// BSD 3-Clause License // // Copyright (c) 2021, Aaron Giles // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are met: // // 1. Redistributions of source code must retain the above copyright notice, this // list of conditions and the following disclaimer. // // 2. Redistributions in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation // and/or other materials provided with the distribution. // // 3. Neither the name of the copyright holder nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #include "ymfm_adpcm.h" namespace ymfm { //********************************************************* // ADPCM "A" REGISTERS //********************************************************* //------------------------------------------------- // reset - reset the register state //------------------------------------------------- void adpcm_a_registers::reset() { std::fill_n(&m_regdata[0], REGISTERS, 0); // initialize the pans to on by default, and max instrument volume; // some neogeo homebrews (for example ffeast) rely on this m_regdata[0x08] = m_regdata[0x09] = m_regdata[0x0a] = m_regdata[0x0b] = m_regdata[0x0c] = m_regdata[0x0d] = 0xdf; } //------------------------------------------------- // save_restore - save or restore the data //------------------------------------------------- void adpcm_a_registers::save_restore(ymfm_saved_state &state) { state.save_restore(m_regdata); } //********************************************************* // ADPCM "A" CHANNEL //********************************************************* //------------------------------------------------- // adpcm_a_channel - constructor //------------------------------------------------- adpcm_a_channel::adpcm_a_channel(adpcm_a_engine &owner, uint32_t choffs, uint32_t addrshift) : m_choffs(choffs), m_address_shift(addrshift), m_playing(0), m_curnibble(0), m_curbyte(0), m_curaddress(0), m_accumulator(0), m_step_index(0), m_regs(owner.regs()), m_owner(owner) { } //------------------------------------------------- // reset - reset the channel state //------------------------------------------------- void adpcm_a_channel::reset() { m_playing = 0; m_curnibble = 0; m_curbyte = 0; m_curaddress = 0; m_accumulator = 0; m_step_index = 0; } //------------------------------------------------- // save_restore - save or restore the data //------------------------------------------------- void adpcm_a_channel::save_restore(ymfm_saved_state &state) { state.save_restore(m_playing); state.save_restore(m_curnibble); state.save_restore(m_curbyte); state.save_restore(m_curaddress); state.save_restore(m_accumulator); state.save_restore(m_step_index); } //------------------------------------------------- // keyonoff - signal key on/off //------------------------------------------------- void adpcm_a_channel::keyonoff(bool on) { // QUESTION: repeated key ons restart the sample? m_playing = on; if (m_playing) { m_curaddress = m_regs.ch_start(m_choffs) << m_address_shift; m_curnibble = 0; m_curbyte = 0; m_accumulator = 0; m_step_index = 0; // don't log masked channels if (((debug::GLOBAL_ADPCM_A_CHANNEL_MASK >> m_choffs) & 1) != 0) debug::log_keyon("KeyOn ADPCM-A%d: pan=%d%d start=%04X end=%04X level=%02X\n", m_choffs, m_regs.ch_pan_left(m_choffs), m_regs.ch_pan_right(m_choffs), m_regs.ch_start(m_choffs), m_regs.ch_end(m_choffs), m_regs.ch_instrument_level(m_choffs)); } } //------------------------------------------------- // clock - master clocking function //------------------------------------------------- bool adpcm_a_channel::clock() { // if not playing, just output 0 if (m_playing == 0) { m_accumulator = 0; return false; } // if we're about to read nibble 0, fetch the data uint8_t data; if (m_curnibble == 0) { // stop when we hit the end address; apparently only low 20 bits are used for // comparison on the YM2610: this affects sample playback in some games, for // example twinspri character select screen music will skip some samples if // this is not correct // // note also: end address is inclusive, so wait until we are about to fetch // the sample just after the end before stopping; this is needed for nitd's // jump sound, for example uint32_t end = (m_regs.ch_end(m_choffs) + 1) << m_address_shift; if (((m_curaddress ^ end) & 0xfffff) == 0) { m_playing = m_accumulator = 0; return true; } m_curbyte = m_owner.intf().ymfm_external_read(ACCESS_ADPCM_A, m_curaddress++); data = m_curbyte >> 4; m_curnibble = 1; } // otherwise just extract from the previosuly-fetched byte else { data = m_curbyte & 0xf; m_curnibble = 0; } // compute the ADPCM delta static uint16_t const s_steps[49] = { 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552 }; int32_t delta = (2 * bitfield(data, 0, 3) + 1) * s_steps[m_step_index] / 8; if (bitfield(data, 3)) delta = -delta; // the 12-bit accumulator wraps on the ym2610 and ym2608 (like the msm5205) m_accumulator = (m_accumulator + delta) & 0xfff; // adjust ADPCM step static int8_t const s_step_inc[8] = { -1, -1, -1, -1, 2, 5, 7, 9 }; m_step_index = clamp(m_step_index + s_step_inc[bitfield(data, 0, 3)], 0, 48); return false; } //------------------------------------------------- // output - return the computed output value, with // panning applied //------------------------------------------------- template void adpcm_a_channel::output(ymfm_output &output) { // volume combines instrument and total levels int vol = (m_regs.ch_instrument_level(m_choffs) ^ 0x1f) + (m_regs.total_level() ^ 0x3f); // if combined is maximum, don't add to outputs if (vol >= 63) return; // convert into a shift and a multiplier // QUESTION: verify this from other sources int8_t mul = 15 - (vol & 7); uint8_t shift = 4 + 1 + (vol >> 3); // m_accumulator is a 12-bit value; shift up to sign-extend; // the downshift is incorporated into 'shift' int16_t value = ((int16_t(m_accumulator << 4) * mul) >> shift) & ~3; // apply to left/right as appropriate if (NumOutputs == 1 || m_regs.ch_pan_left(m_choffs)) { output.data[0] += value; m_lastOut[0] = value; } if (NumOutputs > 1 && m_regs.ch_pan_right(m_choffs)) { output.data[1] += value; m_lastOut[1] = value; } } template void adpcm_a_channel::output<1>(ymfm_output<1> &output); template void adpcm_a_channel::output<2>(ymfm_output<2> &output); //********************************************************* // ADPCM "A" ENGINE //********************************************************* //------------------------------------------------- // adpcm_a_engine - constructor //------------------------------------------------- adpcm_a_engine::adpcm_a_engine(ymfm_interface &intf, uint32_t addrshift) : m_intf(intf) { // create the channels for (int chnum = 0; chnum < CHANNELS; chnum++) m_channel[chnum] = std::make_unique(*this, chnum, addrshift); } //------------------------------------------------- // reset - reset the engine state //------------------------------------------------- void adpcm_a_engine::reset() { // reset register state m_regs.reset(); // reset each channel for (auto &chan : m_channel) chan->reset(); } //------------------------------------------------- // save_restore - save or restore the data //------------------------------------------------- void adpcm_a_engine::save_restore(ymfm_saved_state &state) { // save register state m_regs.save_restore(state); // save channel state for (int chnum = 0; chnum < CHANNELS; chnum++) m_channel[chnum]->save_restore(state); } //------------------------------------------------- // clock - master clocking function //------------------------------------------------- uint32_t adpcm_a_engine::clock(uint32_t chanmask) { // clock each channel, setting a bit in result if it finished uint32_t result = 0; for (int chnum = 0; chnum < CHANNELS; chnum++) if (bitfield(chanmask, chnum)) if (m_channel[chnum]->clock()) result |= 1 << chnum; // return the bitmask of completed samples return result; } //------------------------------------------------- // update - master update function //------------------------------------------------- template void adpcm_a_engine::output(ymfm_output &output, uint32_t chanmask) { // mask out some channels for debug purposes chanmask &= debug::GLOBAL_ADPCM_A_CHANNEL_MASK; // compute the output of each channel for (int chnum = 0; chnum < CHANNELS; chnum++) if (bitfield(chanmask, chnum)) m_channel[chnum]->output(output); } template void adpcm_a_engine::output<1>(ymfm_output<1> &output, uint32_t chanmask); template void adpcm_a_engine::output<2>(ymfm_output<2> &output, uint32_t chanmask); //------------------------------------------------- // write - handle writes to the ADPCM-A registers //------------------------------------------------- void adpcm_a_engine::write(uint32_t regnum, uint8_t data) { // store the raw value to the register array; // most writes are passive, consumed only when needed m_regs.write(regnum, data); // actively handle writes to the control register if (regnum == 0x00) for (int chnum = 0; chnum < CHANNELS; chnum++) if (bitfield(data, chnum)) m_channel[chnum]->keyonoff(bitfield(~data, 7)); } //********************************************************* // ADPCM "B" REGISTERS //********************************************************* //------------------------------------------------- // reset - reset the register state //------------------------------------------------- void adpcm_b_registers::reset() { std::fill_n(&m_regdata[0], REGISTERS, 0); // default limit to wide open m_regdata[0x0c] = m_regdata[0x0d] = 0xff; } //------------------------------------------------- // save_restore - save or restore the data //------------------------------------------------- void adpcm_b_registers::save_restore(ymfm_saved_state &state) { state.save_restore(m_regdata); } //********************************************************* // ADPCM "B" CHANNEL //********************************************************* //------------------------------------------------- // adpcm_b_channel - constructor //------------------------------------------------- adpcm_b_channel::adpcm_b_channel(adpcm_b_engine &owner, uint32_t addrshift) : m_address_shift(addrshift), m_status(STATUS_BRDY), m_curnibble(0), m_curbyte(0), m_dummy_read(0), m_position(0), m_curaddress(0), m_accumulator(0), m_prev_accum(0), m_adpcm_step(STEP_MIN), m_regs(owner.regs()), m_owner(owner) { } //------------------------------------------------- // reset - reset the channel state //------------------------------------------------- void adpcm_b_channel::reset() { m_status = STATUS_BRDY; m_curnibble = 0; m_curbyte = 0; m_dummy_read = 0; m_position = 0; m_curaddress = 0; m_accumulator = 0; m_prev_accum = 0; m_adpcm_step = STEP_MIN; } //------------------------------------------------- // save_restore - save or restore the data //------------------------------------------------- void adpcm_b_channel::save_restore(ymfm_saved_state &state) { state.save_restore(m_status); state.save_restore(m_curnibble); state.save_restore(m_curbyte); state.save_restore(m_dummy_read); state.save_restore(m_position); state.save_restore(m_curaddress); state.save_restore(m_accumulator); state.save_restore(m_prev_accum); state.save_restore(m_adpcm_step); } //------------------------------------------------- // clock - master clocking function //------------------------------------------------- void adpcm_b_channel::clock() { // only process if active and not recording (which we don't support) if (!m_regs.execute() || m_regs.record() || (m_status & STATUS_PLAYING) == 0) { m_status &= ~STATUS_PLAYING; return; } // otherwise, advance the step uint32_t position = m_position + m_regs.delta_n(); m_position = uint16_t(position); if (position < 0x10000) return; // if we're about to process nibble 0, fetch sample if (m_curnibble == 0) { // playing from RAM/ROM if (m_regs.external()) m_curbyte = m_owner.intf().ymfm_external_read(ACCESS_ADPCM_B, m_curaddress); } // extract the nibble from our current byte uint8_t data = uint8_t(m_curbyte << (4 * m_curnibble)) >> 4; m_curnibble ^= 1; // we just processed the last nibble if (m_curnibble == 0) { // if playing from RAM/ROM, check the end/limit address or advance if (m_regs.external()) { // handle the sample end, either repeating or stopping if (at_end()) { // if repeating, go back to the start if (m_regs.repeat()) load_start(); // otherwise, done; set the EOS bit else { m_accumulator = 0; m_prev_accum = 0; m_status = (m_status & ~STATUS_PLAYING) | STATUS_EOS; debug::log_keyon("%s\n", "ADPCM EOS"); return; } } // wrap at the limit address else if (at_limit()) m_curaddress = 0; // otherwise, advance the current address else { m_curaddress++; m_curaddress &= 0xffffff; } } // if CPU-driven, copy the next byte and request more else { m_curbyte = m_regs.cpudata(); m_status |= STATUS_BRDY; } } // remember previous value for interpolation m_prev_accum = m_accumulator; // forecast to next forecast: 1/8, 3/8, 5/8, 7/8, 9/8, 11/8, 13/8, 15/8 int32_t delta = (2 * bitfield(data, 0, 3) + 1) * m_adpcm_step / 8; if (bitfield(data, 3)) delta = -delta; // add and clamp to 16 bits m_accumulator = clamp(m_accumulator + delta, -32768, 32767); // scale the ADPCM step: 0.9, 0.9, 0.9, 0.9, 1.2, 1.6, 2.0, 2.4 static uint8_t const s_step_scale[8] = { 57, 57, 57, 57, 77, 102, 128, 153 }; m_adpcm_step = clamp((m_adpcm_step * s_step_scale[bitfield(data, 0, 3)]) / 64, STEP_MIN, STEP_MAX); } //------------------------------------------------- // output - return the computed output value, with // panning applied //------------------------------------------------- template void adpcm_b_channel::output(ymfm_output &output, uint32_t rshift) { // mask out some channels for debug purposes if ((debug::GLOBAL_ADPCM_B_CHANNEL_MASK & 1) == 0) return; // do a linear interpolation between samples int32_t result = (m_prev_accum * int32_t((m_position ^ 0xffff) + 1) + m_accumulator * int32_t(m_position)) >> 16; // apply volume (level) in a linear fashion and reduce result = (result * int32_t(m_regs.level())) >> (8 + rshift); // apply to left/right if (NumOutputs == 1 || m_regs.pan_left()) { m_lastOut[0] = result; output.data[0] += result; } if (NumOutputs > 1 && m_regs.pan_right()) { m_lastOut[1] = result; output.data[1] += result; } } //------------------------------------------------- // read - handle special register reads //------------------------------------------------- uint8_t adpcm_b_channel::read(uint32_t regnum) { uint8_t result = 0; // register 8 reads over the bus under some conditions if (regnum == 0x08 && !m_regs.execute() && !m_regs.record() && m_regs.external()) { // two dummy reads are consumed first if (m_dummy_read != 0) { load_start(); m_dummy_read--; } // read the data else { // read from outside of the chip result = m_owner.intf().ymfm_external_read(ACCESS_ADPCM_B, m_curaddress++); // did we hit the end? if so, signal EOS if (at_end()) { m_status = STATUS_EOS | STATUS_BRDY; debug::log_keyon("%s\n", "ADPCM EOS"); } else { // signal ready m_status = STATUS_BRDY; } // wrap at the limit address if (at_limit()) m_curaddress = 0; } } return result; } //------------------------------------------------- // write - handle special register writes //------------------------------------------------- void adpcm_b_channel::write(uint32_t regnum, uint8_t value) { // register 0 can do a reset; also use writes here to reset the // dummy read counter if (regnum == 0x00) { if (m_regs.execute()) { load_start(); // don't log masked channels if ((debug::GLOBAL_ADPCM_B_CHANNEL_MASK & 1) != 0) debug::log_keyon("KeyOn ADPCM-B: rep=%d spk=%d pan=%d%d dac=%d 8b=%d rom=%d ext=%d rec=%d start=%04X end=%04X pre=%04X dn=%04X lvl=%02X lim=%04X\n", m_regs.repeat(), m_regs.speaker(), m_regs.pan_left(), m_regs.pan_right(), m_regs.dac_enable(), m_regs.dram_8bit(), m_regs.rom_ram(), m_regs.external(), m_regs.record(), m_regs.start(), m_regs.end(), m_regs.prescale(), m_regs.delta_n(), m_regs.level(), m_regs.limit()); } else m_status &= ~STATUS_EOS; if (m_regs.resetflag()) reset(); if (m_regs.external()) m_dummy_read = 2; } // register 8 writes over the bus under some conditions else if (regnum == 0x08) { // if writing from the CPU during execute, clear the ready flag if (m_regs.execute() && !m_regs.record() && !m_regs.external()) m_status &= ~STATUS_BRDY; // if writing during "record", pass through as data else if (!m_regs.execute() && m_regs.record() && m_regs.external()) { // clear out dummy reads and set start address if (m_dummy_read != 0) { load_start(); m_dummy_read = 0; } // did we hit the end? if so, signal EOS if (at_end()) { debug::log_keyon("%s\n", "ADPCM EOS"); m_status = STATUS_EOS | STATUS_BRDY; } // otherwise, write the data and signal ready else { m_owner.intf().ymfm_external_write(ACCESS_ADPCM_B, m_curaddress++, value); m_status = STATUS_BRDY; } } } } //------------------------------------------------- // address_shift - compute the current address // shift amount based on register settings //------------------------------------------------- uint32_t adpcm_b_channel::address_shift() const { // if a constant address shift, just provide that if (m_address_shift != 0) return m_address_shift; // if ROM or 8-bit DRAM, shift is 5 bits if (m_regs.rom_ram()) return 5; if (m_regs.dram_8bit()) return 5; // otherwise, shift is 2 bits return 2; } //------------------------------------------------- // load_start - load the start address and // initialize the state //------------------------------------------------- void adpcm_b_channel::load_start() { m_status = (m_status & ~STATUS_EOS) | STATUS_PLAYING; m_curaddress = m_regs.external() ? (m_regs.start() << address_shift()) : 0; m_curnibble = 0; m_curbyte = 0; m_position = 0; m_accumulator = 0; m_prev_accum = 0; m_adpcm_step = STEP_MIN; } //********************************************************* // ADPCM "B" ENGINE //********************************************************* //------------------------------------------------- // adpcm_b_engine - constructor //------------------------------------------------- adpcm_b_engine::adpcm_b_engine(ymfm_interface &intf, uint32_t addrshift) : m_intf(intf) { // create the channel (only one supported for now, but leaving possibilities open) m_channel = std::make_unique(*this, addrshift); } //------------------------------------------------- // reset - reset the engine state //------------------------------------------------- void adpcm_b_engine::reset() { // reset registers m_regs.reset(); // reset each channel m_channel->reset(); } //------------------------------------------------- // save_restore - save or restore the data //------------------------------------------------- void adpcm_b_engine::save_restore(ymfm_saved_state &state) { // save our state m_regs.save_restore(state); // save channel state m_channel->save_restore(state); } //------------------------------------------------- // clock - master clocking function //------------------------------------------------- void adpcm_b_engine::clock() { // clock each channel, setting a bit in result if it finished m_channel->clock(); } //------------------------------------------------- // output - master output function //------------------------------------------------- template void adpcm_b_engine::output(ymfm_output &output, uint32_t rshift) { // compute the output of each channel m_channel->output(output, rshift); } template void adpcm_b_engine::output<1>(ymfm_output<1> &output, uint32_t rshift); template void adpcm_b_engine::output<2>(ymfm_output<2> &output, uint32_t rshift); //------------------------------------------------- // write - handle writes to the ADPCM-B registers //------------------------------------------------- void adpcm_b_engine::write(uint32_t regnum, uint8_t data) { // store the raw value to the register array; // most writes are passive, consumed only when needed m_regs.write(regnum, data); // let the channel handle any special writes m_channel->write(regnum, data); } }