diff options
| -rw-r--r-- | sound/mixer.cpp | 191 |
1 files changed, 154 insertions, 37 deletions
diff --git a/sound/mixer.cpp b/sound/mixer.cpp index 9aaae1176c..e528a43b65 100644 --- a/sound/mixer.cpp +++ b/sound/mixer.cpp @@ -242,19 +242,95 @@ SoundMixer::Channel_RAW::Channel_RAW(SoundMixer *mixer, void *sound, uint32 size _size = _size >> 1; } + +/* + * Class that performs cubic interpolation on integer data. + * It is expected that the data is equidistant, i.e. all have the same + * horizontal distance. This is obviously the case for sampled audio. + */ +class CubicInterpolator { +protected: + int x0, x1, x2, x3; + int a, b, c, d; + +public: + CubicInterpolator(int a, int b, int c) : x0(2*a-b), x1(a), x2(b), x3(c) + { + // We use a simple linear interpolation for x0 + updateCoefficients(); + } + + inline void feedData() + { + x0 = x1; + x1 = x2; + x2 = x3; + x3 = 2*x2-x1; // Simple linear interpolation + updateCoefficients(); + } + + inline void feedData(int xNew) + { + x0 = x1; + x1 = x2; + x2 = x3; + x3 = xNew; + updateCoefficients(); + } + + /* t must be a 16.16 fixed point number between 0 and 1 */ + inline int interpolate(uint32 fp_pos) + { + int result = 0; + int t = fp_pos >> 8; + result = (a*t + b) >> 8; + result = (result * t + c) >> 8; + result = (result * t + d) >> 8; + result = (result/3 + 1) >> 1; + + return result; + } + +protected: + inline void updateCoefficients() + { + a = ((-x0*2)+(x1*5)-(x2*4)+x3); + b = ((x0+x2-(2*x1))*6) << 8; + c = ((-4*x0)+x1+(x2*4)-x3) << 8; + d = (x1*6) << 8; + } +}; + static int16 *mix_signed_mono_8(int16 *data, uint * len_ptr, byte **s_ptr, uint32 *fp_pos_ptr, int fp_speed, const int16 *vol_tab, byte *s_end) { uint32 fp_pos = *fp_pos_ptr; byte *s = *s_ptr; uint len = *len_ptr; + + int inc = 1, result; + CubicInterpolator interp(vol_tab[*s], vol_tab[*(s+1)], vol_tab[*(s+2)]); + do { - fp_pos += fp_speed; - *data++ += vol_tab[*s]; - *data++ += vol_tab[*s]; - s += fp_pos >> 16; - fp_pos &= 0x0000FFFF; - } while ((--len) && (s < s_end)); + do { + result = interp.interpolate(fp_pos); + + *data++ += result; + *data++ += result; + + fp_pos += fp_speed; + inc = fp_pos >> 16; + s += inc; + len--; + fp_pos &= 0x0000FFFF; + } while (!inc && len && (s < s_end)); + + if (s+2 < s_end) + interp.feedData(vol_tab[*(s+2)]); + else + interp.feedData(); + + } while (len && (s < s_end)); *fp_pos_ptr = fp_pos; *s_ptr = s; @@ -286,23 +362,13 @@ static int16 *mix_unsigned_mono_8(int16 *data, uint * len_ptr, byte **s_ptr, uin uint32 fp_pos = *fp_pos_ptr; byte *s = *s_ptr; uint len = *len_ptr; - int x0, x1, x2, x3; - int a, b, c, d; - int inc = 1, result, t; - x0 = x1 = vol_tab[*s ^ 0x80]; - x2 = vol_tab[*(s+1) ^ 0x80]; - x3 = vol_tab[*(s+2) ^ 0x80]; + + int inc = 1, result; + CubicInterpolator interp(vol_tab[*s ^ 0x80], vol_tab[*(s+1) ^ 0x80], vol_tab[*(s+2) ^ 0x80]); + do { - a = ((-x0*2)+(x1*5)-(x2*4)+x3); - b = ((x0+x2-(2*x1))*6) << 8; - c = ((-4*x0)+x1+(x2*4)-x3) << 8; - d = (x1*6) << 8; do { - t = fp_pos >> 8; - result = (a*t + b) >> 8; - result = (result * t + c) >> 8; - result = (result * t + d) >> 8; - result = (result/3 + 1) >> 1; + result = interp.interpolate(fp_pos); *data++ += result; *data++ += result; @@ -310,13 +376,15 @@ static int16 *mix_unsigned_mono_8(int16 *data, uint * len_ptr, byte **s_ptr, uin fp_pos += fp_speed; inc = fp_pos >> 16; s += inc; + len--; fp_pos &= 0x0000FFFF; - } while ((--len) && !inc && (s < s_end)); - x0 = x1; - x1 = x2; - x2 = x3; + } while (!inc && len && (s < s_end)); + if (s+2 < s_end) - x3 = vol_tab[*(s+2) ^ 0x80]; + interp.feedData(vol_tab[*(s+2) ^ 0x80]); + else + interp.feedData(); + } while (len && (s < s_end)); *fp_pos_ptr = fp_pos; @@ -336,6 +404,7 @@ static int16 *mix_signed_stereo_8(int16 *data, uint * len_ptr, byte **s_ptr, uin static int16 *mix_unsigned_stereo_8(int16 *data, uint * len_ptr, byte **s_ptr, uint32 *fp_pos_ptr, int fp_speed, const int16 *vol_tab, byte *s_end) { +#if OLD uint32 fp_pos = *fp_pos_ptr; byte *s = *s_ptr; uint len = *len_ptr; @@ -352,10 +421,48 @@ static int16 *mix_unsigned_stereo_8(int16 *data, uint * len_ptr, byte **s_ptr, u *len_ptr = len; return data; +#else + uint32 fp_pos = *fp_pos_ptr; + byte *s = *s_ptr; + uint len = *len_ptr; + + int inc = 1; + CubicInterpolator left(vol_tab[*s ^ 0x80], vol_tab[*(s+2) ^ 0x80], vol_tab[*(s+4) ^ 0x80]); + CubicInterpolator right(vol_tab[*(s+1) ^ 0x80], vol_tab[*(s+3) ^ 0x80], vol_tab[*(s+5) ^ 0x80]); + + do { + do { + *data++ += left.interpolate(fp_pos); + *data++ += right.interpolate(fp_pos); + + fp_pos += fp_speed; + inc = (fp_pos >> 16) << 1; + s += inc; + len--; + fp_pos &= 0x0000FFFF; + } while (!inc && len && (s < s_end)); + + if (s+5 < s_end) { + left.feedData(vol_tab[*(s+4) ^ 0x80]); + right.feedData(vol_tab[*(s+5) ^ 0x80]); + } else { + left.feedData(); + right.feedData(); + } + + } while (len && (s < s_end)); + + *fp_pos_ptr = fp_pos; + *s_ptr = s; + *len_ptr = len; + + return data; +#endif } static int16 *mix_signed_mono_16(int16 *data, uint * len_ptr, byte **s_ptr, uint32 *fp_pos_ptr, int fp_speed, const int16 *vol_tab, byte *s_end) { + printf("mix_signed_mono_16\n"); uint32 fp_pos = *fp_pos_ptr; unsigned char volume = ((int)vol_tab[1]) * 32 / 255; byte *s = *s_ptr; @@ -385,6 +492,7 @@ static int16 *mix_unsigned_mono_16(int16 *data, uint * len_ptr, byte **s_ptr, ui static int16 *mix_signed_stereo_16(int16 *data, uint * len_ptr, byte **s_ptr, uint32 *fp_pos_ptr, int fp_speed, const int16 *vol_tab, byte *s_end) { + printf("mix_signed_stereo_16\n"); uint32 fp_pos = *fp_pos_ptr; unsigned char volume = ((int)vol_tab[1]) * 32 / 255; byte *s = *s_ptr; @@ -604,9 +712,9 @@ SoundMixer::Channel_MP3::Channel_MP3(SoundMixer *mixer, void *sound, uint size, .SO3 file, you may have to change this value. When using Lame, it seems that the sound starts to have some volume about 50 ms - from the start of the sound => we skip about 1024 samples. + from the start of the sound => we skip about 2 frames (at 22.05 khz). */ - _silence_cut = 1024; + _silence_cut = 576 * 2; } static inline int scale_sample(mad_fixed_t sample) @@ -634,18 +742,27 @@ void SoundMixer::Channel_MP3::mix(int16 *data, uint len) real_destroy(); return; } - + while (1) { ch = _synth.pcm.samples[0] + _pos_in_frame; + + /* Skip _silence_cut a the start */ + if ((_pos_in_frame < _synth.pcm.length) && (_silence_cut > 0)) { + int diff = _synth.pcm.length - _pos_in_frame; + + if (diff > _silence_cut) + diff = _silence_cut; + _silence_cut -= diff; + ch += diff; + _pos_in_frame += diff; + } + while ((_pos_in_frame < _synth.pcm.length) && (len > 0)) { - if (_silence_cut > 0) { - _silence_cut--; - } else { - int16 sample = (int16)((scale_sample(*ch++) * volume) / 32); - *data++ += sample; - *data++ += sample; - len--; - } + int16 sample = (int16)((scale_sample(*ch) * volume) / 32); + *data++ += sample; + *data++ += sample; + len--; + ch++; _pos_in_frame++; } if (len == 0) |