clean up dac code a bit

[picodrive.git] / pico / sound / sound.c

/*\r
 * PicoDrive\r
 * (c) Copyright Dave, 2004\r
 * (C) notaz, 2006-2009\r
 *\r
 * This work is licensed under the terms of MAME license.\r
 * See COPYING file in the top-level directory.\r
 */\r
\r
#include <string.h>\r
#include "ym2612.h"\r
#include "sn76496.h"\r
#include "../pico_int.h"\r
#include "../cd/cue.h"\r
#include "mix.h"\r
\r
void (*PsndMix_32_to_16l)(short *dest, int *src, int count) = mix_32_to_16l_stereo;\r
\r
// master int buffer to mix to\r
static int PsndBuffer[2*(44100+100)/50];\r
\r
// dac\r
static unsigned short dac_info[312+4]; // pos in sample buffer\r
\r
// cdda output buffer\r
short cdda_out_buffer[2*1152];\r
\r
// for Pico\r
int PsndRate=0;\r
int PsndLen=0; // number of mono samples, multiply by 2 for stereo\r
int PsndLen_exc_add=0; // this is for non-integer sample counts per line, eg. 22050/60\r
int PsndLen_exc_cnt=0;\r
int PsndDacLine=0;\r
short *PsndOut=NULL; // PCM data buffer\r
static int PsndLen_use;\r
\r
// timers\r
int timer_a_next_oflow, timer_a_step; // in z80 cycles\r
int timer_b_next_oflow, timer_b_step;\r
\r
// sn76496\r
extern int *sn76496_regs;\r
\r
\r
static void dac_recalculate(void)\r
{\r
  int i, dac_cnt, pos, len, lines = Pico.m.pal ? 312 : 262, mid = Pico.m.pal ? 68 : 93;\r
\r
  if (PsndLen <= lines)\r
  {\r
    // shrinking algo\r
    dac_cnt = -PsndLen;\r
    len=1; pos=0;\r
    dac_info[225] = 1;\r
\r
    for(i=226; i != 225; i++)\r
    {\r
      if (i >= lines) i = 0;\r
      if(dac_cnt < 0) {\r
        pos++;\r
        dac_cnt += lines;\r
      }\r
      dac_cnt -= PsndLen;\r
      dac_info[i] = pos;\r
    }\r
  }\r
  else\r
  {\r
    // stretching\r
    dac_cnt = PsndLen;\r
    pos=0;\r
    for(i = 225; i != 224; i++)\r
    {\r
      if (i >= lines) i = 0;\r
      len=0;\r
      while(dac_cnt >= 0) {\r
        dac_cnt -= lines;\r
        len++;\r
      }\r
      if (i == mid) // midpoint\r
        while(pos+len < PsndLen/2) {\r
          dac_cnt -= lines;\r
          len++;\r
        }\r
      dac_cnt += PsndLen;\r
      pos += len;\r
      dac_info[i] = pos;\r
    }\r
  }\r
  for (i = lines; i < sizeof(dac_info) / sizeof(dac_info[0]); i++)\r
    dac_info[i] = dac_info[0];\r
}\r
\r
\r
PICO_INTERNAL void PsndReset(void)\r
{\r
  // PsndRerate calls YM2612Init, which also resets\r
  PsndRerate(0);\r
  timers_reset();\r
}\r
\r
\r
// to be called after changing sound rate or chips\r
void PsndRerate(int preserve_state)\r
{\r
  void *state = NULL;\r
  int target_fps = Pico.m.pal ? 50 : 60;\r
\r
  if (preserve_state) {\r
    state = malloc(0x204);\r
    if (state == NULL) return;\r
    ym2612_pack_state();\r
    memcpy(state, YM2612GetRegs(), 0x204);\r
  }\r
  YM2612Init(Pico.m.pal ? OSC_PAL/7 : OSC_NTSC/7, PsndRate);\r
  if (preserve_state) {\r
    // feed it back it's own registers, just like after loading state\r
    memcpy(YM2612GetRegs(), state, 0x204);\r
    ym2612_unpack_state();\r
  }\r
\r
  if (preserve_state) memcpy(state, sn76496_regs, 28*4); // remember old state\r
  SN76496_init(Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15, PsndRate);\r
  if (preserve_state) memcpy(sn76496_regs, state, 28*4); // restore old state\r
\r
  if (state)\r
    free(state);\r
\r
  // calculate PsndLen\r
  PsndLen=PsndRate / target_fps;\r
  PsndLen_exc_add=((PsndRate - PsndLen*target_fps)<<16) / target_fps;\r
  PsndLen_exc_cnt=0;\r
\r
  // recalculate dac info\r
  dac_recalculate();\r
\r
  // clear all buffers\r
  memset32(PsndBuffer, 0, sizeof(PsndBuffer)/4);\r
  memset(cdda_out_buffer, 0, sizeof(cdda_out_buffer));\r
  if (PsndOut)\r
    PsndClear();\r
\r
  // set mixer\r
  PsndMix_32_to_16l = (PicoOpt & POPT_EN_STEREO) ? mix_32_to_16l_stereo : mix_32_to_16_mono;\r
\r
  if (PicoAHW & PAHW_PICO)\r
    PicoReratePico();\r
}\r
\r
\r
PICO_INTERNAL void PsndStartFrame(void)\r
{\r
  // compensate for float part of PsndLen\r
  PsndLen_use = PsndLen;\r
  PsndLen_exc_cnt += PsndLen_exc_add;\r
  if (PsndLen_exc_cnt >= 0x10000) {\r
    PsndLen_exc_cnt -= 0x10000;\r
    PsndLen_use++;\r
  }\r
\r
  PsndDacLine = 0;\r
  emustatus &= ~1;\r
  dac_info[224] = PsndLen_use;\r
}\r
\r
PICO_INTERNAL void PsndDoDAC(int line_to)\r
{\r
  int pos, pos1, len;\r
  int dout = ym2612.dacout;\r
  int line_from = PsndDacLine;\r
\r
  if (line_to >= 312)\r
    line_to = 311;\r
\r
  pos  = dac_info[line_from];\r
  pos1 = dac_info[line_to + 1];\r
  len = pos1 - pos;\r
  if (len <= 0)\r
    return;\r
\r
  PsndDacLine = line_to + 1;\r
\r
  if (!PsndOut)\r
    return;\r
\r
  if (PicoOpt & POPT_EN_STEREO) {\r
    short *d = PsndOut + pos*2;\r
    for (; len > 0; len--, d+=2) *d = dout;\r
  } else {\r
    short *d = PsndOut + pos;\r
    for (; len > 0; len--, d++)  *d = dout;\r
  }\r
}\r
\r
// cdda\r
static void cdda_raw_update(int *buffer, int length)\r
{\r
  int ret, cdda_bytes, mult = 1;\r
\r
  cdda_bytes = length*4;\r
  if (PsndRate <= 22050 + 100) mult = 2;\r
  if (PsndRate <  22050 - 100) mult = 4;\r
  cdda_bytes *= mult;\r
\r
  ret = pm_read(cdda_out_buffer, cdda_bytes, Pico_mcd->cdda_stream);\r
  if (ret < cdda_bytes) {\r
    memset((char *)cdda_out_buffer + ret, 0, cdda_bytes - ret);\r
    Pico_mcd->cdda_stream = NULL;\r
    return;\r
  }\r
\r
  // now mix\r
  switch (mult) {\r
    case 1: mix_16h_to_32(buffer, cdda_out_buffer, length*2); break;\r
    case 2: mix_16h_to_32_s1(buffer, cdda_out_buffer, length*2); break;\r
    case 4: mix_16h_to_32_s2(buffer, cdda_out_buffer, length*2); break;\r
  }\r
}\r
\r
void cdda_start_play(int lba_base, int lba_offset, int lb_len)\r
{\r
  if (Pico_mcd->cdda_type == CT_MP3)\r
  {\r
    int pos1024 = 0;\r
\r
    if (lba_offset)\r
      pos1024 = lba_offset * 1024 / lb_len;\r
\r
    mp3_start_play(Pico_mcd->cdda_stream, pos1024);\r
    return;\r
  }\r
\r
  pm_seek(Pico_mcd->cdda_stream, (lba_base + lba_offset) * 2352, SEEK_SET);\r
  if (Pico_mcd->cdda_type == CT_WAV)\r
  {\r
    // skip headers, assume it's 44kHz stereo uncompressed\r
    pm_seek(Pico_mcd->cdda_stream, 44, SEEK_CUR);\r
  }\r
}\r
\r
\r
PICO_INTERNAL void PsndClear(void)\r
{\r
  int len = PsndLen;\r
  if (PsndLen_exc_add) len++;\r
  if (PicoOpt & POPT_EN_STEREO)\r
    memset32((int *) PsndOut, 0, len); // assume PsndOut to be aligned\r
  else {\r
    short *out = PsndOut;\r
    if ((long)out & 2) { *out++ = 0; len--; }\r
    memset32((int *) out, 0, len/2);\r
    if (len & 1) out[len-1] = 0;\r
  }\r
}\r
\r
\r
static int PsndRender(int offset, int length)\r
{\r
  int  buf32_updated = 0;\r
  int *buf32 = PsndBuffer+offset;\r
  int stereo = (PicoOpt & 8) >> 3;\r
\r
  offset <<= stereo;\r
\r
  pprof_start(sound);\r
\r
  // PSG\r
  if (PicoOpt & POPT_EN_PSG)\r
    SN76496Update(PsndOut+offset, length, stereo);\r
\r
  if (PicoAHW & PAHW_PICO) {\r
    PicoPicoPCMUpdate(PsndOut+offset, length, stereo);\r
    return length;\r
  }\r
\r
  // Add in the stereo FM buffer\r
  if (PicoOpt & POPT_EN_FM) {\r
    buf32_updated = YM2612UpdateOne(buf32, length, stereo, 1);\r
  } else\r
    memset32(buf32, 0, length<<stereo);\r
\r
//printf("active_chs: %02x\n", buf32_updated);\r
  (void)buf32_updated;\r
\r
  // CD: PCM sound\r
  if (PicoAHW & PAHW_MCD) {\r
    pcd_pcm_update(buf32, length, stereo);\r
    //buf32_updated = 1;\r
  }\r
\r
  // CD: CDDA audio\r
  // CD mode, cdda enabled, not data track, CDC is reading\r
  if ((PicoAHW & PAHW_MCD) && (PicoOpt & POPT_EN_MCD_CDDA)\r
      && Pico_mcd->cdda_stream != NULL\r
      && !(Pico_mcd->s68k_regs[0x36] & 1))\r
  {\r
    // note: only 44, 22 and 11 kHz supported, with forced stereo\r
    if (Pico_mcd->cdda_type == CT_MP3)\r
      mp3_update(buf32, length, stereo);\r
    else\r
      cdda_raw_update(buf32, length);\r
  }\r
\r
  if ((PicoAHW & PAHW_32X) && (PicoOpt & POPT_EN_PWM))\r
    p32x_pwm_update(buf32, length, stereo);\r
\r
  // convert + limit to normal 16bit output\r
  PsndMix_32_to_16l(PsndOut+offset, buf32, length);\r
\r
  pprof_end(sound);\r
\r
  return length;\r
}\r
\r
// to be called on 224 or line_sample scanlines only\r
PICO_INTERNAL void PsndGetSamples(int y)\r
{\r
  static int curr_pos = 0;\r
\r
  if (ym2612.dacen && PsndDacLine < y)\r
    PsndDoDAC(y - 1);\r
\r
  if (y == 224)\r
  {\r
    if (emustatus & 2)\r
         curr_pos += PsndRender(curr_pos, PsndLen-PsndLen/2);\r
    else curr_pos  = PsndRender(0, PsndLen_use);\r
    if (emustatus & 1)\r
         emustatus |=  2;\r
    else emustatus &= ~2;\r
    if (PicoWriteSound)\r
      PicoWriteSound(curr_pos * ((PicoOpt & POPT_EN_STEREO) ? 4 : 2));\r
    // clear sound buffer\r
    PsndClear();\r
    PsndDacLine = 224;\r
    dac_info[224] = 0;\r
  }\r
  else if (emustatus & 3) {\r
    emustatus|= 2;\r
    emustatus&=~1;\r
    curr_pos = PsndRender(0, PsndLen/2);\r
  }\r
}\r
\r
PICO_INTERNAL void PsndGetSamplesMS(void)\r
{\r
  int stereo = (PicoOpt & 8) >> 3;\r
  int length = PsndLen_use;\r
\r
  // PSG\r
  if (PicoOpt & POPT_EN_PSG)\r
    SN76496Update(PsndOut, length, stereo);\r
\r
  // upmix to "stereo" if needed\r
  if (stereo) {\r
    int i, *p;\r
    for (i = length, p = (void *)PsndOut; i > 0; i--, p++)\r
      *p |= *p << 16;\r
  }\r
\r
  if (PicoWriteSound != NULL)\r
    PicoWriteSound(length * ((PicoOpt & POPT_EN_STEREO) ? 4 : 2));\r
  PsndClear();\r
}\r
\r
// vim:shiftwidth=2:ts=2:expandtab\r