in src/diffusers/loaders/single_file_utils.py [0:0]
def convert_ldm_unet_checkpoint(checkpoint, config, extract_ema=False, **kwargs):
"""
Takes a state dict and a config, and returns a converted checkpoint.
"""
# extract state_dict for UNet
unet_state_dict = {}
keys = list(checkpoint.keys())
unet_key = LDM_UNET_KEY
# at least a 100 parameters have to start with `model_ema` in order for the checkpoint to be EMA
if sum(k.startswith("model_ema") for k in keys) > 100 and extract_ema:
logger.warning("Checkpoint has both EMA and non-EMA weights.")
logger.warning(
"In this conversion only the EMA weights are extracted. If you want to instead extract the non-EMA"
" weights (useful to continue fine-tuning), please make sure to remove the `--extract_ema` flag."
)
for key in keys:
if key.startswith("model.diffusion_model"):
flat_ema_key = "model_ema." + "".join(key.split(".")[1:])
unet_state_dict[key.replace(unet_key, "")] = checkpoint.get(flat_ema_key)
else:
if sum(k.startswith("model_ema") for k in keys) > 100:
logger.warning(
"In this conversion only the non-EMA weights are extracted. If you want to instead extract the EMA"
" weights (usually better for inference), please make sure to add the `--extract_ema` flag."
)
for key in keys:
if key.startswith(unet_key):
unet_state_dict[key.replace(unet_key, "")] = checkpoint.get(key)
new_checkpoint = {}
ldm_unet_keys = DIFFUSERS_TO_LDM_MAPPING["unet"]["layers"]
for diffusers_key, ldm_key in ldm_unet_keys.items():
if ldm_key not in unet_state_dict:
continue
new_checkpoint[diffusers_key] = unet_state_dict[ldm_key]
if ("class_embed_type" in config) and (config["class_embed_type"] in ["timestep", "projection"]):
class_embed_keys = DIFFUSERS_TO_LDM_MAPPING["unet"]["class_embed_type"]
for diffusers_key, ldm_key in class_embed_keys.items():
new_checkpoint[diffusers_key] = unet_state_dict[ldm_key]
if ("addition_embed_type" in config) and (config["addition_embed_type"] == "text_time"):
addition_embed_keys = DIFFUSERS_TO_LDM_MAPPING["unet"]["addition_embed_type"]
for diffusers_key, ldm_key in addition_embed_keys.items():
new_checkpoint[diffusers_key] = unet_state_dict[ldm_key]
# Relevant to StableDiffusionUpscalePipeline
if "num_class_embeds" in config:
if (config["num_class_embeds"] is not None) and ("label_emb.weight" in unet_state_dict):
new_checkpoint["class_embedding.weight"] = unet_state_dict["label_emb.weight"]
# Retrieves the keys for the input blocks only
num_input_blocks = len({".".join(layer.split(".")[:2]) for layer in unet_state_dict if "input_blocks" in layer})
input_blocks = {
layer_id: [key for key in unet_state_dict if f"input_blocks.{layer_id}" in key]
for layer_id in range(num_input_blocks)
}
# Retrieves the keys for the middle blocks only
num_middle_blocks = len({".".join(layer.split(".")[:2]) for layer in unet_state_dict if "middle_block" in layer})
middle_blocks = {
layer_id: [key for key in unet_state_dict if f"middle_block.{layer_id}" in key]
for layer_id in range(num_middle_blocks)
}
# Retrieves the keys for the output blocks only
num_output_blocks = len({".".join(layer.split(".")[:2]) for layer in unet_state_dict if "output_blocks" in layer})
output_blocks = {
layer_id: [key for key in unet_state_dict if f"output_blocks.{layer_id}" in key]
for layer_id in range(num_output_blocks)
}
# Down blocks
for i in range(1, num_input_blocks):
block_id = (i - 1) // (config["layers_per_block"] + 1)
layer_in_block_id = (i - 1) % (config["layers_per_block"] + 1)
resnets = [
key for key in input_blocks[i] if f"input_blocks.{i}.0" in key and f"input_blocks.{i}.0.op" not in key
]
update_unet_resnet_ldm_to_diffusers(
resnets,
new_checkpoint,
unet_state_dict,
{"old": f"input_blocks.{i}.0", "new": f"down_blocks.{block_id}.resnets.{layer_in_block_id}"},
)
if f"input_blocks.{i}.0.op.weight" in unet_state_dict:
new_checkpoint[f"down_blocks.{block_id}.downsamplers.0.conv.weight"] = unet_state_dict.get(
f"input_blocks.{i}.0.op.weight"
)
new_checkpoint[f"down_blocks.{block_id}.downsamplers.0.conv.bias"] = unet_state_dict.get(
f"input_blocks.{i}.0.op.bias"
)
attentions = [key for key in input_blocks[i] if f"input_blocks.{i}.1" in key]
if attentions:
update_unet_attention_ldm_to_diffusers(
attentions,
new_checkpoint,
unet_state_dict,
{"old": f"input_blocks.{i}.1", "new": f"down_blocks.{block_id}.attentions.{layer_in_block_id}"},
)
# Mid blocks
for key in middle_blocks.keys():
diffusers_key = max(key - 1, 0)
if key % 2 == 0:
update_unet_resnet_ldm_to_diffusers(
middle_blocks[key],
new_checkpoint,
unet_state_dict,
mapping={"old": f"middle_block.{key}", "new": f"mid_block.resnets.{diffusers_key}"},
)
else:
update_unet_attention_ldm_to_diffusers(
middle_blocks[key],
new_checkpoint,
unet_state_dict,
mapping={"old": f"middle_block.{key}", "new": f"mid_block.attentions.{diffusers_key}"},
)
# Up Blocks
for i in range(num_output_blocks):
block_id = i // (config["layers_per_block"] + 1)
layer_in_block_id = i % (config["layers_per_block"] + 1)
resnets = [
key for key in output_blocks[i] if f"output_blocks.{i}.0" in key and f"output_blocks.{i}.0.op" not in key
]
update_unet_resnet_ldm_to_diffusers(
resnets,
new_checkpoint,
unet_state_dict,
{"old": f"output_blocks.{i}.0", "new": f"up_blocks.{block_id}.resnets.{layer_in_block_id}"},
)
attentions = [
key for key in output_blocks[i] if f"output_blocks.{i}.1" in key and f"output_blocks.{i}.1.conv" not in key
]
if attentions:
update_unet_attention_ldm_to_diffusers(
attentions,
new_checkpoint,
unet_state_dict,
{"old": f"output_blocks.{i}.1", "new": f"up_blocks.{block_id}.attentions.{layer_in_block_id}"},
)
if f"output_blocks.{i}.1.conv.weight" in unet_state_dict:
new_checkpoint[f"up_blocks.{block_id}.upsamplers.0.conv.weight"] = unet_state_dict[
f"output_blocks.{i}.1.conv.weight"
]
new_checkpoint[f"up_blocks.{block_id}.upsamplers.0.conv.bias"] = unet_state_dict[
f"output_blocks.{i}.1.conv.bias"
]
if f"output_blocks.{i}.2.conv.weight" in unet_state_dict:
new_checkpoint[f"up_blocks.{block_id}.upsamplers.0.conv.weight"] = unet_state_dict[
f"output_blocks.{i}.2.conv.weight"
]
new_checkpoint[f"up_blocks.{block_id}.upsamplers.0.conv.bias"] = unet_state_dict[
f"output_blocks.{i}.2.conv.bias"
]
return new_checkpoint