diff --git a/miniaudio.h b/miniaudio.h index fc5db321..bbd0f535 100644 --- a/miniaudio.h +++ b/miniaudio.h @@ -1649,6 +1649,32 @@ ma_result ma_hpf_process_pcm_frames(ma_hpf* pHPF, void* pFramesOut, const void* ma_uint32 ma_hpf_get_latency(ma_hpf* pHPF); +/************************************************************************************************************************************************************** + +Band-Pass Filtering + +**************************************************************************************************************************************************************/ +typedef struct +{ + ma_format format; + ma_uint32 channels; + ma_uint32 sampleRate; + double cutoffFrequency; +} ma_bpf_config; + +ma_bpf_config ma_bpf_config_init(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, double cutoffFrequency); + +typedef struct +{ + ma_biquad bq; /* The band-pass filter is implemented as a biquad filter. */ +} ma_bpf; + +ma_result ma_bpf_init(const ma_bpf_config* pConfig, ma_bpf* pBPF); +ma_result ma_bpf_reinit(const ma_bpf_config* pConfig, ma_bpf* pBPF); +ma_result ma_bpf_process_pcm_frames(ma_bpf* pBPF, void* pFramesOut, const void* pFramesIn, ma_uint64 frameCount); +ma_uint32 ma_bpf_get_latency(ma_bpf* pBPF); + + /************************************************************************************************************************************************************ ************************************************************************************************************************************************************* @@ -29365,6 +29391,115 @@ ma_uint32 ma_hpf_get_latency(ma_hpf* pHPF) } +/************************************************************************************************************************************************************** + +Band-Pass Filtering + +**************************************************************************************************************************************************************/ +ma_bpf_config ma_bpf_config_init(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, double cutoffFrequency) +{ + ma_bpf_config config; + + MA_ZERO_OBJECT(&config); + config.format = format; + config.channels = channels; + config.sampleRate = sampleRate; + config.cutoffFrequency = cutoffFrequency; + + return config; +} + + +static MA_INLINE ma_biquad_config ma_bpf__get_biquad_config(const ma_bpf_config* pConfig) +{ + ma_biquad_config bqConfig; + double q; + double w; + double s; + double c; + double a; + + MA_ASSERT(pConfig != NULL); + + q = 0.707107; + w = 2 * MA_PI_D * pConfig->cutoffFrequency / pConfig->sampleRate; + s = ma_sin(w); + c = ma_cos(w); + a = s / (2*q); + + bqConfig.b0 = q * a; + bqConfig.b1 = 0; + bqConfig.b2 = -q * a; + bqConfig.a0 = 1 + a; + bqConfig.a1 = -2 * c; + bqConfig.a2 = 1 - a; + + bqConfig.format = pConfig->format; + bqConfig.channels = pConfig->channels; + + return bqConfig; +} + +ma_result ma_bpf_init(const ma_bpf_config* pConfig, ma_bpf* pBPF) +{ + ma_result result; + ma_biquad_config bqConfig; + + if (pBPF == NULL) { + return MA_INVALID_ARGS; + } + + MA_ZERO_OBJECT(pBPF); + + if (pConfig == NULL) { + return MA_INVALID_ARGS; + } + + bqConfig = ma_bpf__get_biquad_config(pConfig); + result = ma_biquad_init(&bqConfig, &pBPF->bq); + if (result != MA_SUCCESS) { + return result; + } + + return MA_SUCCESS; +} + +ma_result ma_bpf_reinit(const ma_bpf_config* pConfig, ma_bpf* pBPF) +{ + ma_result result; + ma_biquad_config bqConfig; + + if (pBPF == NULL || pConfig == NULL) { + return MA_INVALID_ARGS; + } + + bqConfig = ma_bpf__get_biquad_config(pConfig); + result = ma_biquad_reinit(&bqConfig, &pBPF->bq); + if (result != MA_SUCCESS) { + return result; + } + + return MA_SUCCESS; +} + +ma_result ma_bpf_process_pcm_frames(ma_bpf* pBPF, void* pFramesOut, const void* pFramesIn, ma_uint64 frameCount) +{ + if (pBPF == NULL) { + return MA_INVALID_ARGS; + } + + return ma_biquad_process_pcm_frames(&pBPF->bq, pFramesOut, pFramesIn, frameCount); +} + +ma_uint32 ma_bpf_get_latency(ma_bpf* pBPF) +{ + if (pBPF == NULL) { + return 0; + } + + return ma_biquad_get_latency(&pBPF->bq); +} + /**************************************************************************************************************************************************************