File size: 12,822 Bytes
8077a04
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
from __future__ import annotations

import logging
from collections.abc import Iterator

import torch

from ltx_core.components.guiders import MultiModalGuider, MultiModalGuiderParams
from ltx_core.components.noisers import GaussianNoiser
from ltx_core.components.schedulers import LTX2Scheduler
from ltx_core.conditioning.types.noise_mask_cond import TemporalRegionMask
from ltx_core.loader import LoraPathStrengthAndSDOps
from ltx_core.loader.registry import Registry
from ltx_core.model.video_vae import TilingConfig, get_video_chunks_number
from ltx_core.quantization import QuantizationPolicy
from ltx_core.types import (
    SpatioTemporalScaleFactors,
)
from ltx_pipelines.utils.args import video_editing_arg_parser
from ltx_pipelines.utils.blocks import (
    AudioConditioner,
    AudioDecoder,
    DiffusionStage,
    ImageConditioner,
    PromptEncoder,
    VideoDecoder,
)
from ltx_pipelines.utils.constants import DISTILLED_SIGMAS, detect_params
from ltx_pipelines.utils.denoisers import GuidedDenoiser, SimpleDenoiser
from ltx_pipelines.utils.helpers import (
    audio_latent_from_file,
    get_device,
    video_latent_from_file,
)
from ltx_pipelines.utils.media_io import (
    encode_video,
    get_videostream_metadata,
)
from ltx_pipelines.utils.types import ModalitySpec, OffloadMode


class RetakePipeline:
    """Regenerate a time region (retake) of an existing video.

    Given a source video file and a time window ``[start_time, end_time]``
    (in seconds), this pipeline keeps the video/audio outside that window
    unchanged and *regenerates* the content inside the window from a text
    prompt using the LTX-2 diffusion model.

    Parameters
    ----------
    checkpoint_path : str
        Path to the LTX-2 model checkpoint.
    gemma_root : str
        Root directory containing Gemma text-encoder weights.
    loras : list[LoraPathStrengthAndSDOps]
        Optional LoRA configs applied to the transformer.
    device : torch.device
        Target device (default: CUDA if available).
    quantization : QuantizationPolicy | None
        Optional quantization policy for the transformer.
    distilled : bool
        Set to ``True`` if using distilled model or passing distillation
        lora with full model. If set to ``True``, distilled sigma schedule
        (``DISTILLED_SIGMA_VALUES``) and a simple (non-guided) denoising
        function will be used during ``__call__``.
    """

    def __init__(
        self,
        checkpoint_path: str,
        gemma_root: str,
        loras: list[LoraPathStrengthAndSDOps],
        device: torch.device | None = None,
        quantization: QuantizationPolicy | None = None,
        registry: Registry | None = None,
        distilled: bool = True,
        torch_compile: bool = False,
        offload_mode: OffloadMode = OffloadMode.NONE,
    ):
        self.device = device or get_device()
        self.dtype = torch.bfloat16
        self.distilled = distilled
        if not distilled:
            self._scheduler = LTX2Scheduler()
        self.prompt_encoder = PromptEncoder(
            checkpoint_path=checkpoint_path,
            gemma_root=gemma_root,
            dtype=self.dtype,
            device=self.device,
            registry=registry,
            offload_mode=offload_mode,
        )
        self.image_conditioner = ImageConditioner(
            checkpoint_path=checkpoint_path,
            dtype=self.dtype,
            device=self.device,
            registry=registry,
        )
        self.audio_conditioner = AudioConditioner(
            checkpoint_path=checkpoint_path,
            dtype=self.dtype,
            device=self.device,
            registry=registry,
        )
        self.stage = DiffusionStage(
            checkpoint_path=checkpoint_path,
            dtype=self.dtype,
            device=self.device,
            loras=tuple(loras),
            quantization=quantization,
            registry=registry,
            torch_compile=torch_compile,
            offload_mode=offload_mode,
        )
        self.video_decoder = VideoDecoder(
            checkpoint_path=checkpoint_path,
            dtype=self.dtype,
            device=self.device,
            registry=registry,
        )
        self.audio_decoder = AudioDecoder(
            checkpoint_path=checkpoint_path,
            dtype=self.dtype,
            device=self.device,
            registry=registry,
        )

    # --------------------------------------------------------------------- #
    #  Public entry point                                                     #
    # --------------------------------------------------------------------- #

    def __call__(  # noqa: PLR0913
        self,
        video_path: str,
        prompt: str,
        start_time: float,
        end_time: float,
        seed: int,
        *,
        negative_prompt: str = "",
        num_inference_steps: int = 40,
        video_guider_params: MultiModalGuiderParams | None = None,
        audio_guider_params: MultiModalGuiderParams | None = None,
        regenerate_video: bool = True,
        regenerate_audio: bool = True,
        enhance_prompt: bool = False,
        tiling_config: TilingConfig | None = None,
        max_batch_size: int = 1,
        sigmas: torch.Tensor | None = None,
    ) -> tuple[Iterator[torch.Tensor], torch.Tensor]:
        """Regenerate ``[start_time, end_time]`` of the source video (retake).

        Parameters
        ----------
        video_path : str
            Path to the source video file (must contain video; audio is optional).
        prompt : str
            Text prompt describing the *regenerated* section.
        start_time, end_time : float
            Time window (in seconds) of the section to regenerate.
        seed : int
            Random seed for reproducibility.
        negative_prompt : str
            Negative prompt for CFG guidance (ignored in distilled mode).
        num_inference_steps : int
            Number of Euler denoising steps (ignored in distilled mode which
            uses a fixed 8-step schedule).
        video_guider_params, audio_guider_params : MultiModalGuiderParams | None
            Guidance parameters for video and audio modalities.  Ignored in
            distilled mode.
        regenerate_video : bool
            If ``True`` (default), regenerate video inside ``[start_time, end_time]``.
            If ``False``, video is preserved as-is (no regeneration).
        regenerate_audio : bool
            If True, regenerate audio in the [start_time, end_time] window; if False,
            audio is preserved as-is (no regeneration).
        enhance_prompt : bool
            Whether to enhance the prompt via the text encoder.

        Returns
        -------
        tuple[Iterator[torch.Tensor], torch.Tensor]
            ``(video_frames_iterator, audio_waveform)``
        """
        if start_time >= end_time:
            raise ValueError(f"start_time ({start_time}) must be less than end_time ({end_time})")

        generator = torch.Generator(device=self.device).manual_seed(seed)
        noiser = GaussianNoiser(generator=generator)
        dtype = self.dtype

        output_shape = get_videostream_metadata(video_path)
        initial_video_latent = self.image_conditioner(
            lambda enc: video_latent_from_file(
                video_encoder=enc,
                file_path=video_path,
                output_shape=output_shape,
                dtype=dtype,
                device=self.device,
            )
        )

        initial_audio_latent = self.audio_conditioner(
            lambda enc: audio_latent_from_file(
                audio_encoder=enc,
                file_path=video_path,
                output_shape=output_shape,
                dtype=dtype,
                device=self.device,
            )
        )

        prompts_to_encode = [prompt] if self.distilled else [prompt, negative_prompt]
        contexts = self.prompt_encoder(
            prompts_to_encode,
            enhance_first_prompt=enhance_prompt,
            enhance_prompt_seed=seed,
        )

        v_context_p, a_context_p = contexts[0].video_encoding, contexts[0].audio_encoding
        video_modality_spec = ModalitySpec(
            context=v_context_p,
            conditionings=[TemporalRegionMask(start_time=start_time, end_time=end_time, fps=output_shape.fps)]
            if regenerate_video
            else [],
            initial_latent=initial_video_latent,
            frozen=not regenerate_video,
        )
        audio_modality_spec = ModalitySpec(
            context=a_context_p,
            conditionings=[TemporalRegionMask(start_time=start_time, end_time=end_time, fps=output_shape.fps)]
            if (initial_audio_latent is not None and regenerate_audio)
            else [],
            initial_latent=initial_audio_latent,
            frozen=initial_audio_latent is not None and not regenerate_audio,
        )

        # Build denoiser and resolve sigma schedule.
        if sigmas is None:
            sigmas = DISTILLED_SIGMAS if self.distilled else self._scheduler.execute(steps=num_inference_steps)
        sigmas = sigmas.to(dtype=torch.float32, device=self.device)

        if self.distilled:
            denoiser = SimpleDenoiser(
                v_context=v_context_p,
                a_context=a_context_p,
            )
        else:
            v_context_n, a_context_n = contexts[1].video_encoding, contexts[1].audio_encoding
            video_guider = MultiModalGuider(
                params=video_guider_params,
                negative_context=v_context_n,
            )
            audio_guider = MultiModalGuider(
                params=audio_guider_params,
                negative_context=a_context_n,
            )
            denoiser = GuidedDenoiser(
                v_context=v_context_p,
                a_context=a_context_p,
                video_guider=video_guider,
                audio_guider=audio_guider,
            )

        # Run diffusion stage
        video_state, audio_state = self.stage(
            denoiser=denoiser,
            sigmas=sigmas,
            noiser=noiser,
            width=output_shape.width,
            height=output_shape.height,
            frames=output_shape.frames,
            fps=output_shape.fps,
            video=video_modality_spec,
            audio=audio_modality_spec,
            max_batch_size=max_batch_size,
        )

        # Decode
        decoded_video = self.video_decoder(video_state.latent, tiling_config, generator)
        decoded_audio = self.audio_decoder(audio_state.latent)

        return decoded_video, decoded_audio


@torch.inference_mode()
def main() -> None:
    """CLI entry point for retake (regenerate a time region)."""
    logging.getLogger().setLevel(logging.INFO)
    parser = video_editing_arg_parser(distilled=True)
    parser.description = "Retake: regenerate a time region of a video with LTX-2."
    args = parser.parse_args()

    if args.start_time >= args.end_time:
        raise ValueError("start_time must be less than end_time")

    # Validate frame count (8k+1) and resolution (multiples of 32) at CLI stage
    video_scale = SpatioTemporalScaleFactors.default()
    src = get_videostream_metadata(args.video_path)
    if (src.frames - 1) % video_scale.time != 0:
        snapped = ((src.frames - 1) // video_scale.time) * video_scale.time + 1
        raise ValueError(
            f"Video frame count must satisfy 8k+1 (e.g. 97, 193). Got {src.frames}; use a video with {snapped} frames."
        )
    if src.width % 32 != 0 or src.height % 32 != 0:
        raise ValueError(f"Video width and height must be multiples of 32. Got {src.width}x{src.height}.")

    pipeline = RetakePipeline(
        checkpoint_path=args.distilled_checkpoint_path,
        gemma_root=args.gemma_root,
        loras=tuple(args.lora) if args.lora else (),
        quantization=args.quantization,
        distilled=args.distilled,
        torch_compile=args.compile,
        offload_mode=args.offload_mode,
    )
    params = detect_params(args.distilled_checkpoint_path)
    tiling_config = TilingConfig.default()
    video_iter, audio = pipeline(
        video_path=args.video_path,
        prompt=args.prompt,
        start_time=args.start_time,
        end_time=args.end_time,
        seed=args.seed,
        video_guider_params=params.video_guider_params,
        audio_guider_params=params.audio_guider_params,
        tiling_config=tiling_config,
        max_batch_size=args.max_batch_size,
    )
    video_chunks_number = get_video_chunks_number(src.frames, tiling_config)
    encode_video(
        video=video_iter,
        fps=int(src.fps),
        audio=audio,
        output_path=args.output_path,
        video_chunks_number=video_chunks_number,
    )


if __name__ == "__main__":
    main()