swrgetdelay

swr_get_delay is a function from FFmpeg’s libswresample library that reports the internal delay of a resampling context. In casual usage it is sometimes referred to by the shorthand name "swrgetdelay," but the canonical API name is swr_get_delay. The function helps applications understand how many input samples are effectively buffered or how far the resampler is offset in producing output samples.

The function takes a SwrContext pointer and a value representing the number of input samples (in_nb_samples) to consider when computing the delay. It returns the delay expressed in output-sample units. The reported delay depends on the configured conversion parameters (input/output sample rates, channel layout, and any applied resampling filters). Knowing the delay assists in buffering decisions and synchronization between audio input and output streams.

Usage notes:

- Call swr_get_delay after configuring and initializing the SwrContext (swr_alloc, swr_alloc_set_opts, swr_init).

- You can pass 0 for in_nb_samples to obtain the current delay without considering additional input.

- The value helps estimate how many output samples will be produced before new input will be fully consumed, aiding in planning memory allocation and timing in streaming or real-time scenarios.

Related functions include swr_alloc, swr_init, swr_convert, and swr_free. While "swrgetdelay" may appear in some codebases as a shorthand, it refers to the same concept as swr_get_delay.