In this guide
PCM represents audio with digital samples. Linear PCM is uncompressed and can be stored in a WAV file, but PCM is an encoding while WAV is a container. A TV's PCM output setting is a playback choice, and its channel support depends on the connection and devices.
PCM stands for pulse-code modulation, a way to represent audio as a sequence of digital samples. Linear PCM (LPCM) uses linear quantization and is commonly used as uncompressed audio in WAV files, digital audio work and playback systems. A PCM setting may also appear in the audio-output menu of a TV, receiver or soundbar.
PCM is a representation of audio, not a promise about a recording's source or quality. The Library of Congress PCM description distinguishes linear PCM from other variants; its LPCM description explains sampling and linear quantization.
How does PCM audio work?
When analog sound is digitized, a converter samples the changing signal at regular intervals and represents those values digitally. The sample rate describes how many sample frames occur per second. For fixed-point integer PCM, bit depth describes the number of bits used to represent each sample. Channel count describes how many audio channels are stored or carried.
For example, 48 kHz, 16-bit stereo PCM has 48,000 frames each second, with one 16-bit sample for each of two channels in a frame. These properties describe the representation, not whether the source was noisy, clipped or previously compressed. Read what audio sample rate means for a closer look at frames and frequency.
PCM vs. WAV, FLAC and MP3
| Term | What it describes | What it means in practice |
|---|---|---|
| Linear PCM | An uncompressed representation of audio samples. | Sample rate, bit depth and channels affect storage and compatibility. |
| WAV | A container that often holds PCM or floating-point audio. | A .wav extension does not prove the file uses a particular encoding. |
| FLAC | A lossless codec for supported PCM audio. | It can reproduce the samples it encodes while using a different file representation. |
| MP3 | A lossy audio encoding. | Encoding can discard information; decoding an MP3 to PCM cannot restore it. |
WAV and PCM are related but not interchangeable names: PCM is audio encoding; WAV is a file container that can hold different encodings. For practical comparisons, see what a WAV file is and lossy vs. lossless audio.
How large is PCM audio?
For uncompressed fixed-width PCM, multiply sample rate by channels, bits per sample and duration, then divide by eight. One minute of 48 kHz, 16-bit stereo PCM has an audio payload of 11,520,000 bytes (11.52 decimal MB): 48,000 × 2 × 16 × 60 ÷ 8. A WAV header and metadata add bytes.
At the same rate and duration, 24-bit stereo PCM has a larger payload than 16-bit stereo; doubling channels also doubles payload. Use the audio file size calculator for other settings. It estimates PCM or fixed-bitrate audio, not the size of video data or a precise FLAC compression ratio.
What does PCM mean in a TV audio setting?
A TV's digital audio-output menu may offer PCM alongside options such as automatic or pass-through output. Choosing PCM generally asks the device to output decoded PCM rather than pass a supported encoded stream through unchanged. Exactly which formats and channel layouts are available depend on the TV, connection, audio system and selected source.
If a connected device has no sound or reports an unsupported signal, consult its manual and test a compatible output setting. For certain Sony devices, Sony recommends PCM or two-channel output when the connected system cannot accept the signal. This is a troubleshooting example, not a universal setting: changing it may change the available channel layout or surround behavior. Restore the original setting if the result is unsuitable.
How to check whether a WAV contains PCM
- Choose the original WAV in the WAV file inspector. It reads supported local RIFF/WAVE headers without decoding or uploading the audio.
- Read the encoding, sample rate, channel count and sample container bits. The inspector supports common integer PCM and IEEE-float WAV variants; unsupported compression or layouts require another inspector.
- Compare the result with your delivery requirements. A header check describes stored fields; it does not prove the recording was never lossy or that the sound is undistorted.
If you need to create a new PCM WAV from a supported short file, check the relevant converter's output settings. For example, MP3 to WAV produces 16-bit PCM at 44.1 or 48 kHz from a supported mono or stereo MP3 up to five minutes and 50 MiB; the output must also fit 50 MiB. It cannot reverse the MP3's earlier lossy encoding. Resampling and rounding can change samples; retain the original and listen to the actual export.
Common questions
Is PCM the same as WAV?
No. PCM is a way to represent audio; WAV is a container that can store PCM and other audio encodings. Inspect the actual file.
Is PCM always uncompressed?
Linear PCM is uncompressed. PCM is a broader family with variants, including compressed forms used in some applications, so specify LPCM when the distinction matters.
Does converting MP3 to PCM make it lossless?
The PCM copy can represent the decoded MP3 output without a further MP3 encode, but it cannot recover information discarded earlier. Conversion settings can change the samples too.
Does PCM mean stereo?
No. PCM can be carried as mono, stereo or multiple channels. The output connection, device and file format determine what layouts are supported.
Should I always choose PCM on a TV?
No single setting fits every system. PCM can help with compatibility on some connections, but available channel layouts and decoding behavior vary. Check the device manuals and listen to the result.