38 struct echo_reference {  struct
39     struct echo_reference_itfe itfe;  argument
40     int status;                     // init status
41     uint32_t state;                 // active state: reading, writing or both
42     audio_format_t rd_format;       // read sample format
43     uint32_t rd_channel_count;      // read number of channels
44     uint32_t rd_sampling_rate;      // read sampling rate in Hz
45     size_t rd_frame_size;           // read frame size (bytes per sample)
46     audio_format_t wr_format;       // write sample format
47     uint32_t wr_channel_count;      // write number of channels
71 int echo_reference_get_next_buffer(struct resampler_buffer_provider *buffer_provider,  in echo_reference_get_next_buffer()  argument
74     struct echo_reference *er;  in echo_reference_get_next_buffer()  argument
134 static int echo_reference_write(struct echo_reference_itfe *echo_reference,  in echo_reference_write()
308 static int echo_reference_read(struct echo_reference_itfe *echo_reference,  in echo_reference_read()
517                             struct echo_reference_itfe **echo_reference)  in create_echo_reference()
559 void release_echo_reference(struct echo_reference_itfe *echo_reference) {  in release_echo_reference()