AVSAMPLEFMTS16

AVSAMPLEFMTS16 refers to a 16-bit signed integer audio sample format commonly used in multimedia processing libraries, particularly within FFmpeg’s libavutil. In FFmpeg, the equivalent official identifier is AV_SAMPLE_FMT_S16, which denotes PCM audio data where each sample is a signed 16-bit value. This format is widely used for stereo and multi-channel audio, often stored in interleaved (packed) form, where consecutive samples from different channels appear sequentially in memory.

Key characteristics

- Sample size and range: Each sample occupies 2 bytes, with values typically in the range -32768 to 32767 for 16-bit signed integers.

- Layout: Packed (interleaved) AV_SAMPLE_FMT_S16 stores one sample per channel in sequence for each audio frame. Planar AV_SAMPLE_FMT_S16P, by contrast, stores all samples for one channel contiguously before the next channel’s samples.

- Endianness: The interpretation of the 16-bit values depends on endianness. In practice, conversions may be required when exchanging data between systems with different byte orders.

Usage and role

- Data layout: The format informs how decoders and encoders allocate buffers, read samples, and write frames. It also affects the choice of APIs for buffer allocation and data access, such as av_samples_alloc and related helpers.

- Interoperability: Since AV_SAMPLE_FMT_S16 is widely supported, AVSAMPLEFMTS16-compatible data is readily compatible with many audio codecs, containers, and processing pipelines.

- conversions: If input or output targets require different layouts or endianness, format converters (such as libswresample) can transform between packed and planar forms or adjust bit depth and endianness.

Notes

- The term AVSAMPLEFMTS16 is not a formal FFmpeg constant; in FFmpeg sources the standard identifier is AV_SAMPLE_FMT_S16. In documentation, AVSAMPLEFMTS16 is often used informally to describe the same 16-bit signed PCM concept.