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Merge pull request #17 from aliaspider/master

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added an optional audio resampler for systems not powerful enough for the blipper ( like the psp ).
This commit is contained in:
Twinaphex 2014-03-01 02:37:45 +01:00
commit e04707b4c7
2 changed files with 99 additions and 4 deletions
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7
libgambatte/Makefile.libretro
View File

@ -81,9 +81,10 @@ else ifeq ($(platform), psp1)
CC = psp-gcc$(EXE_EXT)
CXX = psp-g++$(EXE_EXT)
AR = psp-ar$(EXE_EXT)
PLATFORM_DEFINES := -DPSP
CFLAGS += -G0
STATIC_LINKING = 1
PLATFORM_DEFINES := -DPSP -DALTERNATIVE_RESAMPLER
CFLAGS += -G0
CXXFLAGS += -G0
STATIC_LINKING = 1
else ifeq ($(platform), xenon)
TARGET := $(TARGET_NAME)_libretro_xenon360.a
CC = xenon-gcc$(EXE_EXT)

96
libgambatte/libretro/libretro.cpp
View File

@ -44,8 +44,10 @@ class SNESInput : public gambatte::InputGetter
}
} static gb_input;
#ifndef ALTERNATIVE_RESAMPLER
static blipper_t *resampler_l;
static blipper_t *resampler_r;
#endif
void retro_get_system_info(struct retro_system_info *info)
{
@ -80,7 +82,7 @@ void retro_init()
double fps = 4194304.0 / 70224.0;
double sample_rate = fps * 35112;
#ifndef ALTERNATIVE_RESAMPLER
resampler_l = blipper_new(32, 0.85, 6.5, 64, 1024, NULL);
resampler_r = blipper_new(32, 0.85, 6.5, 64, 1024, NULL);
@ -89,12 +91,21 @@ void retro_init()
g_timing.fps = fps;
g_timing.sample_rate = sample_rate / 64; // ~32k
}
#else
if (environ_cb)
{
g_timing.fps = fps;
g_timing.sample_rate = sample_rate / 32; // ~64k
}
#endif
}
void retro_deinit()
{
#ifndef ALTERNATIVE_RESAMPLER
blipper_free(resampler_l);;
blipper_free(resampler_r);;
#endif
}
void retro_set_environment(retro_environment_t cb)
@ -424,6 +435,7 @@ size_t retro_get_memory_size(unsigned id)
return 0;
}
#ifndef ALTERNATIVE_RESAMPLER
static void render_audio(const int16_t *samples, unsigned frames)
{
if (!frames)
@ -432,12 +444,35 @@ static void render_audio(const int16_t *samples, unsigned frames)
blipper_push_samples(resampler_l, samples + 0, frames, 2);
blipper_push_samples(resampler_r, samples + 1, frames, 2);
}
#endif
void retro_run()
{
static uint64_t samples_count = 0;
static uint64_t frames_count = 0;
#ifdef ALTERNATIVE_RESAMPLER
static const int16_t CS_kernel[32]=
{
0x01FF, 0x01FE, 0x01FA, 0x01F4, 0x01EC, 0x01E1, 0x01D4, 0x01C5,
0x01B4, 0x01A2, 0x018E, 0x0178, 0x0161, 0x014A, 0x0131, 0x0119,
0x0100, 0x00E6, 0x00CE, 0x00B5, 0x009E, 0x0087, 0x0071, 0x005D,
0x004B, 0x003A, 0x002B, 0x001E, 0x0013, 0x000B, 0x0005, 0x0001
};
static int32_t l_sample_current = 0;
static int32_t r_sample_current = 0;
static int32_t l_sample_next = 0;
static int32_t r_sample_next = 0;
static int32_t capacitor = 0;
static unsigned int accumulated_samples = 0;
static unsigned int write_pos = 0;
union
{
gambatte::uint_least32_t u32[512];
int16_t i16[2 * 512];
} static out_buf;
#endif
input_poll_cb();
uint64_t expected_frames = samples_count / 35112;
@ -463,6 +498,8 @@ void retro_run()
gambatte::uint_least32_t video_pitch = 256;
while (gb.runFor(video_buf, video_pitch, sound_buf.u32, samples) == -1)
{
#ifndef ALTERNATIVE_RESAMPLER
render_audio(sound_buf.i16, samples);
unsigned read_avail = blipper_read_avail(resampler_l);
@ -472,13 +509,42 @@ void retro_run()
blipper_read(resampler_r, sound_buf.i16 + 1, read_avail, 2);
audio_batch_cb(sound_buf.i16, read_avail);
}
#else
for (int i=0; i < (samples << 1); i+=2)
{
l_sample_current += sound_buf.i16[i] * CS_kernel[accumulated_samples];
l_sample_next += sound_buf.i16[i] * CS_kernel[31 - accumulated_samples];
r_sample_current += sound_buf.i16[i + 1] * CS_kernel[accumulated_samples];
r_sample_next += sound_buf.i16[i + 1] * CS_kernel[31 - accumulated_samples];
accumulated_samples++;
if (accumulated_samples == 32)
{
capacitor += ((l_sample_current ) - capacitor) >> 14;
out_buf.i16[write_pos++] = (l_sample_current>>14) - (capacitor >> 14);
out_buf.i16[write_pos++] = (r_sample_current>>14) - (capacitor >> 14);
accumulated_samples = 0;
l_sample_current = l_sample_next;
r_sample_current = r_sample_next;
l_sample_next = 0;
r_sample_next = 0;
if (write_pos == 1024){
audio_batch_cb(out_buf.i16, 512);
write_pos = 0;
}
}
}
#endif
samples_count += samples;
samples = 2064;
}
samples_count += samples;
#ifndef ALTERNATIVE_RESAMPLER
render_audio(sound_buf.i16, samples);
#endif
#ifdef VIDEO_RGB565
video_cb(video_buf, 160, 144, 512);
@ -486,10 +552,38 @@ void retro_run()
video_cb(video_buf, 160, 144, 1024);
#endif
#ifndef ALTERNATIVE_RESAMPLER
unsigned read_avail = blipper_read_avail(resampler_l);
blipper_read(resampler_l, sound_buf.i16 + 0, read_avail, 2);
blipper_read(resampler_r, sound_buf.i16 + 1, read_avail, 2);
audio_batch_cb(sound_buf.i16, read_avail);
#else
for (int i=0; i < (samples << 1); i+=2)
{
l_sample_current += sound_buf.i16[i] * CS_kernel[accumulated_samples];
l_sample_next += sound_buf.i16[i] * CS_kernel[31 - accumulated_samples];
r_sample_current += sound_buf.i16[i + 1] * CS_kernel[accumulated_samples];
r_sample_next += sound_buf.i16[i + 1] * CS_kernel[31 - accumulated_samples];
accumulated_samples++;
if (accumulated_samples == 32)
{
capacitor += ((l_sample_current ) - capacitor) >> 14;
out_buf.i16[write_pos++] = (l_sample_current>>14) - (capacitor >> 14);
out_buf.i16[write_pos++] = (r_sample_current>>14) - (capacitor >> 14);
accumulated_samples = 0;
l_sample_current = l_sample_next;
r_sample_current = r_sample_next;
l_sample_next = 0;
r_sample_next = 0;
if (write_pos == 1024){
audio_batch_cb(out_buf.i16, 512);
write_pos = 0;
}
}
}
#endif
frames_count++;