WARNING: Hardware acceleration will usually produce lower quality results than when using Software encoding.

• Hardware acceleration is definitely not using the same encoder ported to a GPU (or to any other hardware accelerator), it is actually using a fully different encoder.
  • And the point is that not only the algorithms are different, but also the parameters do not match between them.
    • e.g. the crf parameter in an encoder does not necessarily have the same effect in another encoder, and the same value can result in completely different effective quality (the parameters and their scales are not standardized).

• The hardware encoder in the graphics card is usually tailored for speed; above quality.
  • This is a trade-off in order to keep complexity down.
  • Hardware encoding uses fixed function blocks which are far less versatile and adaptable than software encoders.
  • As a result a software encoder will get better results 99 times out of 100.

• A huge amount of development effort, time and cost would be needed to get hardware to be as full-featured as a software encoder.