File size: 2,732 Bytes
6eb4316 | 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 | import os
import logging
from typing import Iterable
import cv2
import numpy as np
from tqdm import tqdm
log = logging.getLogger(__name__)
def extract_dji_rgb(
video_path: str,
frame_indices: Iterable[int],
) -> np.ndarray:
"""
Extract selected RGB frames from DJI video (MP4/MKV).
Parameters:
- video_path: path to the video file recorded by `src/djiRecorder.py`.
- frame_indices: iterable of DJI frame indices to keep
(e.g. the `dji_frame_idx` column from `sync_triples.csv`).
Returns:
- rgb: array of shape (N, H, W, 3), dtype uint8, RGB frames.
Note: The video was already flipped (UD+LR) during recording, so no
additional transformations are needed here.
"""
if not os.path.exists(video_path):
raise FileNotFoundError(f"DJI video not found: {video_path}")
indices = np.asarray(list(frame_indices), dtype=np.int64)
if indices.size == 0:
return np.empty((0, 0, 0, 3), dtype=np.uint8)
# Ensure indices are sorted and unique
indices = np.unique(indices)
indices_set = set(indices.tolist())
# Open video
cap = cv2.VideoCapture(video_path)
if not cap.isOpened():
raise RuntimeError(f"Failed to open DJI video: {video_path}")
total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
fps = cap.get(cv2.CAP_PROP_FPS)
log.info(f"DJI video: {width}x{height} @ {fps:.2f} FPS, {total_frames} frames")
log.info(f"Extracting {len(indices)} frame indices (min={indices.min()}, max={indices.max()})")
rgb_frames = []
frame_idx = 0
extracted_count = 0
with tqdm(total=len(indices), desc="DJI extraction", unit="frame") as pbar:
while frame_idx < total_frames:
ret, frame = cap.read()
if not ret:
break
if frame_idx in indices_set:
# OpenCV reads in BGR, convert to RGB
rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
rgb_frames.append(rgb)
extracted_count += 1
pbar.update(1)
if extracted_count == len(indices):
break
frame_idx += 1
cap.release()
log.info(f"Finished: Extracted {extracted_count}/{len(indices)} DJI frames from {frame_idx} total frames")
if not rgb_frames:
log.warning("No DJI frames were extracted!")
return np.empty((0, 0, 0, 3), dtype=np.uint8)
rgb_arr = np.stack(rgb_frames, axis=0)
log.info(f"Final DJI RGB array: {rgb_arr.shape}")
return rgb_arr
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