[quality_extension_descriptor.metric_code]
Bits = 32
0x70736e72 = PSRN, Peak Signal Noise Ratio
0x7373696d = SSIM, Structural Similarity Index
0x6d73696d = MS-SSIM, Multi-Scale Structural Similarity Index
0x6a313434 = VQM,Video Quality Metric
0x6a323437 = PEVQ, Perceptual Evaluation of Video Quality
0x6d6f7073 = MOS, Mean Opinion Score
0x66736967 = FSIG, Frame Significance
