Changeset 358 for pjproject/trunk/pjmedia/include/pjmedia/resample.h

Timestamp:

Mar 24, 2006 8:41:20 PM (18 years ago)

Author:

bennylp

Message:

Added WAVE writer and resample port, and also found out why audio quality is poor with DirectSound?

File:

• pjproject/trunk/pjmedia/include/pjmedia/resample.h (modified) (3 diffs)

pjproject/trunk/pjmedia/include/pjmedia/resample.h

@@ -26 +26 @@
  * @brief Sample rate converter.
  */
-#include "pjmedia/types.h"
+#include <pjmedia/types.h>
+#include <pjmedia/port.h>
+
 
 PJ_BEGIN_DECL
+
+/*
+ * This file declares two types of API:
+ *
+ * Application can use #pjmedia_resample_create() and #pjmedia_resample_run()
+ * to convert a frame from source rate to destination rate. The inpuit frame 
+ * must have a constant length.
+ *
+ * Alternatively, application can create a resampling port with
+ * #pjmedia_resample_port_create() and connect the port to other ports to
+ * change the sampling rate of the samples.
+ */
+
 
 /**
@@ -60 +75 @@
 
 /**
- * Resample a frame.
+ * Use the resample session to resample a frame. The frame must have the
+ * same size and settings as the resample session, or otherwise the
+ * behavior is undefined.
  *
  * @param resample              The resample session.
@@ -71 +88 @@
 
 
+/**
+ * Get the input frame size of a resample session.
+ *
+ * @param resample              The resample session.
+ *
+ * @return                      The frame size, in number of samples.
+ */
+PJ_DECL(unsigned) pjmedia_resample_get_input_size(pjmedia_resample *resample);
+
+
+/**
+ * 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 upstream
+ * port's 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's port clock rate before giving the frame
+ * to the downstream port.
+ *
+ * @param pool                  Pool to allocate the structure and buffers.
+ * @param high_quality          If true, then high quality conversion will be
+ *                              used, at the expense of more CPU and memory,
+ *                              because temporary buffer needs to be created.
+ * @param large_filter          If true, large filter size will be used.
+ * @param downstream_rate       The sampling rate of the downstream port.
+ * @param upstream_rate         The sampling rate of the upstream port.
+ * @param channel_count         The number of channels. This argument is only
+ *                              used for the port information. It does not
+ *                              change the behavior of the resample port.
+ * @param samples_per_frame     Number of samples per frame from the downstream
+ *                              port.
+ * @param p_port                Pointer to receive the resample port instance.
+ *
+ * @return PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_resample_port_create( pj_pool_t *pool,
+                                                   pj_bool_t high_quality,
+                                                   pj_bool_t large_filter,
+                                                   unsigned downstream_rate,
+                                                   unsigned upstream_rate,
+                                                   unsigned channel_count,
+                                                   unsigned samples_per_frame,
+                                                   pjmedia_port **p_port );
+
+
 PJ_END_DECL