This freely downloadable report measures the qualitative impact of GOP sizes on animated, general entertainment, sports, and office footage for H.264 and HEVC.
![The impact of GOP size on VMAF quality](https://streaminglearningcenter.com/wp-content/uploads/2023/11/Gop-size-graphic-852x525.png)
One of the most fundamental encoding decisions is GOP size or the frequency of I-frames in our encoded files. I-frames, also called keyframes, start each “group of pictures” comprised of I-, B-, and P-frames. Most of the time, our GOP size, or I-frame interval, is dictated by adaptive bitrate considerations like choosing a GOP size that divides evenly into your segment size. But even then, you have multiple options. In addition, what GOP size should you use when encoding a single file for disk-based playback or progressive download?
This report helps you decide. It measures:
- VMAF quality
- Of 13 files in four genres (animations, general entertainment, sports, office)
- With keyframe intervals ranging from 1/2 second to 20 seconds
- Encoded with x264 and x265
No registration is required; click here to download the report. GOP-Size_report_11_16.pdf (1216 downloads )