00C0 : 33 34 34 44 BC BB CC CB  43 44 43 34 CC CC BC CB   344D....CDC4....
00D0 : 33 33 43 34 CC CB CC CC  33 34 34 33 CC CB CB CC   33C4....3443....
00E0 : 34 33 33 43 CB BC CC BC  34 33 44 33 CC CB BB DC   433C....43D3....
00F0 : 43 34 33 34 BC CC CC BB  43 33 43 43 BD DB BC CC   C434....C3CC....
0100 : 33 34 43 34 CC BC BC CB  43 43 43 34 CC BC BC CC   34C4....CCC4....
0110 : 33 44 44 43 CC CB CB BC  1A 1A 1A 1A 1A 1A 1A 1A   3DDC............
0120 : 1A 1A 1A 1A 1A 1A 1A 1A  33 44 43 44 CC BB BC BB   ........3DCD....
0130 : 33 44 43 43 CB CC CC BC  35 33 33 43 CB BC BC BC   3DCC....533C....
0140 : 43 43 44 43 BC BC BB CC  44 44 44 34 BB CA CB CB   CCDC....DDD4....
0150 : 44 44 34 34 BB BC BC CB  44 34 43 34 BC CB BB CC   DD44....D4C4....
0160 : 43 44 44 33 CC BB CC CC  33 44 33 33 CC BC CC CC   CDD3....3D33....
0170 : 44 43 33 33 BB BC CC CC  43 43 33 43 BC CC CC CC   DC33....CC3C....
0180 : 43 33 33 34 BC BC CC BB  43 44 34 43 CD CB CB BC   C334....CD4C....
0190 : 32 44 44 44 BC BB BB CB  1A 1A 1A 1A 1A 1A 1A 1A   2DDD............
01A0 : 1A 1A 1A 1A 1A 1A 1A 1A  34 34 43 34 CB CC BC CB   ........44C4....
01B0 : 33 43 44 34 CC CC CB CB  34 33 34 44 DB CC CB BC   3CD4....434D....
01C0 : 34 33 34 43 CB CC CC CC  34 33 43 33 CB CD BC CC   434C....43C3....
01D0 : 34 43 33 34 CB BB CC CC  34 34 34 43 CC CB CB CB   4C34....444C....
01E0 : 33 34 43 34 CC DC BC CB  43 33 43 34 BC BC BD CC   34C4....C3C4....
01F0 : 43 44 43 33 BC CB CB CC  43 33 34 33 BC CC CB CC   CDC3....C343....
0200 : 43 34 33 33 BC CC CC CC  44 43 33 44 BB BC CC BB   C433....DC3D....
0210 : 44 33 34 34 CB CC CB CB  1A 1A 1A 1A 1A 1A 1A 1A   D344............
0220 : 1A 1A 1A 1A 1A 1A 1A 1A  33 43 33 33 CC BC CC CC   ........3C33....
0230 : 34 43 34 33 CB BC CC CC  33 43 33 33 CC CC CC CC   4C43....3C33....
0240 : 43 34 43 34 BC CB BC CB  44 34 33 34 CB CB CC CB   C4C4....D434....
0250 : 34 33 43 34 CC CC BC CB  33 34 44 34 CC CC BB CC   43C4....34D4....
0260 : 33 43 34 43 CC BB CC BC  33 34 33 43 CC CC CC BC   3C4C....343C....
0270 : 43 43 33 44 BC CC CC CB  44 34 44 34 CB CB BB CB   CC3D....D4D4....
0280 : 34 34 34 34 CB CB CB CC  34 44 44 33 CC BB BC CB   4444....4DD3....
0290 : 33 44 43 34 CC CB BC CB  1A 1A 1A 1A 1A 1A 1A 1A   3DC4............
02A0 : 1A 1A 1A 1A 1A 1A 1A 1A  44 33 43 33 BB CC BC CC   ........D3C3....
02B0 : 44 33 33 43 CB CC CC BC  34 33 33 33 BB CC CC CC   D33C....4333....
02C0 : 44 34 44 33 CB CB BB CC  34 34 34 34 BC CC CB CB   D4D3....4444....
02D0 : 43 33 44 34 CC CC BB CB  33 44 44 34 CC BB BC CB   C3D4....3DD4....
02E0 : 34 33 43 34 CB CC BB CC  34 44 44 33 CB BB CB CB   43C4....4DD3....
02F0 : 34 44 34 34 CB CB CB CC  34 34 34 33 CC CC CC DC   4D44....4443....
0300 : 43 43 43 33 BC BC CD CB  44 33 32 34 BB CC CC CC   CCC3....D324....
0310 : 44 33 34 34 CC CC CC CB  1A 1A 1A 1A 1A 1A 1A 1A   D344............
0320 : 1A 1A 1A 1A 1A 1A 1A 1A  33 33 34 43 CC CC CC BC   ........334C....
0330 : 33 34 33 33 CC CB CB CC  34 44 34 44 CB BB CC CB   3433....4D4D....
0340 : 34 44 43 34 CB CB BC CC  33 43 43 44 CC AC CC BB   4DC4....3CCD....
0350 : 34 43 34 44 CB CC CB BB  33 34 34 44 CC CB CC BC   4C4D....344D....
0360 : 34 44 43 43 CB BB BC CC  44 44 43 33 BB BC CC CC   4DCC....DDC3....
0370 : 44 33 33 34 CC CB CC CB  33 34 34 33 CC CB CB CC   D334....3443....
0380 : 33 34 34 33 CC CB CB CC  33 34 34 43 CD CB CC BC   3443....344C....
0390 : 32 34 33 43 CC DB CC BC  1A 1A 1A 1A 1A 1A 1A 1A   243C............
03A0 : 1A 1A 1A 1A 1A 1A 1A 1A  43 43 33 33 BB CC CC CC   ........CC33....
03B0 : 33 33 34 33 BD CC CB BC  43 34 34 44 CC CB CC CC   3343....C44D....
03C0 : 33 34 43 33 CC CB BC CC  44 34 43 33 BB CB BC CC   34C3....D4C3....
03D0 : 34 34 43 34 CB CC BC CB  44 33 44 43 BC CC BB AC   44C4....D3DC....
03E0 : 43 34 34 44 BC CB CB CB  43 34 44 34 BC CB BC CB   C44D....C4D4....
03F0 : 43 44 43 33 CC BB CC CC  34 34 33 34 CB CB BC CB   CDC3....4434....
0400 : 33 44 43 34 BC BC CC CC  44 43 33 43 CD CC CC BC   3DC4....DC3C....
0410 : 42 33 34 43 AC CC CB CC  1A 1A 1A 1A 1A 1A 1A 1A   B34C............
0420 : 1A 1A 1A 1A 1A 1A 1A 1A  34 34 33 34 CB CC BC CB   ........4434....
0430 : 34 43 44 34 BC BC CC CC  43 43 33 32 CC CC CC CD   4CD4....CC32....
0440 : 33 34 33 33 CC BB CC CC  33 44 33 34 CC CB CC CB   3433....3D34....
0450 : 44 34 43 34 BB CB BC CB  34 34 44 34 CB CB CC CB   D4C4....44D4....
0460 : 44 34 33 34 BB CC BC CC  34 43 43 43 CC BC CC BC   D434....4CCC....
0470 : 33 43 33 43 CC BC CC BC  33 43 34 43 BC BC CC CC   3C3C....3C4C....
0480 : 43 43 43 34 CC BC BC CB  34 43 43 34 CB BC CC CB   CCC4....4CC4....
0490 : 34 43 33 44 CB CC CC BB  1A 1A 1A 1A 1A 1A 1A 1A   4C3D............
04A0 : 1A 1A 1A 1A 1A 1A 1A 1A  44 34 34 43 CC DC CC CB   ........D44C....
04B0 : 33 33 33 33 CC CC CC CC  33 33 34 44 CC CC CB BB   3333....334D....
04C0 : 33 33 43 44 CD CC BC CC  33 43 34 33 BC BC CB CC   33CD....3C43....
04D0 : 43 44 34 44 CC BB CB BB  33 34 33 33 CC CB CC CC   CD4D....3433....
04E0 : 43 34 43 34 BC CB BC CB  34 34 44 44 CB CB BC BC   C4C4....44DD....
04F0 : 34 44 43 43 CC BC BB BC  33 33 44 43 CC CB CC BC   4DCC....33DC....
0500 : 43 34 33 43 BC CC CC CC  43 34 43 33 BC CB BD CC   C43C....C4C3....
0510 : 44 33 43 34 BB CC BC CC  1A 1A 1A 1A 1A 1A 1A 1A   D3C4............
0520 : 1A 1A 1A 1A 1A 1A 1A 1A  43 43 33 43 CC BC CC BC   ........CC3C....
0530 : 23 33 43 43 DC CC CC CC  33 33 33 34 CC CC BC CB   #3CC....3334....
0540 : 34 34 43 34 CB CB BC CB  33 33 43 34 CC CC CC CB   44C4....33C4....
0550 : 43 33 34 34 CC CC CB CB  23 33 43 34 DC CC BC CC   C344....#3C4....
0560 : 34 33 44 43 CC DC BC BC  43 34 43 33 BC CB BC CC   43DC....C4C3....
0570 : 43 23 44 43 CC DC CB BC  34 34 33 43 CB CC CC CC   C#DC....443C....
0580 : 34 33 34 33 CB CB CB CC  34 34 34 43 CB CB CC BC   4343....444C....
0590 : 34 34 33 34 CC CC CC CC  1A 1A 1A 1A 1A 1A 1A 1A   4434............
05A0 : 1A 1A 1A 1A 1A 1A 1A 1A  43 43 33 33 BC BC CC CC   ........CC33....
05B0 : 43 44 33 33 BB BB CB CC  44 44 35 44 BC BB CB BB   CD33....DD5D....
05C0 : 43 44 33 44 BC CC CC BB  33 33 34 44 CC CC CB BB   CD3D....334D....
05D0 : 43 34 44 44 CC CB BB BB  34 34 44 44 CB CB BC CB   C4DD....44DD....
05E0 : 34 34 43 34 CB CC BC CC  34 43 43 33 CC BC CC CC   44C4....4CC3....
05F0 : 33 33 33 43 CC CC CC BC  43 43 33 43 BC BC CC CC   333C....CC3C....
0600 : 43 44 43 33 BC BB BC CC  44 44 44 34 BC CB BC CB   CDC3....DDD4....
0610 : 43 34 43 43 BC CC CC BC  1A 1A 1A 1A 1A 1A 1A 1A   C4CC............
0620 : 1A 1A 1A 1A 1A 1A 1A 1A  43 33 43 44 BC CC BC BB   ........C3CD....
0630 : 44 33 44 44 BB CC BB CB  44 34 44 34 CB CC BC CC   D3DD....D4D4....
0640 : 33 43 43 33 CC BC BB CC  34 43 44 43 CC CC CB BC   3CC3....4CDC....
0650 : 43 33 34 44 BC BC CC BB  43 44 33 44 BC CB CB BC   C34D....CD3D....
0660 : 43 33 43 43 BC CC BC CC  43 34 33 33 CC CB BC CC   C3CC....C433....
0670 : 43 43 43 33 BC BC CC CC  44 44 33 33 BB CB CC CC   CCC3....DD33....
0680 : 43 34 33 33 BC CB CC CC  44 34 34 33 BB CC CB CC   C433....D443....
0690 : 43 33 44 33 CC CC BB CC  1A 1A 1A 1A 1A 1A 1A 1A   C3D3............
06A0 : 1A 1A 1A 1A 1A 1A 1A 1A  33 43 24 33 CC BC CB CC   ........3C$3....
06B0 : 43 44 34 33 BC CB CB CC  43 34 44 34 BC CB BC CB   CD43....C4D4....
06C0 : 44 34 43 33 CB CB CB CC  34 34 34 44 CB CC CC CB   D4C3....444D....
06D0 : 34 43 33 34 CB CC CC CC  44 33 33 33 BB CC CC CC   4C34....D333....
06E0 : 43 33 44 33 BC CC BB CC  34 33 33 33 CB CC CC CC   C3D3....4333....
06F0 : 44 34 43 33 CB CC BC CC  34 43 43 33 CB CC BC CC   D4C3....4CC3....
0700 : 34 33 43 33 CB CC CC CC  34 33 34 43 CC CC BB CD   43C3....434C....
0710 : 33 34 43 42 CC DB CC AC  1A 1A 1A 1A 1A 1A 1A 1A   34CB............
0720 : 1A 1A 1A 1A 1A 1A 1A 1A  43 33 44 44 BC BC CB BC   ........C3DD....
0730 : 44 43 34 43 CB BC CC CC  34 43 43 33 CB CC BC BC   DC4C....4CC3....
0740 : 34 33 43 43 CB CC BC CC  34 34 43 34 CB CC BC CC   43CC....44C4....
0750 : 34 33 43 33 CB CC BC CB  34 43 44 34 CC BC BB CC   43C3....4CD4....
0760 : 33 43 44 33 CC BC CC CC  43 44 33 33 CC CB BC CC   3CD3....CD33....
0770 : 33 24 44 33 BC CC BB CC  44 43 43 33 CC BC BC CC   3$D3....DCC3....
0780 : 33 33 43 33 CC CC CC CC  43 43 34 34 BC BC CB CB   33C3....CC44....
0790 : 33 43 33 34 DC BC CC CC  1A 1A 1A 1A 1A 1A 1A 1A   3C34............
07A0 : 1A 1A 1A 1A 1A 1A 1A 1A  33 33 33 33 CC CC CC CC   ........3333....
07B0 : 33 43 33 34 CC BC CC CB  33 33 34 44 CC CC CB BB   3C34....334D....
07C0 : 33 43 34 44 CC BC CC BC  33 43 43 43 DC BC BC CC   3C4D....3CCC....
07D0 : 33 43 33 33 CD BC CC CC  33 43 43 33 CB CC BC CC   3C33....3CC3....
07E0 : 34 33 44 33 CB CC BB CC  43 43 44 43 BC BC CC CC   43D3....CCDC....
07F0 : 43 43 33 33 CC BC CC BC  33 44 33 44 CC CB CC CB   CC33....3D3D....
0800 : 33 44 33 34 CC BC CC CB  33 43 33 34 CC CC CC CB   3D34....3C34....
0810 : 33 33 33 34 CC CC CC CC  1A 1A 1A 1A 1A 1A 1A 1A   3334............
0820 : 1A 1A 1A 1A 1A 1A 1A 1A  33 44 33 44 CC BB CC BC   ........3D3D....
0830 : 33 44 44 43 CC CC BB BC  34 33 43 43 CB CC BC CC   3DDC....43CC....
0840 : 44 33 43 33 BB CC CC CC  34 33 33 33 CB BC CC CC   D3C3....4333....
0850 : 44 44 34 33 BB CB BB BC  44 34 44 43 BC CC CC BC   DD43....D4DC....
0860 : 43 33 33 43 CC CC CC CC  33 33 33 33 CC CC CC CC   C33C....3333....
0870 : 34 33 34 34 CB CC CB CB  44 33 34 44 BB CC CC CC   4344....D34D....
0880 : 44 33 43 33 BB CB BC CD  43 34 43 33 BC CC BC CC   D3C3....C4C3....
0890 : 43 33 44 33 BC CC BB DC  1A 1A 1A 1A 1A 1A 1A 1A   C3D3............
08A0 : 1A 1A 1A 1A 1A 1A 1A 1A  23 33 34 43 CC CC CB BC   ........#34C....
08B0 : 33 34 34 43 CC CB CC BC  33 34 33 44 CC CC CC CB   344C....343D....
08C0 : 34 43 44 33 CB BC BB CD  43 43 43 32 CC BC BC CC   4CD3....CCC2....
08D0 : 23 44 33 33 CC CC CC CD  33 43 33 32 CC BC CC CC   #D33....3C32....
08E0 : 44 33 34 43 BC CC CB BC  43 33 34 43 BC BC CC BC   D34C....C34C....
08F0 : 43 43 33 44 BB CB CC CB  44 33 44 33 BB BD BB CC   CC3D....D3D3....
0900 : 44 43 44 43 BB CC CB BC  44 43 34 44 BC CC CB BB   DCDC....DC4D....
0910 : 43 34 34 43 CC CB CC BC  00 00 00 00 00 00 00 00   C44C............
0920 : 00 00 00 00 00 00 00 00  00 00 00 00 1E 63 98 EB   .............c..

Code: Select all

LBA: 4.350

0000 : 00 FF FF FF FF FF FF FF  FF FF FF 00 01 00 00 02   ................
0010 : 00 00 64 01 00 00 64 01  01 01 02 02 01 01 02 02   ..d...d.........
0020 : 03 03 04 04 03 03 04 04  00 00 00 F0 00 00 00 0F   ................
0030 : 00 00 00 0F 00 00 00 F0  00 00 00 F0 00 00 00 0F   ................
0040 : 00 00 00 00 00 00 00 FF  00 00 00 0F 00 00 00 FF   ................
0050 : 00 00 00 0F 00 00 00 F0  00 00 00 0F 00 00 FF FF   ................
0060 : 00 00 00 FF 00 00 FF FF  00 00 0F 00 00 00 F0 0F   ................
0070 : 00 00 F0 FF 00 00 F0 FF  00 00 FF F0 00 00 00 0F   ................
0080 : 00 00 F0 0F 00 00 00 0F  00 00 FF 0F 00 00 00 00   ................
0090 : 00 00 FF 0F 00 00 00 FF  05 05 06 06 05 05 06 06   ................
00A0 : 07 07 08 08 07 07 08 08  0F 0F FF FF F0 FF F0 F0   ................
00B0 : F0 0F FF FF 00 F0 F0 F0  F0 00 FF 0F 0F F0 0F F0   ................
00C0 : FF 00 FF 0F 00 FF FF F0  F0 0F F0 FF 0F F0 0F FF   ................
00D0 : FF 00 00 0F 00 F0 0F FF  F0 0F 00 00 0F 0F 0F FF   ................
00E0 : F0 F0 00 F0 00 0F FF 0F  FF FF 00 FF F0 00 FF 0F   ................
00F0 : F0 F0 0F FF 0F 00 FF FF  00 FF F0 FF 0F 0F FF 00   ................
0100 : 0F FF FF FF FF 00 FF 00  F0 0F 0F FF F0 00 00 00   ................
0110 : 00 0F 0F FF F0 00 00 F0  09 09 0A 0A 09 09 0A 0A   ................
0120 : 0B 0B 0C 0C 0B 0B 0C 0C  FF F0 F0 00 FF FF FF FF   ................
0130 : F0 F0 0F 0F FF FF 0F 0F  00 F0 F0 00 FF FF 00 0F   ................
0140 : 00 FF 0F 0F FF F0 F0 00  00 FF FF FF FF 00 00 00   ................
0150 : 0F 0F 0F 0F F0 00 00 0F  0F 0F F0 00 00 00 F0 0F   ................
0160 : 0F 0F 00 F0 F0 00 F0 FF  0F 0F F0 00 00 F0 00 F0   ................
0170 : FF FF F0 FF 00 0F FF F0  FF F0 F0 F0 00 0F FF F0   ................
0180 : FF 00 00 FF F0 0F 0F FF  00 00 00 FF 0F FF F0 FF   ................
0190 : F0 F0 00 F0 0F FF 00 0F  0C 0C 0C 0C 0C 0C 0C 0C   ................
01A0 : 0C 0C 0C 0C 0C 0C 0C 0C  0F 00 00 F0 00 0F FF 0F   ................
01B0 : 0F 0F FF 00 00 F0 F0 0F  F0 0F 00 00 F0 00 00 00   ................
01C0 : FF FF 00 0F FF 10 00 0F  FF FF FF FF 0F 00 00 00   ................
01D0 : F0 E0 0F 00 0F 0F 00 FF  F0 F0 0F FF 0F 1F 00 00   ................
01E0 : 00 FF F0 0F 00 0F 0F FF  00 F0 0F F0 00 0F 00 F0   ................
01F0 : 00 FF 00 0F FF 0F 0F FF  0F 0F F0 0F E0 FF 0F 00   ................
0200 : 00 10 FF F0 FF FF FF 00  F0 10 F0 0F F0 E0 0F 00   ................
0210 : 00 0F F0 0F 00 FF 0F F0  0C 0C 0C 0C 0C 0C 0C 0C   ................
0220 : 0C 0C 0C 0C 0C 0C 0C 0C  FF FF FF 0F F0 00 01 F1   ................
0230 : FF FF 0F 0F FF F1 F1 00  00 0F 0F 0F 0F 01 F0 F0   ................
0240 : F0 FF FF 0F FF 00 FF 00  F0 FF 00 0F FF FF 0F 00   ................
0250 : 00 FF 00 00 0F FF 0F FF  00 00 F0 00 0F FF 0F FF   ................
0260 : 00 F0 F1 00 0F 0F 0F FF  00 F0 F0 01 FF FF 0F FF   ................
0270 : F0 F1 F0 00 F0 F0 0F FF  FF 00 F0 F0 FF FF 0F FF   ................
0280 : F0 00 F0 0F FF 0F 0F F0  00 FF F0 00 F0 F0 F0 00   ................
0290 : FF FF FF FF F0 F0 F0 0F  0C 0C 0C 0C 0C 0C 0C 0C   ................
02A0 : 0C 0C 0C 0C 0C 0C 0C 0C  FF 00 F0 0F 00 EF 0F 1F   ................
02B0 : FF 00 F0 F0 00 FF 0F 0F  FF 0F F0 00 00 F0 0F 0F   ................
02C0 : FF 0F FF 0F 00 00 0F FF  FF 0F 0F FF 00 F0 FF FF   ................
02D0 : FF FE 0F 00 FF 00 F0 FF  00 FF FF 0F 0F F0 00 0F   ................
02E0 : F1 0F FF 0F 0F 0F F0 F0  F1 0F FF 00 0F 00 F0 0F   ................
02F0 : F0 0F 0F FF 0F 0F 0F FF  00 FF 0F 00 00 0F F0 FF   ................
0300 : F0 0F FF 0F 00 0F F0 FF  00 F0 FF FF F0 0F FF FF   ................
0310 : 0F F0 F0 00 FF 0F FF FF  0C 0C 0C 0C 0C 0C 0C 0C   ................
0320 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 00 F0 0F F0 F0 FF FF   ................
0330 : FF 0F F0 00 FF FF FF FF  FF F0 0F F0 F0 FF F0 00   ................
0340 : FF 00 0F F0 00 0F FF 0F  0F F0 00 F0 F0 FF F0 0F   ................
0350 : FF 00 F0 F0 F0 0F 00 00  FF 00 0F F0 0F 0F 00 0F   ................
0360 : F0 0F 0F F0 F0 FF 00 0F  F0 F0 0F 0F F0 FF 00 FF   ................
0370 : FF FF 00 00 00 0F 00 F0  0F 00 00 0F 00 00 F0 F0   ................
0380 : 00 F0 00 0F 0F 00 00 F0  00 F0 0F F0 F0 FF 0F F0   ................
0390 : 0F FF F0 F0 0F F0 FF FF  0C 0C 0C 0C 0C 0C 0C 0C   ................
03A0 : 0C 0C 0C 0C 0C 0C 0C 0C  FF 00 FF 00 00 FF 0F FF   ................
03B0 : 0F 0F 0F 0F FF F0 0F FF  FF F0 FF 0F F0 F0 FF 0F   ................
03C0 : FF FF 0F 0F F0 F0 0F 00  FF 0F 0F FF 0F 00 F0 FF   ................
03D0 : 00 0F FF FF 0F 0F 0F F0  FF FF 0F FF 00 F0 F0 00   ................
03E0 : FF F0 F0 0F F0 0F FF F0  F0 0F 00 0F F0 00 0F F0   ................
03F0 : F0 F0 00 FF FF 0F 0F 00  00 FF 0F F0 0F 0F 0F 00   ................
0400 : F0 0F FF 0F FF 0F 0F FF  FF 0F 0F F0 0F F0 0F 0F   ................
0410 : 0F F0 0F F0 0F FF FF FF  0C 0C 0C 0C 0C 0C 0C 0C   ................
0420 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 F0 FF FF FF 0F F0 FF   ................
0430 : F0 F0 FF 0F 0E 0F FF 00  00 F0 F0 0F 0F F0 0F 0F   ................
0440 : F0 0F 00 FF 0F F0 FF FF  00 FF F0 0F F0 F0 0F 00   ................
0450 : FF FE F0 0F F0 F1 0F F0  0F 0F F0 F0 F0 F0 00 00   ................
0460 : FF FF 00 F0 00 F0 0F F0  FF FF 0F 00 FF 0F 00 0F   ................
0470 : FF 00 0F F0 FF FF 0F 00  FF 00 0F 00 F0 00 F0 FF   ................
0480 : F0 00 0F FF FF 00 00 00  F0 F0 0F 00 F0 F0 00 FF   ................
0490 : F0 F0 FF F0 FF FF F0 FF  0C 0C 0C 0C 0C 0C 0C 0C   ................
04A0 : 0C 0C 0C 0C 0C 0C 0C 0C  00 00 F0 00 00 FF 0F FE   ................
04B0 : 00 00 F0 00 0F FF 0F 0F  00 0F F0 00 00 0F 00 F0   ................
04C0 : 00 00 FF 0F FF 0F 10 F0  0F FF EF FF 00 F0 00 00   ................
04D0 : 00 0F FF FF 00 0F 00 00  FF 0F FF FF 00 00 F0 00   ................
04E0 : 0F 0F FF FF 0F F0 00 F0  FF 0E 0F FF 00 00 F0 F0   ................
04F0 : FF 0F F0 FF 00 F0 00 FF  FE 00 00 F0 00 FF 00 FF   ................
0500 : FF 00 00 F0 0F FF FF F0  FF 00 00 F0 0F FF FF FF   ................
0510 : F0 00 F0 F0 0F FE FF 0F  0C 0C 0C 0C 0C 0C 0C 0C   ................
0520 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 F0 0F 0F 0E 0F F0 00   ................
0530 : F0 01 00 00 0F 0F F0 00  00 01 00 FF 00 0F 0F F0   ................
0540 : 0F 00 00 F0 01 FF 0F FF  F0 00 00 00 F0 00 00 FF   ................
0550 : FF 0F 00 FF F0 00 0F FF  FF F0 00 FF F0 F0 FF 00   ................
0560 : FF F0 F0 FF F0 F0 00 00  00 0F F0 F0 F0 00 FF 00   ................
0570 : 00 0F FF 00 F0 FF 00 FF  FF FF 00 F0 0F 00 00 F0   ................
0580 : 00 FF F0 FF F0 F0 00 F0  00 FF FF FF 00 F0 F0 F0   ................
0590 : 00 FF F0 0F 0F 00 F0 00  0C 0C 0C 0C 0C 0C 0C 0C   ................
05A0 : 0C 0C 0C 0C 0C 0C 0C 0C  0F F0 0F F0 0F 0F 0F F0   ................
05B0 : FF 00 0F FF 0F 00 0F FF  F0 F0 0F F0 0F 0F FF F0   ................
05C0 : F0 0F 0F F0 0F 00 FF 0F  0F 0F 0F 00 FF 0F 00 00   ................
05D0 : FF FF 00 FF 0F 0F 00 F0  00 0F 00 FF F0 FF FF F0   ................
05E0 : 0F 00 FF 0F FF 0F F0 0F  00 FF 00 0F FF F0 0F FF   ................
05F0 : 0F FF 0F 0F FF 00 0F 00  0F F0 F0 0F 0F FF FF F0   ................
0600 : F0 FF FF 0F 0F F0 00 FF  FF F0 0F 0F F0 FF 00 00   ................
0610 : FF FF 0F F0 0F FF 00 FF  0C 0C 0C 0C 0C 0C 0C 0C   ................
0620 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 0F F0 F0 0F 00 0F 0E   ................
0630 : F0 FF FF F0 FF 00 FF FF  F0 FF FF FF 0F F0 FF 0F   ................
0640 : 00 0F FF 0F FF 00 00 F0  F0 0F FF 0F FF 00 F1 FF   ................
0650 : 00 0F FE 0F FF F0 F0 00  0F 0F FF 0F FF FF 00 00   ................
0660 : 0F 00 0F 0F FF FF 00 00  0F 0F 0F 0E 00 FF F0 00   ................
0670 : FF F0 0F 0F 0F 0F 0F 00  0F 00 F0 FF 0F 0F 0F F0   ................
0680 : 0F F0 F0 F0 F0 FF FE 0E  F0 F0 F0 F0 0F FF FE 0F   ................
0690 : F0 00 F0 F0 0F F0 FF 0E  0C 0C 0C 0C 0C 0C 0C 0C   ................
06A0 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 EF 0F 0E 0E 0F 00 00   ................
06B0 : 0F EF 0F FF FF 00 00 F0  0F FF 0F FF FF 00 F0 00   ................
06C0 : 1F 0F FF 0F F0 F0 00 F0  0F 0F FF F0 F0 F0 0F F0   ................
06D0 : 0F 0F F0 FF FF FF 0F FF  0F 0F FF F0 F0 F0 0F 00   ................
06E0 : 0F 0F F0 F0 00 FF 0F F0  00 00 00 00 0F FF 0F 00   ................
06F0 : F0 0F F0 00 FF FE FF 0F  F1 00 00 F0 0E 0F 00 0F   ................
0700 : F0 F1 00 0F 0F FF FF FF  F0 F0 0F 00 0F 0F F0 FF   ................
0710 : FF F0 FE F0 0F F0 F0 F0  0C 0C 0C 0C 0C 0C 0C 0C   ................
0720 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 FF F0 00 00 F0 F0 FF   ................
0730 : F0 0F 0F 00 00 F0 0F 0F  0F 0F FF 0F 0F FF F0 F0   ................
0740 : 0F 00 00 FF F0 00 F0 00  FF F0 0F FF FF F0 0F 00   ................
0750 : FF F0 00 FF 0F 0F 00 0F  F0 FF 00 EF 00 F0 00 10   ................
0760 : 0F F0 F0 FF F0 00 FF 00  FF 00 00 FF FF FF F0 00   ................
0770 : F0 F0 FF FF F0 F0 0F FF  FF 00 00 00 FF 00 00 F0   ................
0780 : FF FF 00 00 FF F0 F0 0F  0F F0 00 00 0F F0 FF FF   ................
0790 : F0 FF 0F 00 FF 0F FF FF  0C 0C 0C 0C 0C 0C 0C 0C   ................
07A0 : 0C 0C 0C 0C 0C 0C 0C 0C  00 00 FF 0F FF F0 0F F0   ................
07B0 : 00 F0 FF FF EF 0F F0 F0  00 FF FF F0 FF FF 00 F0   ................
07C0 : 0F 0F FF 0F F0 F0 00 F0  1E 0F FF 0F F0 F0 F0 00   ................
07D0 : 0F FF 0F FF 01 F0 00 00  0E 0F F0 0F 00 F0 0F F0   ................
07E0 : FF 0F 00 00 00 F0 FF FF  FF 0F F1 00 0F FF FE 0F   ................
07F0 : E0 00 F1 01 0F FF 0F FF  F0 01 00 00 0F FE FF 0E   ................
0800 : F0 00 F0 F0 0E 0F FF F0  F0 00 F0 F0 0F FF 00 FF   ................
0810 : 00 0F FF F0 0F FF F0 00  0C 0C 0C 0C 0C 0C 0C 0C   ................
0820 : 0C 0C 0C 0C 0C 0C 0C 0C  0F FF F0 F0 FF FF FF FF   ................
0830 : FF 00 0F FF F0 00 FF 0F  00 00 00 0F 00 0F 00 00   ................
0840 : FF 00 00 0F 00 0F F0 0F  0F 0F F0 0F 00 00 00 FF   ................
0850 : FF 0F F0 0F F0 00 00 FF  F0 FF F0 0F 00 0F 0F FF   ................
0860 : 0F F0 F0 0F 00 0F 00 00  F0 FF FF 0F F0 0F 0F FF   ................
0870 : 0F 00 FF 00 FF 00 F0 FF  00 0F F0 0F 00 0F FF 0F   ................
0880 : 00 00 00 FF FF 00 F0 00  00 0F 00 FF 0F FF 0F 00   ................
0890 : 00 00 00 FF FF F0 F0 00  0C 0C 0C 0C 0C 0C 0C 0C   ................
08A0 : 0C 0C 0C 0C 0C 0C 0C 0C  F0 F0 F0 F0 FF 0F F0 0F   ................
08B0 : 0F F0 F0 F0 0F 0F 0F 0F  0F F0 00 E0 0F 0F FF 0F   ................
08C0 : FF 0F 00 F0 FF FF FF 0F  0F 0F F0 FF 00 F0 0F 10   ................
08D0 : F0 0F 00 FF 00 F0 F0 00  FF 0F FF F0 0F F0 F1 00   ................
08E0 : 0F 0E 0F 0F 00 F0 00 00  0F 0F FE 0F FF F0 00 F0   ................
08F0 : 00 FF 0F 0F FF 00 F0 FF  0F FF 0F 0F 0F 0F F0 0F   ................
0900 : 0F F0 0F 00 0F 00 FF FF  FF F0 0F 10 FF 0F FF FF   ................
0910 : 00 0F 00 00 FF 0F 0F FF  00 00 00 00 00 00 00 00   ................
0920 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................

[IsoBuster]

I'm starting to think this is BGM CD (Background Music CD) but without a CD-i program on the disc.
I just came across this: viewtopic.php?f=3&t=903 and it looks oddly similar.

[Shroo-man]

Did you find out anything since you posted last year?

You realize that your post was the first topic posted here since 2021? I just posted a topic myself but having just seen the date of the last two threads. each with no replies whether anyone is even going to see it let alone reply to it.

I actually never came across a BGM CD. The CD-i was capable of playing many obscure CD formats. The only type I have is a CD+G graphics CD format which is also very rare obscure. Barely any CD's were released in this format. The one I have is Jimi Hendrix Smash Hits which provides trippy graphics that float across the screen while you play the songs on the disc. It's quite a cool little novelty to own that's for sure.

I actually was trying to find BGM CD's back in the day but was never able to find any. I didn't even know what to look for. Apparently some elevator music and shopping mall music was recorded as this format. I would love to find something now, of course I need to obtain a CD-i again unless the PS3 can read it.. I know the PS3 can read CD+G with one of the homebrew applications, maybe there is one for BGM CD's too...

[IsoBuster]

No, I fear nobody will see this
I had to get passed two scary screens on my system warning me the link is unsafe etc.
The cert for this site has expired

[cdifan]

I'm starting to think this is BGM CD (Background Music CD) but without a CD-i program on the disc.
I just came across this: viewtopic.php?f=3&t=903 and it looks oddly similar.

It doesn’t feel like a bgm disc as you describe it, but I do not have the exact specs. The iso fs was technically required but microcontroller based player often didn’t use it so this could have worked.

[cdifan]

No, I fear nobody will see this
I had to get passed two scary screens on my system warning me the link is unsafe etc.
The cert for this site has expired

This site never had a certificate

[IsoBuster]

> so this could have worked.

My guess (still) is these are background music discs. I have no idea how to interpret the data. Assuming it's a wave format (like Audio CD) then I could simply add a *.wav header and play the audio. Perhaps it's not that simple though, perhaps a compression was used, I have no idea,

[cdifan]

Assuming it's a wave format (like Audio CD) then I could simply add a *.wav header and play the audio.

If it’s an actual BGM disc then the audio will be in CD-i ADPCM format, but that should be detectable from the sector subheader bytes? I could check if you send me some sector samples (or a whole image ).

PS. I mostly hang out on the Philips CD-i Community Discord these days at https://discord.gg/TKPejTfw6D

[IsoBuster]

Thanks, I sent you a PM.