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Diffstat (limited to 'pjmedia/src/pjmedia/jbuf.h')
| -rw-r--r-- | pjmedia/src/pjmedia/jbuf.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/pjmedia/src/pjmedia/jbuf.h b/pjmedia/src/pjmedia/jbuf.h new file mode 100644 index 00000000..5bd4a5e9 --- /dev/null +++ b/pjmedia/src/pjmedia/jbuf.h @@ -0,0 +1,126 @@ +/* $Header: /pjproject-0.3/pjmedia/src/pjmedia/jbuf.h 7 10/14/05 12:23a Bennylp $ */
+
+#ifndef __PJMEDIA_JBUF_H__
+#define __PJMEDIA_JBUF_H__
+
+
+/**
+ * @file jbuf.h
+ * @brief Adaptive jitter buffer implementation.
+ */
+/**
+ * @defgroup PJMED_JBUF Adaptive jitter buffer
+ * @ingroup PJMEDIA
+ * @{
+ */
+
+#include <pj/types.h>
+
+
+PJ_BEGIN_DECL
+
+
+/**
+ * Opaque declaration of internal frame type used by jitter buffer.
+ */
+struct pj_jbframe;
+
+
+/**
+ * Miscelaneous operation result/status.
+ */
+typedef enum jb_op_status
+{
+ PJ_JB_STATUS_TOO_OLD = -2, /** The packet is too old. */
+ PJ_JB_STATUS_TOO_SOON = -3, /** The packet is too soon. */
+ PJ_JB_STATUS_FRAME_NULL = -4, /** No packet can be retrieved */
+ PJ_JB_STATUS_FRAME_MISSING = -5, /** The specified packet is missing/lost */
+} jb_op_status;
+
+
+/*
+ * Frame list, container abstraction for ordered list with fixed maximum
+ * size. It is used internally by the jitter buffer.
+ */
+typedef struct pj_jbframelist
+{
+ unsigned head, count, maxcount;
+ struct pj_jbframe *frames;
+} pj_jbframelist;
+
+
+/**
+ * Jitter buffer implementation.
+ */
+typedef struct pj_jitter_buffer
+{
+ pj_jbframelist lst; /** The frame list. */
+ int level; /** Current, real-time jitter level. */
+ int max_level; /** Maximum level for the period. */
+ unsigned prefetch; /** Prefetch count currently used. */
+ unsigned get_cnt; /** Number of get operation during prefetch state. */
+ unsigned min; /** Minimum jitter size, in packets. */
+ unsigned max; /** Maximum jitter size, in packets. */
+ pj_uint32_t lastseq; /** Last sequence number put to jitter buffer. */
+ unsigned upd_count; /** Internal counter to manage update interval. */
+ int state; /** Jitter buffer state (1==operational) */
+ int last_op; /** Last jitter buffer operation. */
+} pj_jitter_buffer;
+
+
+/**
+ * Initialize jitter buffer with the specified parameters.
+ * This function will allocate internal frame buffer from the specified pool.
+ * @param jb The jitter buffer to be initialized.
+ * @param pool Pool where memory will be allocated for the frame buffer.
+ * @param min The minimum value of jitter buffer, in packets.
+ * @param max The maximum value of jitter buffer, in packets.
+ * @param maxcount The maximum number of delay, in packets, which must be
+ * greater than max.
+ * @return PJ_SUCCESS on success.
+ */
+PJ_DECL(pj_status_t) pj_jb_init(pj_jitter_buffer *jb, pj_pool_t *pool,
+ unsigned min, unsigned max, unsigned maxcount);
+
+/**
+ * Reset jitter buffer according to the parameters specified when the jitter
+ * buffer was initialized. Any packets currently in the buffer will be
+ * discarded.
+ */
+PJ_DECL(void) pj_jb_reset(pj_jitter_buffer *jb);
+
+/**
+ * Put a pointer to the buffer with the specified sequence number. The pointer
+ * normally points to a buffer held by application, and this pointer will be
+ * returned later on when pj_jb_get() is called. The jitter buffer will not try
+ * to interpret the content of this pointer.
+ * @return:
+ * - PJ_SUCCESS on success.
+ * - PJ_JB_STATUS_TOO_OLD when the packet is too old.
+ * - PJ_JB_STATUS_TOO_SOON when the packet is too soon.
+ */
+PJ_DECL(pj_status_t) pj_jb_put( pj_jitter_buffer *jb, pj_uint32_t extseq, void *buf );
+
+/**
+ * Get the earliest data from the jitter buffer. ONLY when the operation succeeds,
+ * the function returns both sequence number and a pointer in the parameters.
+ * This returned data corresponds to sequence number and pointer that were
+ * given to jitter buffer in the previous pj_jb_put operation.
+ * @return
+ * - PJ_SUCCESS on success
+ * - PJ_JB_STATUS_FRAME_NULL when there is no frames to be returned.
+ * - PJ_JB_STATUS_FRAME_MISSING if the jitter buffer detects that the packet
+ * is lost. Application may run packet concealment algorithm when it
+ * receives this status.
+ */
+PJ_DECL(pj_status_t) pj_jb_get( pj_jitter_buffer *jb, pj_uint32_t *extseq, void **buf );
+
+
+
+PJ_END_DECL
+
+/**
+ * @}
+ */
+
+#endif /* __PJMEDIA_JBUF_H__ */
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