Add support for cogvideo models

[mudler]

Is your feature request related to a problem? Please describe.
Cogvideo has been released. It would be great to have support to that in LocalAI with the diffusers backend

Describe the solution you'd like
LocalAI to support models like https://huggingface.co/THUDM/CogVideoX-5b

Describe alternatives you've considered

Additional context

[ljluestc]

package api


import (
    "encoding/json"
    "net/http"
    "github.com/go-chi/chi/v5"
    "github.com/mudler/LocalAI/backend"
)

// VideoRequest defines the request payload for video generation
type VideoRequest struct {
    Model            string  `json:"model"`
    Prompt           string  `json:"prompt"`
    OutputPath       string  `json:"output_path"`
    NumFrames        int     `json:"num_frames"`
    NumInferenceSteps int     `json:"num_inference_steps"`
    GuidanceScale    float32 `json:"guidance_scale"`
    Seed             int     `json:"seed"`
}

// VideoResponse defines the response payload
type VideoResponse struct {
    OutputPath string `json:"output_path"`
    Error      string `json:"error,omitempty"`
}

// SetupVideoRoutes adds video generation endpoints to the API
func SetupVideoRoutes(r chi.Router) {
    r.Post("/v1/video/generate", func(w http.ResponseWriter, r *http.Request) {
        var req VideoRequest
        if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
            http.Error(w, "Invalid request body", http.StatusBadRequest)
            return
        }

        // Validate request
        if req.Prompt == "" {
            http.Error(w, "Prompt is required", http.StatusBadRequest)
            return
        }
        if req.Model == "" {
            req.Model = "THUDM/CogVideoX-5b"
        }
        if req.OutputPath == "" {
            req.OutputPath = "output.mp4"
        }
        if req.NumFrames == 0 {
            req.NumFrames = 49
        }
        if req.NumInferenceSteps == 0 {
            req.NumInferenceSteps = 50
        }
        if req.GuidanceScale == 0 {
            req.GuidanceScale = 6.0
        }
        if req.Seed == 0 {
            req.Seed = 42
        }

        // Call the backend
        outputPath, err := backend.GenerateVideo(req.Model, req.Prompt, req.OutputPath, req.NumFrames, req.NumInferenceSteps, req.GuidanceScale, req.Seed)
        resp := VideoResponse{OutputPath: outputPath}
        if err != nil {
            resp.Error = err.Error()
            w.WriteHeader(http.StatusInternalServerError)
        }

        w.Header().Set("Content-Type", "application/json")
        json.NewEncoder(w).Encode(resp)
    })
}