Blackmagic Desktop Video User Manual H.265 Hardware Encoder

Capturing H.265 Video with UltraStudio 4K Extreme

Blackmagic UltraStudio 4K Extreme has a powerful built in H.265 hardware encoder that lets you capture the latest H.265 video in real time. This gives you the ability to capture video using encoding technology that maintains stunning video quality at the lowest possible bitrate.

To capture H.265 video using Blackmagic UltraStudio 4K Extreme, set the capture file format in Media Express preferences to MP4 H.265.

To capture video using the built in H.265 encoder:

1. Launch the Blackmagic Media Express software. Open Media Express ‘preferences’ and set the ‘capture file format’ to MP4 H.265.

2. Set the bitrate for your H.265 capture by clicking on the ‘quality’ button located next to the H.265 setting and dragging the ‘encoding settings’ slider left or right. Close the ‘encoding settings’ window to confirm your setting. Your Blackmagic UltraStudio 4K Extreme is now ready to encode H.265 video using Blackmagic Media Express. For information about how to capture and play back video using Media Express, refer to the ‘Blackmagic Media Express’ section of this manual.

Setting the Bitrate

The default bitrate is set to 15 Mb/s which is a good choice for high quality Ultra HD video that is streamed online, but you can set it anywhere between 3 to 50 Mb/s. For online streaming of HD video, a good choice is between 3 to 5 Mb/s.

Drag the ‘encoding settings’ slider to the left if you need to capture video with a smaller file size and a lower bitrate, or drag to the right if file sizes are not an issue and you want the best possible video quality. Setting the bitrate too low will result in compression artifacts in your picture, such as visible macro blocking, pixelation or banding. However, the H.265 hardware encoder is very efficient and keeps artifacts to a minimum, so you can set the bitrate lower than you normally would for H.264 video and still retain great video quality.

Set the bitrate for H.265 capture by clicking on the ‘quality’ button and dragging the ‘encoding settings’ slider left or right.

When encoding H.265 video, or any type of video encoding for online streaming, it’s often helpful to consider a few things, such as the bandwidth of your intended delivery system, the amount of movement and contrast between frames in your video, and the frame rate of your video. For example, if there is a large number of people streaming your video, you may need to lower the bitrate in your encoding so audience members with slower internet connections can watch without download interruptions. Higher bitrates are better for video content with lots of contrast and movement between frames, such as bright to dark, or high energy sporting events and graphics. Video with high frame rates also require higher bitrates compared to video at lower frame rates.

Choosing a bitrate for your encoding can often be an experimental process to achieve the best video quality in the smallest file size, so it’s worth testing a variety of bitrate settings for the best results.