Add the mimi audio-tokenizer. (#2488)

* Add the mimi audio-tokenizer.

* Formatting tweaks.

* Add a full example.

* Use the transformers names.

* More renamings.

* Get encoding and decoding to work.

* Clippy fixes.

3 files changed, 426 insertions, 0 deletions

diff --git a/candle-examples/examples/mimi/README.md b/candle-examples/examples/mimi/README.md
new file mode 100644
index 00000000..bbcfcdb7
--- /dev/null
+++ b/candle-examples/examples/mimi/README.md
@@ -0,0 +1,20 @@
+# candle-mimi
+
+[Mimi](https://huggingface.co/kyutai/mimi) is a state of the art audio
+compression model using an encoder/decoder architecture with residual vector
+quantization. The candle implementation supports streaming meaning that it's
+possible to encode or decode a stream of audio tokens on the flight to provide
+low latency interaction with an audio model.
+
+## Running one example
+
+Generating some audio tokens from an audio files.
+```bash
+wget https://github.com/metavoiceio/metavoice-src/raw/main/assets/bria.mp3
+cargo run --example mimi --features mimi --release -- audio-to-code bria.mp3 bria.safetensors
+```
+
+And decoding the audio tokens back into a sound file.
+```bash
+cargo run --example mimi --features mimi --release -- code-to-audio bria.safetensors bria.wav
+```
diff --git a/candle-examples/examples/mimi/audio_io.rs b/candle-examples/examples/mimi/audio_io.rs
new file mode 100644
index 00000000..2103dd4a
--- /dev/null
+++ b/candle-examples/examples/mimi/audio_io.rs
@@ -0,0 +1,275 @@
+#![allow(unused)]
+use anyhow::{Context, Result};
+use std::sync::{Arc, Mutex};
+
+pub const SAMPLE_RATE: usize = 24_000;
+
+pub(crate) struct AudioOutputData_ {
+    resampled_data: std::collections::VecDeque<f32>,
+    resampler: rubato::FastFixedIn<f32>,
+    output_buffer: Vec<f32>,
+    input_buffer: Vec<f32>,
+    input_len: usize,
+}
+
+impl AudioOutputData_ {
+    pub(crate) fn new(input_sample_rate: usize, output_sample_rate: usize) -> Result<Self> {
+        use rubato::Resampler;
+
+        let resampled_data = std::collections::VecDeque::with_capacity(output_sample_rate * 10);
+        let resample_ratio = output_sample_rate as f64 / input_sample_rate as f64;
+        let resampler = rubato::FastFixedIn::new(
+            resample_ratio,
+            f64::max(resample_ratio, 1.0),
+            rubato::PolynomialDegree::Septic,
+            1024,
+            1,
+        )?;
+        let input_buffer = resampler.input_buffer_allocate(true).remove(0);
+        let output_buffer = resampler.output_buffer_allocate(true).remove(0);
+        Ok(Self {
+            resampled_data,
+            resampler,
+            input_buffer,
+            output_buffer,
+            input_len: 0,
+        })
+    }
+
+    pub fn reset(&mut self) {
+        use rubato::Resampler;
+        self.output_buffer.fill(0.);
+        self.input_buffer.fill(0.);
+        self.resampler.reset();
+        self.resampled_data.clear();
+    }
+
+    pub(crate) fn take_all(&mut self) -> Vec<f32> {
+        let mut data = Vec::with_capacity(self.resampled_data.len());
+        while let Some(elem) = self.resampled_data.pop_back() {
+            data.push(elem);
+        }
+        data
+    }
+
+    pub(crate) fn is_empty(&self) -> bool {
+        self.resampled_data.is_empty()
+    }
+
+    // Assumes that the input buffer is large enough.
+    fn push_input_buffer(&mut self, samples: &[f32]) {
+        self.input_buffer[self.input_len..self.input_len + samples.len()].copy_from_slice(samples);
+        self.input_len += samples.len()
+    }
+
+    pub(crate) fn push_samples(&mut self, samples: &[f32]) -> Result<()> {
+        use rubato::Resampler;
+
+        let mut pos_in = 0;
+        loop {
+            let rem = self.input_buffer.len() - self.input_len;
+            let pos_end = usize::min(pos_in + rem, samples.len());
+            self.push_input_buffer(&samples[pos_in..pos_end]);
+            pos_in = pos_end;
+            if self.input_len < self.input_buffer.len() {
+                break;
+            }
+            let (_, out_len) = self.resampler.process_into_buffer(
+                &[&self.input_buffer],
+                &mut [&mut self.output_buffer],
+                None,
+            )?;
+            for &elem in self.output_buffer[..out_len].iter() {
+                self.resampled_data.push_front(elem)
+            }
+            self.input_len = 0;
+        }
+        Ok(())
+    }
+}
+
+type AudioOutputData = Arc<Mutex<AudioOutputData_>>;
+
+pub(crate) fn setup_output_stream() -> Result<(cpal::Stream, AudioOutputData)> {
+    use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
+
+    println!("Setup audio output stream!");
+    let host = cpal::default_host();
+    let device = host
+        .default_output_device()
+        .context("no output device available")?;
+    let mut supported_configs_range = device.supported_output_configs()?;
+    let config_range = match supported_configs_range.find(|c| c.channels() == 1) {
+        // On macOS, it's commonly the case that there are only stereo outputs.
+        None => device
+            .supported_output_configs()?
+            .next()
+            .context("no audio output available")?,
+        Some(config_range) => config_range,
+    };
+    let sample_rate = cpal::SampleRate(SAMPLE_RATE as u32).clamp(
+        config_range.min_sample_rate(),
+        config_range.max_sample_rate(),
+    );
+    let config: cpal::StreamConfig = config_range.with_sample_rate(sample_rate).into();
+    let channels = config.channels as usize;
+    println!(
+        "cpal device: {} {} {config:?}",
+        device.name().unwrap_or_else(|_| "unk".to_string()),
+        config.sample_rate.0
+    );
+    let audio_data = Arc::new(Mutex::new(AudioOutputData_::new(
+        SAMPLE_RATE,
+        config.sample_rate.0 as usize,
+    )?));
+    let ad = audio_data.clone();
+    let stream = device.build_output_stream(
+        &config,
+        move |data: &mut [f32], _: &cpal::OutputCallbackInfo| {
+            data.fill(0.);
+            let mut ad = ad.lock().unwrap();
+            let mut last_elem = 0f32;
+            for (idx, elem) in data.iter_mut().enumerate() {
+                if idx % channels == 0 {
+                    match ad.resampled_data.pop_back() {
+                        None => break,
+                        Some(v) => {
+                            last_elem = v;
+                            *elem = v
+                        }
+                    }
+                } else {
+                    *elem = last_elem
+                }
+            }
+        },
+        move |err| eprintln!("cpal error: {err}"),
+        None, // None=blocking, Some(Duration)=timeout
+    )?;
+    stream.play()?;
+    Ok((stream, audio_data))
+}
+
+pub(crate) fn setup_input_stream() -> Result<(cpal::Stream, AudioOutputData)> {
+    use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
+
+    println!("Setup audio input stream!");
+    let host = cpal::default_host();
+    let device = host
+        .default_input_device()
+        .context("no input device available")?;
+    let mut supported_configs_range = device.supported_input_configs()?;
+    let config_range = supported_configs_range
+        .find(|c| c.channels() == 1)
+        .context("no audio input available")?;
+    let sample_rate = cpal::SampleRate(SAMPLE_RATE as u32).clamp(
+        config_range.min_sample_rate(),
+        config_range.max_sample_rate(),
+    );
+    let config: cpal::StreamConfig = config_range.with_sample_rate(sample_rate).into();
+    println!(
+        "cpal device: {} {} {config:?}",
+        device.name().unwrap_or_else(|_| "unk".to_string()),
+        config.sample_rate.0
+    );
+    let audio_data = Arc::new(Mutex::new(AudioOutputData_::new(
+        config.sample_rate.0 as usize,
+        SAMPLE_RATE,
+    )?));
+    let ad = audio_data.clone();
+    let stream = device.build_input_stream(
+        &config,
+        move |data: &[f32], _: &cpal::InputCallbackInfo| {
+            let mut ad = ad.lock().unwrap();
+            if let Err(err) = ad.push_samples(data) {
+                eprintln!("error processing audio input {err:?}")
+            }
+        },
+        move |err| eprintln!("cpal error: {err}"),
+        None, // None=blocking, Some(Duration)=timeout
+    )?;
+    stream.play()?;
+    Ok((stream, audio_data))
+}
+
+fn conv<T>(samples: &mut Vec<f32>, data: std::borrow::Cow<symphonia::core::audio::AudioBuffer<T>>)
+where
+    T: symphonia::core::sample::Sample,
+    f32: symphonia::core::conv::FromSample<T>,
+{
+    use symphonia::core::audio::Signal;
+    use symphonia::core::conv::FromSample;
+    samples.extend(data.chan(0).iter().map(|v| f32::from_sample(*v)))
+}
+
+pub(crate) fn pcm_decode<P: AsRef<std::path::Path>>(path: P) -> Result<(Vec<f32>, u32)> {
+    use symphonia::core::audio::{AudioBufferRef, Signal};
+
+    let src = std::fs::File::open(path)?;
+    let mss = symphonia::core::io::MediaSourceStream::new(Box::new(src), Default::default());
+    let hint = symphonia::core::probe::Hint::new();
+    let meta_opts: symphonia::core::meta::MetadataOptions = Default::default();
+    let fmt_opts: symphonia::core::formats::FormatOptions = Default::default();
+    let probed = symphonia::default::get_probe().format(&hint, mss, &fmt_opts, &meta_opts)?;
+    let mut format = probed.format;
+    let track = format
+        .tracks()
+        .iter()
+        .find(|t| t.codec_params.codec != symphonia::core::codecs::CODEC_TYPE_NULL)
+        .expect("no supported audio tracks");
+    let mut decoder = symphonia::default::get_codecs()
+        .make(&track.codec_params, &Default::default())
+        .expect("unsupported codec");
+    let track_id = track.id;
+    let sample_rate = track.codec_params.sample_rate.unwrap_or(0);
+    let mut pcm_data = Vec::new();
+    while let Ok(packet) = format.next_packet() {
+        while !format.metadata().is_latest() {
+            format.metadata().pop();
+        }
+        if packet.track_id() != track_id {
+            continue;
+        }
+        match decoder.decode(&packet)? {
+            AudioBufferRef::F32(buf) => pcm_data.extend(buf.chan(0)),
+            AudioBufferRef::U8(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::U16(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::U24(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::U32(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::S8(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::S16(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::S24(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::S32(data) => conv(&mut pcm_data, data),
+            AudioBufferRef::F64(data) => conv(&mut pcm_data, data),
+        }
+    }
+    Ok((pcm_data, sample_rate))
+}
+
+pub(crate) fn resample(pcm_in: &[f32], sr_in: usize, sr_out: usize) -> Result<Vec<f32>> {
+    use rubato::Resampler;
+
+    let mut pcm_out =
+        Vec::with_capacity((pcm_in.len() as f64 * sr_out as f64 / sr_in as f64) as usize + 1024);
+
+    let mut resampler = rubato::FftFixedInOut::<f32>::new(sr_in, sr_out, 1024, 1)?;
+    let mut output_buffer = resampler.output_buffer_allocate(true);
+    let mut pos_in = 0;
+    while pos_in + resampler.input_frames_next() < pcm_in.len() {
+        let (in_len, out_len) =
+            resampler.process_into_buffer(&[&pcm_in[pos_in..]], &mut output_buffer, None)?;
+        pos_in += in_len;
+        pcm_out.extend_from_slice(&output_buffer[0][..out_len]);
+    }
+
+    if pos_in < pcm_in.len() {
+        let (_in_len, out_len) = resampler.process_partial_into_buffer(
+            Some(&[&pcm_in[pos_in..]]),
+            &mut output_buffer,
+            None,
+        )?;
+        pcm_out.extend_from_slice(&output_buffer[0][..out_len]);
+    }
+
+    Ok(pcm_out)
+}
diff --git a/candle-examples/examples/mimi/main.rs b/candle-examples/examples/mimi/main.rs
new file mode 100644
index 00000000..cfc1a553
--- /dev/null
+++ b/candle-examples/examples/mimi/main.rs
@@ -0,0 +1,131 @@
+#[cfg(feature = "mkl")]
+extern crate intel_mkl_src;
+
+#[cfg(feature = "accelerate")]
+extern crate accelerate_src;
+
+use anyhow::Result;
+use candle::{DType, IndexOp, Tensor};
+use candle_nn::VarBuilder;
+use candle_transformers::models::mimi::{Config, Model};
+use clap::{Parser, ValueEnum};
+use hf_hub::api::sync::Api;
+
+mod audio_io;
+
+#[derive(Clone, Debug, Copy, PartialEq, Eq, ValueEnum)]
+enum Action {
+    AudioToAudio,
+    AudioToCode,
+    CodeToAudio,
+}
+
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Args {
+    /// The action to be performed, specifies the format for the input and output data.
+    action: Action,
+
+    /// The input file, either an audio file or some mimi tokens stored as safetensors.
+    in_file: String,
+
+    /// The output file, either a wave audio file or some mimi tokens stored as safetensors.
+    out_file: String,
+
+    /// Run on CPU rather than on GPU.
+    #[arg(long)]
+    cpu: bool,
+
+    /// The model weight file, in safetensor format.
+    #[arg(long)]
+    model: Option<String>,
+}
+
+fn main() -> Result<()> {
+    let args = Args::parse();
+    let device = candle_examples::device(args.cpu)?;
+    let model = match args.model {
+        Some(model) => std::path::PathBuf::from(model),
+        None => Api::new()?
+            .model("kyutai/mimi".to_string())
+            .get("model.safetensors")?,
+    };
+    let vb = unsafe { VarBuilder::from_mmaped_safetensors(&[model], DType::F32, &device)? };
+    let config = Config::v0_1(None);
+    let mut model = Model::new(config, vb)?;
+
+    let codes = match args.action {
+        Action::CodeToAudio => {
+            let codes = candle::safetensors::load(args.in_file, &device)?;
+            codes.get("codes").expect("no codes in input file").clone()
+        }
+        Action::AudioToCode | Action::AudioToAudio => {
+            let pcm = if args.in_file == "-" {
+                println!(">>>> RECORDING AUDIO, PRESS ENTER ONCE DONE <<<<");
+                let (stream, input_audio) = audio_io::setup_input_stream()?;
+                let mut pcms = vec![];
+                let stdin = std::thread::spawn(|| {
+                    let mut s = String::new();
+                    std::io::stdin().read_line(&mut s)
+                });
+                while !stdin.is_finished() {
+                    let input = input_audio.lock().unwrap().take_all();
+                    if input.is_empty() {
+                        std::thread::sleep(std::time::Duration::from_millis(100));
+                        continue;
+                    }
+                    pcms.push(input)
+                }
+                drop(stream);
+                pcms.concat()
+            } else {
+                let (pcm, sample_rate) = audio_io::pcm_decode(args.in_file)?;
+                if sample_rate != 24_000 {
+                    println!("WARNING: mimi uses a 24khz sample rate, input uses {sample_rate}, resampling...");
+                    audio_io::resample(&pcm, sample_rate as usize, 24_000)?
+                } else {
+                    pcm
+                }
+            };
+            let pcm_len = pcm.len();
+            let pcm = Tensor::from_vec(pcm, (1, 1, pcm_len), &device)?;
+            println!("input pcm shape: {:?}", pcm.shape());
+            model.encode(&pcm)?
+        }
+    };
+    println!("codes shape: {:?}", codes.shape());
+
+    match args.action {
+        Action::AudioToCode => {
+            codes.save_safetensors("codes", &args.out_file)?;
+        }
+        Action::AudioToAudio | Action::CodeToAudio => {
+            let pcm = model.decode(&codes)?;
+            println!("output pcm shape: {:?}", pcm.shape());
+            let pcm = pcm.i(0)?.i(0)?;
+            let pcm = candle_examples::audio::normalize_loudness(&pcm, 24_000, true)?;
+            let pcm = pcm.to_vec1::<f32>()?;
+            if args.out_file == "-" {
+                let (stream, ad) = audio_io::setup_output_stream()?;
+                {
+                    let mut ad = ad.lock().unwrap();
+                    ad.push_samples(&pcm)?;
+                }
+                loop {
+                    let ad = ad.lock().unwrap();
+                    if ad.is_empty() {
+                        break;
+                    }
+                    // That's very weird, calling thread::sleep here triggers the stream to stop
+                    // playing (the callback doesn't seem to be called anymore).
+                    // std::thread::sleep(std::time::Duration::from_millis(100));
+                }
+                drop(stream)
+            } else {
+                let mut output = std::fs::File::create(&args.out_file)?;
+                candle_examples::wav::write_pcm_as_wav(&mut output, &pcm, 24_000)?;
+            }
+        }
+    }
+    Ok(())
+}