PCM Audio over HDMI: Compatibility and Output Settings

Short answer: does HDMI carry PCM audio?

Yes. Linear PCM is the baseline audio format of HDMI, and audio-capable HDMI displays and receivers are expected to accept two-channel PCM. That makes stereo PCM the most compatible choice when sound is missing or unreliable. HDMI can also carry multichannel PCM, up to eight channels. Whether you actually get 5.1 or 7.1 PCM depends on what the receiving device reports it supports, not on the cable.

Choose PCM on the source when you want the source to decode audio itself, when a TV, monitor or capture card stays silent with other settings, or when you need predictable stereo. Choose bitstream when an AV receiver or soundbar should decode Dolby or DTS formats on its own.

How PCM over HDMI works

PCM is uncompressed digital audio: a stream of samples described by sample rate, bit depth and channel count. When a source outputs PCM, it has already decoded any compressed track, such as Dolby Digital or DTS, and sends plain samples. The receiving device only has to turn those samples into sound. It does not need to support the original codec.

Before sending audio, the source reads a capability list from the connected device, known as EDID. This list states which audio formats, channel counts and sample rates the TV, receiver, monitor or capture card accepts. The source then picks a format within those limits. This is why the same player can send 7.1 PCM to one receiver but only stereo to a TV.

Audio output options on players, consoles, cameras and computers usually fall into a few groups. Their exact names and locations vary by manufacturer and firmware version.

• PCM or LPCM: the source decodes audio and sends uncompressed samples.
• Bitstream or passthrough: compressed formats are sent unchanged for the receiving device to decode.
• Stereo or downmix: multichannel content is reduced to two channels before output.
• Auto: behaviour depends on the device and often follows what the connected device reports.

Choosing the right output setting

• TV or monitor speakers: two-channel PCM is the safest choice, because displays generally play stereo PCM even when they reject other formats.
• AV receiver connected directly by HDMI: multichannel PCM works if the receiver reports support for it; bitstream lets the receiver decode the track and show its original format.
• Soundbar through the TV's ARC: standard ARC carries stereo PCM but not multichannel PCM, so surround over ARC needs a compressed format.
• Soundbar or receiver through eARC: the eARC specification supports multichannel PCM, but the TV and the audio device must both support eARC and have it enabled.
• HDMI capture card for streaming or video calls: set the camera, console or computer to stereo PCM. Capture devices commonly expect two-channel PCM, and a bitstream signal may arrive as silence or noise.
• Computer connected to a display: the HDMI port appears as an output device in the system sound settings. Select it as the default output and check which formats and sample rates it offers.

An HDMI capture card used for video calls or recording also appears as an input device. Select it explicitly in the call or recording app, then watch the input level meter while the source plays sound. If the meter moves but the other side hears nothing, look at the app's settings. If the meter stays flat, check the source's audio output and the capture link.

Sample rate also matters. 48 kHz is the usual rate for video, cameras and capture workflows, while 44.1 kHz is common for music. When the source and the receiving device or software use different rates, something has to resample the audio. Matching rates where your devices allow it avoids unnecessary conversion and reduces format switching, which on some equipment causes a brief mute.

Limits and related questions

Does choosing PCM reduce quality? PCM itself is uncompressed. Decoding a lossy track to PCM does not restore detail, and decoding a lossless track keeps its audio samples. What can be lost is format-specific information: object-based formats such as Dolby Atmos may not reach the receiver in full when the source converts them to PCM, depending on the player.

Why does the receiver display PCM instead of Dolby or DTS? Because the source is doing the decoding. With a PCM setting this is expected and not a fault. Some apps and devices also output PCM for certain content regardless of the setting.

No sound with PCM selected usually has one of a few causes: the wrong output device is selected, the receiving device does not accept the channel count being sent, an intermediate switch, splitter or older receiver limits the capability list, or the TV's own audio output setting does not match the connection in use. Switching the source to stereo PCM is a quick way to narrow it down.

Because HDMI carries audio digitally, hiss or hum in a recording usually originates at the source, its microphone or an analog stage, not in the HDMI link. Dropouts, clicks or sudden silence are more typical of a handshake or format mismatch between devices.

Supported channel counts, sample rates and eARC behaviour depend on each device's hardware and firmware. Confirm them in the manufacturer's documentation for your specific models rather than assuming them from an HDMI version number.