"""Video quality metrics comparison tool."""
from typing import Dict, Any
from utils.ffmpeg import (
calculate_psnr,
calculate_ssim,
calculate_vmaf,
FFmpegError
)
def compare_quality_metrics(reference: str, distorted: str) -> Dict[str, Any]:
"""
Compare quality metrics between reference and distorted video.
Args:
reference: Path to reference video
distorted: Path to distorted/transcoded video
Returns:
Dictionary containing PSNR, SSIM, and VMAF scores
Raises:
FFmpegError: If comparison fails
"""
result = {
"psnr": None,
"ssim": None,
"vmaf": None
}
errors = []
# Calculate PSNR
try:
psnr_result = calculate_psnr(reference, distorted)
result["psnr"] = {
"y": round(psnr_result["y"], 2),
"u": round(psnr_result["u"], 2),
"v": round(psnr_result["v"], 2)
}
except FFmpegError as e:
errors.append(f"PSNR calculation failed: {str(e)}")
except Exception as e:
errors.append(f"PSNR calculation error: {str(e)}")
# Calculate SSIM
try:
ssim_score = calculate_ssim(reference, distorted)
result["ssim"] = round(ssim_score, 4)
except FFmpegError as e:
errors.append(f"SSIM calculation failed: {str(e)}")
except Exception as e:
errors.append(f"SSIM calculation error: {str(e)}")
# Calculate VMAF
try:
vmaf_result = calculate_vmaf(reference, distorted)
result["vmaf"] = {
"score": round(vmaf_result["score"], 2),
"model": vmaf_result["model"]
}
except FFmpegError as e:
errors.append(f"VMAF calculation failed: {str(e)}")
except Exception as e:
errors.append(f"VMAF calculation error: {str(e)}")
# If all metrics failed, raise error
if not result["psnr"] and not result["ssim"] and not result["vmaf"]:
raise FFmpegError(f"All quality metrics failed: {'; '.join(errors)}")
# Add warnings if some metrics failed
if errors:
result["warnings"] = errors
return result
