H264 encoding profile & level control

H.264 Four image quality levels

Namely baseline, extended, main, high：

1. Baseline Profile： Basic picture quality . Support I/P frame , Only no interleaving is supported （Progressive） and CAVLC;
2. Extended profile： Advanced quality . Support I/P/B/SP/SI frame , Only no interleaving is supported （Progressive） and CAVLC;( Less use )
3. Main profile： Mainstream quality . Provide I/P/B frame , Support no interlacing （Progressive） And interlace （Interlaced）, Also support CAVLC and CABAC Support for ;
4. High profile： High quality . stay main Profile That's an increase from 8x8 Internal Forecasting 、 Custom quantization 、 Lossless video coding and more YUV Format ;

H.264 Baseline profile、Extended profile and Main profile All aimed at 8 Bit sample data 、4:2:0 Format (YUV) Video sequence of . In the same configuration ,High profile（HP） Comparable Main profile（MP） Reduce 10% Bit rate of . Depending on the field of application ,Baseline profile Most of them are used in the field of real-time communication ,Main profile Most of them are used in the field of streaming media ,High profile They are mostly used in the fields of broadcasting and storage .

In terms of compression ratio ,baseline< main < high , For online video with limited bandwidth , May choose high, But sometimes , Make a little video , I hope all the devices can decode &