Encoding in H.264 or H.265 (HEVC)

Some Macs support hardware-accelerated encoding and decoding for H.264 and HEVC (H.265), which helps reduce CPU usage. However, there are limitations depending on your Mac model and macOS version.

H.264 and HEVC will be encoded on the hardware-acceleration chip when available, and thus it will not use the CPU and GPU to do so.

Computers limitations 

Apple silicon Macs

All Apple Silicon Macs (M1–M4) include dedicated Media Engines for H.264 and HEVC encoding/decoding. The number of Media Engines varies by model:

💡 HEVC encoding is generally more efficient than H.264 on Apple Silicon, so we recommend using HEVC when possible.

💡 Performance Between Media Engine Generations: While newer Apple Silicon chips bring improvements in general processing power, which impact codecs encoded on the CPU, we have not observed significant performance differences between individual Media Engines across different chip generations. A Media Engine in an M1 performs similarly to one in an M4, so there won't be major changed for the encoding of H.264/HEVC. The most important factor for encoding speed is the number of available Media Engines in your Mac. If you need better performance, choosing a Mac with more Media Engines (e.g., M3 Ultra) will make the biggest impact. Note that performance could vary depending on the macOS version, so we recommend testing when changing macOS version.

Intel Macs

Most Intel Macs from 2016 or later support hardware-accelerated H.264 and HEVC encoding using Intel Quick Sync. This includes Macs with Core i3, i5, i7, and i9 processors (Mac mini, iMac, iMac Pro, MacBook Pro).

• 2019 Mac Pro also supports hardware acceleration via the graphics card, though performance depends on the specific GPU:
  • H.264 encoding/decoding: A 2018 Mac mini outperforms a Mac Pro, even with a Radeon Pro Vega II.
  • HEVC encoding/decoding: A Mac Pro with a Radeon Pro Vega II performs better than a Mac mini.
• 2013 Mac Pros do not support hardware acceleration for H.264 or HEVC, as Xeon processors lack Quick Sync. A Mac mini will perform better for these tasks.

💡 eGPUs do not improve hardware acceleration for H.264/HEVC.
💡 Only H.264 and HEVC benefit from Quick Sync—other codecs rely entirely on the CPU.

Factors Affecting Performance

Apple silicon Macs

Media Engines are separate from the CPU/GPU, so encoding performance remains unaffected by other CPU/GPU-intensive tasks. This means that the CPU and GPU are available for other tasks.

Intel Macs

Since Quick Sync uses the integrated GPU, running other applications that use the built-in GPU may reduce encoding performance.

In MovieRecorder, effects (e.g., rotation, deinterlacing) and overlays (e.g., timecode, images) rely on the GPU, which can significantly impact H.264/HEVC encoding performance.

macOS limitations 

Apple silicon Macs

No known limitations, except ensuring you use a macOS version supported by your Mac.

Intel Macs

•  For best performance with H.264, use macOS 10.13 or later. Older versions only support one hardware-accelerated H.264 channel.
• HEVC encoding is supported only on macOS 10.13 or later.

Level and Profile limitations

H.264

The maximum resolution, frame rate, and bitrate depend on the profile and level selected:

💡 If “Automatic Level” is selected, the best level is chosen based on the video format and bitrate.

H.265

Only Main Automatic Level is supported, meaning the best level is automatically chosen based on the video format and bitrate.

What Happens if You Use an Unsupported Profile or Level?

Since the AVPreset is set in advance, we can’t predict which format and frame rate it will be used with. If you select a profile or level that isn’t supported for the actual video format, the encoder won’t work, and the destination will not start recording. To avoid this, we recommend using “Auto”, which ensures the best compatible profile and level are applied based on the incoming video.

About the bitrate

The bitrate for HEVC and H.264 encoders is an average bitrate, meaning the actual bitrate of your recorded file will vary based on the type of video signal, the format, frame rate, and codec you use. Additionally, the maximum achievable bitrate can depend on your Mac model and macOS version. 

Also, if the signal is very easy to compress (e.g., color bars), the recorded file may have a lower bitrate than what you set.

What Happens if You Set a Bitrate Too High?

Since the AVPreset is set in the preferences—before knowing what type of video it will be used for—we can’t prevent you from choosing a bitrate that exceeds what is supported.

If you select a bitrate higher than the supported maximum, the encoder will cap it at the highest possible value for your system, format, and codec. This means:
✔️ The file will still be encoded, just not at the exact bitrate you set.
✔️ Always check the resulting file to confirm the actual applied bitrate.