Does DisplayPort Support Dolby TrueHD and DTS-HD MA?

DisplayPort cables can transmit uncompressed, high-resolution audio formats, including Dolby TrueHD and DTS-HD Master Audio. This article examines DisplayPort's audio specifications, explains how bitstream passthrough functions over the connection, and highlights the hardware requirements necessary to output lossless surround sound to your audio system.

DisplayPort Audio Capabilities

Starting with the DisplayPort 1.2 specification, the interface includes native support for High Bit Rate (HBR) audio. This standard provides sufficient bandwidth to carry up to eight channels (a 7.1 surround sound layout) of uncompressed audio at a 192 kHz sample rate and 24-bit depth.

Because of this bandwidth capacity, DisplayPort handles both uncompressed multi-channel Linear PCM (LPCM) and bitstreamed high-definition audio formats without quality loss. This capability extends to object-based immersive formats such as Dolby Atmos and DTS:X, provided they are packaged inside Dolby TrueHD or DTS-HD Master Audio bitstreams.

Bitstream Passthrough Explained

To output formats like Dolby TrueHD or DTS-HD Master Audio over DisplayPort, the system utilizes "bitstream passthrough." Rather than having your computer's operating system or media player decode the audio, the raw, compressed audio stream is transmitted directly over the DisplayPort link to an external audio processor or Audio/Video Receiver (AVR). The receiver then decodes the lossless signal and distributes it to the appropriate speaker channels.

If the source device decodes the audio internally instead of bitstreaming it, the stream is converted into uncompressed multi-channel LPCM. DisplayPort carries this uncompressed LPCM signal with zero loss in fidelity, delivering identical acoustic performance even if the receiver's front panel does not display the proprietary Dolby or DTS logo.

Hardware and Setup Considerations

While the DisplayPort specification fully supports these formats, real-world deployment requires specific hardware configurations:

  • Source Device: Modern dedicated GPUs from NVIDIA and AMD, as well as Intel integrated graphics, support high-definition audio over DisplayPort. The graphics driver must include the appropriate audio driver component.
  • Audio Receiver Inputs: Most dedicated AV receivers feature HDMI inputs rather than DisplayPort inputs. Connecting a DisplayPort source to an HDMI-based receiver typically requires a high-quality DisplayPort-to-HDMI cable or an active adapter that supports HBR audio pass-through.
  • Playback Software: Media playback software (such as Kodi, VLC, or MPC-BE) must be explicitly configured to enable audio passthrough/bitstreaming for TrueHD and DTS-HD MA formats within its output settings.
  • Monitors: Standard computer monitors with integrated speakers or 3.5mm headphone jacks generally only decode two-channel PCM stereo and cannot process multi-channel lossless bitstreams. For full surround playback, the audio stream must terminate at an AVR or compatible soundbar.