Basic Video Operations

Learn about fundamental video operations in FMUS-VID.

Video Properties

import fmusvid

video = fmusvid.load("input.mp4")

# Access video properties
print(f"Duration: {video.duration}")
print(f"Frame count: {video.frame_count}")
print(f"Frame rate: {video.fps}")
print(f"Resolution: {video.width}x{video.height}")
print(f"Has audio: {video.has_audio()}")

Trimming and Cutting

# Trim by time
trimmed = video.trim(start=5.0, end=15.0)

# Trim by frame numbers
trimmed = video.trim_frames(start_frame=150, end_frame=450)

# Cut into segments
segments = video.cut([
    (0, 10),    # First 10 seconds
    (20, 30),   # 20-30 seconds
    (40, 50)    # 40-50 seconds
])

Resizing and Scaling

# Resize by width (maintain aspect ratio)
resized = video.resize(width=1920)

# Resize by height
resized = video.resize(height=1080)

# Specify both dimensions
resized = video.resize(width=1280, height=720)

# Scale by factor
scaled = video.scale(1.5)  # Scale up by 50%

Rotation and Flipping

# Rotate by degrees
rotated = video.rotate(90)

# Flip horizontally or vertically
flipped_h = video.flip(horizontal=True)
flipped_v = video.flip(vertical=True)

Speed Adjustment

# Speed up or slow down
fast = video.speed(2.0)     # 2x speed
slow = video.speed(0.5)     # Half speed

# Speed with frame interpolation
smooth = video.speed(
    factor=0.5,
    interpolation="flow"    # Use optical flow
)

Filters and Effects

# Basic filters
grayscale = video.grayscale()
blurred = video.blur(radius=2.0)

# Color adjustments
adjusted = (video
    .brightness(1.2)        # Increase brightness
    .contrast(1.1)         # Adjust contrast
    .saturation(0.8)       # Reduce saturation
)

# Advanced effects
stylized = (video
    .sharpen(amount=1.5)
    .denoise(strength=0.5)
    .vignette(intensity=0.3)
)

Audio Processing

# Volume control
quiet = video.volume(0.5)
muted = video.mute()

# Add background music
with_music = video.add_audio(
    "music.mp3",
    start=0,               # Start time
    volume=0.3,           # Background volume
    fade_in=2.0,          # Fade in duration
    fade_out=2.0          # Fade out duration
)

# Extract audio
video.extract_audio("audio.mp3")

Batch Processing

from pathlib import Path

# Process multiple videos
input_dir = Path("input_videos")
output_dir = Path("output_videos")
output_dir.mkdir(exist_ok=True)

for video_path in input_dir.glob("*.mp4"):
    video = fmusvid.load(video_path)

    # Process each video
    processed = (video
        .resize(height=720)
        .brightness(1.2)
        .contrast(1.1)
    )

    # Save with same name
    output_path = output_dir / video_path.name
    processed.save(output_path)

Progress Tracking

def progress_callback(progress: float):
    print(f"Progress: {progress:.1%}")

# Track processing progress
video.save(
    "output.mp4",
    progress_callback=progress_callback
)

Best Practices

Chain Operations
- Use method chaining for cleaner code
- Operations are applied in order
Memory Management
- Process in chunks for large files
- Use cleanup() to free resources

Error Handling

try:
    video = fmusvid.load("input.mp4")
    processed = video.resize(width=1280).rotate(90)
    processed.save("output.mp4")
except fmusvid.VideoError as e:
    print(f"Error processing video: {e}")
finally:
    video.cleanup()

Performance Tips
- Use appropriate codec for output
- Enable hardware acceleration when available
- Process in batches for multiple files