Struct OpusMSDecoder 

pub struct OpusMSDecoder { /* private fields */ }

Multistream decoder: decode each stream and remux to the output channels.

Implementations

impl OpusMSDecoder

pub fn new( sample_rate: i32, channels: usize, mapping_family: u8, ) -> Result<Self>

Create a surround decoder for channels channels.

mapping_family selects the layout, as in OpusMSEncoder::new; for a stream read from a file it is the one OpusHead::mapping_family carries.

pub fn decode( &mut self, packet: &[u8], frame_size: usize, output: &mut [f32], ) -> Result<usize>

Decode a multistream packet into interleaved output (nb_channels per sample). Returns the number of samples per channel. Decode one multistream packet into interleaved float PCM.

As with OpusDecoder::decode, the output is not bounded by ±1.

pub fn decode_s16( &mut self, packet: &[u8], frame_size: usize, output: &mut [i16], ) -> Result<usize>

Decode one multistream packet into interleaved 16-bit PCM.

Each stream is soft-clipped on its own before the channels are remuxed, which is where libopus applies it too (opus_multistream_decode_native hands soft_clip to each stream’s decoder). Clipping the remuxed result instead would let one stream’s peak bend another’s audio.

pub fn layout(&self) -> &ChannelLayout

The channel layout this decoder produces.

pub fn nb_streams(&self) -> usize

Opus streams this decoder expects in each packet.

pub fn channels(&self) -> usize

The number of output channels this decoder produces.

pub fn sample_rate(&self) -> i32

The sample rate this decoder was created with, in Hz.

pub fn streams_mut(&mut self) -> &mut [OpusDecoder]

The per-stream decoders, so every OpusDecoder setting is reachable.

The counterpart of OpusMSEncoder::streams_mut, and the only route to gain_q8 — which is not a nicety. RFC 7845 §5.1 says a player SHOULD apply the gain a file declares, and it says nothing about mapping family, so a surround stream carrying a non-zero OpusHead::output_gain_q8 plays at the wrong level with no other symptom. A multistream decoder is N ordinary decoders and the gain belongs on every one of them:

let mut dec = OpusMSDecoder::new(48_000, 6, head.mapping_family)?;
for d in dec.streams_mut() {
    d.gain_q8 = head.output_gain_q8 as i32;
}

For mono and stereo, OpusHead::decoder does this for you and there is nothing to remember.

pub fn streams(&self) -> &[OpusDecoder]

The per-stream decoders, for reading. See streams_mut to change their settings.

final_range per stream is what a conformance check compares against a reference decoder’s.

pub fn reset_state(&mut self) -> Result<()>

Discard every stream’s coding state, as OpusDecoder::reset_state does for one.

Trait Implementations

impl Debug for OpusMSDecoder

Shows the layout, not the decoders’ coding state.

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.