File size: 13,184 Bytes
ebfc6b3
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
# ruff: noqa: PLC0415

"""
Model loader for LTX-2 trainer using the new ltx-core package.

This module provides a unified interface for loading LTX-2 model components
for training, using SingleGPUModelBuilder from ltx-core.

Example usage:
    # Load individual components
    vae_encoder = load_video_vae_encoder("/path/to/checkpoint.safetensors", device="cuda")
    vae_decoder = load_video_vae_decoder("/path/to/checkpoint.safetensors", device="cuda")
    text_encoder = load_text_encoder("/path/to/checkpoint.safetensors", "/path/to/gemma", device="cuda")

    # Load all components at once
    components = load_model("/path/to/checkpoint.safetensors", text_encoder_path="/path/to/gemma")
"""

from __future__ import annotations

from dataclasses import dataclass
from pathlib import Path
from typing import TYPE_CHECKING

import torch

from ltx_trainer import logger

# Type alias for device specification
Device = str | torch.device

# Type checking imports (not loaded at runtime)
if TYPE_CHECKING:
    from ltx_core.model.audio_vae.audio_vae import Decoder as AudioVAEDecoder
    from ltx_core.model.audio_vae.audio_vae import Encoder as AudioVAEEncoder
    from ltx_core.model.audio_vae.vocoder import Vocoder
    from ltx_core.model.clip.gemma.encoders.av_encoder import AVGemmaTextEncoderModel
    from ltx_core.model.transformer.model import LTXModel
    from ltx_core.model.video_vae.video_vae import Decoder as VideoVAEDecoder
    from ltx_core.model.video_vae.video_vae import Encoder as VideoVAEEncoder
    from ltx_core.pipeline.components.schedulers import LTX2Scheduler


def _to_torch_device(device: Device) -> torch.device:
    """Convert device specification to torch.device."""
    return torch.device(device) if isinstance(device, str) else device


# =============================================================================
# Individual Component Loaders
# =============================================================================


def load_transformer(
    checkpoint_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "LTXModel":
    """Load the LTX transformer model.

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        device: Device to load model on
        dtype: Data type for model weights

    Returns:
        Loaded LTXModel transformer
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.transformer.model_configurator import (
        LTXV_MODEL_COMFY_RENAMING_MAP,
        LTXModelConfigurator,
    )

    return SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=LTXModelConfigurator,
        model_sd_ops=LTXV_MODEL_COMFY_RENAMING_MAP,
    ).build(device=_to_torch_device(device), dtype=dtype)


def load_video_vae_encoder(
    checkpoint_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "VideoVAEEncoder":
    """Load the video VAE encoder (for preprocessing).

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        device: Device to load model on
        dtype: Data type for model weights

    Returns:
        Loaded VideoVAEEncoder
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.video_vae.model_configurator import VAE_ENCODER_COMFY_KEYS_FILTER
    from ltx_core.model.video_vae.model_configurator import (
        VAEEncoderConfigurator as VideoVAEEncoderConfigurator,
    )

    return SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=VideoVAEEncoderConfigurator,
        model_sd_ops=VAE_ENCODER_COMFY_KEYS_FILTER,
    ).build(device=_to_torch_device(device), dtype=dtype)


def load_video_vae_decoder(
    checkpoint_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "VideoVAEDecoder":
    """Load the video VAE decoder (for inference/validation).

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        device: Device to load model on
        dtype: Data type for model weights

    Returns:
        Loaded VideoVAEDecoder
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.video_vae.model_configurator import VAE_DECODER_COMFY_KEYS_FILTER
    from ltx_core.model.video_vae.model_configurator import (
        VAEDecoderConfigurator as VideoVAEDecoderConfigurator,
    )

    return SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=VideoVAEDecoderConfigurator,
        model_sd_ops=VAE_DECODER_COMFY_KEYS_FILTER,
    ).build(device=_to_torch_device(device), dtype=dtype)


def load_audio_vae_encoder(
    checkpoint_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "AudioVAEEncoder":
    """Load the audio VAE encoder (for preprocessing).

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        device: Device to load model on
        dtype: Data type for model weights (default bfloat16, but float32 recommended for quality)

    Returns:
        Loaded AudioVAEEncoder
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.audio_vae.model_configurator import AUDIO_VAE_ENCODER_COMFY_KEYS_FILTER
    from ltx_core.model.audio_vae.model_configurator import (
        VAEEncoderConfigurator as AudioVAEEncoderConfigurator,
    )

    return SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=AudioVAEEncoderConfigurator,
        model_sd_ops=AUDIO_VAE_ENCODER_COMFY_KEYS_FILTER,
    ).build(device=_to_torch_device(device), dtype=dtype)


def load_audio_vae_decoder(
    checkpoint_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "AudioVAEDecoder":
    """Load the audio VAE decoder.

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        device: Device to load model on
        dtype: Data type for model weights

    Returns:
        Loaded AudioVAEDecoder
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.audio_vae.model_configurator import AUDIO_VAE_DECODER_COMFY_KEYS_FILTER
    from ltx_core.model.audio_vae.model_configurator import (
        VAEDecoderConfigurator as AudioVAEDecoderConfigurator,
    )

    return SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=AudioVAEDecoderConfigurator,
        model_sd_ops=AUDIO_VAE_DECODER_COMFY_KEYS_FILTER,
    ).build(device=_to_torch_device(device), dtype=dtype)


def load_vocoder(
    checkpoint_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "Vocoder":
    """Load the vocoder (for audio waveform generation).

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        device: Device to load model on
        dtype: Data type for model weights

    Returns:
        Loaded Vocoder
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.audio_vae.model_configurator import VOCODER_COMFY_KEYS_FILTER, VocoderConfigurator

    return SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=VocoderConfigurator,
        model_sd_ops=VOCODER_COMFY_KEYS_FILTER,
    ).build(device=_to_torch_device(device), dtype=dtype)


def load_text_encoder(
    checkpoint_path: str | Path,
    gemma_model_path: str | Path,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
) -> "AVGemmaTextEncoderModel":
    """Load the Gemma text encoder.

    Args:
        checkpoint_path: Path to the LTX-2 safetensors checkpoint file
        gemma_model_path: Path to Gemma model directory
        device: Device to load model on
        dtype: Data type for model weights

    Returns:
        Loaded AVGemmaTextEncoderModel
    """
    from ltx_core.loader.single_gpu_model_builder import SingleGPUModelBuilder
    from ltx_core.model.clip.gemma.encoders.av_encoder import (
        AV_GEMMA_TEXT_ENCODER_KEY_OPS,
        AVGemmaTextEncoderModelConfigurator,
    )
    from ltx_core.model.clip.gemma.encoders.base_encoder import module_ops_from_gemma_root

    if not Path(gemma_model_path).is_dir():
        raise ValueError(f"Gemma model path is not a directory: {gemma_model_path}")

    torch_device = _to_torch_device(device)
    text_encoder = SingleGPUModelBuilder(
        model_path=str(checkpoint_path),
        model_class_configurator=AVGemmaTextEncoderModelConfigurator,
        model_sd_ops=AV_GEMMA_TEXT_ENCODER_KEY_OPS,
        module_ops=module_ops_from_gemma_root(str(gemma_model_path)),
    ).build(device=torch_device, dtype=dtype)

    return text_encoder


# =============================================================================
# Combined Component Loader
# =============================================================================


@dataclass
class LtxModelComponents:
    """Container for all LTX-2 model components."""

    transformer: "LTXModel"
    video_vae_encoder: "VideoVAEEncoder | None" = None
    video_vae_decoder: "VideoVAEDecoder | None" = None
    audio_vae_decoder: "AudioVAEDecoder | None" = None
    vocoder: "Vocoder | None" = None
    text_encoder: "AVGemmaTextEncoderModel | None" = None
    scheduler: "LTX2Scheduler | None" = None


def load_model(
    checkpoint_path: str | Path,
    text_encoder_path: str | Path | None = None,
    device: Device = "cpu",
    dtype: torch.dtype = torch.bfloat16,
    with_video_vae_encoder: bool = False,
    with_video_vae_decoder: bool = True,
    with_audio_vae_decoder: bool = True,
    with_vocoder: bool = True,
    with_text_encoder: bool = True,
) -> LtxModelComponents:
    """
    Load LTX-2 model components from a safetensors checkpoint.

    This is a convenience function that loads multiple components at once.
    For loading individual components, use the dedicated functions:
    - load_transformer()
    - load_video_vae_encoder()
    - load_video_vae_decoder()
    - load_audio_vae_decoder()
    - load_vocoder()
    - load_text_encoder()

    Args:
        checkpoint_path: Path to the safetensors checkpoint file
        text_encoder_path: Path to Gemma model directory (required if with_text_encoder=True)
        device: Device to load models on ("cuda", "cpu", etc.)
        dtype: Data type for model weights
        with_video_vae_encoder: Whether to load the video VAE encoder (for preprocessing)
        with_video_vae_decoder: Whether to load the video VAE decoder (for inference/validation)
        with_audio_vae_decoder: Whether to load the audio VAE decoder
        with_vocoder: Whether to load the vocoder
        with_text_encoder: Whether to load the text encoder

    Returns:
        LtxModelComponents containing all loaded model components
    """
    from ltx_core.pipeline.components.schedulers import LTX2Scheduler

    checkpoint_path = Path(checkpoint_path)

    # Validate checkpoint exists
    if not checkpoint_path.exists():
        raise FileNotFoundError(f"Checkpoint not found: {checkpoint_path}")

    logger.info(f"Loading LTX-2 model from {checkpoint_path}")

    torch_device = _to_torch_device(device)

    # Load transformer
    logger.debug("Loading transformer...")
    transformer = load_transformer(checkpoint_path, torch_device, dtype)

    # Load video VAE encoder
    video_vae_encoder = None
    if with_video_vae_encoder:
        logger.debug("Loading video VAE encoder...")
        video_vae_encoder = load_video_vae_encoder(checkpoint_path, torch_device, dtype)

    # Load video VAE decoder
    video_vae_decoder = None
    if with_video_vae_decoder:
        logger.debug("Loading video VAE decoder...")
        video_vae_decoder = load_video_vae_decoder(checkpoint_path, torch_device, dtype)

    # Load audio VAE decoder
    audio_vae_decoder = None
    if with_audio_vae_decoder:
        logger.debug("Loading audio VAE decoder...")
        audio_vae_decoder = load_audio_vae_decoder(checkpoint_path, torch_device, dtype)

    # Load vocoder
    vocoder = None
    if with_vocoder:
        logger.debug("Loading vocoder...")
        vocoder = load_vocoder(checkpoint_path, torch_device, dtype)

    # Load text encoder
    text_encoder = None
    if with_text_encoder:
        if text_encoder_path is None:
            raise ValueError("text_encoder_path must be provided when with_text_encoder=True")
        logger.debug("Loading Gemma text encoder...")
        text_encoder = load_text_encoder(checkpoint_path, text_encoder_path, torch_device, dtype)

    # Create scheduler (stateless, no loading needed)
    scheduler = LTX2Scheduler()

    return LtxModelComponents(
        transformer=transformer,
        video_vae_encoder=video_vae_encoder,
        video_vae_decoder=video_vae_decoder,
        audio_vae_decoder=audio_vae_decoder,
        vocoder=vocoder,
        text_encoder=text_encoder,
        scheduler=scheduler,
    )