This implements the changes described at #370.
This commit implements only the `null` and `alsa` backends - the rest
will be implemented in follow-up commits.
Closes#370.
Seeing as a few large refactors have landed recently, I thought I'd take
this opportunity to do a `cargo fmt` run and standardise on the default
rustfmt settings.
This is a potential alternative to #359. This PR is based on #359.
This approach opts for a dynamically checked sample type approach with
the aim of minimising compile time and binary size.
You can read more discussion on this [here](https://github.com/RustAudio/cpal/pull/359#issuecomment-575931461)
Implemented backends:
- [x] null
- [x] ALSA
- [ ] CoreAudio
- [ ] WASAPI
- [ ] ASIO
- [ ] Emscripten
This is an implementation of the planned changes described in #119.
For a quick overview of how the API has changed, check out the updated
examples.
**TODO:**
- [x] Update API.
- [x] Update examples.
- [ ] Remove `data_type` field from `Format` (see [here](https://github.com/RustAudio/cpal/issues/119#issuecomment-573788380)).
- Update backends:
- [x] null
- [x] ALSA
- [ ] ASIO
- [ ] WASAPI
- [ ] CoreAudio
- [ ] Emscripten
Closes#119Closes#260
Originally this restriction was placed due to uncertainty around the
thread safety of the ASIO API. While the ASIO API itself makes no
thread-safety guarantees that we are aware of, the `asio-sys` high-level
bindings enforce synchronised access to the API and state transitions
via a mutex.
This is in order to ensure consistent restrictions across platforms in a
manner that ensures thread safety across each of the supported
platforms.
Please see added comments in the diff for details on which platforms
impose these restrictions.
- Shares the `Device`'s `driver` and `asio_streams` `Arc`s with the
`Stream`s to ensure they remain valid if the `Host` or `Device` are
dropped early.
- Ensures that a stream's callback is removed upon `Drop`.
For the most part, behaviour should be largely unchanged, however each
individual stream now has its own `set_timeout` callback loop, rather
than using one for processing all streams at once.
Many TODOs remain within the `emscripten` backend. These were left
untouched for the most part in favour of addressing this in a more
web-focused, future PR.
This works by detecting output devices in build_input_stream() and
setting the AUDCLNT_STREAMFLAGS_LOOPBACK flag to enable loopback
recording.
closes#251
Currently CPAL only really uses `failure` for its `derive` capabilities
and the ability to easily generate implementations for `Display`. That
said there are a few issues with using the `failure` crate:
- `failure` does not provie a `std::error::Error` implementation without
first converting error types into `failure::Error`.
- It leaks significantly into the public API and expects downstream
users to also depend on `failure` and the non-std `Fail` trait for
their own error handling.
- Solved problems such as downcasting of causal errors which have since
been addressed in `std`.
- Provides application-friendly `Fail` trait and `failure::Error` type,
not particularly useful to libraries like CPAL.
The [`thiserror` crate](https://github.com/dtolnay/thiserror) is better
targeted towards libraries, does not leak into the public API while
providing easy generation of `Display`, `From` and `std::error::Error`
implementations including proper handling of the newish
`std::error::Error::source` method.
The hardcoded errno was replaced by a constant, and `snd_pcm_prepare` was replaced by `snd_pcm_recover` per best practice (the underlying implementation seems same for now, though).
This existed prior to the introduction of the `Host` API, but was lost
in translation. This re-adds the bounds so that downstream code does not
suddenly break due to a lacking `Hash` implementation in the next
CPAL version.
Most of this is an attempt at improving readability and modularity of
the asio-sys crate while attempting to review it for correctness. Still
unsure why glitching is occasionally occuring on output, but recorded
input sounds perfectly clean.
ASIO has a limitation where it only supports loading a single audio
driver at a time. This fixes a common error where CPAL users would
request both the default input device and output device in separate
`load_driver` calls. Now, `load_driver` will return another handle to
the existing driver if the existing driver has the same name.
Instead, we use some traits and generics in an attempt to retain a
little readability. See the remaining TODOs in this section for required
future work.
mitchmindtree
Benjamin Saunders
Alex Moon
Jan Beich
msiglreith
Viktor Lazarev
Tatsuyuki Ishi
Sebastian Imlay
Ryan Adolf
est31
lucy
Luni-4
Alex Butler
est31
Richard Dodd (dodj)