+int apple_chan_chunk(pcm_io_context_t *io, uint32_t chunk_size,
+ pcm_sample_description_t *fmt, uint8_t *mapping);
+
+pcm_reader_t *wav_open(pcm_io_context_t *io, int ignore_length);
+pcm_reader_t *raw_open(pcm_io_context_t *io,
+ const pcm_sample_description_t *desc);
+pcm_reader_t *caf_open(pcm_io_context_t *io,
+ aacenc_tag_callback_t tag_callback, void *tag_ctx);
+
+pcm_reader_t *pcm_open_native_converter(pcm_reader_t *reader);
+pcm_reader_t *pcm_open_float_converter(pcm_reader_t *reader);
+pcm_reader_t *pcm_open_sint16_converter(pcm_reader_t *reader);
+
+pcm_reader_t *extrapolater_open(pcm_reader_t *reader);
+