servius/songbird
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Driver: Add toggle for softclip (#137)

Browse Source 
This adds the `use_softclip` field to `Config`, which can currently provide a ~10us reduction in mixing cost from both a removed memcpy and the softclip itself.

This PR was tested using cargo make ready.

Closes #134.
This commit is contained in:
Kyle Simpson
2022-07-25 16:36:47 +01:00
parent 0beb0f0d76
commit 13946b47ce
3 changed files with 78 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

50
src/driver/tasks/mixer/mod.rs
View File

@@ -569,7 +569,7 @@ impl Mixer {
}
pub fn cycle(&mut self) -> Result<()> {
let mut mix_buffer = [0f32; STEREO_FRAME_SIZE];
let mut softclip_buffer = [0f32; STEREO_FRAME_SIZE];
// symph_mix is an `AudioBuffer` (planar format), we need to convert this
// later into an interleaved `SampleBuffer` for libopus.
@@ -635,22 +635,31 @@ impl Mixer {
self.silence_frames = 5;
if let MixType::MixedPcm(n) = mix_len {
// FIXME: When impling #134, prevent this copy from happening if softclip disabled.
// Offer sample_buffer.samples() to prep_and_send_packet.
#[cfg(test)]
let do_copy = true;
#[cfg(not(test))]
let do_copy = self.config.use_softclip;
// to apply soft_clip, we need this to be in a normal f32 buffer.
// unfortunately, SampleBuffer does not expose a `.samples_mut()`.
// hence, an extra copy...
let samples_to_copy = self.config.mix_mode.channels() * n;
if do_copy {
// to apply soft_clip, we need this to be in a normal f32 buffer.
// unfortunately, SampleBuffer does not expose a `.samples_mut()`.
// hence, an extra copy...
//
// also just copy in for #[cfg(test)] to simplify the below logic
// for handing out audio data to the outside world.
let samples_to_copy = self.config.mix_mode.channels() * n;
(&mut mix_buffer[..samples_to_copy])
.copy_from_slice(&self.sample_buffer.samples()[..samples_to_copy]);
(&mut softclip_buffer[..samples_to_copy])
.copy_from_slice(&self.sample_buffer.samples()[..samples_to_copy]);
}
self.soft_clip.apply(
(&mut mix_buffer[..])
.try_into()
.expect("Mix buffer is known to have a valid sample count (softclip)."),
)?;
if self.config.use_softclip {
self.soft_clip.apply(
(&mut softclip_buffer[..])
.try_into()
.expect("Mix buffer is known to have a valid sample count (softclip)."),
)?;
}
}
}
@@ -662,6 +671,8 @@ impl Mixer {
// usually a 20ms tick, in test modes this is either a finite number of runs or user input.
self.march_deadline();
let send_buffer = self.config.use_softclip.then(|| &softclip_buffer[..]);
#[cfg(test)]
if let Some(OutputMode::Raw(tx)) = &self.config.override_connection {
let msg = match mix_len {
@@ -677,17 +688,17 @@ impl Mixer {
OutputMessage::Passthrough(opus_frame)
},
MixType::MixedPcm(_) => OutputMessage::Mixed(
mix_buffer[..self.config.mix_mode.sample_count_in_frame()].to_vec(),
softclip_buffer[..self.config.mix_mode.sample_count_in_frame()].to_vec(),
),
};
drop(tx.send(msg.into()));
} else {
self.prep_and_send_packet(&mix_buffer, mix_len)?;
self.prep_and_send_packet(send_buffer, mix_len)?;
}
#[cfg(not(test))]
self.prep_and_send_packet(&mix_buffer, mix_len)?;
self.prep_and_send_packet(send_buffer, mix_len)?;
// Zero out all planes of the mix buffer if any audio was written.
if matches!(mix_len, MixType::MixedPcm(a) if a > 0) {
@@ -704,7 +715,8 @@ impl Mixer {
}
#[inline]
fn prep_and_send_packet(&mut self, buffer: &[f32; 1920], mix_len: MixType) -> Result<()> {
fn prep_and_send_packet(&mut self, buffer: Option<&[f32]>, mix_len: MixType) -> Result<()> {
let send_buffer = buffer.unwrap_or_else(|| self.sample_buffer.samples());
let conn = self
.conn_active
.as_mut()
@@ -726,7 +738,7 @@ impl Mixer {
MixType::MixedPcm(_samples) => {
let total_payload_space = payload.len() - crypto_mode.payload_suffix_len();
self.encoder.encode_float(
&buffer[..self.config.mix_mode.sample_count_in_frame()],
&send_buffer[..self.config.mix_mode.sample_count_in_frame()],
&mut payload[TAG_SIZE..total_payload_space],
)?
},