WAVE Audio File Format (WAV/RIFF)
WAV is the universal file format for call recordings, IVR prompts, voicemail exports, and PSTN debug captures. Every telephony platform (Twilio, Asterisk, FreeSWITCH) reads and writes WAV-wrapped G.711.
What It Defines
RIFF container with `RIFF`/`WAVE` magic, `fmt` chunk (codec ID, sample rate, channels, bit depth), and `data` chunk of PCM or compressed audio. Standard envelope for G.711 A-law/μ-law (format tag 6/7), G.722, and linear PCM recordings. MIME type: `audio/wav`, `audio/wave`.
Canonical (Normative)
Convenient (Practical)
Related References
Publishes the ECMAScript (JavaScript) language specification and related standards. TC39 is the committee responsible for ECMAScript evolution.
Related Specs
G.711 is the common denominator of telephony. Every PSTN gateway and legacy SIP trunk speaks G.711. When codec negotiation fails and you're left with 64 kbps PCM, this is why.
G.722 is the standard for HD voice in SIP and enterprise telephony. When you enable 'HD Voice' on a SIP trunk, G.722 is typically what's negotiated. Essential for enterprise UC deployments.
Every upload, download, attachment, and asset pipeline crosses these layers. Misunderstanding header vs envelope causes MIME spoofing bugs, parser differentials, and broken file validation. Start here before diving into individual format specs.
Legacy GSM voice and older Asterisk/voicemail systems still produce `.gsm` files. Distinct from the GSM cellular network spec — this is the audio codec bitstream format.
FLAC is the standard lossless audio format for archival and audiophile distribution. Metadata block chain is a clean example of typed extensible headers.