sound support functions :
-------------------------


Checked/changed functions:

i_sound.c
  stopchan [done]
  addsfx [done]
  S_StartSoundAtVolume [done]
  updateSoundParams [done]
  I_SetChannels [done]
  I_GetSfxLumpNum [done]
  I_StartSound [done]
  I_StopSound [done]
  I_AnySoundStillPlaying [done]
  I_UpdateSound [done]
  I_ShutdownSound [done]
  I_InitSound [done]
  I_UpdateSoundParams [done]


s_sound.c
  S_StopChannel [done]
  S_AdjustSoundParams [done]   TBD : check r_main.c R_PointToAngle
  S_getChannel [done]

sounds.c
  [done]
  

check if all callers do proper callings or preparations

bug : i_sound.c/addsfx()/
channelinfo[channel].samplerate = (channelinfo[channel].data[3]<<8)+channelinfo[channel].data[2]
gives strange values : should be == SAMPLERATE. Check if channelinfo have correct values
(fixed : padding was done after loading the sound lumps from wad, so heading (data[0] to data[7]) were chopped.)


-----------------

I_UpdateSound is called after mixing and was hooked by Mix_SetPostMix. Accordingly to Mix_SetPostMix :

/* Set a function that is called after all mixing is performed.
   This can be used to provide real-time visual display of the audio stream
   or add a custom mixer filter for the stream data.

-----------------

S_sfx[38].data[17] = 158   = pos data[25] in prboom+		(now fixed by leaving 8 header bytes)


test : dumping first i_sound.c addsfx() call :

sfxid = 1, channel = 0, len = 5661

 data[0] = 126		== data[8] under prboom+ : so prboom+ has 8 extra header bytes (data[0] to data[7]. get those!)
 data[1] = 126
 data[2] = 126
 data[3] = 126
 data[4] = 126
 data[5] = 126
 data[6] = 126
 data[7] = 126
 data[8] = 126
 data[9] = 126
 data[10] = 126
 data[11] = 126
 data[12] = 126
 data[13] = 126
 data[14] = 126
 data[15] = 126
 data[16] = 126
 data[17] = 125
 data[18] = 125
 data[19] = 124
 data[20] = 90
 data[21] = 37
 data[22] = 18
 data[23] = 0
 data[24] = 0
 data[25] = 0
 data[26] = 0
 data[27] = 4
 data[28] = 35
 data[29] = 118
 data[30] = 255
 data[31] = 255
 data[32] = 251
 data[33] = 224
 data[34] = 198
 data[35] = 196
 data[36] = 178
 data[37] = 180
 data[38] = 171
 data[39] = 172
 data[40] = 159
 data[41] = 159
 data[42] = 154
 data[43] = 108
 data[44] = 24
 data[45] = 117
 data[46] = 189
 data[47] = 47
 data[48] = 86
 data[49] = 213
 data[50] = 172
 data[51] = 157
 data[52] = 151
 data[53] = 90
 data[54] = 139
 data[55] = 158
 data[56] = 43
 data[57] = 59
 data[58] = 73
 data[59] = 84
 data[60] = 89
 data[61] = 92
 data[62] = 93
 data[63] = 76
 data[64] = 82
 data[65] = 85
 data[66] = 92
 data[67] = 94
 data[68] = 96
 data[69] = 100
 data[70] = 98
 data[71] = 98
 data[72] = 102
 data[73] = 106
 data[74] = 106
 data[75] = 108
 data[76] = 107
 data[77] = 108
 data[78] = 112
 data[79] = 111
 data[80] = 114
 data[81] = 113
 data[82] = 114
 data[83] = 117
 data[84] = 117
 data[85] = 150
 data[86] = 255
 data[87] = 240
 data[88] = 213
 data[89] = 205
 data[90] = 194
 data[91] = 195
 data[92] = 186
 data[93] = 185
 data[94] = 179
 data[95] = 176
 data[96] = 170
 data[97] = 170
 data[98] = 165
 data[99] = 164
 (---)
 data[5561] = 126
 data[5562] = 128
 data[5563] = 127
 data[5564] = 127
 data[5565] = 127
 data[5566] = 127
 data[5567] = 126
 data[5568] = 127
 data[5569] = 126
 data[5570] = 127
 data[5571] = 126
 data[5572] = 127
 data[5573] = 126
 data[5574] = 127
 data[5575] = 126
 data[5576] = 127
 data[5577] = 126
 data[5578] = 126
 data[5579] = 126
 data[5580] = 127
 data[5581] = 128
 data[5582] = 127
 data[5583] = 127
 data[5584] = 128
 data[5585] = 128
 data[5586] = 128
 data[5587] = 128
 data[5588] = 128
 data[5589] = 128
 data[5590] = 128
 data[5591] = 128
 data[5592] = 128
 data[5593] = 128
 data[5594] = 129
 data[5595] = 128
 data[5596] = 128
 data[5597] = 127
 data[5598] = 128
 data[5599] = 128
 data[5600] = 128
 data[5601] = 128
 data[5602] = 128
 data[5603] = 128
 data[5604] = 128
 data[5605] = 128
 data[5606] = 128
 data[5607] = 128
 data[5608] = 127
 data[5609] = 128
 data[5610] = 128
 data[5611] = 128
 data[5612] = 128
 data[5613] = 128
 data[5614] = 128
 data[5615] = 127
 data[5616] = 127
 data[5617] = 127
 data[5618] = 127
 data[5619] = 127
 data[5620] = 127
 data[5621] = 127
 data[5622] = 127
 data[5623] = 127
 data[5624] = 127
 data[5625] = 127
 data[5626] = 126
 data[5627] = 127
 data[5628] = 126
 data[5629] = 127
 data[5630] = 126
 data[5631] = 127
 data[5632] = 126
 data[5633] = 127
 data[5634] = 126
 data[5635] = 127
 data[5636] = 126
 data[5637] = 127
 data[5638] = 126
 data[5639] = 127
 data[5640] = 126
 data[5641] = 127
 data[5642] = 126
 data[5643] = 127
 data[5644] = 126
 data[5645] = 126
 data[5646] = 126
 data[5647] = 126
 data[5648] = 126
 data[5649] = 126
 data[5650] = 126
 data[5651] = 126
 data[5652] = 126
 data[5653] = 126
 data[5654] = 126
 data[5655] = 126
 data[5656] = 126
 data[5657] = 126
 data[5658] = 126
 data[5659] = 126
 data[5660] = 126




crash here i_sound.c I_UpdateSound :
				dl += channelinfo[chan].leftvol_lookup[sample];
				dr += channelinfo[chan].rightvol_lookup[sample];

if code at addsfx() is executed :
  channelinfo[channel].data += 8; // Skip header
  channelinfo[channel].stepremainder = 0;
  // Should be gametic, I presume.
  channelinfo[channel].starttime = gametic;
  // Preserve sound SFX id,
  //  e.g. for avoiding duplicates of chainsaw.
  channelinfo[channel].id = sfxid;

does PS2 sdl works for 11025 rate ?