Finished new pjmedia rewrite

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@159 74dad513-b988-da41-8d7b-12977e46ad98

8 files changed, 823 insertions, 433 deletions

diff --git a/pjmedia/include/pjmedia/codec.h b/pjmedia/include/pjmedia/codec.h
index 3069f31c..75135d62 100644
--- a/pjmedia/include/pjmedia/codec.h
+++ b/pjmedia/include/pjmedia/codec.h
@@ -25,6 +25,7 @@
  * @brief Codec framework.
  */
 
+#include <pjmedia/types.h>
 #include <pj/list.h>
 
 PJ_BEGIN_DECL
@@ -36,312 +37,393 @@ PJ_BEGIN_DECL
  * @{
  */
 
-/** Top most media type. */
-typedef enum pj_media_type
-{
-    /** No type. */
-    PJ_MEDIA_TYPE_NONE = 0,
-
-    /** The media is audio */
-    PJ_MEDIA_TYPE_AUDIO = 1,
-
-    /** The media is video. */
-    PJ_MEDIA_TYPE_VIDEO = 2,
-
-    /** Unknown media type, in this case the name will be specified in 
-     *  encoding_name.
-     */
-    PJ_MEDIA_TYPE_UNKNOWN = 3,
-
-} pj_media_type;
-
-
-/** Media direction. */
-typedef enum pj_media_dir_t
-{
-    /** None */
-    PJ_MEDIA_DIR_NONE = 0,
-
-    /** Encoding (outgoing to network) stream */
-    PJ_MEDIA_DIR_ENCODING = 1,
-
-    /** Decoding (incoming from network) stream. */
-    PJ_MEDIA_DIR_DECODING = 2,
-
-    /** Incoming and outgoing stream. */
-    PJ_MEDIA_DIR_ENCODING_DECODING = 3,
 
-} pj_media_dir_t;
-
-
-/** Standard RTP paylist types. */
-typedef enum pj_rtp_pt
-{
-    PJ_RTP_PT_PCMU = 0,		/* audio PCMU */
-    PJ_RTP_PT_GSM  = 3,		/* audio GSM */
-    PJ_RTP_PT_G723 = 4,		/* audio G723 */
-    PJ_RTP_PT_DVI4_8K = 5,	/* audio DVI4 8KHz */
-    PJ_RTP_PT_DVI4_16K = 6,	/* audio DVI4 16Khz */
-    PJ_RTP_PT_LPC = 7,		/* audio LPC */
-    PJ_RTP_PT_PCMA = 8,		/* audio PCMA */
-    PJ_RTP_PT_G722 = 9,		/* audio G722 */
-    PJ_RTP_PT_L16_2 = 10,	/* audio 16bit linear 44.1KHz stereo */
-    PJ_RTP_PT_L16_1 = 11,	/* audio 16bit linear 44.1KHz mono */
-    PJ_RTP_PT_QCELP = 12,	/* audio QCELP */
-    PJ_RTP_PT_CN = 13,		/* audio Comfort Noise */
-    PJ_RTP_PT_MPA = 14,		/* audio MPEG1 or MPEG2 as elementary streams */
-    PJ_RTP_PT_G728 = 15,	/* audio G728 */
-    PJ_RTP_PT_DVI4_11K = 16,	/* audio DVI4 11.025KHz mono */
-    PJ_RTP_PT_DVI4_22K = 17,	/* audio DVI4 22.050KHz mono */
-    PJ_RTP_PT_G729 = 18,	/* audio G729 */
-    PJ_RTP_PT_CELB = 25,	/* video/comb Cell-B by Sun Microsystems (RFC 2029) */
-    PJ_RTP_PT_JPEG = 26,	/* video JPEG */
-    PJ_RTP_PT_NV = 28,		/* video NV implemented by nv program by Xerox */
-    PJ_RTP_PT_H261 = 31,	/* video H261 */
-    PJ_RTP_PT_MPV = 32,		/* video MPEG1 or MPEG2 elementary streams */
-    PJ_RTP_PT_MP2T = 33,	/* video MPEG2 transport */
-    PJ_RTP_PT_H263 = 34,	/* video H263 */
-
-    PJ_RTP_PT_DYNAMIC = 96,	/* start of dynamic RTP payload */
-} pj_rtp_pt;
-
-
-/** Identification used to search for codec factory that supports specific 
- *  codec specification. 
+/** 
+ * Standard RTP static payload types, as defined by RFC 3551. 
  */
-typedef struct pj_codec_id
+enum pjmedia_rtp_pt
 {
-    /** Media type. */
-    pj_media_type   type;
+    PJMEDIA_RTP_PT_PCMU = 0,	    /* audio PCMU			    */
+    PJMEDIA_RTP_PT_GSM  = 3,	    /* audio GSM			    */
+    PJMEDIA_RTP_PT_G723 = 4,	    /* audio G723			    */
+    PJMEDIA_RTP_PT_DVI4_8K = 5,	    /* audio DVI4 8KHz			    */
+    PJMEDIA_RTP_PT_DVI4_16K = 6,    /* audio DVI4 16Khz			    */
+    PJMEDIA_RTP_PT_LPC = 7,	    /* audio LPC			    */
+    PJMEDIA_RTP_PT_PCMA = 8,	    /* audio PCMA			    */
+    PJMEDIA_RTP_PT_G722 = 9,	    /* audio G722			    */
+    PJMEDIA_RTP_PT_L16_2 = 10,	    /* audio 16bit linear 44.1KHz stereo    */
+    PJMEDIA_RTP_PT_L16_1 = 11,	    /* audio 16bit linear 44.1KHz mono	    */
+    PJMEDIA_RTP_PT_QCELP = 12,	    /* audio QCELP			    */
+    PJMEDIA_RTP_PT_CN = 13,	    /* audio Comfort Noise		    */
+    PJMEDIA_RTP_PT_MPA = 14,	    /* audio MPEG1/MPEG2 elementary streams */
+    PJMEDIA_RTP_PT_G728 = 15,	    /* audio G728			    */
+    PJMEDIA_RTP_PT_DVI4_11K = 16,   /* audio DVI4 11.025KHz mono	    */
+    PJMEDIA_RTP_PT_DVI4_22K = 17,   /* audio DVI4 22.050KHz mono	    */
+    PJMEDIA_RTP_PT_G729 = 18,	    /* audio G729			    */
+
+    PJMEDIA_RTP_PT_CELB = 25,	    /* video/comb Cell-B by Sun (RFC 2029)  */
+    PJMEDIA_RTP_PT_JPEG = 26,	    /* video JPEG			    */
+    PJMEDIA_RTP_PT_NV = 28,	    /* video NV  by nv program by Xerox	    */
+    PJMEDIA_RTP_PT_H261 = 31,	    /* video H261			    */
+    PJMEDIA_RTP_PT_MPV = 32,	    /* video MPEG1 or MPEG2 elementary	    */
+    PJMEDIA_RTP_PT_MP2T = 33,	    /* video MPEG2 transport		    */
+    PJMEDIA_RTP_PT_H263 = 34,	    /* video H263			    */
+
+    PJMEDIA_RTP_PT_DYNAMIC = 96,    /* start of dynamic RTP payload	    */
 
-    /** Payload type (can be dynamic). */
-    unsigned	    pt;
-
-    /** Encoding name, must be present if the payload type is dynamic. */
-    pj_str_t	    encoding_name;
-
-    /** Sampling rate. */
-    unsigned	    sample_rate;
-} pj_codec_id;
+};
 
 
-/** Detailed codec attributes used both to configure a codec and to query
- *  the capability of codec factories.
+/** 
+ * Identification used to search for codec factory that supports specific 
+ * codec specification. 
  */
-typedef struct pj_codec_attr
+struct pjmedia_codec_info
 {
-    pj_uint32_t	sample_rate;	    /* Sampling rate in Hz */
-    pj_uint32_t	avg_bps;	    /* Average bandwidth in bits per second */
-
-    pj_uint8_t	pcm_bits_per_sample;/* Bits per sample in the PCM side */
-    pj_uint16_t	ptime;		    /* Packet time in miliseconds */
-
-    unsigned	pt:8;		    /* Payload type. */
-    unsigned    vad_enabled:1;	    /* Voice Activity Detector. */
-    unsigned    cng_enabled:1;	    /* Comfort Noise Generator. */
-    unsigned    lpf_enabled:1;	    /* Low pass filter */
-    unsigned    hpf_enabled:1;	    /* High pass filter */
-    unsigned    penh_enabled:1;	    /* Perceptual Enhancement */
-    unsigned    concl_enabled:1;    /* Packet loss concealment */
-    unsigned    reserved_bit:1;
+    pjmedia_type    type;	    /**< Media type.			*/
+    unsigned	    pt;		    /**< Payload type (can be dynamic). */
+    pj_str_t	    encoding_name;  /**< Encoding name.			*/
+    unsigned	    sample_rate;    /**< Sampling rate.			*/
+};
 
-} pj_codec_attr;
 
-/** Types of audio frame. */
-typedef enum pj_audio_frame_type
+/** 
+ * Detailed codec attributes used both to configure a codec and to query
+ * the capability of codec factories.
+ */
+struct pjmedia_codec_param
 {
-    /** The frame is a silence audio frame. */
-    PJ_AUDIO_FRAME_SILENCE,
+    pj_uint32_t	sample_rate;	    /**< Sampling rate in Hz		*/
+    pj_uint32_t	avg_bps;	    /**< Average bandwidth in bits/sec	*/
 
-    /** The frame is a non-silence audio frame. */
-    PJ_AUDIO_FRAME_AUDIO,
+    pj_uint8_t	pcm_bits_per_sample;/**< Bits/sample in the PCM side	*/
+    pj_uint16_t	ptime;		    /**< Packet time in miliseconds	*/
 
-} pj_audio_frame_type;
+    unsigned	pt:8;		    /**< Payload type.			*/
+    unsigned    vad_enabled:1;	    /**< Voice Activity Detector.	*/
+    unsigned    cng_enabled:1;	    /**< Comfort Noise Generator.	*/
+    unsigned    lpf_enabled:1;	    /**< Low pass filter		*/
+    unsigned    hpf_enabled:1;	    /**< High pass filter		*/
+    unsigned    penh_enabled:1;	    /**< Perceptual Enhancement		*/
+    unsigned    concl_enabled:1;    /**< Packet loss concealment	*/
+    unsigned    reserved_bit:1;	    /**< Reserved, must be NULL.	*/
 
-typedef struct pj_codec pj_codec;
-typedef struct pj_codec_factory pj_codec_factory;
+};
 
 
-/** This structure describes an audio frame. */
-struct pj_audio_frame
+/** 
+ * Types of media frame. 
+ */
+enum pjmedia_frame_type
 {
-    /** Type: silence or non-silence. */
-    pj_audio_frame_type type;
+    PJMEDIA_FRAME_TYPE_SILENCE_AUDIO,	/**< Silence audio frame.	*/
+    PJMEDIA_FRAME_TYPE_AUDIO,		/**< Normal audio frame.	*/
 
-    /** Pointer to buffer. */
-    void	*buf;
+};
 
-    /** Frame size in bytes. */
-    unsigned	 size;
+/** 
+ * This structure describes a media frame. 
+ */
+struct pjmedia_frame
+{
+    pjmedia_frame_type	 type;	/**< Frame type.		    */
+    void		*buf;	/**< Pointer to buffer.		    */
+    pj_size_t		 size;	/**< Frame size in bytes.	    */
 };
 
 /**
- * Operations that must be supported by the codec.
+ * This structure describes codec operations. Each codec MUST implement
+ * all of these functions.
  */
-typedef struct pj_codec_op
+struct pjmedia_codec_op
 {
-    /** Get default attributes. */
-    pj_status_t (*default_attr) (pj_codec *codec, pj_codec_attr *attr);
-
-    /** Open and initialize codec using the specified attribute.
-     *  @return zero on success.
+    /** 
+     * Get default attributes for this codec. 
+     *
+     * @param codec	The codec instance.
+     * @param attr	Pointer to receive default codec attributes.
+     *
+     * @return		PJ_SUCCESS on success.
      */
-    pj_status_t	(*init)( pj_codec *codec, pj_pool_t *pool );
-
-    /** Close and shutdown codec.
+    pj_status_t (*default_attr)(pjmedia_codec *codec, 
+				pjmedia_codec_param *attr);
+
+    /** 
+     * Initialize codec using the specified attribute.
+     *
+     * @param codec	The codec instance.
+     * @param pool	Pool to use when the codec needs to allocate
+     *			some memory.
+     *
+     * @return		PJ_SUCCESS on success.
      */
-    pj_status_t	(*open)( pj_codec *codec, pj_codec_attr *attr );
-
-    /** Close and shutdown codec.
+    pj_status_t	(*init)(pjmedia_codec *codec, 
+			pj_pool_t *pool );
+
+    /** 
+     * Open the codec and initialize with the specified parameter..
+     *
+     * @param codec	The codec instance.
+     * @param param	Codec initialization parameter.
+     *
+     * @return		PJ_SUCCESS on success.
      */
-    pj_status_t (*close)( pj_codec *codec );
-
-    /** Encode frame.
+    pj_status_t	(*open)(pjmedia_codec *codec, 
+			pjmedia_codec_param *param );
+
+    /** 
+     * Close and shutdown codec, releasing all resources allocated by
+     * this codec, if any.
+     *
+     * @param codec	The codec instance.
+     *
+     * @return		PJ_SUCCESS on success.
      */
-    pj_status_t (*encode)( pj_codec *codec, const struct pj_audio_frame *input,
-			   unsigned output_buf_len, struct pj_audio_frame *output);
-
-    /** Decode frame.
+    pj_status_t (*close)(pjmedia_codec *codec);
+
+
+    /** 
+     * Instruct the codec to encode the specified input frame.
+     *
+     * @param codec	The codec instance.
+     * @param input	The input frame.
+     * @param out_size	The length of buffer in the output frame.
+     * @param output	The output frame.
+     *
+     * @return		PJ_SUCCESS on success;
      */
-    pj_status_t (*decode)( pj_codec *codec, const struct pj_audio_frame *input,
-			   unsigned output_buf_len, struct pj_audio_frame *output);
+    pj_status_t (*encode)(pjmedia_codec *codec, 
+			  const struct pjmedia_frame *input,
+			  unsigned out_size, 
+			  struct pjmedia_frame *output);
+
+    /** 
+     * Instruct the codec to decode the specified input frame.
+     *
+     * @param codec	The codec instance.
+     * @param input	The input frame.
+     * @param out_size	The length of buffer in the output frame.
+     * @param output	The output frame.
+     *
+     * @return		PJ_SUCCESS on success;
+     */
+    pj_status_t (*decode)(pjmedia_codec *codec, 
+			  const struct pjmedia_frame *input,
+			  unsigned out_size, 
+			  struct pjmedia_frame *output);
+
+};
 
-} pj_codec_op;
 
 /**
- * A codec describes an instance to encode or decode media frames. 
+ * This structure describes a codec instance. 
  */
-struct pj_codec
+struct pjmedia_codec
 {
     /** Entries to put this codec instance in codec factory's list. */
-    PJ_DECL_LIST_MEMBER(struct pj_codec);
+    PJ_DECL_LIST_MEMBER(struct pjmedia_codec);
 
     /** Codec's private data. */
     void	*codec_data;
 
     /** Codec factory where this codec was allocated. */
-    pj_codec_factory *factory;
+    pjmedia_codec_factory *factory;
 
     /** Operations to codec. */
-    pj_codec_op	*op;
+    pjmedia_codec_op	*op;
 };
 
+
 /**
- * This structure describes operations that must be supported by codec factories.
+ * This structure describes operations that must be supported by codec 
+ * factories.
  */
-typedef struct pj_codec_factory_op
+struct pjmedia_codec_factory_op
 {
-    /** Check whether the factory can create codec with the specified ID.
-     *  @param factory The codec factory.
-     *  @param id  The codec ID.
-     *  @return zero it matches.
+    /** 
+     * Check whether the factory can create codec with the specified 
+     * codec info.
+     *
+     * @param factory	The codec factory.
+     * @param info	The codec info.
+     *
+     * @return		PJ_SUCCESS if this factory is able to create an
+     *			instance of codec with the specified info.
      */
-    pj_status_t	(*match_id)( pj_codec_factory *factory, const pj_codec_id *id );
-
-    /** Create default attributes for the specified codec ID. This function can
-     *  be called by application to get the capability of the codec.
-     *  @param factory The codec factory.
-     *  @param id  The codec ID.
-     *  @param attr The attribute to be initialized.
-     *  @return zero if success.
+    pj_status_t	(*test_alloc)(pjmedia_codec_factory *factory, 
+			      const pjmedia_codec_info *info );
+
+    /** 
+     * Create default attributes for the specified codec ID. This function
+     * can be called by application to get the capability of the codec.
+     *
+     * @param factory	The codec factory.
+     * @param info	The codec info.
+     * @param attr	The attribute to be initialized.
+     *
+     * @return		PJ_SUCCESS if success.
      */
-    pj_status_t (*default_attr)( pj_codec_factory *factory, const pj_codec_id *id,
-				 pj_codec_attr *attr );
-
-    /** Enumerate supported codecs.
-     *  @param factory The codec factory.
-     *  @param count Number of entries in the array.
-     *  @param codecs The codec array.
-     *  @return the total number of supported codecs, which can be less or 
-     *          greater than requested.
+    pj_status_t (*default_attr)(pjmedia_codec_factory *factory, 
+				const pjmedia_codec_info *info,
+				pjmedia_codec_param *attr );
+
+    /** 
+     * Enumerate supported codecs that can be created using this factory.
+     * 
+     *  @param factory	The codec factory.
+     *  @param count	On input, specifies the number of elements in
+     *			the array. On output, the value will be set to
+     *			the number of elements that have been initialized
+     *			by this function.
+     *  @param info	The codec info array, which contents will be 
+     *			initialized upon return.
+     *
+     *  @return		PJ_SUCCESS on success.
      */
-    unsigned (*enum_codecs) (pj_codec_factory *factory, unsigned count, pj_codec_id codecs[]);
-
-    /** This function is called by codec manager to instantiate one codec
-     *  instance.
-     *  @param factory The codec factory.
-     *  @param id  The codec ID.
-     *  @return the instance of the codec, or NULL if codec can not be created.
+    pj_status_t (*enum_info)(pjmedia_codec_factory *factory, 
+			     unsigned *count, 
+			     pjmedia_codec_info codecs[]);
+
+    /** 
+     * Create one instance of the codec with the specified codec info.
+     *
+     * @param factory	The codec factory.
+     * @param info	The codec info.
+     * @param p_codec	Pointer to receive the codec instance.
+     *
+     * @return		PJ_SUCCESS on success.
      */
-    pj_codec* (*alloc_codec)( pj_codec_factory *factory, const pj_codec_id *id);
-
-    /** This function is called by codec manager to return a particular instance
-     *  of codec back to the codec factory.
-     *  @param factory The codec factory.
-     *  @param codec The codec instance to be returned.
+    pj_status_t (*alloc_codec)(pjmedia_codec_factory *factory, 
+			       const pjmedia_codec_info *info,
+			       pjmedia_codec **p_codec);
+
+    /** 
+     * This function is called by codec manager to return a particular 
+     * instance of codec back to the codec factory.
+     *
+     * @param factory	The codec factory.
+     * @param codec	The codec instance to be returned.
+     *
+     * @return		PJ_SUCCESS on success.
      */
-    void (*dealloc_codec)( pj_codec_factory *factory, pj_codec *codec );
+    pj_status_t (*dealloc_codec)(pjmedia_codec_factory *factory, 
+				 pjmedia_codec *codec );
+
+};
 
-} pj_codec_factory_op;
 
 /**
  * Codec factory describes a module that is able to create codec with specific
  * capabilities. These capabilities can be queried by codec manager to create
  * instances of codec.
  */
-struct pj_codec_factory
+struct pjmedia_codec_factory
 {
     /** Entries to put this structure in the codec manager list. */
-    PJ_DECL_LIST_MEMBER(struct pj_codec_factory);
+    PJ_DECL_LIST_MEMBER(struct pjmedia_codec_factory);
 
     /** The factory's private data. */
-    void		*factory_data;
+    void		     *factory_data;
 
     /** Operations to the factory. */
-    pj_codec_factory_op *op;
+    pjmedia_codec_factory_op *op;
 
 };
 
 /**
  * Declare maximum codecs
  */
-#define PJ_CODEC_MGR_MAX_CODECS	    32
+#define PJMEDIA_CODEC_MGR_MAX_CODECS	    32
 
 /**
  * Codec manager maintains codec factory etc.
  */
-typedef struct pj_codec_mgr
+typedef struct pjmedia_codec_mgr
 {
-    pj_codec_factory factory_list;
-    unsigned	     codec_cnt;
-    pj_codec_id	     codecs[PJ_CODEC_MGR_MAX_CODECS];
-} pj_codec_mgr;
+    pjmedia_codec_factory   factory_list;
+    unsigned		    codec_cnt;
+    pjmedia_codec_info	    codecs[PJMEDIA_CODEC_MGR_MAX_CODECS];
+} pjmedia_codec_mgr;
+
+
 
 /**
- * Init codec manager.
+ * Initialize codec manager.
+ *
+ * @param mgr	    Codec manager instance.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
-PJ_DECL(pj_status_t) 
-pj_codec_mgr_init (pj_codec_mgr *mgr);
+PJ_DECL(pj_status_t) pjmedia_codec_mgr_init(pjmedia_codec_mgr *mgr);
+
 
 /** 
- * Register codec to codec manager. 
+ * Register codec factory to codec manager. 
+ *
+ * @param mgr	    The codec manager.
+ * @param factory   The codec factory to be registered.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
 PJ_DECL(pj_status_t) 
-pj_codec_mgr_register_factory (pj_codec_mgr *mgr, pj_codec_factory *factory);
+pjmedia_codec_mgr_register_factory( pjmedia_codec_mgr *mgr,
+				    pjmedia_codec_factory *factory);
 
 /**
- * Unregister codec.
+ * Unregister codec factory from the codec manager.
+ *
+ * @param mgr	    The codec manager.
+ * @param factory   The codec factory to be unregistered.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
-PJ_DECL(void) 
-pj_codec_mgr_unregister_factory (pj_codec_mgr *mgr, pj_codec_factory *factory);
+PJ_DECL(pj_status_t) 
+pjmedia_codec_mgr_unregister_factory( pjmedia_codec_mgr *mgr, 
+				      pjmedia_codec_factory *factory);
 
 /**
- * Enumerate codecs.
+ * Enumerate all supported codec.
+ *
+ * @param mgr	    The codec manager.
+ * @param count	    On input, specifies the number of elements in
+ *		    the array. On output, the value will be set to
+ *		    the number of elements that have been initialized
+ *		    by this function.
+ * @param info	    The codec info array, which contents will be 
+ *		    initialized upon return.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
-PJ_DECL(unsigned)
-pj_codec_mgr_enum_codecs (pj_codec_mgr *mgr, unsigned count, const pj_codec_id *codecs[]);
+PJ_DECL(pj_status_t) pjmedia_codec_mgr_enum_codecs( pjmedia_codec_mgr *mgr, 
+						    unsigned *count, 
+						    pjmedia_codec_info info[]);
 
 /**
- * Open codec.
+ * Request the codec manager to allocate one instance of codec with the
+ * specified codec info. The codec will enumerate all codec factories
+ * until it finds factory that is able to create the specified codec.
+ *
+ * @param mgr	    The codec manager.
+ * @param info	    The information about the codec to be created.
+ * @param p_codec   Pointer to receive the codec instance.
+ *
+ * @return	    PJ_SUCCESS on success.
  */
-PJ_DECL(pj_codec*) 
-pj_codec_mgr_alloc_codec (pj_codec_mgr *mgr, const struct pj_codec_id *id);
+PJ_DECL(pj_status_t) pjmedia_codec_mgr_alloc_codec(pjmedia_codec_mgr *mgr, 
+						   const pjmedia_codec_info *info,
+						   pjmedia_codec **p_codec);
 
 /**
- * Close codec.
+ * Deallocate the specified codec instance. The codec manager will return
+ * the instance of the codec back to its factory.
+ *
+ * @param mgr	    The codec manager.
+ * @param codec	    The codec instance.
+ *
+ * @return	    PJ_SUCESS on success.
  */
-PJ_DECL(void) 
-pj_codec_mgr_dealloc_codec (pj_codec_mgr *mgr, pj_codec *codec);
+PJ_DECL(pj_status_t) pjmedia_codec_mgr_dealloc_codec(pjmedia_codec_mgr *mgr, 
+						     pjmedia_codec *codec);
 
 /**
  * @}
diff --git a/pjmedia/include/pjmedia/endpoint.h b/pjmedia/include/pjmedia/endpoint.h
new file mode 100644
index 00000000..27e8f4bf
--- /dev/null
+++ b/pjmedia/include/pjmedia/endpoint.h
@@ -0,0 +1,131 @@
+/* $Id$ */
+/* 
+ * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+#ifndef __PJMEDIA_MEDIAMGR_H__
+#define __PJMEDIA_MEDIAMGR_H__
+
+
+/**
+ * @file mediamgr.h
+ * @brief Media Manager.
+ */
+/**
+ * @defgroup PJMED_ENDPT Media Endpoint
+ * @ingroup PJMEDIA
+ * @{
+ *
+ * The media endpoint acts as placeholder for endpoint capabilities. Each 
+ * media endpoint will have a codec manager to manage list of codecs installed
+ * in the endpoint and a sound device factory.
+ *
+ * A reference to media endpoint instance is required when application wants
+ * to create a media session (#pj_media_session_create or 
+ * #pj_media_session_create_from_sdp).
+ */
+
+#include <pjmedia/sound.h>
+#include <pjmedia/codec.h>
+
+
+PJ_BEGIN_DECL
+
+
+
+/**
+ * Create an instance of media endpoint.
+ *
+ * @param pf		Pool factory, which will be used by the media endpoint
+ *			throughout its lifetime.
+ * @param p_endpt	Pointer to receive the endpoint instance.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_endpt_create( pj_pool_factory *pf,
+					   pjmedia_endpt **p_endpt);
+
+/**
+ * Destroy media endpoint instance.
+ *
+ * @param endpt		Media endpoint instance.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_endpt_destroy(pjmedia_endpt *endpt);
+
+
+/**
+ * Request the media endpoint to create pool.
+ *
+ * @param endpt		The media endpoint instance.
+ * @param name		Name to be assigned to the pool.
+ * @param initial	Initial pool size, in bytes.
+ * @param increment	Increment size, in bytes.
+ *
+ * @return		Memory pool.
+ */
+PJ_DECL(pj_pool_t*) pjmedia_endpt_create_pool( pjmedia_endpt *endpt,
+					       const char *name,
+					       pj_size_t initial,
+					       pj_size_t increment);
+
+/**
+ * Get the codec manager instance of the media endpoint.
+ *
+ * @param endpt		The media endpoint instance.
+ *
+ * @return		The instance of codec manager belonging to
+ *			this media endpoint.
+ */
+PJ_DECL(pjmedia_codec_mgr*) pjmedia_endpt_get_codec_mgr(pjmedia_endpt *mgr);
+
+
+/**
+ * Create a SDP session description that describes the endpoint
+ * capability.
+ *
+ * @param endpt		The media endpoint.
+ * @param pool		Pool to use to create the SDP descriptor.
+ * @param stream_cnt	Number of elements in the sock_info array. This
+ *			also denotes the maximum number of streams (i.e.
+ *			the "m=" lines) that will be created in the SDP.
+ * @param sock_info	Array of socket transport information. One 
+ *			transport is needed for each media stream, and
+ *			each transport consists of an RTP and RTCP socket
+ *			pair.
+ * @param p_sdp		Pointer to receive SDP session descriptor.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_endpt_create_sdp( pjmedia_endpt *endpt,
+					       pj_pool_t *pool,
+					       unsigned stream_cnt,
+					       const pjmedia_sock_info sock_info[],
+					       pjmedia_sdp_session **p_sdp );
+
+
+
+PJ_END_DECL
+
+
+/**
+ * @}
+ */
+
+
+
+#endif	/* __PJMEDIA_MEDIAMGR_H__ */
diff --git a/pjmedia/include/pjmedia/errno.h b/pjmedia/include/pjmedia/errno.h
index 14da37de..8d1f6e14 100644
--- a/pjmedia/include/pjmedia/errno.h
+++ b/pjmedia/include/pjmedia/errno.h
@@ -259,6 +259,42 @@ PJ_DECL(pj_str_t) pjmedia_strerror( pj_status_t status, char *buffer,
 #define PJMEDIA_SDP_ETIMENOTEQUAL   (PJMEDIA_ERRNO_START+72)    /* 220072 */
 
 
+/************************************************************
+ * CODEC
+ ***********************************************************/
+/**
+ * @hideinitializer
+ * Unsupported codec.
+ */
+#define PJMEDIA_CODEC_EUNSUP	    (PJMEDIA_ERRNO_START+80)    /* 220080 */
+
+
+/************************************************************
+ * MEDIA
+ ***********************************************************/
+/**
+ * @hideinitializer
+ * Invalid remote IP address (in SDP).
+ */
+#define PJMEDIA_EINVALIDIP	    (PJMEDIA_ERRNO_START+100)    /* 220100 */
+/**
+ * @hideinitializer
+ * Asymetric codec is not supported.
+ */
+#define PJMEDIA_EASYMCODEC	    (PJMEDIA_ERRNO_START+101)    /* 220101 */
+/**
+ * @hideinitializer
+ * Invalid payload type.
+ */
+#define PJMEDIA_EINVALIDPT	    (PJMEDIA_ERRNO_START+102)    /* 220102 */
+/**
+ * @hideinitializer
+ * Missing rtpmap.
+ */
+#define PJMEDIA_EMISSINGRTPMAP	    (PJMEDIA_ERRNO_START+103)    /* 220103 */
+
+
+
 PJ_END_DECL
 
 #endif	/* __PJMEDIA_ERRNO_H__ */
diff --git a/pjmedia/include/pjmedia/mediamgr.h b/pjmedia/include/pjmedia/mediamgr.h
deleted file mode 100644
index 148038ec..00000000
--- a/pjmedia/include/pjmedia/mediamgr.h
+++ /dev/null
@@ -1,100 +0,0 @@
-/* $Id$ */
-/* 
- * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
- */
-#ifndef __PJMEDIA_MEDIAMGR_H__
-#define __PJMEDIA_MEDIAMGR_H__
-
-
-/**
- * @file mediamgr.h
- * @brief Media Manager.
- */
-/**
- * @defgroup PJMED_MGR Media Manager
- * @ingroup PJMEDIA
- * @{
- *
- * The media manager acts as placeholder for endpoint capabilities. Each 
- * media manager will have a codec manager to manage list of codecs installed
- * in the endpoint and a sound device factory.
- *
- * A reference to media manager instance is required when application wants
- * to create a media session (#pj_media_session_create or 
- * #pj_media_session_create_from_sdp).
- */
-
-#include <pjmedia/sound.h>
-#include <pjmedia/codec.h>
-
-
-PJ_BEGIN_DECL
-
-
-/** Opague declaration of media manager. */
-typedef struct pj_med_mgr_t pj_med_mgr_t;
-
-/**
- * Create an instance of media manager.
- *
- * @param pf		Pool factory.
- * @param conn_addr	Connection address to be used by this media manager.
- *
- * @return A new instance of media manager, or NULL if failed.
- */
-PJ_DECL(pj_med_mgr_t*) pj_med_mgr_create (pj_pool_factory *pf);
-
-/**
- * Destroy media manager instance.
- *
- * @param mgr		Media manager instance.
- *
- * @return zero on success.
- */
-PJ_DECL(pj_status_t) pj_med_mgr_destroy (pj_med_mgr_t *mgr);
-
-/**
- * Get pool factory of the media manager as specified when the media
- * manager was created.
- *
- * @param mgr		The media manager instance.
- *
- * @return Pool factory instance of the media manager.
- */
-PJ_DECL(pj_pool_factory*) pj_med_mgr_get_pool_factory (pj_med_mgr_t *mgr);
-
-/**
- * Get the codec manager instance.
- *
- * @param mgr		The media manager instance.
- *
- * @return The instance of codec manager.
- */
-PJ_DECL(pj_codec_mgr*) pj_med_mgr_get_codec_mgr (pj_med_mgr_t *mgr);
-
-
-
-PJ_END_DECL
-
-
-/**
- * @}
- */
-
-
-
-#endif	/* __PJMEDIA_MEDIAMGR_H__ */
diff --git a/pjmedia/include/pjmedia/rtp.h b/pjmedia/include/pjmedia/rtp.h
index 54c1e32e..bbb38f53 100644
--- a/pjmedia/include/pjmedia/rtp.h
+++ b/pjmedia/include/pjmedia/rtp.h
@@ -79,14 +79,14 @@ PJ_BEGIN_DECL
  */
 enum pj_rtp_error_t
 {
-    PJ_RTP_ERR_RTP_PACKING,	    /**< Invalid RTP packet. */
-    PJ_RTP_ERR_INVALID_VERSION,	    /**< Invalid RTP version. */
-    PJ_RTP_ERR_INVALID_SSRC,	    /**< Invalid SSRC. */
-    PJ_RTP_ERR_INVALID_PT,	    /**< Invalid payload type. */
-    PJ_RTP_ERR_INVALID_PACKET,	    /**< Invalid packet. */
-    PJ_RTP_ERR_SESSION_RESTARTED,   /**< Session has just been restarted. */
-    PJ_RTP_ERR_SESSION_PROBATION,   /**< Session in probation. */
-    PJ_RTP_ERR_BAD_SEQUENCE,	    /**< Bad RTP sequence number. */
+    PJMEDIA_RTP_ERR_RTP_PACKING,	    /**< Invalid RTP packet. */
+    PJMEDIA_RTP_ERR_INVALID_VERSION,	    /**< Invalid RTP version. */
+    PJMEDIA_RTP_ERR_INVALID_SSRC,	    /**< Invalid SSRC. */
+    PJMEDIA_RTP_ERR_INVALID_PT,	    /**< Invalid payload type. */
+    PJMEDIA_RTP_ERR_INVALID_PACKET,	    /**< Invalid packet. */
+    PJMEDIA_RTP_ERR_SESSION_RESTARTED,   /**< Session has just been restarted. */
+    PJMEDIA_RTP_ERR_SESSION_PROBATION,   /**< Session in probation. */
+    PJMEDIA_RTP_ERR_BAD_SEQUENCE,	    /**< Bad RTP sequence number. */
 };
 
 #pragma pack(1)
diff --git a/pjmedia/include/pjmedia/session.h b/pjmedia/include/pjmedia/session.h
index d9efeb81..f6a9fc11 100644
--- a/pjmedia/include/pjmedia/session.h
+++ b/pjmedia/include/pjmedia/session.h
@@ -25,8 +25,7 @@
  * @brief Media Session.
  */
 
-#include <pj/types.h>
-#include <pjmedia/mediamgr.h>
+#include <pjmedia/endpoint.h>
 #include <pjmedia/stream.h>
 #include <pjmedia/sdp.h>
 
@@ -38,109 +37,140 @@ PJ_BEGIN_DECL
  * @{
  */
 
-/** Opaque declaration of media session. */
-typedef struct pj_media_session_t pj_media_session_t;
-
-/** Media socket info. */
-typedef struct pj_media_sock_info
-{
-    pj_sock_t	    rtp_sock, rtcp_sock;
-    pj_sockaddr_in  rtp_addr_name;
-} pj_media_sock_info;
-
-/** Stream info. */
-typedef struct pj_media_stream_info
-{
-    pj_str_t		type;
-    pj_media_dir_t	dir;
-    pj_str_t		transport;
-    pj_media_sock_info	sock_info;
-    pj_str_t		rem_addr;
-    unsigned short	rem_port;
-    unsigned		fmt_cnt;
-    pj_codec_id		fmt[PJSDP_MAX_FMT];
-
-} pj_media_stream_info;
-
-/** Flag for modifying stream. */
-enum
-{
-    PJ_MEDIA_STREAM_MODIFY_DIR = 1,
-};
 
 /**
- * Create new session offering.
+ * Create new session offering based on the local and remote SDP.
+ * The session initially will be inactive.
+ *
+ * @param endpt		The PJMEDIA endpoint instance.
+ * @param stream_cnt	Maximum number of streams to be created. This
+ *			also denotes the number of elements in the
+ *			socket information.
+ * @param skinfo	Array of socket informations. The argument stream_cnt
+ *			specifies the number of elements in this array. One
+ *			element is needed for each media stream to be
+ *			created in the session.
+ * @param local_sdp	The SDP describing local capability.
+ * @param rem_sdp	The SDP describing remote capability.
+ * @param p_session	Pointer to receive the media session.
+ *
+ * @return		PJ_SUCCESS if media session can be created 
+ *			successfully.
  */
-PJ_DECL(pj_media_session_t*) 
-pj_media_session_create ( pj_med_mgr_t *mgr, const pj_media_sock_info *skinfo );
+PJ_DECL(pj_status_t) pjmedia_session_create( pjmedia_endpt *endpt, 
+					     unsigned stream_cnt,
+					     const pjmedia_sock_info skinfo[],
+					     const pjmedia_sdp_session *local_sdp,
+					     const pjmedia_sdp_session *rem_sdp,
+					     pjmedia_session **p_session );
 
-/**
- * Create new session based on peer's offering.
- */
-PJ_DECL(pj_media_session_t*) 
-pj_media_session_create_from_sdp ( pj_med_mgr_t *mgr, const pjsdp_session_desc *sdp,
-				   const pj_media_sock_info *skinfo);
 
 /**
- * Duplicate session. The new session is inactive.
+ * Activate all streams in media session for the specified direction.
+ *
+ * @param session	The media session.
+ * @param dir		The direction to activate.
+ *
+ * @return		PJ_SUCCESS if success.
  */
-PJ_DECL(pj_media_session_t*)
-pj_media_session_clone (const pj_media_session_t *session);
+PJ_DECL(pj_status_t) pjmedia_session_resume(pjmedia_session *session,
+					    pjmedia_dir dir);
 
-/**
- * Create SDP description from the session.
- */
-PJ_DECL(pjsdp_session_desc*)
-pj_media_session_create_sdp ( const pj_media_session_t *session, pj_pool_t *pool,
-			      pj_bool_t only_first_fmt);
 
 /**
- * Update session with SDP answer from peer. The session must NOT active.
+ * Suspend receipt and transmission of all streams in media session
+ * for the specified direction.
+ *
+ * @param session	The media session.
+ * @param dir		The media direction to suspend.
+ *
+ * @return		PJ_SUCCESS if success.
  */
-PJ_DECL(pj_status_t)
-pj_media_session_update ( pj_media_session_t *session, 
-			  const pjsdp_session_desc *sdp);
+PJ_DECL(pj_status_t) pjmedia_session_pause(pjmedia_session *session,
+					   pjmedia_dir dir);
 
 /**
- * Enumerate media streams in the session.
- * @return the actual number of streams.
+ * Suspend receipt and transmission of individual stream in media session
+ * for the specified direction.
+ *
+ * @param session	The media session.
+ * @param index		The stream index.
+ * @param dir		The media direction to pause.
+ *
+ * @return		PJ_SUCCESS on success.
  */
-PJ_DECL(unsigned)
-pj_media_session_enum_streams (const pj_media_session_t *session, 
-			       unsigned count, const pj_media_stream_info *info[]);
+PJ_DECL(pj_status_t) pjmedia_session_pause_stream( pjmedia_session *session,
+						   unsigned index,
+						   pjmedia_dir dir);
 
 /**
- * Get stream statistics.
+ * Activate individual stream in media session for the specified direction.
+ *
+ * @param session	The media session.
+ * @param index		The stream index.
+ * @param dir		The media direction to activate.
+ *
+ * @return		PJ_SUCCESS on success.
  */
-PJ_DECL(pj_status_t)
-pj_media_session_get_stat (const pj_media_session_t *session, unsigned index,
-			   pj_media_stream_stat *tx_stat,
-			   pj_media_stream_stat *rx_stat);
+PJ_DECL(pj_status_t) pjmedia_session_resume_stream(pjmedia_session *session,
+						   unsigned index,
+						   pjmedia_dir dir);
 
 /**
- * Modify stream, only when stream is inactive.
+ * Enumerate media streams in the session.
+ *
+ * @param session	The media session.
+ * @param count		On input, specifies the number of elements in
+ *			the array. On output, the number will be filled
+ *			with number of streams in the session.
+ * @param strm_info	Array of stream info.
+ *
+ * @return		PJ_SUCCESS on success.
  */
-PJ_DECL(pj_status_t)
-pj_media_session_modify_stream (pj_media_session_t *session, unsigned index,
-				unsigned modify_flag, const pj_media_stream_info *info);
+PJ_DECL(pj_status_t) pjmedia_session_enum_streams(const pjmedia_session *session,
+						  unsigned *count, 
+						  pjmedia_stream_info strm_info[]);
+
 
 /**
- * Activate all streams in media session.
+ * Get session statistics. The stream statistic shows various
+ * indicators such as packet count, packet lost, jitter, delay, etc.
+ *
+ * @param session	The media session.
+ * @param count		On input, specifies the number of elements in
+ *			the array. On output, the number will be filled
+ *			with number of streams in the session.
+ * @param stat		Array of stream statistics.
+ *
+ * @return		PJ_SUCCESS on success.
  */
-PJ_DECL(pj_status_t)
-pj_media_session_activate (pj_media_session_t *session);
+PJ_DECL(pj_status_t) pjmedia_session_get_stat(const pjmedia_session *session,
+					      unsigned *count,
+					      pjmedia_stream_stat stat[]);
 
 /**
- * Activate individual stream in media session.
+ * Get individual stream statistics. The stream statistic shows various
+ * indicators such as packet count, packet lost, jitter, delay, etc.
+ *
+ * @param s		The media session.
+ * @param index		The stream index.
+ * @param stat		Stream statistics.
+ *
+ * @return		PJ_SUCCESS on success.
  */
-PJ_DECL(pj_status_t)
-pj_media_session_activate_stream (pj_media_session_t *session, unsigned index);
+PJ_DECL(pj_status_t) pjmedia_session_get_stream_stat(const pjmedia_session *s,
+						     unsigned index,
+						     pjmedia_stream_stat *stat);
 
 /**
  * Destroy media session.
+ *
+ * @param session	The media session.
+ *
+ * @return		PJ_SUCCESS if success.
  */
-PJ_DECL(pj_status_t)
-pj_media_session_destroy (pj_media_session_t *session);
+PJ_DECL(pj_status_t) pjmedia_session_destroy(pjmedia_session *session);
+
 
 
 /**
diff --git a/pjmedia/include/pjmedia/stream.h b/pjmedia/include/pjmedia/stream.h
index 09f6acf1..83f7e14e 100644
--- a/pjmedia/include/pjmedia/stream.h
+++ b/pjmedia/include/pjmedia/stream.h
@@ -27,7 +27,7 @@
 
 #include <pjmedia/sound.h>
 #include <pjmedia/codec.h>
-#include <pjmedia/mediamgr.h>
+#include <pjmedia/endpoint.h>
 #include <pj/sock.h>
 
 PJ_BEGIN_DECL
@@ -39,55 +39,124 @@ PJ_BEGIN_DECL
  * @{
  */
 
-typedef struct pj_media_stream_t pj_media_stream_t;
+/**
+ * Opaque declaration for media channel.
+ * Media channel is unidirectional flow of media from sender to
+ * receiver.
+ */
+typedef struct pjmedia_channel pjmedia_channel;
 
-/** Parameter for creating channel. */
-typedef struct pj_media_stream_create_param
+/** 
+ * This structure describes media stream information. Each media stream
+ * corresponds to one "m=" line in SDP session descriptor, and it has
+ * its own RTP/RTCP socket pair.
+ */
+struct pjmedia_stream_info
 {
-    /** Codec ID, must NOT be NULL. */
-    pj_codec_id		 *codec_id;
+    pjmedia_type	type;	    /**< Media type (audio, video)	    */
+    pjmedia_dir		dir;	    /**< Media direction.		    */
+    pjmedia_sock_info	sock_info;  /**< Media transport (RTP/RTCP sockets) */
+    pj_sockaddr_in	rem_addr;   /**< Remote RTP address		    */
+    pjmedia_codec_info	fmt;	    /**< Codec format info.		    */
+    pj_uint32_t		ssrc;	    /**< RTP SSRC.			    */
+    int			jb_min;	    /**< Jitter buffer min delay.	    */
+    int			jb_max;	    /**< Jitter buffer max delay.	    */
+    int			jb_maxcnt;  /**< Jitter buffer max delay.	    */
+};
 
-    /** Media manager, must NOT be NULL. */
-    pj_med_mgr_t	 *mediamgr;
 
-    /** Direction: IN_OUT, or IN only, or OUT only. */
-    pj_media_dir_t	  dir;
+/**
+ * Individual channel statistic.
+ */
+struct pjmedia_channel_stat
+{
+    pj_uint32_t pkt;	    /**< Total number of packets.		    */
+    pj_uint32_t bytes;	    /**< Total number of bytes, including RTP hdr.  */
+    pj_uint32_t lost;	    /**< Total number of packet lost		    */
+};
 
-    /** RTP socket. */
-    pj_sock_t		 rtp_sock;
+/**
+ * Stream statistic.
+ */
+struct pjmedia_stream_stat
+{
+    pjmedia_channel_stat    enc;    /**< Encoder statistics.		    */
+    pjmedia_channel_stat    dec;    /**< Decoder statistics.		    */
+};
 
-    /** RTCP socket. */
-    pj_sock_t		 rtcp_sock;
 
-    /** Address of remote */
-    pj_sockaddr_in	 *remote_addr;
+/**
+ * Create a media stream based on the specified stream parameter.
+ * All channels in the stream initially will be inactive.
+ *
+ * @param endpt		Media endpoint.
+ * @param pool		Pool to allocate memory for the stream. A large
+ *			number of memory may be needed because jitter
+ *			buffer needs to preallocate some storage.
+ * @param info		Stream information.
+ * @param p_stream	Pointer to receive the media stream.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_create(pjmedia_endpt *endpt,
+					   pj_pool_t *pool,
+					   const pjmedia_stream_info *info,
+					   pjmedia_stream **p_stream);
 
-    /** RTP SSRC */
-    pj_uint32_t		  ssrc;
+/**
+ * Destroy the media stream.
+ *
+ * @param stream	The media stream.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_destroy(pjmedia_stream *stream);
 
-    /** Jitter buffer parameters. */
-    int			  jb_min, jb_max, jb_maxcnt;
+/**
+ * Start the media stream. This will start the appropriate channels
+ * in the media stream, depending on the media direction that was set
+ * when the stream was created.
+ *
+ * @param stream	The media stream.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_start(pjmedia_stream *stream);
 
-} pj_media_stream_create_param;
 
-typedef struct pj_media_stream_stat
-{
-    pj_uint32_t pkt_tx, pkt_rx;	/* packets transmitted/received */
-    pj_uint32_t oct_tx, oct_rx;	/* octets transmitted/received */
-    pj_uint32_t jitter;		/* receive jitter in ms */
-    pj_uint32_t pkt_lost;	/* total packet lost count */
-} pj_media_stream_stat;
-
-PJ_DECL(pj_status_t) pj_media_stream_create (pj_pool_t *pool,
-					     pj_media_stream_t **enc_stream,
-					     pj_media_stream_t **dec_stream,
-					     pj_media_stream_create_param *param);
-PJ_DECL(pj_status_t) pj_media_stream_start (pj_media_stream_t *stream);
-PJ_DECL(pj_status_t) pj_media_stream_get_stat (const pj_media_stream_t *stream,
-					       pj_media_stream_stat *stat);
-PJ_DECL(pj_status_t) pj_media_stream_pause (pj_media_stream_t *stream);
-PJ_DECL(pj_status_t) pj_media_stream_resume (pj_media_stream_t *stream);
-PJ_DECL(pj_status_t) pj_media_stream_destroy (pj_media_stream_t *stream);
+/**
+ * Get the stream statistics.
+ *
+ * @param stream	The media stream.
+ * @param stat		Media stream statistics.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_get_stat( const pjmedia_stream *stream,
+					      pjmedia_stream_stat *stat);
+
+/**
+ * Pause the individual channel in the stream.
+ *
+ * @param channel	The media channel.
+ * @param dir		Which direction to pause.
+ *
+ * @return		PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_pause( pjmedia_stream *stream,
+					   pjmedia_dir dir);
+
+/**
+ * Resume the individual channel in the stream.
+ *
+ * @param channel	The media channel.
+ * @param dir		Which direction to resume.
+ *
+ * @return		PJ_SUCCESS on success;
+ */
+PJ_DECL(pj_status_t) pjmedia_stream_resume(pjmedia_stream *stream,
+					   pjmedia_dir dir);
+
 
 /**
  * @}
diff --git a/pjmedia/include/pjmedia/types.h b/pjmedia/include/pjmedia/types.h
index 217a001b..6dd44bf7 100644
--- a/pjmedia/include/pjmedia/types.h
+++ b/pjmedia/include/pjmedia/types.h
@@ -20,8 +20,150 @@
 #define __PJMEDIA_TYPES_H__
 
 #include <pj/types.h>
+#include <pj/sock.h>
 
 
+/** 
+ * Top most media type. 
+ */
+enum pjmedia_type
+{
+    /** No type. */
+    PJMEDIA_TYPE_NONE = 0,
+
+    /** The media is audio */
+    PJMEDIA_TYPE_AUDIO = 1,
+
+    /** The media is video. */
+    PJMEDIA_TYPE_VIDEO = 2,
+
+    /** Unknown media type, in this case the name will be specified in 
+     *  encoding_name.
+     */
+    PJMEDIA_TYPE_UNKNOWN = 3,
+
+};
+
+
+/** 
+ * Media direction. 
+ */
+enum pjmedia_dir
+{
+    /** None */
+    PJMEDIA_DIR_NONE = 0,
+
+    /** Encoding (outgoing to network) stream */
+    PJMEDIA_DIR_ENCODING = 1,
+
+    /** Decoding (incoming from network) stream. */
+    PJMEDIA_DIR_DECODING = 2,
+
+    /** Incoming and outgoing stream. */
+    PJMEDIA_DIR_ENCODING_DECODING = 3,
+
+};
+
+
+/**
+ * Top level media type.
+ */
+typedef enum pjmedia_type pjmedia_type;
+
+/**
+ * Media direction.
+ */
+typedef enum pjmedia_dir pjmedia_dir;
+
+/**
+ * Codec info.
+ */
+typedef struct pjmedia_codec_info pjmedia_codec_info;
+
+/**
+ * Codec initialization parameter.
+ */
+typedef struct pjmedia_codec_param pjmedia_codec_param;
+
+/** 
+ * Types of media frames. 
+ */
+typedef enum pjmedia_frame_type pjmedia_frame_type;
+
+/** 
+ * This structure describes a media frame. 
+ */
+typedef struct pjmedia_frame pjmedia_frame;
+
+/**
+ * Codec instance.
+ */
+typedef struct pjmedia_codec pjmedia_codec;
+
+/**
+ * Codec factory.
+ */
+typedef struct pjmedia_codec_factory pjmedia_codec_factory;
+
+/**
+ * Codec operation.
+ */
+typedef struct pjmedia_codec_op pjmedia_codec_op;
+
+/**
+ * Codec factory operation.
+ */
+typedef struct pjmedia_codec_factory_op pjmedia_codec_factory_op;
+
+/**
+ * Codec manager.
+ */
+typedef struct pjmedia_codec_mgr pjmedia_codec_mgr;
+
+/** 
+ * Opague declaration of media endpoint. 
+ */
+typedef struct pjmedia_endpt pjmedia_endpt;
+
+
+/** 
+ * Media socket info. 
+ */
+typedef struct pjmedia_sock_info
+{
+
+    pj_sock_t	    rtp_sock;
+    pj_sock_t	    rtcp_sock;
+    pj_sockaddr_in  rtp_addr_name;
+
+} pjmedia_sock_info;
+
+
+/**
+ * Typedef for media stream information.
+ */
+typedef struct pjmedia_stream_info pjmedia_stream_info;
+
+/**
+ * Typedef for media stream statistic.
+ */
+typedef struct pjmedia_stream_stat pjmedia_stream_stat;
+
+/**
+ * Typedef for media stream.
+ */
+typedef struct pjmedia_stream pjmedia_stream;
+
+/**
+ * Individual channel statistic.
+ */
+typedef struct pjmedia_channel_stat pjmedia_channel_stat;
+
+/** 
+ * Opaque declaration of media session. 
+ */
+typedef struct pjmedia_session pjmedia_session;
+
 /**
  * Forward declaration for SDP attribute (sdp.h)
  */