Changeset 2850 for pjproject/trunk/pjmedia/include/pjmedia/wsola.h

Timestamp:

Aug 1, 2009 9:20:59 AM (15 years ago)

Author:

bennylp

Message:

Initial commit for ticket #929: Improve packet lost concealment (PLC) when handling burst of lost packets

WSOLA improvements:

• Introduce fade-out and fade-in effect
• Limit the number of continuous synthetic samples (only take effect when fading is used)
• Export many settings as macros:
  • PJMEDIA_WSOLA_DELAY_MSEC (was HANNING_PTIME)
  • PJMEDIA_WSOLA_TEMPLATE_LENGTH_MSEC (was TEMPLATE_PTIME)
  • PJMEDIA_WSOLA_MAX_EXPAND_MSEC

PLC:

• added compile time macro PJMEDIA_WSOLA_PLC_NO_FADING to disable fading (default enabled)

Stream:

• fixed bug when stream is not PLC-ing subsequent packet loss (only the first)
• also add maximum PLC limit just as precaution if PLC doesn't limit number of synthetic frames
• unrelated: fixed warning about unused send_keep_alive() function

Delaybuf:

• modified to NOT use fading in WSOLA since we don't expect it to generate many continuous synthetic frames

File:

• pjproject/trunk/pjmedia/include/pjmedia/wsola.h (modified) (2 diffs)

pjproject/trunk/pjmedia/include/pjmedia/wsola.h

@@ -70 +70 @@
      * non-contiguous buffer.
      */
-    PJMEDIA_WSOLA_NO_DISCARD = 4
+    PJMEDIA_WSOLA_NO_DISCARD = 4,
+
+    /**
+     * Disable fade-in and fade-out feature in the transition between
+     * actual and synthetic frames in WSOLA. With fade feature enabled, 
+     * WSOLA will only generate a limited number of synthetic frames 
+     * (configurable with #pjmedia_wsola_set_max_expand()), fading out 
+     * the volume on every more samples it generates, and when it reaches
+     * the limit it will only generate silence.
+     */
+    PJMEDIA_WSOLA_NO_FADING = 8
 };
 
@@ -94 +104 @@
                                           unsigned options,
                                           pjmedia_wsola **p_wsola);
+
+
+/**
+ * Specify maximum number of continuous synthetic frames that can be
+ * generated by WSOLA, in milliseconds. This option will only take
+ * effect if fading is not disabled via the option when the WSOLA
+ * session was created. Default value is PJMEDIA_WSOLA_MAX_EXPAND_MSEC
+ * (see also the documentation of PJMEDIA_WSOLA_MAX_EXPAND_MSEC for
+ * more information).
+ *
+ * @param wsola     The WSOLA session
+ * @param msec      The duration.
+ *
+ * @return          PJ_SUCCESS normally.
+ */
+PJ_DECL(pj_status_t) pjmedia_wsola_set_max_expand(pjmedia_wsola *wsola,
+                                                  unsigned msec);