void NarrowbandFMAudio::execute(buffer_c8_t buffer) {
/* Called every 2048/3072000 second -- 1500Hz. */
auto decimator_out = decimator.execute(buffer);
const buffer_c16_t work_baseband_buffer {
(complex16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
/* 96kHz complex<int16_t>[64]
* -> FIR filter, <6kHz (0.063fs) pass, gain 1.0
* -> 48kHz int16_t[32] */
auto channel = channel_filter.execute(decimator_out, work_baseband_buffer);
// TODO: Feed channel_stats post-decimation data?
feed_channel_stats(channel);
feed_channel_spectrum(
channel,
decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
);
const buffer_s16_t work_audio_buffer {
(int16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
/* 48kHz complex<int16_t>[32]
* -> FM demodulation
* -> 48kHz int16_t[32] */
auto audio = demod.execute(channel, work_audio_buffer);
static uint64_t audio_present_history = 0;
const auto audio_present_now = squelch.execute(audio);
audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0);
const bool audio_present = (audio_present_history != 0);
if( !audio_present ) {
// Zero audio buffer.
for(size_t i=0; i<audio.count; i++) {
audio.p[i] = 0;
}
}
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}
void AudioOutput::on_block(
const buffer_f32_t& audio
) {
const auto audio_present_now = squelch.execute(audio);
hpf.execute_in_place(audio);
deemph.execute_in_place(audio);
audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0);
const bool audio_present = (audio_present_history != 0);
if( !audio_present ) {
for(size_t i=0; i<audio.count; i++) {
audio.p[i] = 0;
}
}
fill_audio_buffer(audio, audio_present);
}
/*--------------------------- sound callback ------------------------------*/
int
record_sound ( const void *inputBuffer, unsigned long numSamples, void *userData )
{
struct paRecordData *pdata = (struct paRecordData*)userData;
__LOCK_MUTEX( __AMUTEX );
gboolean capVid = pdata->capVid;
int channels = pdata->channels;
int skip_n = pdata->skip_n;
__UNLOCK_MUTEX( __AMUTEX );
const SAMPLE *rptr = (const SAMPLE*) inputBuffer;
int i;
UINT64 numFrames = numSamples / channels;
/* buffer ends at timestamp "now", calculate beginning timestamp */
UINT64 nsec_per_frame = G_NSEC_PER_SEC / pdata->samprate;
UINT64 ts = ns_time_monotonic() - numFrames * nsec_per_frame;
if (skip_n > 0) /*skip audio while were skipping video frames*/
{
if(capVid)
{
__LOCK_MUTEX( __AMUTEX );
pdata->snd_begintime = ns_time_monotonic(); /*reset first time stamp*/
__UNLOCK_MUTEX( __AMUTEX );
return (0); /*still capturing*/
}
else
{ __LOCK_MUTEX( __AMUTEX );
pdata->streaming=FALSE;
__LOCK_MUTEX( __AMUTEX );
return (-1); /*capture has stopped*/
}
}
// __LOCK_MUTEX( __AMUTEX );
// pdata->streaming=TRUE;
// __UNLOCK_MUTEX( __AMUTEX );
for( i=0; i<numSamples; i++ )
{
pdata->recordedSamples[pdata->sampleIndex] = inputBuffer ? *rptr++ : 0;
pdata->sampleIndex++;
fill_audio_buffer(pdata, ts);
/* increment timestamp accordingly while copying */
if (i % channels == 0)
ts += nsec_per_frame;
}
if(capVid) return (0); /*still capturing*/
else
{
__LOCK_MUTEX( __AMUTEX );
pdata->streaming=FALSE;
/* mark current buffer as ready to process */
pdata->audio_buff_flag[pdata->bw_ind] = AUD_PROCESS;
__UNLOCK_MUTEX( __AMUTEX );
}
return(-1); /* audio capture stopped*/
}
