There is probably some followup cleanup which can be done, but keeping
the general structure intact might help if there are future changes on
available (non-E2EE) algorithms.
This PR adds support for the new AEAD cryptosystems advertised by Discord, AES256-GCM and XChaCha20Poly1305. These schemes will shortly become mandatory, and provider stronger integrity/authentication guarantees over the cleartext portions of any voice packet by correctly specifying additional authenticated data.
To provide smooth switchover, we've added basic negotiation over the `CryptoMode`. This ensures that any clients who are manually specifying one of the legacy modes will automatically migrate to `Aes256Gcm` when Discord cease to advertise their original preference.
Closes#246.
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Co-authored-by: Kyle Simpson <kyleandrew.simpson@gmail.com>
As of v0.9.1, `xsalsa20poly1305` has been deprecated. This is a mostly seamless replacement, as it appears to be the same crate authors / code / etc.
Co-authored-by: Kyle Simpson <kyleandrew.simpson@gmail.com>
This PR implements a custom scheduler for audio threads, which reduces thread use and (often) memory consumption.
To save threads and memory (e.g., packet buffer allocations), Songbird parks Mixer tasks which do not have any live Tracks.
These are now all co-located on a single async 'Idle' task.
This task is responsible for managing UDP keepalive messages for each task, maintaining event state, and executing any Mixer task messages.
Whenever any message arrives which adds a `Track`, the mixer task is moved to a live thread.
The Idle task inspects task counts and execution time on each thread, choosing the first live thread with room, and creating a new one if needed.
Each live thread is responsible for running as many live mixers as it can in a single tick every 20ms: this currently defaults to 16 mixers per thread, but is user-configurable.
A live thread also stores RTP packet blocks to be written into by each sub-task.
Each live thread has a conservative limit of 18ms that it will aim to stay under: if all work takes longer than this, it will offload the task with the highest mixing cost once per tick onto another (possibly new) live worker thread.
This PR Introduces a new `VoiceTick` event which collects and reorders all RTP packets to smooth over network instability, as well as to synchronise user audio streams. Raw packet events have been moved to `RtpPacket`, while `SpeakingUpdate`s have been removed as they can be easily computed using the `silent`/`speaking` audio maps included in each event.
Closes#146.
This PR makes use of `SampleBuffer::samples_mut` to remove a 7680B stack allocation in general, and memcopy when softclip is used. This appears to offer ~1.5% performance boost according to `cargo make bench`.
Adds a new field to Config, disposer, an Option<Sender<DisposalMessage>> responsible for dropping the DisposalMessage on a separate thread.
If this is not set, and the Config is passed into manager::Songbird, a thread is spawned for this purpose (which previously was spawned per driver).
If this is not set, and the Config is passed directly into Driver or Call, a thread is spawned locally, which is the current behavior as there is no where to store the Sender.
This disposer is then used in Driver as previously, to run possibly blocking destructors (which should only block the disposal thread). I cannot see this disposal thread getting overloaded, but if it is the DisposalMessages will simply be queued in the flume channel until it can be dropped.
Co-authored-by: Kyle Simpson <kyleandrew.simpson@gmail.com>
Adds the "receive" feature, which is disabled by default. When this is disabled, the UDP receive task is not compiled and not run, and as an optimisation the UDP receive buffer size is set to 0. All related events are also removed.
This also removes the UDP Tx task, and moves packet and keepalive sends back into the mixer thread. This allows us to entirely remove channels and various allocations between the mixer and an async task created only for sending data (i.e., fewer memcopies).
If "receive" is enabled, UDP sends are now non-blocking due to technical constraints -- failure to send is non-fatal, but *will* drop affected packets. Given that blocking on a UDP send indicates that the OS cannot clear send buffers fast enough, this should alleviate OS load.
Closes#131.
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 extensive PR rewrites the internal mixing logic of the driver to use symphonia for parsing and decoding audio data, and rubato to resample audio. Existing logic to decode DCA and Opus formats/data have been reworked as plugins for symphonia. The main benefit is that we no longer need to keep yt-dlp and ffmpeg processes alive, saving a lot of memory and CPU: all decoding can be done in Rust! In exchange, we now need to do a lot of the HTTP handling and resumption ourselves, but this is still a huge net positive.
`Input`s have been completely reworked such that all default (non-cached) sources are lazy by default, and are no longer covered by a special-case `Restartable`. These now span a gamut from a `Compose` (lazy), to a live source, to a fully `Parsed` source. As mixing is still sync, this includes adapters for `AsyncRead`/`AsyncSeek`, and HTTP streams.
`Track`s have been reworked so that they only contain initialisation state for each track. `TrackHandles` are only created once a `Track`/`Input` has been handed over to the driver, replacing `create_player` and related functions. `TrackHandle::action` now acts on a `View` of (im)mutable state, and can request seeks/readying via `Action`.
Per-track event handling has also been improved -- we can now determine and propagate the reason behind individual track errors due to the new backend. Some `TrackHandle` commands (seek etc.) benefit from this, and now use internal callbacks to signal completion.
Due to associated PRs on felixmcfelix/songbird from avid testers, this includes general clippy tweaks, API additions, and other repo-wide cleanup. Thanks go out to the below co-authors.
Co-authored-by: Gnome! <45660393+GnomedDev@users.noreply.github.com>
Co-authored-by: Alakh <36898190+alakhpc@users.noreply.github.com>
