Initial commit: Revids REST API for LTX-2.3 image-to-video generation

- FastAPI with job polling: POST /generate, GET /jobs/{id}, /download, /health
- SQLite job persistence (aiosqlite), background task processing
- LTX-2.3 DistilledPipeline via native ltx-pipelines (editable install from submodule)
- Configurable model paths, LoRA support, FP8 quantization via env vars
- Single-concurrency GPU lock for safe inference
- LTX-2 as git submodule under libs/

app/main.py

@@ -0,0 +1,133 @@
+from __future__ import annotations
+
+import logging
+from contextlib import asynccontextmanager
+from typing import AsyncGenerator
+
+from fastapi import FastAPI, File, Form, HTTPException, UploadFile
+from fastapi.responses import FileResponse, JSONResponse
+
+from app.config import settings
+from app.models import JobSubmitResponse, JobStatusResponse
+from app.service import get_service
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")
+logger = logging.getLogger(__name__)
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI) -> AsyncGenerator:
+    logger.info("Starting Revids API...")
+    await get_service()
+    yield
+    logger.info("Shutting down Revids API.")
+
+
+app = FastAPI(
+    title=settings.app_name,
+    version="0.1.0",
+    lifespan=lifespan,
+)
+
+
+@app.get("/health")
+async def health() -> JSONResponse:
+    import torch
+
+    gpu_available = torch.cuda.is_available()
+    return JSONResponse({
+        "status": "ok",
+        "gpu": gpu_available,
+        "gpu_name": torch.cuda.get_device_name(0) if gpu_available else None,
+    })
+
+
+@app.post("/generate", status_code=201)
+async def generate(
+    image: UploadFile = File(..., description="Input image (PNG, JPG, etc.)"),
+    prompt: str | None = Form(None),
+    width: int = Form(768),
+    height: int = Form(512),
+    num_frames: int = Form(65),
+    fps: float = Form(24.0),
+    seed: int | None = Form(None),
+) -> JobSubmitResponse:
+    from PIL import Image
+
+    img_bytes = await image.read()
+    pil_image = Image.open(img_bytes).convert("RGB")
+
+    validate_frame_count(num_frames)
+
+    svc = await get_service()
+    job = await svc.submit_job(pil_image, {
+        "prompt": prompt,
+        "width": width,
+        "height": height,
+        "num_frames": num_frames,
+        "fps": fps,
+        "seed": seed,
+    })
+    return JobSubmitResponse(job_id=job.id)
+
+
+@app.get("/jobs/{job_id}")
+async def get_job(job_id: str) -> JobStatusResponse:
+    svc = await get_service()
+    job = await svc.get_job(job_id)
+    if job is None:
+        raise HTTPException(status_code=404, detail="Job not found")
+    return JobStatusResponse(
+        job_id=job.id,
+        status=job.status,
+        prompt=job.prompt,
+        params=job.params,
+        error=job.error,
+        created_at=job.created_at,
+        completed_at=job.completed_at,
+    )
+
+
+@app.get("/jobs/{job_id}/download")
+async def download_video(job_id: str) -> FileResponse:
+    svc = await get_service()
+    job = await svc.get_job(job_id)
+    if job is None:
+        raise HTTPException(status_code=404, detail="Job not found")
+    if job.status != "completed":
+        raise HTTPException(status_code=404, detail="Video not ready")
+
+    video_path = await svc.get_video_path(job_id)
+    if video_path is None:
+        raise HTTPException(status_code=404, detail="Video file missing")
+    return FileResponse(video_path, media_type="video/mp4", filename=f"{job_id}.mp4")
+
+
+@app.delete("/jobs/{job_id}")
+async def delete_job(job_id: str) -> dict:
+    svc = await get_service()
+    job = await svc.get_job(job_id)
+    if job is None:
+        raise HTTPException(status_code=404, detail="Job not found")
+    deleted, _ = await svc.delete_job(job_id)
+    if not deleted:
+        raise HTTPException(status_code=404, detail="Job not found")
+    return {"deleted": job_id}
+
+
+def validate_frame_count(num_frames: int) -> None:
+    valid = {8 * n + 1 for n in range(1, 129)}
+    if num_frames not in valid:
+        candidates = sorted(f for f in valid if abs(f - num_frames) <= 8)
+        raise HTTPException(
+            status_code=400,
+            detail=f"num_frames must be 8n+1. Got {num_frames}. Closest valid: {candidates[:4]}",
+        )
+
+
+@app.exception_handler(HTTPException)
+async def http_exception_handler(_, exc: HTTPException) -> JSONResponse:
+    return JSONResponse(
+        status_code=exc.status_code,
+        content={"error": exc.detail},
+    )