Encodec model. (#1771)

* Encodec model.

* Fixes.

* Add the padding functions.

* Get the LSTM bit to work.

* Get the encodec model to generate some tokens (decoder only for now).

* Minor tweak.

* Minor tweak.

candle-examples/examples/encodec/main.rs

@@ -0,0 +1,57 @@
+#[cfg(feature = "mkl")]
+extern crate intel_mkl_src;
+
+#[cfg(feature = "accelerate")]
+extern crate accelerate_src;
+
+use anyhow::Result;
+use candle::{DType, IndexOp};
+use candle_nn::VarBuilder;
+use candle_transformers::models::encodec::{Config, Model};
+use clap::Parser;
+use hf_hub::api::sync::Api;
+
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Args {
+    /// Run on CPU rather than on GPU.
+    #[arg(long)]
+    cpu: bool,
+
+    /// The model weight file, in safetensor format.
+    #[arg(long)]
+    model: Option<String>,
+
+    /// Input file as a safetensors containing the encodec tokens.
+    #[arg(long)]
+    code_file: String,
+
+    /// Output file that will be generated in wav format.
+    #[arg(long)]
+    out: 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("facebook/encodec_24khz".to_string())
+            .get("model.safetensors")?,
+    };
+    let vb = unsafe { VarBuilder::from_mmaped_safetensors(&[model], DType::F32, &device)? };
+    let config = Config::default();
+    let model = Model::new(&config, vb)?;
+
+    let codes = candle::safetensors::load(args.code_file, &device)?;
+    let codes = codes.get("codes").expect("no codes in input file").i(0)?;
+    println!("codes shape: {:?}", codes.shape());
+    let pcm = model.decode(&codes)?;
+    let pcm = pcm.i(0)?.i(0)?.to_vec1::<f32>()?;
+
+    let mut output = std::fs::File::create(&args.out)?;
+    candle_examples::wav::write_pcm_as_wav(&mut output, &pcm, 24_000)?;
+
+    Ok(())
+}