decord

import os from decord import VideoReader, cpu, gpu, AudioReader from decord import DECORD_LOG_STREAM, logging # Configure Decord's logging level to suppress verbose FFmpeg messages DECORD_LOG_STREAM.set_level(logging.ERROR) # --- Quickstart requires a video file --- # Replace 'path/to/your/video.mp4' with an actual video file path. # You can also set this via an environment variable for easier testing: # export DECORD_VIDEO_PATH="/path/to/your/video.mp4" video_file_path = os.environ.get('DECORD_VIDEO_PATH', 'path/to/your/video.mp4') if not os.path.exists(video_file_path): print(f"WARNING: Video file not found at '{video_file_path}'. Please provide a valid path.") print("Skipping Decord quickstart execution.") else: try: print(f"Processing video: {video_file_path}") # 1. Initialize VideoReader with CPU context # Use gpu(0) for GPU context if available and Decord is built with CUDA support. vr = VideoReader(video_file_path, ctx=cpu(0)) # Get video properties print(f"Total frames: {len(vr)}") print(f"Frame rate: {vr.get_avg_fps()} fps") print(f"Video resolution: {vr.width}x{vr.height}") # Read a single frame (e.g., the first frame) frame_0 = vr[0].asnumpy() # Returns a NumPy array (H, W, C) in RGB print(f"Shape of first frame (NumPy): {frame_0.shape}") # Read a batch of frames (e.g., frames at index 10, 20, 30) if len(vr) > 30: frames_batch = vr.get_batch([10, 20, 30]).asnumpy() # Returns (N, H, W, C) print(f"Shape of batch frames (NumPy): {frames_batch.shape}") else: print("Video too short to get a batch of frames.") # Iterate through frames (e.g., first 5 frames) print("\nIterating through first 5 frames:") for i, frame in enumerate(vr): if i >= 5: break print(f" Frame {i} shape: {frame.shape}") # 2. Initialize AudioReader (available from Decord v0.6.0+) # Requires the video file to contain audio tracks. if hasattr(decord, 'AudioReader'): try: ar = AudioReader(video_file_path, ctx=cpu(0)) print(f"\nTotal audio samples (frames): {len(ar)}") # Read a chunk of audio samples (e.g., first 1024 samples) audio_chunk = ar[:1024].asnumpy() # Returns (Samples, Channels) print(f"Shape of first audio chunk (NumPy): {audio_chunk.shape}") except Exception as e: print(f"Could not initialize AudioReader: {e}. Ensure video has audio tracks.") else: print("\nAudioReader not available in this Decord version (requires v0.6.0+).") except Exception as e: print(f"An error occurred during Decord processing: {e}") print("Common issues include corrupted video files, missing FFmpeg dependencies, or incorrect Decord installation.")