Create ctranslate2 Moonshine implementation.

Adds the following:
- c++ moonshine model
- pybind for python moonshine model
- moonshine model spec
- safetensor moonshine model converter
- support for GroupNorm-style weights for LayerNorm
- support for multi-axis cuda layernorm

CMakeLists.txt

@@ -129,6 +129,7 @@ set(SOURCES
   src/layers/wav2vec2.cc
   src/layers/wav2vec2bert.cc
   src/layers/whisper.cc
+  src/layers/moonshine.cc
   src/logging.cc
   src/models/language_model.cc
   src/models/model.cc
@@ -139,6 +140,7 @@ set(SOURCES
   src/models/wav2vec2.cc
   src/models/wav2vec2bert.cc
   src/models/whisper.cc
+  src/models/moonshine.cc
   src/ops/activation.cc
   src/ops/add.cc
   src/ops/alibi_add.cc

include/ctranslate2/layers/moonshine.h

@@ -0,0 +1,75 @@
+#include "ctranslate2/layers/transformer.h"
+
+namespace ctranslate2 {
+  namespace layers {
+
+    class MoonshinePreprocessor : public Layer {
+    public:
+      MoonshinePreprocessor(const models::Model& model, const std::string& scope);
+
+      void operator()(const StorageView& features, StorageView& output);
+
+      DataType output_type() const override {
+        return _conv3.output_type();
+      }
+
+      dim_t output_size() const override {
+        return _conv3.output_size();
+      }
+
+      dim_t input_size() const {
+        return _conv1.input_size();
+      }
+    private:
+      const Conv1D _conv1;
+      const ops::Tanh _tanh;
+      const LayerNorm _norm;
+      const Conv1D _conv2;
+      const ops::GELU _gelu1;
+      const Conv1D _conv3;
+      const ops::GELU _gelu2;
+      const ops::Transpose _transpose;
+    };
+
+
+    class MoonshineEncoder : public Layer {
+    public:
+      MoonshineEncoder(const models::Model& model, const std::string& scope);
+
+      void operator()(const StorageView& features, StorageView& output);
+
+      DataType output_type() const override {
+        return _output_norm.output_type();
+      }
+
+      dim_t output_size() const override {
+        return _output_norm.output_size();
+      }
+
+      bool is_encoded(const StorageView& features) const {
+        // Input features shape: [batch_size, input_size, input_time]
+        // Encoder output shape: [batch_size, input_time // 2, output_size]
+        //
+        // input_time is variable so we check that dimension 1 is different than its original value.
+
+        return (features.rank() == 3
+                && features.dim(2) == output_size()
+                && features.dim(1) != 1);
+      }
+
+    private:
+      const dim_t _num_heads;
+      const std::vector<std::unique_ptr<const TransformerEncoderLayer>> _layers;
+      const LayerNorm _output_norm;
+    };
+
+    class MoonshineDecoder : public TransformerDecoder {
+    public:
+      using TransformerDecoder::TransformerDecoder;
+
+      bool return_normalized_attention() const override {
+        return false;
+      }
+    };
+  }
+}

include/ctranslate2/models/moonshine.h

@@ -0,0 +1,134 @@
+#pragma once
+
+#include "ctranslate2/generation.h"
+#include "ctranslate2/layers/moonshine.h"
+#include "ctranslate2/models/model.h"
+#include "ctranslate2/replica_pool.h"
+
+namespace ctranslate2 {
+  namespace models {
+
+    struct MoonshineOptions {
+      // Beam size to use for beam search (set 1 to run greedy search).
+      size_t beam_size = 5;
+
+      // Beam search patience factor, as described in https://arxiv.org/abs/2204.05424.
+      // The decoding will continue until beam_size*patience hypotheses are finished.
+      float patience = 1;
+
+      // Exponential penalty applied to the length during beam search.
+      float length_penalty = 1;
+
+      // Penalty applied to the score of previously generated tokens, as described in
+      // https://arxiv.org/abs/1909.05858 (set > 1 to penalize).
+      float repetition_penalty = 1;
+
+      // Prevent repetitions of ngrams with this size (set 0 to disable).
+      size_t no_repeat_ngram_size = 0;
+
+      // Maximum generation length.
+      size_t max_length = 448;
+
+      // Randomly sample from the top K candidates (set 0 to sample from the full distribution).
+      size_t sampling_topk = 1;
+
+      // High temperatures increase randomness.
+      float sampling_temperature = 1;
+
+      // Number of hypotheses to include in the result.
+      size_t num_hypotheses = 1;
+
+      // Include scores in the result.
+      bool return_scores = false;
+
+      // Suppress blank outputs at the beginning of the sampling.
+      bool suppress_blank = true;
+
+      // List of token IDs to suppress.
+      // -1 will suppress a default set of symbols as defined in the model config.json file.
+      std::vector<int> suppress_tokens = {-1};
+    };
+
+    struct MoonshineGenerationResult {
+      std::vector<std::vector<std::string>> sequences;
+      std::vector<std::vector<size_t>> sequences_ids;
+      std::vector<float> scores;
+
+      size_t num_sequences() const {
+        return sequences.size();
+      }
+
+      bool has_scores() const {
+        return !scores.empty();
+      }
+    };
+
+    class MoonshineModel : public Model {
+    public:
+      const Vocabulary& get_vocabulary() const;
+
+      size_t current_spec_revision() const override;
+      bool is_quantizable(const std::string& variable_name) const override;
+      bool is_linear_weight(const std::string& variable_name) const override;
+      std::unique_ptr<Model> clone() const override;
+
+      bool use_global_int16_scale() const override {
+        return false;
+      }
+
+    protected:
+      void initialize(ModelReader& model_reader) override;
+
+    private:
+      std::shared_ptr<const Vocabulary> _vocabulary;
+    };
+
+    class MoonshineReplica : public ModelReplica {
+    public:
+      static std::unique_ptr<MoonshineReplica> create_from_model(const Model& model);
+
+      MoonshineReplica(const std::shared_ptr<const MoonshineModel>& model);
+
+      StorageView encode(StorageView features, const bool to_cpu);
+
+      std::vector<MoonshineGenerationResult>
+      generate(StorageView features,
+               const std::vector<std::vector<std::string>>& prompts,
+               const MoonshineOptions& options);
+
+      std::vector<MoonshineGenerationResult>
+      generate(StorageView features,
+               const std::vector<std::vector<size_t>>& prompts,
+               const MoonshineOptions& options);
+
+    private:
+      const std::shared_ptr<const MoonshineModel> _model;
+      const std::unique_ptr<layers::MoonshinePreprocessor> _preprocessor;
+      const std::unique_ptr<layers::MoonshineEncoder> _encoder;
+      const std::unique_ptr<layers::MoonshineDecoder> _decoder;
+
+      size_t _sot_id;
+      size_t _eot_id;
+
+      StorageView maybe_encode(StorageView features);
+    };
+
+    class Moonshine : public ReplicaPool<MoonshineReplica> {
+    public:
+      using ReplicaPool::ReplicaPool;
+
+      std::future<StorageView> encode(const StorageView& features, const bool to_cpu);
+
+      std::vector<std::future<MoonshineGenerationResult>>
+      generate(const StorageView& features,
+               std::vector<std::vector<std::string>> prompts,
+               MoonshineOptions options = {});
+
+      std::vector<std::future<MoonshineGenerationResult>>
+      generate(const StorageView& features,
+               std::vector<std::vector<size_t>> prompts,
+               MoonshineOptions options = {});
+    };
+
+  }
+}

include/ctranslate2/ops/layer_norm.h

@@ -7,7 +7,7 @@ namespace ctranslate2 {
 
     class LayerNorm : public TernaryOp {
     public:
-      LayerNorm(const dim_t axis = -1, const float epsilon = 1e-5);
+      LayerNorm(const dim_t axis = -1, const float epsilon = 1e-5, const bool multi_axis=false);
 
       using TernaryOp::operator();
       void operator()(const StorageView& beta,
@@ -32,10 +32,12 @@ namespace ctranslate2 {
                    const dim_t outer_size,
                    const dim_t axis_size,
                    const dim_t inner_size,
+                   const bool multi_axis,
                    StorageView& output) const;
 
       const dim_t _axis;
       const float _epsilon;
+      const bool _multi_axis;
     };
 
   }

python/cpp/module.cc

@@ -89,4 +89,5 @@ PYBIND11_MODULE(_ext, m)
   ctranslate2::python::register_wav2vec2(m);
   ctranslate2::python::register_wav2vec2bert(m);
   ctranslate2::python::register_mpi(m);
+  ctranslate2::python::register_moonshine(m);
 }

python/cpp/module.h

@@ -20,6 +20,7 @@ namespace ctranslate2 {
     void register_wav2vec2(py::module& m);
     void register_wav2vec2bert(py::module& m);
     void register_mpi(py::module& m);
+    void register_moonshine(py::module& m);
 
   }
 }