视频编码器对比系列(硬件编码器)

目前市面上主流的硬件编码器有Intel QuickSync, Nvidia NVEnc以及AMD Advanced Media Framework SDK.

先简单介绍下，Intel QuickSync用的是CPU中自带的集成显卡里面的硬件编码器，NVEnc则是用Nvidia的显卡内的硬件编码器，而AMD AMF则是使用opencl来做一定的加速。后续会从压缩效率(客观指标)，速度和主观质量这三个方面来做对比。

Nvidia NVENC 功能

码率控制

支持CBR, VBR, Q，Target quality，其中Target quality是支持最大码率限制的；

多遍编码

1-pass per frame encoding (NV_ENC_MULTI_PASS_DISABLED)
2-passes per frame, with first pass in quarter resolution and second pass in full resolution (NV_ENC_TWO_PASS_QUARTER_RESOLUTION)
2-passes per frame, with both passes in full resolution (NV_ENC_TWO_PASS_FULL_RESOLUION).

高级特性

1. Look-ahead

2. B-Frames As Reference

3. Adaptive Quantization (AQ)

支持Spatial AQ和Temporal AQ

4. Weighted Prediction

5. Long-Term Reference

6. Emphasis MAP

也就是ROI功能。

7. Alpha Layer Encoding support in HEVC

8. Temporal Scalable Video Coding (SVC) in H.264

9. Error Resiliency features

10.Reference Picture Invalidation

11. Intra Refresh

参考:
https://blog.mobcrush.com/boost-your-stream-quality-choose-the-right-encoder-243fb685d3b8
https://www.amd.com/system/files/documents/broadcast-quality-hi-density-hevc-encoding-beamr-amd-epyc.pdf