Merge pull request #6 from tomaka/clean-convert-channels

Cleanup and add tests for convert_channels
This commit is contained in:
tomaka 2014-12-22 15:57:15 +01:00
commit 4239fae948
1 changed files with 41 additions and 6 deletions

View File

@ -39,9 +39,21 @@ pub fn convert_samples_rate<T>(input: &[T], from: ::SamplesRate, to: ::SamplesRa
unimplemented!() unimplemented!()
} }
/// Converts between a certain number of channels.
///
/// If the target number is inferior to the source number, additional channels are removed.
///
/// If the target number is superior to the source number, the value of channel `N` is equal
/// to the value of channel `N % source_channels`.
///
/// ## Panic
///
/// Panics if `from` is 0, `to` is 0, or if the data length is not a multiple of `from`.
pub fn convert_channels<T>(input: &[T], from: ::ChannelsCount, to: ::ChannelsCount) -> Vec<T> pub fn convert_channels<T>(input: &[T], from: ::ChannelsCount, to: ::ChannelsCount) -> Vec<T>
where T: Copy where T: Copy
{ {
assert!(from != 0);
assert!(to != 0);
assert!(input.len() % from as uint == 0); assert!(input.len() % from as uint == 0);
let mut result = Vec::new(); let mut result = Vec::new();
@ -53,18 +65,41 @@ pub fn convert_channels<T>(input: &[T], from: ::ChannelsCount, to: ::ChannelsCou
} }
// adding extra ones // adding extra ones
for i in range(0, ::std::cmp::max(0, to - from)) { if to > from {
for i in range(0, to - from) {
result.push(element[i as uint % element.len()]); result.push(element[i as uint % element.len()]);
} }
} }
}
result result
} }
/*#[cfg(test)] #[cfg(test)]
mod test { mod test {
#[test] use super::convert_channels;
fn test_convert_channels() {
#[test]
fn remove_channels() {
let result = convert_channels(&[1u16, 2, 3, 1, 2, 3], 3, 2);
assert_eq!(result.as_slice(), [1, 2, 1, 2]);
let result = convert_channels(&[1u16, 2, 3, 4, 1, 2, 3, 4], 4, 1);
assert_eq!(result.as_slice(), [1, 1]);
} }
}*/
#[test]
fn add_channels() {
let result = convert_channels(&[1u16, 2, 1, 2], 2, 3);
assert_eq!(result.as_slice(), [1, 2, 1, 1, 2, 1]);
let result = convert_channels(&[1u16, 2, 1, 2], 2, 4);
assert_eq!(result.as_slice(), [1, 2, 1, 2, 1, 2, 1, 2]);
}
#[test]
#[should_fail]
fn convert_channels_wrong_data_len() {
convert_channels(&[1u16, 2, 3], 2, 1);
}
}