This commit is contained in:
bursteratom
2024-12-05 14:59:51 -05:00
parent 169116a50f
commit dc055a4ef7

View File

@@ -42,9 +42,124 @@ class MultiModalChatDataCollator(DataCollatorMixin):
)
return self.__class__.process_rows(
examples, self.processor, self.chat_template, self.max_images
examples,
self.processor,
self.chat_template,
self.max_images,
chat_template_type=self.chat_template_type,
)
@staticmethod
def preprocess(examples: list[dict]) -> list[dict]:
"""
Preprocess conversation examples to ensure consistent format.
Converts different conversation formats to OpenAI format with 'messages'.
Supports two formats:
1. OpenAI format with 'messages'
2. Legacy format with 'conversations'
Args:
examples: list of conversation dictionaries
Returns:
dict in OpenAI format with 'messages' key
Raises:
ValueError: If the conversation format is not supported
"""
role_mapping = {
"human": "user",
"gpt": "assistant",
}
def normalize_role(role: str) -> str:
"""Normalize role names to OpenAI format. Default to original role if not found."""
return role_mapping.get(role, role)
def convert_legacy_format(example: dict) -> dict:
"""Convert legacy 'conversations' format to OpenAI 'messages' format."""
messages = [
{
"role": normalize_role(convo["from"]),
"content": convo["value"],
}
for convo in example["conversations"]
]
# Create new dict without 'conversations' key
result = deepcopy(example)
result.pop("conversations")
return {"messages": messages, **result}
processed_examples = []
for example in examples:
# OpenAI format
if "messages" in example:
processed_examples.append(example)
# Legacy format
elif "conversations" in example:
processed_examples.append(convert_legacy_format(example))
else:
raise ValueError(
"Only `messages` and `conversations` message keys are currently supported."
)
return processed_examples
@staticmethod
def process_images(examples, max_images):
"""
Process images from examples, ensuring consistency in image presence and applying max_images limit.
Args:
examples: List of dictionaries that may contain 'images' key
max_images: Maximum number of images to keep per example (0 means no limit)
Returns:
Either None (if no images) or List[Image objects] (if all examples have images)
Raises:
ValueError: If there's a mix of None and non-None images
"""
def get_image(example):
if "images" not in example:
return None
images = example["images"]
if isinstance(images, str):
return Image.open(images)
return images
images = [get_image(example) for example in examples]
# Count None and non-None images
none_count = sum(1 for img in images if img is None)
# All images are None
if none_count == len(images):
return None
# Mix of None and non-None images
if none_count > 0:
raise ValueError(
"All images should be either None or not None. "
"Please provide images for all examples or None."
)
# Apply max_images limit if specified
if max_images > 0:
images = [
(
img_batch[:max_images]
if isinstance(img_batch, (list, tuple))
else img_batch
)
for img_batch in images
]
return images
@staticmethod
def pixtral_chat_conversion(messages):
is_single_message = not isinstance(messages, list)
@@ -68,136 +183,42 @@ class MultiModalChatDataCollator(DataCollatorMixin):
return messages
@staticmethod
def process_rows(examples, processor, chat_template, max_images, length_only=False):
def process_rows(
examples,
processor,
chat_template,
max_images,
length_only=False,
chat_template_type=None,
):
# HINT: use `_torch_collate_batch` to stack and pad tensors
# see also DataCollatorWithFlattening and DefaultDataCollator
# *** This is COPIED from the trl example sft_vlm.py code ***
# use this as a starting point
def _preprocess(examples: list[dict]) -> list[dict]:
"""
Preprocess conversation examples to ensure consistent format.
Converts different conversation formats to OpenAI format with 'messages'.
Supports two formats:
1. OpenAI format with 'messages'
2. Legacy format with 'conversations'
Args:
examples: list of conversation dictionaries
Returns:
dict in OpenAI format with 'messages' key
Raises:
ValueError: If the conversation format is not supported
"""
role_mapping = {
"human": "user",
"gpt": "assistant",
}
def normalize_role(role: str) -> str:
"""Normalize role names to OpenAI format. Default to original role if not found."""
return role_mapping.get(role, role)
def convert_legacy_format(example: dict) -> dict:
"""Convert legacy 'conversations' format to OpenAI 'messages' format."""
messages = [
{
"role": normalize_role(convo["from"]),
"content": convo["value"],
}
for convo in example["conversations"]
]
# Create new dict without 'conversations' key
result = deepcopy(example)
result.pop("conversations")
return {"messages": messages, **result}
processed_examples = []
for example in examples:
# OpenAI format
if "messages" in example:
processed_examples.append(example)
# Legacy format
elif "conversations" in example:
processed_examples.append(convert_legacy_format(example))
else:
raise ValueError(
"Only `messages` and `conversations` message keys are currently supported."
)
return processed_examples
def _process_images(examples, max_images):
"""
Process images from examples, ensuring consistency in image presence and applying max_images limit.
Args:
examples: List of dictionaries that may contain 'images' key
max_images: Maximum number of images to keep per example (0 means no limit)
Returns:
Either None (if no images) or List[Image objects] (if all examples have images)
Raises:
ValueError: If there's a mix of None and non-None images
"""
def get_image(example):
if "images" not in example:
return None
images = example["images"]
if isinstance(images, str):
return Image.open(images)
return images
images = [get_image(example) for example in examples]
# Count None and non-None images
none_count = sum(1 for img in images if img is None)
# All images are None
if none_count == len(images):
return None
# Mix of None and non-None images
if none_count > 0:
raise ValueError(
"All images should be either None or not None. "
"Please provide images for all examples or None."
)
# Apply max_images limit if specified
if max_images > 0:
images = [
(
img_batch[:max_images]
if isinstance(img_batch, (list, tuple))
else img_batch
)
for img_batch in images
]
return images
# Preprocess the examples
examples = _preprocess(examples)
examples = __class__.preprocess(examples)
# Get the texts and images, and apply the chat template
texts = [
processor.apply_chat_template(
example["messages"], chat_template=chat_template, tokenize=False
)
for example in examples
]
if chat_template_type == "pixtral":
texts = [
processor.apply_chat_template(
__class__.pixtral_chat_conversion(example["messages"]),
chat_template=chat_template,
tokenize=False,
)
for example in examples
]
else:
texts = [
processor.apply_chat_template(
example["messages"], chat_template=chat_template, tokenize=False
)
for example in examples
]
images = _process_images(examples, max_images=max_images)
images = __class__.process_images(examples, max_images=max_images)
# Tokenize the texts and process the images
batch = processor(text=texts, images=images, return_tensors="pt", padding=True)