app.py

import os
import torch
import numpy as np
import gradio as gr
from PIL import Image
from transformers import AutoProcessor, AutoModelForCausalLM
from sam2.build_sam import build_sam2_video_predictor, build_sam2
from sam2.sam2_image_predictor import SAM2ImagePredictor
import cv2
import traceback
import matplotlib.pyplot as plt

# CUDA optimizations
torch.autocast(device_type="cuda", dtype=torch.bfloat16).__enter__()
if torch.cuda.get_device_properties(0).major >= 8:
    torch.backends.cuda.matmul.allow_tf32 = True
    torch.backends.cudnn.allow_tf32 = True

# Initialize models
sam2_checkpoint = "../checkpoints/sam2_hiera_large.pt"
model_cfg = "sam2_hiera_l.yaml"

video_predictor = build_sam2_video_predictor(model_cfg, sam2_checkpoint)
sam2_model = build_sam2(model_cfg, sam2_checkpoint, device="cuda")
image_predictor = SAM2ImagePredictor(sam2_model)

model_id = 'microsoft/Florence-2-large'
florence_model = AutoModelForCausalLM.from_pretrained(model_id, trust_remote_code=True, torch_dtype=torch.bfloat16).eval().cuda()
florence_processor = AutoProcessor.from_pretrained(model_id, trust_remote_code=True)

def apply_color_mask(frame, mask, obj_id):
    cmap = plt.get_cmap("tab10")
    color = np.array(cmap(obj_id % 10)[:3])  # Use modulo 10 to cycle through colors
    
    # Ensure mask has the correct shape
    if mask.ndim == 4:
        mask = mask.squeeze()  # Remove singleton dimensions
    if mask.ndim == 3 and mask.shape[0] == 1:
        mask = mask[0]  # Take the first channel if it's a single-channel 3D array
    
    # Reshape mask to match frame dimensions
    mask = cv2.resize(mask.astype(np.float32), (frame.shape[1], frame.shape[0]), interpolation=cv2.INTER_LINEAR)
    
    # Expand dimensions of mask and color for broadcasting
    mask = np.expand_dims(mask, axis=2)
    color = color.reshape(1, 1, 3)
    
    colored_mask = mask * color
    return frame * (1 - mask) + colored_mask * 255

def run_florence(image, text_input):
    with torch.cuda.amp.autocast(dtype=torch.bfloat16):
        task_prompt = '<OPEN_VOCABULARY_DETECTION>'
        prompt = task_prompt + text_input
        inputs = florence_processor(text=prompt, images=image, return_tensors="pt").to('cuda', torch.bfloat16)
        generated_ids = florence_model.generate(
            input_ids=inputs["input_ids"].cuda(),
            pixel_values=inputs["pixel_values"].cuda(),
            max_new_tokens=1024,
            early_stopping=False,
            do_sample=False,
            num_beams=3,
        )
        generated_text = florence_processor.batch_decode(generated_ids, skip_special_tokens=False)[0]
        parsed_answer = florence_processor.post_process_generation(
            generated_text, 
            task=task_prompt, 
            image_size=(image.width, image.height)
        )
    return parsed_answer[task_prompt]['bboxes'][0]

def remove_directory_contents(directory):
    for root, dirs, files in os.walk(directory, topdown=False):
        for name in files:
            os.remove(os.path.join(root, name))
        for name in dirs:
            os.rmdir(os.path.join(root, name))

def process_video(video_path, prompt, chunk_size=30):
    try:
        video = cv2.VideoCapture(video_path)
        if not video.isOpened():
            raise ValueError("Unable to open video file")
        
        fps = video.get(cv2.CAP_PROP_FPS)
        frame_count = int(video.get(cv2.CAP_PROP_FRAME_COUNT))
        
        # Process video in chunks
        all_segmented_frames = []
        for chunk_start in range(0, frame_count, chunk_size):
            chunk_end = min(chunk_start + chunk_size, frame_count)
            
            frames = []
            video.set(cv2.CAP_PROP_POS_FRAMES, chunk_start)
            for _ in range(chunk_end - chunk_start):
                ret, frame = video.read()
                if not ret:
                    break
                frames.append(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))
            
            if not frames:
                print(f"No frames extracted for chunk starting at {chunk_start}")
                continue
            
            # Florence detection on first frame of the chunk
            first_frame = Image.fromarray(frames[0])
            mask_box = run_florence(first_frame, prompt)
            print("Original mask box:", mask_box)
            
            # Convert mask_box to numpy array and ensure it's in the correct format
            mask_box = np.array(mask_box)
            print("Reshaped mask box:", mask_box)
            
            # SAM2 segmentation on first frame
            with torch.cuda.amp.autocast(dtype=torch.bfloat16):
                image_predictor.set_image(first_frame)
                masks, _, _ = image_predictor.predict(
                    point_coords=None,
                    point_labels=None,
                    box=mask_box[None, :],
                    multimask_output=False,
                )
            print("masks.shape",masks.shape)
            
            mask = masks.squeeze().astype(bool)
            print("Mask shape:", mask.shape)
            print("Frame shape:", frames[0].shape)
            
            # SAM2 video propagation
            temp_dir = f"temp_frames_{chunk_start}"
            os.makedirs(temp_dir, exist_ok=True)
            for i, frame in enumerate(frames):
                cv2.imwrite(os.path.join(temp_dir, f"{i:04d}.jpg"), cv2.cvtColor(frame, cv2.COLOR_RGB2BGR))
            
            with torch.cuda.amp.autocast(dtype=torch.bfloat16):
                inference_state = video_predictor.init_state(video_path=temp_dir)
                _, _, _ = video_predictor.add_new_mask(
                    inference_state=inference_state,
                    frame_idx=0,
                    obj_id=1,
                    mask=mask
                )
                
                video_segments = {}
                for out_frame_idx, out_obj_ids, out_mask_logits in video_predictor.propagate_in_video(inference_state):
                    video_segments[out_frame_idx] = {
                        out_obj_id: (out_mask_logits[i] > 0.0).cpu().numpy()
                        for i, out_obj_id in enumerate(out_obj_ids)
                    }

            print('segmenting for main vid done')
            
            # Apply segmentation masks to frames
            for i, frame in enumerate(frames):
                if i in video_segments:
                    for out_obj_id, mask in video_segments[i].items():
                        frame = apply_color_mask(frame, mask, out_obj_id)
                    all_segmented_frames.append(frame.astype(np.uint8))
                else:
                    all_segmented_frames.append(frame)
            
            # Clean up temporary files
            remove_directory_contents(temp_dir)
            os.rmdir(temp_dir)
        
        video.release()
        
        if not all_segmented_frames:
            raise ValueError("No frames were processed successfully")

        # Create video from segmented frames
        output_path = "segmented_video.mp4"
        out = cv2.VideoWriter(output_path, cv2.VideoWriter_fourcc(*'mp4v'), fps, 
                              (all_segmented_frames[0].shape[1], all_segmented_frames[0].shape[0]))
        for frame in all_segmented_frames:
            out.write(cv2.cvtColor(frame, cv2.COLOR_RGB2BGR))
        out.release()
        
        return output_path

    except Exception as e:
        print(f"Error in process_video: {str(e)}")
        print(traceback.format_exc())  # This will print the full stack trace
        return None

def segment_video(video_file, prompt, chunk_size):
    if video_file is None:
        return None
    output_video = process_video(video_file, prompt, int(chunk_size))
    return output_video

demo = gr.Interface(
    fn=segment_video,
    inputs=[
        gr.Video(label="Upload Video"),
        gr.Textbox(label="Enter prompt (e.g., 'a gymnast')"),
        gr.Slider(minimum=10, maximum=100, step=10, value=30, label="Chunk Size (frames)")
    ],
    outputs=gr.Video(label="Segmented Video"),
    title="Video Object Segmentation with Florence and SAM2",
    description="Upload a video and provide a text prompt to segment a specific object throughout the video."
)

demo.launch()