SLN to CAF Converter

SLN (Signed Linear) is a headerless raw audio format storing 16-bit signed linear PCM samples at 8000 Hz mono, most closely associated with Asterisk) — the open-source PBX framework developed by Digium (now Sangoma Technologies). Within Asterisk, SLN serves as the native internal audio representation: every codec transcoding operation passes through signed linear as an intermediate step. This makes SLN the backbone of Asterisk's codec translation architecture. The format contains nothing but raw samples — no headers, no metadata, no framing — so parameters must be known in advance. While this lack of self-description might seem limiting, it is actually an advantage in telephony where sample format is fixed by convention and every overhead byte matters across thousands of simultaneous channels. The 8000 Hz rate aligns with the G.711 standard for traditional telephony, capturing the full 300-3400 Hz voice band. Asterisk also supports extended variants (sln16, sln32, sln48) for wideband audio. SLN files require no decoding — just direct memory mapping — making them ideal for real-time mixing, conferencing, and prompt playback in high-density VoIP environments.

CAF (Core Audio Format) is a flexible audio container developed by Apple and introduced with Mac OS X 10.4 Tiger in 2005. Built to overcome limitations of older formats, CAF eliminates the 4 GB file size ceiling that constrains WAV and AIFF, theoretically supporting unlimited length. The container accommodates virtually any codec — AAC, ALAC, MP3, linear PCM, IMA ADPCM, and more — within a unified wrapper. Its chunk-based architecture stores audio alongside rich metadata including channel layouts, marker regions, annotations, and MIDI data. A defining advantage is handling extremely long recordings: broadcasters and field recordists can capture hours of continuous audio without size boundaries. Flexible codec support is another strength, as one container works whether the content is high-resolution 24-bit/192 kHz lossless audio or compressed speech. Apple's Core Audio framework provides native support on macOS and iOS, ensuring low-latency playback in professional applications like Logic Pro and Final Cut Pro. For Apple ecosystem workflows requiring both versatility and scale, CAF is an exceptionally capable choice.