127 lines
3.2 KiB
Rust
127 lines
3.2 KiB
Rust
//! Sound representation.
|
|
|
|
use crate::durandal::err::*;
|
|
use std::io;
|
|
|
|
/// Writes a WAVE file from a sound.
|
|
pub fn write_wav(out: &mut impl io::Write, snd: &impl Sound) -> ResultS<()>
|
|
{
|
|
let rate = u32::from(snd.rate());
|
|
let bps = rate * 2;
|
|
let dat_size = snd.len() as u32 * 2;
|
|
let hdr_size = 36 + dat_size;
|
|
|
|
out.write_all(b"RIFF")?;
|
|
out.write_all(&u32::to_le_bytes(hdr_size))?;
|
|
out.write_all(b"WAVE")?;
|
|
out.write_all(b"fmt ")?;
|
|
out.write_all(&u32::to_le_bytes(16))?;
|
|
out.write_all(&u16::to_le_bytes(1))?; // PCM
|
|
out.write_all(&u16::to_le_bytes(1))?; // mono
|
|
out.write_all(&u32::to_le_bytes(rate))?;
|
|
out.write_all(&u32::to_le_bytes(bps))?;
|
|
out.write_all(&u16::to_le_bytes(2))?; // block alignment
|
|
out.write_all(&u16::to_le_bytes(16))?; // bits per sample
|
|
out.write_all(b"data")?;
|
|
out.write_all(&u32::to_le_bytes(dat_size))?;
|
|
|
|
for p in 0..snd.len() {
|
|
let sample = snd.index(p);
|
|
out.write_all(&sample.to_le_bytes())?;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Any PCM stream which may be represented as a 16-bit PCM stream.
|
|
pub trait Sound
|
|
{
|
|
/// Returns the sample rate.
|
|
fn rate(&self) -> u16;
|
|
|
|
/// Returns the number of samples.
|
|
fn len(&self) -> usize;
|
|
|
|
/// Returns the `n`th sample.
|
|
///
|
|
/// May panic if `n` exceeds the length of this sound.
|
|
fn index(&self, n: usize) -> i16;
|
|
|
|
/// Returns the number of the first sample of the loop, or `0`.
|
|
fn lp_beg(&self) -> usize;
|
|
|
|
/// Returns the number of the last sample of the loop, or `0`.
|
|
fn lp_end(&self) -> usize;
|
|
|
|
/// Returns `true` if there are no samples in this sound.
|
|
fn is_empty(&self) -> bool {self.len() == 0}
|
|
|
|
/// The same as `index`, but will not panic if out of bounds.
|
|
fn get(&self, n: usize) -> Option<i16>
|
|
{
|
|
if n < self.len() {
|
|
Some(self.index(n))
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
}
|
|
|
|
impl Sound16
|
|
{
|
|
/// Creates a new `Sound16`.
|
|
pub fn new(rate: u16, lp_beg: usize, lp_end: usize, len: usize) -> Self
|
|
{
|
|
Self{rate, lp_beg, lp_end, data: Vec::with_capacity(len)}
|
|
}
|
|
|
|
/// Creates a new `Sound16` from an unsigned 8-bit stream.
|
|
pub fn new_from_8(rate: u16, lp_beg: usize, lp_end: usize, b: &[u8])
|
|
-> Self
|
|
{
|
|
let mut snd = Self::new(rate, lp_beg, lp_end, b.len());
|
|
|
|
for &sample in b {
|
|
snd.data.push(Self::sample_from_8(sample));
|
|
}
|
|
|
|
snd
|
|
}
|
|
|
|
/// Creates a new `Sound16` from a signed 16-bit stream.
|
|
pub fn new_from_16(rate: u16, lp_beg: usize, lp_end: usize, b: &[u8])
|
|
-> Self
|
|
{
|
|
let mut snd = Self::new(rate, lp_beg, lp_end, b.len() / 2);
|
|
|
|
for i in (0..b.len()).step_by(2) {
|
|
snd.data.push(i16::from_le_bytes([b[i], b[i + 1]]));
|
|
}
|
|
|
|
snd
|
|
}
|
|
|
|
/// Creates a signed 16-bit sample from an unsigned 8-bit sample.
|
|
pub fn sample_from_8(sample: u8) -> i16 {(i16::from(sample) - 0x80) << 8}
|
|
}
|
|
|
|
impl Sound for Sound16
|
|
{
|
|
fn rate(&self) -> u16 {self.rate}
|
|
fn len(&self) -> usize {self.data.len()}
|
|
fn index(&self, p: usize) -> i16 {self.data[p]}
|
|
fn lp_beg(&self) -> usize {self.lp_beg}
|
|
fn lp_end(&self) -> usize {self.lp_end}
|
|
}
|
|
|
|
/// A 16-bit PCM stream.
|
|
pub struct Sound16
|
|
{
|
|
rate: u16,
|
|
lp_beg: usize,
|
|
lp_end: usize,
|
|
pub data: Vec<i16>,
|
|
}
|
|
|
|
// EOF
|