From 47dd6bd17f3cc7ef95672ea16e443e58ce5eb1bf Mon Sep 17 00:00:00 2001
From: Anchen
Date: Sat, 24 Feb 2024 01:49:53 +1100
Subject: [PATCH] chore(clip): update the clip example to make it compatible
with HF format (#472)
* chore(clip): update the clip model to be HF format
* Update clip/convert.py
Co-authored-by: Awni Hannun
* chore: address comments
* chore: rename ClipVisionModel and ClipTextModel
* chore: add output hidden_states support
* chore: remove custom conv2d and apply weight transpose during weight sanitizing
* Update clip/model.py
* Update clip/model.py
---------
Co-authored-by: Awni Hannun
---
clip/convert.py | 107 ++++++++++--------
clip/model.py | 250 ++++++++++++++++++++++++++++++++----------
clip/requirements.txt | 2 +-
clip/test.py | 12 +-
4 files changed, 267 insertions(+), 104 deletions(-)
diff --git a/clip/convert.py b/clip/convert.py
index 5ce13e10..a646f93f 100644
--- a/clip/convert.py
+++ b/clip/convert.py
@@ -1,15 +1,68 @@
# Copyright © 2023-2024 Apple Inc.
import argparse
+import json
import shutil
from pathlib import Path
-from typing import Tuple
+from typing import Any, Dict, Union
import mlx.core as mx
import torch
from huggingface_hub import snapshot_download
+def make_shards(weights: dict, max_file_size_gb: int = 5) -> list:
+ max_file_size_bytes = max_file_size_gb << 30
+ shards = []
+ shard, shard_size = {}, 0
+ for k, v in weights.items():
+ if shard_size + v.nbytes > max_file_size_bytes:
+ shards.append(shard)
+ shard, shard_size = {}, 0
+ shard[k] = v
+ shard_size += v.nbytes
+ shards.append(shard)
+ return shards
+
+
+def save_weights(save_path: Union[str, Path], weights: Dict[str, Any]) -> None:
+ """Save model weights into specified directory."""
+ if isinstance(save_path, str):
+ save_path = Path(save_path)
+ save_path.mkdir(parents=True, exist_ok=True)
+
+ shards = make_shards(weights)
+ shards_count = len(shards)
+ shard_file_format = (
+ "model-{:05d}-of-{:05d}.safetensors"
+ if shards_count > 1
+ else "model.safetensors"
+ )
+
+ total_size = sum(v.nbytes for v in weights.values())
+ index_data = {"metadata": {"total_size": total_size}, "weight_map": {}}
+
+ for i, shard in enumerate(shards):
+ shard_name = shard_file_format.format(i + 1, shards_count)
+ shard_path = save_path / shard_name
+
+ mx.save_safetensors(str(shard_path), shard)
+
+ for weight_name in shard.keys():
+ index_data["weight_map"][weight_name] = shard_name
+
+ index_data["weight_map"] = {
+ k: index_data["weight_map"][k] for k in sorted(index_data["weight_map"])
+ }
+
+ with open(save_path / "model.safetensors.index.json", "w") as f:
+ json.dump(
+ index_data,
+ f,
+ indent=4,
+ )
+
+
def get_model_path(path_or_hf_repo: str) -> Path:
model_path = Path(path_or_hf_repo)
if not model_path.exists():
@@ -32,44 +85,6 @@ def torch_to_mx(a: torch.Tensor, *, dtype: str) -> mx.array:
return mx.array(a.numpy(), getattr(mx, dtype))
-def map_weights(key: str, value: torch.Tensor) -> Tuple[str, mx.array]:
- key = key.replace("embeddings.", "")
- key = key.replace("encoder.", "")
- key = key.replace("position_embedding.weight", "position_embedding")
-
- # Map attention layers
- if "self_attn." in key:
- key = key.replace("self_attn.", "attention.")
- if "q_proj." in key:
- key = key.replace("q_proj.", "query_proj.")
- if "k_proj." in key:
- key = key.replace("k_proj.", "key_proj.")
- if "v_proj." in key:
- key = key.replace("v_proj.", "value_proj.")
- if "layer_norm1." in key:
- key = key.replace("layer_norm1.", "ln1.")
- if "layer_norm2." in key:
- key = key.replace("layer_norm2.", "ln2.")
- # Map ffn layers
- if "mlp.fc1" in key:
- key = key.replace("mlp.fc1", "linear1")
- if "mlp.fc2" in key:
- key = key.replace("mlp.fc2", "linear2")
- # Fix layernorm typo
- if "pre_layrnorm" in key:
- # Fix typo in weights :)
- key = key.replace("pre_layrnorm", "pre_layernorm")
- if "patch_embedding.weight" in key:
- # Initially, value: [out_channels, in_channels, kH, KW].
- # We want [out_channels, kH, KW, in_channels]
- value = value.permute(0, 2, 3, 1)
- return (key, torch_to_mx(value, dtype=str(value.dtype).replace("torch.", "")))
-
-
-def should_keep_weight(key: str):
- return not ("position_ids" in key)
-
-
if __name__ == "__main__":
parser = argparse.ArgumentParser(
description="Download and Convert (OpenAI) CLIP weights to MLX"
@@ -86,7 +101,12 @@ if __name__ == "__main__":
default="mlx_model",
help="Path to save the MLX model.",
)
-
+ parser.add_argument(
+ "--dtype",
+ help="The data type to save the converted model.",
+ type=str,
+ default="float32",
+ )
args = parser.parse_args()
torch_path = get_model_path(args.hf_repo)
@@ -96,10 +116,11 @@ if __name__ == "__main__":
print("[INFO] Loading")
torch_weights = torch.load(torch_path / "pytorch_model.bin")
print("[INFO] Converting")
- mlx_weights = dict(map_weights(k, v) for (k, v) in torch_weights.items())
- mlx_weights = {k: v for (k, v) in mlx_weights.items() if should_keep_weight(k)}
+ mlx_weights = {
+ k: torch_to_mx(v, dtype=args.dtype) for k, v in torch_weights.items()
+ }
print("[INFO] Saving")
- mx.savez(str(mlx_path / "weights.npz"), **mlx_weights)
+ save_weights(mlx_path, mlx_weights)
for fn in ["config.json", "merges.txt", "vocab.json", "preprocessor_config.json"]:
shutil.copyfile(
str(torch_path / f"{fn}"),
diff --git a/clip/model.py b/clip/model.py
index 407a5e6c..384fd59a 100644
--- a/clip/model.py
+++ b/clip/model.py
@@ -1,9 +1,12 @@
# Copyright © 2023-2024 Apple Inc.
+import glob
import json
+import logging
+import math
from dataclasses import dataclass
from pathlib import Path
-from typing import Any, Optional
+from typing import Optional, Union
import mlx.core as mx
import mlx.nn as nn
@@ -16,6 +19,7 @@ from mlx.utils import tree_flatten
class CLIPVisionOutput:
pooler_output: mx.array
last_hidden_state: mx.array
+ hidden_states: Optional[mx.array]
@dataclass
@@ -41,6 +45,7 @@ class CLIPTextConfig:
num_attention_heads: int
max_position_embeddings: int
vocab_size: int
+ layer_norm_eps: float
@dataclass
@@ -52,6 +57,7 @@ class CLIPVisionConfig:
num_channels: int
image_size: int
patch_size: int
+ layer_norm_eps: float
@dataclass
@@ -75,50 +81,133 @@ def clip_loss(logits: mx.array) -> mx.array:
return (caption_loss + image_loss) / 2.0
-class CLIPEncoderLayer(nn.TransformerEncoderLayer):
+class Attention(nn.Module):
+ def __init__(
+ self,
+ dims: int,
+ num_heads: int,
+ query_input_dims: Optional[int] = None,
+ key_input_dims: Optional[int] = None,
+ value_input_dims: Optional[int] = None,
+ value_dims: Optional[int] = None,
+ value_output_dims: Optional[int] = None,
+ bias: bool = False,
+ ):
+ super().__init__()
+
+ if (dims % num_heads) != 0:
+ raise ValueError(
+ "The input feature dimensions should be divisible by the "
+ f"number of heads ({dims} % {num_heads}) != 0"
+ )
+
+ query_input_dims = query_input_dims or dims
+ key_input_dims = key_input_dims or dims
+ value_input_dims = value_input_dims or key_input_dims
+ value_dims = value_dims or dims
+ value_output_dims = value_output_dims or dims
+
+ self.num_heads = num_heads
+ self.q_proj = nn.Linear(query_input_dims, dims, bias=bias)
+ self.k_proj = nn.Linear(key_input_dims, dims, bias=bias)
+ self.v_proj = nn.Linear(value_input_dims, value_dims, bias=bias)
+ self.out_proj = nn.Linear(value_dims, value_output_dims, bias=bias)
+
+ def __call__(self, queries, keys, values, mask=None):
+ queries = self.q_proj(queries)
+ keys = self.k_proj(keys)
+ values = self.v_proj(values)
+
+ num_heads = self.num_heads
+ B, L, D = queries.shape
+ _, S, _ = keys.shape
+ queries = queries.reshape(B, L, num_heads, -1).transpose(0, 2, 1, 3)
+ keys = keys.reshape(B, S, num_heads, -1).transpose(0, 2, 3, 1)
+ values = values.reshape(B, S, num_heads, -1).transpose(0, 2, 1, 3)
+
+ scale = math.sqrt(1 / queries.shape[-1])
+ scores = (queries * scale) @ keys
+ if mask is not None:
+ scores = scores + mask.astype(scores.dtype)
+ scores = mx.softmax(scores, axis=-1)
+ values_hat = (scores @ values).transpose(0, 2, 1, 3).reshape(B, L, -1)
+
+ return self.out_proj(values_hat)
+
+
+class MLP(nn.Module):
+ def __init__(self, config: CLIPTextConfig):
+ super().__init__()
+ self.config = config
+ self.activation_fn = quick_gelu
+ self.fc1 = nn.Linear(config.hidden_size, config.intermediate_size)
+ self.fc2 = nn.Linear(config.intermediate_size, config.hidden_size)
+
+ def __call__(self, x: mx.array) -> mx.array:
+ x = self.activation_fn(self.fc1(x))
+ x = self.fc2(x)
+ return x
+
+
+class EncoderLayer(nn.Module):
"""The transformer encoder layer from CLIP."""
- def __init__(self, hidden_dim: int, intermediate_dim: int, num_heads: int):
- super().__init__(
- dims=hidden_dim,
- mlp_dims=intermediate_dim,
- num_heads=num_heads,
- activation=quick_gelu,
- norm_first=True,
- )
+ def __init__(self, config: CLIPTextConfig):
+ super().__init__()
+ self.embed_dim = config.hidden_size
# Add biases to the attention projections
- self.attention = nn.MultiHeadAttention(hidden_dim, num_heads, bias=True)
+ self.self_attn = Attention(
+ config.hidden_size, config.num_attention_heads, bias=True
+ )
+ self.layer_norm1 = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_eps)
+ self.mlp = MLP(config)
+ self.layer_norm2 = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_eps)
+
+ def __call__(self, x: mx.array, mask: Optional[mx.array] = None) -> mx.array:
+ y = self.layer_norm1(x)
+ y = self.self_attn(y, y, y, mask)
+ x = x + y
+ y = self.layer_norm2(x)
+ y = self.mlp(y)
+ return x + y
-class CLIPTextModel(nn.Module):
+class TextEmbeddings(nn.Module):
+ def __init__(self, config: CLIPTextConfig):
+ super().__init__()
+ embed_dim = config.hidden_size
+
+ self.token_embedding = nn.Embedding(config.vocab_size, embed_dim)
+ self.position_embedding = nn.Embedding(
+ config.max_position_embeddings, embed_dim
+ )
+
+ def __call__(self, x: mx.array) -> mx.array:
+ embeddings = self.token_embedding(x)
+ embeddings += self.position_embedding.weight[: x.shape[1]]
+ return embeddings
+
+
+class Encoder(nn.Module):
+ def __init__(self, config: CLIPTextConfig):
+ self.layers = [EncoderLayer(config) for _ in range(config.num_hidden_layers)]
+
+
+class ClipTextModel(nn.Module):
"""Implements the text encoder transformer from CLIP."""
def __init__(self, config: CLIPTextConfig):
super().__init__()
-
- self.token_embedding = nn.Embedding(config.vocab_size, config.hidden_size)
- self.position_embedding = mx.zeros(
- (config.max_position_embeddings, config.hidden_size)
- )
- self.layers = [
- CLIPEncoderLayer(
- config.hidden_size, config.intermediate_size, config.num_attention_heads
- )
- for _ in range(config.num_hidden_layers)
- ]
+ self.embeddings = TextEmbeddings(config)
+ self.encoder = Encoder(config)
self.final_layer_norm = nn.LayerNorm(config.hidden_size)
- def _embed(self, x: mx.array) -> mx.array:
- embeddings = self.token_embedding(x)
- embeddings += self.position_embedding[: x.shape[1]]
- return embeddings
-
def __call__(self, x: mx.array) -> CLIPTextOutput:
B, N = x.shape
eot_tokens = mx.argmax(x, axis=-1)
- x = self._embed(x)
+ x = self.embeddings(x)
mask = nn.MultiHeadAttention.create_additive_causal_mask(N, x.dtype)
- for l in self.layers:
+ for l in self.encoder.layers:
x = l(x, mask)
last_hidden_state = self.final_layer_norm(x)
pooler_output = last_hidden_state[mx.arange(B), eot_tokens]
@@ -128,33 +217,29 @@ class CLIPTextModel(nn.Module):
)
-class CLIPVisionModel(nn.Module):
- """Implements the vision encoder transformer from CLIP."""
-
+class VisionEmbeddings(nn.Module):
def __init__(self, config: CLIPVisionConfig):
super().__init__()
+ self.config = config
+ self.embed_dim = config.hidden_size
+ self.image_size = config.image_size
+ self.patch_size = config.patch_size
self.class_embedding = mx.zeros((config.hidden_size,))
+
self.patch_embedding = nn.Conv2d(
in_channels=config.num_channels,
- out_channels=config.hidden_size,
- kernel_size=config.patch_size,
- stride=config.patch_size,
+ out_channels=self.embed_dim,
+ kernel_size=self.patch_size,
+ stride=self.patch_size,
bias=False,
)
- num_patches = (config.image_size // config.patch_size) ** 2
- num_positions = num_patches + 1
- self.position_embedding = mx.zeros((num_positions, config.hidden_size))
- self.pre_layernorm = nn.LayerNorm(config.hidden_size)
- self.layers = [
- CLIPEncoderLayer(
- config.hidden_size, config.intermediate_size, config.num_attention_heads
- )
- for _ in range(config.num_hidden_layers)
- ]
- self.post_layernorm = nn.LayerNorm(config.hidden_size)
- def _embed(self, x: mx.array) -> mx.array:
+ self.num_patches = (self.image_size // self.patch_size) ** 2
+ self.num_positions = self.num_patches + 1
+ self.position_embedding = nn.Embedding(self.num_positions, self.embed_dim)
+
+ def __call__(self, x: mx.array) -> mx.array:
batch_size = x.shape[0]
# Patchify using conv:
# [batch_size, sqrt(num_patches), sqrt(num_patches), embed_dim]
@@ -170,25 +255,48 @@ class CLIPVisionModel(nn.Module):
# [batch_size, num_patches + 1, embed_dim]
embeddings = mx.concatenate((cls_embeddings, patch_embeddings), axis=1)
# Add positional encoding
- embeddings += self.position_embedding
+ embeddings += self.position_embedding.weight
return embeddings
- def __call__(self, x: mx.array) -> CLIPVisionOutput:
- x = self._embed(x)
- x = self.pre_layernorm(x)
- for l in self.layers:
+class ClipVisionModel(nn.Module):
+ """Implements the vision encoder transformer from CLIP."""
+
+ def __init__(self, config: CLIPVisionConfig):
+ super().__init__()
+ self.embeddings = VisionEmbeddings(config)
+ self.pre_layrnorm = nn.LayerNorm(config.hidden_size)
+ self.encoder = Encoder(config)
+ self.post_layernorm = nn.LayerNorm(config.hidden_size)
+
+ def __call__(
+ self,
+ x: mx.array,
+ output_hidden_states: Optional[bool] = None,
+ ) -> CLIPVisionOutput:
+ x = self.embeddings(x)
+ x = self.pre_layrnorm(x)
+
+ encoder_states = (x,) if output_hidden_states else None
+
+ for l in self.encoder.layers:
x = l(x, mask=None)
+ if output_hidden_states:
+ encoder_states = encoder_states + (x,)
# Extract token embedding
pooler_output = self.post_layernorm(x[:, 0, :])
- return CLIPVisionOutput(pooler_output=pooler_output, last_hidden_state=x)
+ return CLIPVisionOutput(
+ pooler_output=pooler_output,
+ last_hidden_state=x,
+ hidden_states=encoder_states,
+ )
class CLIPModel(nn.Module):
def __init__(self, config: CLIPConfig):
- self.text_model = CLIPTextModel(config.text_config)
- self.vision_model = CLIPVisionModel(config.vision_config)
+ self.text_model = ClipTextModel(config.text_config)
+ self.vision_model = ClipVisionModel(config.vision_config)
text_embed_dim = config.text_config.hidden_size
vision_embed_dim = config.vision_config.hidden_size
@@ -259,6 +367,7 @@ class CLIPModel(nn.Module):
num_attention_heads=text_config["num_attention_heads"],
max_position_embeddings=text_config["max_position_embeddings"],
vocab_size=text_config["vocab_size"],
+ layer_norm_eps=text_config["layer_norm_eps"],
)
vision_config = config["vision_config"]
@@ -271,6 +380,7 @@ class CLIPModel(nn.Module):
num_channels=3,
image_size=vision_config["image_size"],
patch_size=vision_config["patch_size"],
+ layer_norm_eps=vision_config["layer_norm_eps"],
)
config = CLIPConfig(
@@ -279,5 +389,31 @@ class CLIPModel(nn.Module):
projection_dim=config["projection_dim"],
)
model = CLIPModel(config)
- model.load_weights(str(path / "weights.npz"))
+ weight_files = glob.glob(str(path / "*.safetensors"))
+ if not weight_files:
+ logging.error(f"No safetensors found in {path}")
+ raise FileNotFoundError(f"No safetensors found in {path}")
+
+ weights = {}
+ for wf in weight_files:
+ weights.update(mx.load(wf))
+
+ weights = model.sanitize(weights)
+ model.load_weights(list(weights.items()))
return model
+
+ @staticmethod
+ def sanitize(weights):
+ sanitized_weights = {}
+ for k, v in weights.items():
+ if "position_ids" in k:
+ # Remove unused position_ids
+ continue
+ elif "patch_embedding.weight" in k:
+ # pytorch conv2d expects the weight tensor to be of shape [out_channels, in_channels, kH, KW]
+ # mlx conv2d expects the weight tensor to be of shape [out_channels, kH, KW, in_channels]
+ sanitized_weights[k] = v.transpose(0, 2, 3, 1)
+ else:
+ sanitized_weights[k] = v
+
+ return sanitized_weights
diff --git a/clip/requirements.txt b/clip/requirements.txt
index a6f2f1ca..74f826ea 100644
--- a/clip/requirements.txt
+++ b/clip/requirements.txt
@@ -3,4 +3,4 @@ numpy
transformers
torch
huggingface_hub
-Pillow
\ No newline at end of file
+Pillow
diff --git a/clip/test.py b/clip/test.py
index d8a2f84d..63086953 100644
--- a/clip/test.py
+++ b/clip/test.py
@@ -86,12 +86,14 @@ class TestCLIP(unittest.TestCase):
with torch.inference_mode():
# Get expected
x_tc = torch.tensor(x)
- expected_out = self.hf_clip.vision_model(x_tc)
+ expected_out = self.hf_clip.vision_model(x_tc, output_hidden_states=True)
expected_last_hidden = expected_out.last_hidden_state.numpy()
expected_pooler_output = expected_out.pooler_output.numpy()
-
+ expected_hidden_states = [hs.numpy() for hs in expected_out.hidden_states]
# Test MLX vision encoder
- out = self.mx_clip.vision_model(mx.array(x.transpose(0, 2, 3, 1)))
+ out = self.mx_clip.vision_model(
+ mx.array(x.transpose(0, 2, 3, 1)), output_hidden_states=True
+ )
self.assertTrue(
np.allclose(
out.last_hidden_state, expected_last_hidden, rtol=1e-4, atol=1e-3
@@ -102,6 +104,10 @@ class TestCLIP(unittest.TestCase):
out.pooler_output, expected_pooler_output, rtol=1e-4, atol=1e-3
),
)
+ for expected_hs, out_hs in zip(expected_hidden_states, out.hidden_states):
+ self.assertTrue(
+ np.allclose(expected_hs, out_hs, rtol=1e-4, atol=1e-3),
+ )
def test_clip_model(self):
image_input = self.hf_image_proc(