Group PJMEDIA_RESAMPLE_PORT

group PJMEDIA_RESAMPLE_PORT

Audio sample rate conversion.

This section describes media port abstraction for Resampling Algorithm.

Enums

enum pjmedia_resample_port_options

Option flags that can be specified when creating resample port.

Values:

enumerator PJMEDIA_RESAMPLE_USE_LINEAR

Do not use high quality resampling algorithm, but use linear algorithm instead.

enumerator PJMEDIA_RESAMPLE_USE_SMALL_FILTER

Use small filter workspace when high quality resampling is used.

enumerator PJMEDIA_RESAMPLE_DONT_DESTROY_DN

Do not destroy downstream port when resample port is destroyed.

Functions

pj_status_t pjmedia_resample_port_create(pj_pool_t *pool, pjmedia_port *dn_port, unsigned clock_rate, unsigned options, pjmedia_port **p_port)

Create a resample port. This creates a bidirectional resample session, which will resample frames when the port’s get_frame() and put_frame() is called.

When the resample port’s get_frame() is called, this port will get a frame from the downstream port and resample the frame to the target clock rate before returning it to the caller.

When the resample port’s put_frame() is called, this port will resample the frame to the downstream port’s clock rate before giving the frame to the downstream port.

Parameters:

• pool – Pool to allocate the structure and buffers.

• dn_port – The downstream port, which clock rate is to be converted to the target clock rate.

• clock_rate – Target clock rate.

• options – Flags from pjmedia_resample_port_options. When this flag is zero, the default behavior is to use high quality resampling with large filter, and to destroy downstream port when resample port is destroyed.

• p_port – Pointer to receive the resample port instance.

Returns:

PJ_SUCCESS on success.