7e4392ae68
This implements a proof-of-concept for an improved audio frontend. The largest change is the introduction of events and event handling: both by time elapsed and by track events, such as ending or looping. Following on from this, the library now includes a basic, event-driven track queue system (which people seem to ask for unusually often). A new sample, `examples/13_voice_events`, demonstrates both the `TrackQueue` system and some basic events via the `~queue` and `~play_fade` commands. Locks are removed from around the control of `Audio` objects, which should allow the backend to be moved to a more granular futures-based backend solution in a cleaner way.
42 lines
1.5 KiB
Rust
42 lines
1.5 KiB
Rust
//! Utility methods for seeking or decoding.
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use crate::constants::*;
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use audiopus::{coder::Decoder, Channels, Result as OpusResult, SampleRate};
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use std::{mem, time::Duration};
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/// Calculates the sample position in a FloatPCM stream from a timestamp.
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pub fn timestamp_to_sample_count(timestamp: Duration, stereo: bool) -> usize {
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((timestamp.as_millis() as usize) * (MONO_FRAME_SIZE / FRAME_LEN_MS)) << stereo as usize
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}
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/// Calculates the time position in a FloatPCM stream from a sample index.
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pub fn sample_count_to_timestamp(amt: usize, stereo: bool) -> Duration {
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Duration::from_millis((((amt * FRAME_LEN_MS) / MONO_FRAME_SIZE) as u64) >> stereo as u64)
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}
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/// Calculates the byte position in a FloatPCM stream from a timestamp.
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///
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/// Each sample is sized by `mem::size_of::<f32>() == 4usize`.
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pub fn timestamp_to_byte_count(timestamp: Duration, stereo: bool) -> usize {
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timestamp_to_sample_count(timestamp, stereo) * mem::size_of::<f32>()
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}
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/// Calculates the time position in a FloatPCM stream from a byte index.
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///
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/// Each sample is sized by `mem::size_of::<f32>() == 4usize`.
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pub fn byte_count_to_timestamp(amt: usize, stereo: bool) -> Duration {
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sample_count_to_timestamp(amt / mem::size_of::<f32>(), stereo)
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}
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/// Create an Opus decoder outputting at a sample rate of 48kHz.
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pub fn decoder(stereo: bool) -> OpusResult<Decoder> {
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Decoder::new(
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SampleRate::Hz48000,
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if stereo {
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Channels::Stereo
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} else {
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Channels::Mono
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},
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)
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}
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