Changeset 2850 for pjproject/trunk/pjmedia/include/pjmedia/config.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/config.h (modified) (1 diff)

pjproject/trunk/pjmedia/include/pjmedia/config.h

@@ -150 +150 @@
 #ifndef PJMEDIA_WSOLA_IMP
 #   define PJMEDIA_WSOLA_IMP                PJMEDIA_WSOLA_IMP_WSOLA
+#endif
+
+
+/**
+ * Specify the default maximum duration of synthetic audio that is generated
+ * by WSOLA. This value should be long enough to cover burst of packet losses. 
+ * but not too long, because as the duration increases the quality would 
+ * degrade considerably.
+ *
+ * Note that this limit is only applied when fading is enabled in the WSOLA
+ * session.
+ *
+ * Default: 80
+ */
+#ifndef PJMEDIA_WSOLA_MAX_EXPAND_MSEC
+#   define PJMEDIA_WSOLA_MAX_EXPAND_MSEC    80
+#endif
+
+
+/**
+ * Specify WSOLA template length, in milliseconds. The longer the template,
+ * the smoother signal to be generated at the expense of more computation
+ * needed, since the algorithm will have to compare more samples to find
+ * the most similar pitch.
+ *
+ * Default: 5
+ */
+#ifndef PJMEDIA_WSOLA_TEMPLATE_LENGTH_MSEC
+#   define PJMEDIA_WSOLA_TEMPLATE_LENGTH_MSEC   5
+#endif
+
+
+/**
+ * Specify WSOLA algorithm delay, in milliseconds. The algorithm delay is
+ * used to merge synthetic samples with real samples in the transition
+ * between real to synthetic and vice versa. The longer the delay, the 
+ * smoother signal to be generated, at the expense of longer latency and
+ * a slighty more computation.
+ *
+ * Default: 5
+ */
+#ifndef PJMEDIA_WSOLA_DELAY_MSEC
+#   define PJMEDIA_WSOLA_DELAY_MSEC         5
+#endif
+
+
+/**
+ * Set this to non-zero to disable fade-out/in effect in the PLC when it
+ * instructs WSOLA to generate synthetic frames. The use of fading may
+ * or may not improve the quality of audio, depending on the nature of
+ * packet loss and the type of audio input (e.g. speech vs music).
+ * Disabling fading also implicitly remove the maximum limit of synthetic
+ * audio samples generated by WSOLA (see PJMEDIA_WSOLA_MAX_EXPAND_MSEC).
+ *
+ * Default: 0
+ */
+#ifndef PJMEDIA_WSOLA_PLC_NO_FADING
+#   define PJMEDIA_WSOLA_PLC_NO_FADING      0
 #endif