From 9416d364631de23ff88dd679c8cdcb95f40d9c8a Mon Sep 17 00:00:00 2001 From: Stian Selnes Date: Mon, 1 Aug 2016 20:27:03 +0200 Subject: netsim: Add "delay-distribution" property plus normal distribution By using the property "delay-distribution" the user can control how the delay applied to delayed packets is distributed. This is either the uniform distribution (as before) or the normal distribution. "min-delay" and "max-delay" control both distributions. For the normal distribution it defines the bounds of the 95% confidence interval. --- gst/netsim/Makefile.am | 2 +- gst/netsim/gstnetsim.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++--- gst/netsim/gstnetsim.h | 15 +++++++ gst/netsim/meson.build | 2 +- 4 files changed, 116 insertions(+), 7 deletions(-) (limited to 'gst/netsim') diff --git a/gst/netsim/Makefile.am b/gst/netsim/Makefile.am index 22c2002f0..102843a3c 100644 --- a/gst/netsim/Makefile.am +++ b/gst/netsim/Makefile.am @@ -2,7 +2,7 @@ plugin_LTLIBRARIES = libgstnetsim.la libgstnetsim_la_SOURCES = gstnetsim.c libgstnetsim_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) -libgstnetsim_la_LIBADD = $(GST_PLUGINS_BASE_LIBS) $(GST_BASE_LIBS) $(GST_LIBS) +libgstnetsim_la_LIBADD = $(GST_PLUGINS_BASE_LIBS) $(GST_BASE_LIBS) $(GST_LIBS) $(LIBM) libgstnetsim_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS) noinst_HEADERS = gstnetsim.h diff --git a/gst/netsim/gstnetsim.c b/gst/netsim/gstnetsim.c index c95e1d73a..44aa1d20a 100644 --- a/gst/netsim/gstnetsim.c +++ b/gst/netsim/gstnetsim.c @@ -27,17 +27,37 @@ #include "config.h" #endif -#include #include "gstnetsim.h" +#include +#include +#include GST_DEBUG_CATEGORY (netsim_debug); #define GST_CAT_DEFAULT (netsim_debug) +static GType +distribution_get_type (void) +{ + static volatile gsize g_define_type_id__volatile = 0; + if (g_once_init_enter (&g_define_type_id__volatile)) { + static const GEnumValue values[] = { + {DISTRIBUTION_UNIFORM, "uniform", "uniform"}, + {DISTRIBUTION_NORMAL, "normal", "normal"}, + {0, NULL, NULL} + }; + GType g_define_type_id = + g_enum_register_static ("GstNetSimDistribution", values); + g_once_init_leave (&g_define_type_id__volatile, g_define_type_id); + } + return g_define_type_id__volatile; +} + enum { PROP_0, PROP_MIN_DELAY, PROP_MAX_DELAY, + PROP_DELAY_DISTRIBUTION, PROP_DELAY_PROBABILITY, PROP_DROP_PROBABILITY, PROP_DUPLICATE_PROBABILITY, @@ -49,6 +69,7 @@ enum /* these numbers are nothing but wild guesses and dont reflect any reality */ #define DEFAULT_MIN_DELAY 200 #define DEFAULT_MAX_DELAY 400 +#define DEFAULT_DELAY_DISTRIBUTION DISTRIBUTION_UNIFORM #define DEFAULT_DELAY_PROBABILITY 0.0 #define DEFAULT_DROP_PROBABILITY 0.0 #define DEFAULT_DUPLICATE_PROBABILITY 0.0 @@ -199,6 +220,41 @@ push_buffer_ctx_push (PushBufferCtx * ctx) return FALSE; } +static gint +get_random_value_uniform (GRand * rand_seed, gint32 min_value, gint32 max_value) +{ + return g_rand_int_range (rand_seed, min_value, max_value); +} + +/* Generate a value from a normal distributation with 95% confidense interval + * between LOW and HIGH, using the Box-Muller transform. */ +static gint +get_random_value_normal (GRand * rand_seed, gint32 low, gint32 high, + NormalDistributionState * state) +{ + gdouble u1, u2, t1, t2; + gdouble mu = (high + low) / 2.0; + gdouble sigma = (high - low) / (2 * 1.96); /* 95% confidence interval */ + + state->generate = !state->generate; + + if (!state->generate) + return round (state->z1 * sigma + mu); + + do { + u1 = g_rand_double (rand_seed); + u2 = g_rand_double (rand_seed); + } while (u1 <= DBL_EPSILON); + + t1 = sqrt (-2.0 * log (u1)); + t2 = 2.0 * G_PI * u2; + state->z0 = t1 * cos (t2); + state->z1 = t1 * sin (t2); + + return round (state->z0 * sigma + mu); +} + + static GstFlowReturn gst_net_sim_delay_buffer (GstNetSim * netsim, GstBuffer * buf) { @@ -207,10 +263,29 @@ gst_net_sim_delay_buffer (GstNetSim * netsim, GstBuffer * buf) g_mutex_lock (&netsim->loop_mutex); if (netsim->main_loop != NULL && netsim->delay_probability > 0 && g_rand_double (netsim->rand_seed) < netsim->delay_probability) { - PushBufferCtx *ctx = push_buffer_ctx_new (netsim->srcpad, buf); - gint delay = g_rand_int_range (netsim->rand_seed, - netsim->min_delay, netsim->max_delay); - GSource *source = g_timeout_source_new (delay); + gint delay; + PushBufferCtx *ctx; + GSource *source; + + switch (netsim->delay_distribution) { + case DISTRIBUTION_UNIFORM: + delay = get_random_value_uniform (netsim->rand_seed, netsim->min_delay, + netsim->max_delay); + break; + case DISTRIBUTION_NORMAL: + delay = get_random_value_normal (netsim->rand_seed, netsim->min_delay, + netsim->max_delay, &netsim->delay_state); + break; + default: + g_assert_not_reached (); + break; + } + + if (delay < 0) + delay = 0; + + ctx = push_buffer_ctx_new (netsim->srcpad, buf); + source = g_timeout_source_new (delay); GST_DEBUG_OBJECT (netsim, "Delaying packet by %d", delay); g_source_set_callback (source, (GSourceFunc) push_buffer_ctx_push, @@ -361,6 +436,9 @@ gst_net_sim_set_property (GObject * object, case PROP_MAX_DELAY: netsim->max_delay = g_value_get_int (value); break; + case PROP_DELAY_DISTRIBUTION: + netsim->delay_distribution = g_value_get_enum (value); + break; case PROP_DELAY_PROBABILITY: netsim->delay_probability = g_value_get_float (value); break; @@ -400,6 +478,9 @@ gst_net_sim_get_property (GObject * object, case PROP_MAX_DELAY: g_value_set_int (value, netsim->max_delay); break; + case PROP_DELAY_DISTRIBUTION: + g_value_set_enum (value, netsim->delay_distribution); + break; case PROP_DELAY_PROBABILITY: g_value_set_float (value, netsim->delay_probability); break; @@ -510,6 +591,19 @@ gst_net_sim_class_init (GstNetSimClass * klass) G_MININT, G_MAXINT, DEFAULT_MAX_DELAY, G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS)); + /** + * GstNetSim:delay-distribution: + * + * Distribution for the amount of delay. + * + * Since: 1.14 + */ + g_object_class_install_property (gobject_class, PROP_DELAY_DISTRIBUTION, + g_param_spec_enum ("delay-distribution", "Delay Distribution", + "Distribution for the amount of delay", + distribution_get_type (), DEFAULT_DELAY_DISTRIBUTION, + G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS)); + g_object_class_install_property (gobject_class, PROP_DELAY_PROBABILITY, g_param_spec_float ("delay-probability", "Delay Probability", "The Probability a buffer is delayed", diff --git a/gst/netsim/gstnetsim.h b/gst/netsim/gstnetsim.h index c066774dc..8e4d75032 100644 --- a/gst/netsim/gstnetsim.h +++ b/gst/netsim/gstnetsim.h @@ -46,6 +46,19 @@ G_BEGIN_DECLS typedef struct _GstNetSim GstNetSim; typedef struct _GstNetSimClass GstNetSimClass; +typedef enum +{ + DISTRIBUTION_UNIFORM, + DISTRIBUTION_NORMAL +} GstNetSimDistribution; + +typedef struct +{ + gboolean generate; + gdouble z0; + gdouble z1; +} NormalDistributionState; + struct _GstNetSim { GstElement parent; @@ -60,10 +73,12 @@ struct _GstNetSim GRand *rand_seed; gsize bucket_size; GstClockTime prev_time; + NormalDistributionState delay_state; /* properties */ gint min_delay; gint max_delay; + GstNetSimDistribution delay_distribution; gfloat delay_probability; gfloat drop_probability; gfloat duplicate_probability; diff --git a/gst/netsim/meson.build b/gst/netsim/meson.build index d2cc1d322..2cd65db75 100644 --- a/gst/netsim/meson.build +++ b/gst/netsim/meson.build @@ -6,7 +6,7 @@ gstnetsim = library('gstnetsim', netsim_sources, c_args : gst_plugins_bad_args, include_directories : [configinc], - dependencies : [gstbase_dep], + dependencies : [gstbase_dep, libm], install : true, install_dir : plugins_install_dir, ) -- cgit v1.2.1