A new contender in the high quality streaming field has appeared: Intel! Their current generation of encoder hardware is capable of matching (and sometimes exceeding) the fast preset in x264, while exceeding real-time speeds at that quality. This makes Intel a good alternative to NVIDIA Turing/Ampere GPUs for budget builds, and as such makes Dual-PC streaming far more affordable.
With StreamFX's NVENC you can achieve the quality targets in one of two ways: Constant Quantization Parameters (CQP) or Variable Bitrate with Constant Quality (VBR-CQ). Both have their own advantages and downsides, and it depends entirely on your requirements which one you should use. Modern NVIDIA GPUs (Pascal and newer) also all support 4:4:4 and 4:2:0 encoding at most of the quality levels shown here.
Streaming with more than one PC has been the leader in H.264 encoding for years, but NVIDIAs Turing and Ampere generation has put a significant dent into that lead. The new generation of GPUs with the brand new encoder brought comparable quality x264 medium – if you can find a GPU that is. Let’s take a look at what’s needed to set up your stream for massively improved quality.
The x264 encoder supports both 4:4:4 as well as 4:2:0, as long as the underlying hardware is fast enough to handle it. It also has two different ways to reach each quality level: Constant Quantization Parameter (CQP) and Constant Rate Factor (CRF). Unfortunately OBS Studio only offers the latter, so for now we are stuck with that. With a single-PC setup, 4:4:4 recording using CRF will be very expensive. You might have to lower the preset used in order to maintain reasonable performance in game and encodes.
ProRes only supports RGB and I444 and requires next to no additional setup, all you need to do is adjust the profile setting according to the table below. Due to there being no further profiles to support 4:4:4 at lower quality, 4:2:2 subsampling is used. This halves the horizontal chroma samples, while keeping the vertical chroma samples in tact – not exactly ideal for text and other high contrast content.
For the unfortunate souls who bought an AMD GPU on the belief that AMD can fix their encoder via Drivers, unfortunately "Fine Wine™" only goes so far. AMDs encoder lacks features that other vendors had for years, and simply do not hold a candle to Intels and NVIDIAs encoder. Still, you're not quite out of luck, as you still have NV12 recording as an option, which limits you to High or Acceptable Quality.
Ever since publishing the guide on how to achieve the best possible NVIDIA NVENC quality with FFmpeg 4.3.x and below, people repeatedly ask me what the best possible recording settings are. So today, as a Christmas present, let me answer this question to the best of my knowledge and help all of you achieve a quality you’ve never seen before.