What is the PCM file format?
.pcm is an audio file format for storing uncompressed audio data as a raw, headerless stream. A typical .pcm file stores 2-channel audio (stereo), but the format supports single- and multi-channel audio. Unlike a .WAV or .AIFF file, .pcm carries no container wrapper and no metadata - the sample rate, bit depth, channel count and byte order are not stored in the file and must be supplied externally; guessing wrong produces noise or a chipmunk/slow-motion effect.
Pulse-code modulation (PCM) is the basic form of representing analog signals as digital signals. The input signal is quantized - divided into a set of discrete sampling points - and each sample is assigned a value. Sampling frequency (or rate) determines the number of samples taken in a given time interval, while sampling resolution determines the size of the numbers used to write the samples, which in turn determines the audio quality. A sampling rate of 44.1 kHz with 16-bit resolution covers all frequencies in the human hearing range. The most common raw variant is signed 16-bit little-endian (s16le), used widely in DSP pipelines, telephony, and audio tools such as FFmpeg.
Security & safety
RISK: LOWRaw PCM is pure audio sample data with no header, no metadata and no executable content, so the file itself cannot carry a virus or run code. The only practical risks are cosmetic: wrong import settings produce loud noise (protect your ears/speakers by lowering volume before playing an unknown .pcm), and because there is no length field a truncated or corrupt file simply ends early with no warning.
Format details
in a nutshell- Sound Blaster / VOC-era raw audio (.pcm) - Legacy raw audio dumps from old sound editors and game tools, same headerless concept.
- BIOS / firmware PCM region images - Some motherboard flashing tools name configuration/microcode blobs .pcm - unrelated to audio.
Programs that open PCM files
Windows4 apps
Awave Studio
Paid Open the raw file and specify its sample format in the import dialog; converts to WAV and dozens of formats. 
Audacity
Open-source File > Import > Raw Data, pick the .pcm, then set encoding (Signed 16-bit PCM), byte order, channels and sample rate; click Import. Adjust if it sounds wrong. 
Adobe Audition
Paid Open the .pcm; in the 'Interpret Sample Format' dialog set sample rate, channels, bit depth and byte order. 
FFmpeg
Open-source Convert by declaring the layout: ffmpeg -f s16le -ar 44100 -ac 2 -i in.pcm out.wav 
macOS3 apps
MPlayer
Open-source Play with explicit settings: mplayer -demuxer rawaudio -rawaudio rate=44100:channels=2:samplesize=2 in.pcm 
Linux3 apps
Technical details
deep spec| Encoding | Binary linear PCM sample values - most commonly signed 16-bit integer; also 8-bit unsigned, 24-bit, 32-bit integer and 32-bit float |
| Container | Raw sample stream with no RIFF, AIFF or other wrapper - the .pcm file carries only the bare audio payload |
| Header / magic bytes | The file begins immediately with the first audio sample; no magic bytes or file signature, so it cannot be auto-detected by format-sniffing software |
| Compression | Linear PCM is uncompressed by definition; it is the source format from which compressed codecs such as MP3 and AAC are derived |
| Byte order | Little-endian by default; big-endian variants also exist - endianness must be specified explicitly on import or conversion |
| Sample rate | Not stored in the file; common values are 8 000 Hz (telephony), 16 000 Hz (wideband voice), 44 100 Hz (CD quality) and 48 000 Hz (broadcast/professional) |
| Channel layout | Multi-channel samples are interleaved per frame (L, R, L, R, …); channel count is not stored in the file and must be declared externally |
| Typical file size | ~10 MB per minute at CD quality (44.1 kHz / 16-bit / stereo ≈ 176 KB/s); grows linearly with sample rate, bit depth and channel count |
| Embedded metadata | No embedded tags of any kind - no ID3, RIFF INFO, Vorbis comment or any other tag structure; all descriptive information must be stored out-of-band |
| MIME type | audio/L16 (IANA-registered for 16-bit linear PCM); also recognised as audio/x-pcm or application/octet-stream |
| Most common variant | Signed 16-bit little-endian (s16le) - the default raw PCM output in FFmpeg and the most widespread convention in DSP and streaming pipelines |
| Telephony use | G.711 µ-law and A-law VoIP payloads are 8 kHz mono PCM with 8-bit logarithmic companding; raw 8 kHz 16-bit PCM is also common in IVR and call-recording systems |
| Relation to WAV | A WAV file wraps the same linear PCM samples in a RIFF header that records all playback parameters; PCM is the audio payload and WAV is the self-describing container |
| Error detection | No CRC, checksum or frame boundary markers; truncation or bit-level corruption is silently undetectable |
| Platform support | Cross-platform (Windows, macOS, Linux); primary format in embedded DSP, telephony, real-time audio streaming and professional audio pipeline tools |
| Released | PCM telephony deployed from the 1960s; .pcm raw dumps used since early digital audio editing |
| Latest version | N/A (raw sample stream has no versioning) |
| Open standard | Yes · royalty-free |
| Specification | en.wikipedia.org |
PCM conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about PCM files.
