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USE 64bit intermediary results in sound_stream::generate_resampled_data. This will allow sound drivers to make use of the full width of stream_sample_t. [Couriersud]

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Couriersud 2014-07-11 19:52:43 +00:00
parent e1da86fee5
commit b401a1dbd9
1 changed files with 8 additions and 8 deletions
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16
src/emu/sound.c
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@ -642,7 +642,7 @@ stream_sample_t *sound_stream::generate_resampled_data(stream_input &input, UINT
// grab data from the output // grab data from the output
stream_output &output = *input.m_source; stream_output &output = *input.m_source;
sound_stream &input_stream = *output.m_stream; sound_stream &input_stream = *output.m_stream;
int gain = (input.m_gain * input.m_user_gain * output.m_gain) >> 16; INT64 gain = (input.m_gain * input.m_user_gain * output.m_gain) >> 16;
// determine the time at which the current sample begins, accounting for the // determine the time at which the current sample begins, accounting for the
// latency we calculated between the input and output streams // latency we calculated between the input and output streams
@ -673,7 +673,7 @@ stream_sample_t *sound_stream::generate_resampled_data(stream_input &input, UINT
while (numsamples--) while (numsamples--)
{ {
// compute the sample // compute the sample
stream_sample_t sample = *source++; INT64 sample = *source++;
*dest++ = (sample * gain) >> 8; *dest++ = (sample * gain) >> 8;
} }
} }
@ -700,7 +700,7 @@ stream_sample_t *sound_stream::generate_resampled_data(stream_input &input, UINT
int endfrac = nextfrac >> (FRAC_BITS - 12); int endfrac = nextfrac >> (FRAC_BITS - 12);
// blend between the two samples accordingly // blend between the two samples accordingly
stream_sample_t sample = (source[0] * (0x1000 - startfrac) + source[1] * (endfrac - 0x1000)) / (endfrac - startfrac); INT64 sample = ((INT64) source[0] * (0x1000 - startfrac) + (INT64) source[1] * (endfrac - 0x1000)) / (endfrac - startfrac);
*dest++ = (sample * gain) >> 8; *dest++ = (sample * gain) >> 8;
// advance // advance
@ -716,19 +716,19 @@ stream_sample_t *sound_stream::generate_resampled_data(stream_input &input, UINT
int smallstep = step >> (FRAC_BITS - 8); int smallstep = step >> (FRAC_BITS - 8);
while (numsamples--) while (numsamples--)
{ {
int remainder = smallstep; INT64 remainder = smallstep;
int tpos = 0; int tpos = 0;
// compute the sample // compute the sample
int scale = (FRAC_ONE - basefrac) >> (FRAC_BITS - 8); INT64 scale = (FRAC_ONE - basefrac) >> (FRAC_BITS - 8);
stream_sample_t sample = source[tpos++] * scale; INT64 sample = (INT64) source[tpos++] * scale;
remainder -= scale; remainder -= scale;
while (remainder > 0x100) while (remainder > 0x100)
{ {
sample += source[tpos++] * 0x100; sample += (INT64) source[tpos++] * (INT64) 0x100;
remainder -= 0x100; remainder -= 0x100;
} }
sample += source[tpos] * remainder; sample += (INT64) source[tpos] * remainder;
sample /= smallstep; sample /= smallstep;
*dest++ = (sample * gain) >> 8; *dest++ = (sample * gain) >> 8;