All codecs and encoding tools have a configuration option that controls the quality/encoding time tradeoff. With x264 (and x265) the preset controls that tradeoff.
When choosing a preset you should consider 3 criteria:
- Overall quality – the overall quality produced by that preset
- Low frame quality – the quality of the lowest frame produced by that preset, which indicates the potential for transient quality issues
- Encoding time – this determines the throughput and cost of your encodings
This presentation goes through that analysis for choosing an x264 preset. It’s excerpted from my upcoming pre-conference session at Streaming Media West entitled Introduction to ABR Technologies.
Click Choosing an x264 Preset to download the presentation.