/* GStreamer * * Copyright (C) 2007,2009 Sebastian Dröge * * gstinterpolationcontrolsource.c: Control source that provides several * interpolation methods * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ /** * SECTION:gstinterpolationcontrolsource * @title: GstInterpolationControlSource * @short_description: interpolation control source * * #GstInterpolationControlSource is a #GstControlSource, that interpolates values between user-given * control points. It supports several interpolation modes and property types. * * To use #GstInterpolationControlSource get a new instance by calling * gst_interpolation_control_source_new(), bind it to a #GParamSpec and set some * control points by calling gst_timed_value_control_source_set(). * * All functions are MT-safe. * */ #include #include #include "gstinterpolationcontrolsource.h" #include "gst/glib-compat-private.h" #include "gst/math-compat.h" #define GST_CAT_DEFAULT controller_debug GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT); /* helper functions */ static inline gboolean _get_nearest_control_points (GstTimedValueControlSource * self, GstClockTime ts, GstControlPoint ** cp1, GstControlPoint ** cp2) { GSequenceIter *iter; iter = gst_timed_value_control_source_find_control_point_iter (self, ts); if (iter) { *cp1 = g_sequence_get (iter); iter = g_sequence_iter_next (iter); if (iter && !g_sequence_iter_is_end (iter)) { *cp2 = g_sequence_get (iter); } else { *cp2 = NULL; } return TRUE; } return FALSE; } static inline void _get_nearest_control_points2 (GstTimedValueControlSource * self, GstClockTime ts, GstControlPoint ** cp1, GstControlPoint ** cp2, GstClockTime * next_ts) { GSequenceIter *iter1, *iter2 = NULL; *cp1 = *cp2 = NULL; iter1 = gst_timed_value_control_source_find_control_point_iter (self, ts); if (iter1) { *cp1 = g_sequence_get (iter1); iter2 = g_sequence_iter_next (iter1); } else { if (G_LIKELY (self->values)) { /* all values in the control point list come after the given timestamp */ iter2 = g_sequence_get_begin_iter (self->values); /* why this? if !cp1 we don't interpolate anyway * if we can eliminate this, we can also use _get_nearest_control_points() * here, is this just to set next_ts? */ } else { /* no values */ iter2 = NULL; } } if (iter2 && !g_sequence_iter_is_end (iter2)) { *cp2 = g_sequence_get (iter2); *next_ts = (*cp2)->timestamp; } else { *next_ts = GST_CLOCK_TIME_NONE; } } /* steps-like (no-)interpolation, default */ /* just returns the value for the most recent key-frame */ static inline gdouble _interpolate_none (GstTimedValueControlSource * self, GstControlPoint * cp) { return cp->value; } static gboolean interpolate_none_get (GstTimedValueControlSource * self, GstClockTime timestamp, gdouble * value) { gboolean ret = FALSE; GSequenceIter *iter; GstControlPoint *cp; g_mutex_lock (&self->lock); iter = gst_timed_value_control_source_find_control_point_iter (self, timestamp); if (iter) { cp = g_sequence_get (iter); *value = _interpolate_none (self, cp); ret = TRUE; } g_mutex_unlock (&self->lock); return ret; } static gboolean interpolate_none_get_value_array (GstTimedValueControlSource * self, GstClockTime timestamp, GstClockTime interval, guint n_values, gdouble * values) { gboolean ret = FALSE; guint i; GstClockTime ts = timestamp; GstClockTime next_ts = 0; GstControlPoint *cp1 = NULL, *cp2 = NULL; g_mutex_lock (&self->lock); for (i = 0; i < n_values; i++) { GST_LOG ("values[%3d] : ts=%" GST_TIME_FORMAT ", next_ts=%" GST_TIME_FORMAT, i, GST_TIME_ARGS (ts), GST_TIME_ARGS (next_ts)); if (ts >= next_ts) { _get_nearest_control_points2 (self, ts, &cp1, &cp2, &next_ts); } if (cp1) { *values = _interpolate_none (self, cp1); ret = TRUE; GST_LOG ("values[%3d]=%lf", i, *values); } else { *values = NAN; GST_LOG ("values[%3d]=-", i); } ts += interval; values++; } g_mutex_unlock (&self->lock); return ret; } /* linear interpolation */ /* smoothes in between values */ static inline gdouble _interpolate_linear (GstClockTime timestamp1, gdouble value1, GstClockTime timestamp2, gdouble value2, GstClockTime timestamp) { if (GST_CLOCK_TIME_IS_VALID (timestamp2)) { gdouble slope; slope = (value2 - value1) / gst_guint64_to_gdouble (timestamp2 - timestamp1); return value1 + (gst_guint64_to_gdouble (timestamp - timestamp1) * slope); } else { return value1; } } static gboolean interpolate_linear_get (GstTimedValueControlSource * self, GstClockTime timestamp, gdouble * value) { gboolean ret = FALSE; GstControlPoint *cp1, *cp2; g_mutex_lock (&self->lock); if (_get_nearest_control_points (self, timestamp, &cp1, &cp2)) { *value = _interpolate_linear (cp1->timestamp, cp1->value, (cp2 ? cp2->timestamp : GST_CLOCK_TIME_NONE), (cp2 ? cp2->value : 0.0), timestamp); ret = TRUE; } g_mutex_unlock (&self->lock); return ret; } static gboolean interpolate_linear_get_value_array (GstTimedValueControlSource * self, GstClockTime timestamp, GstClockTime interval, guint n_values, gdouble * values) { gboolean ret = FALSE; guint i; GstClockTime ts = timestamp; GstClockTime next_ts = 0; GstControlPoint *cp1 = NULL, *cp2 = NULL; g_mutex_lock (&self->lock); for (i = 0; i < n_values; i++) { GST_LOG ("values[%3d] : ts=%" GST_TIME_FORMAT ", next_ts=%" GST_TIME_FORMAT, i, GST_TIME_ARGS (ts), GST_TIME_ARGS (next_ts)); if (ts >= next_ts) { _get_nearest_control_points2 (self, ts, &cp1, &cp2, &next_ts); } if (cp1) { *values = _interpolate_linear (cp1->timestamp, cp1->value, (cp2 ? cp2->timestamp : GST_CLOCK_TIME_NONE), (cp2 ? cp2->value : 0.0), ts); ret = TRUE; GST_LOG ("values[%3d]=%lf", i, *values); } else { *values = NAN; GST_LOG ("values[%3d]=-", i); } ts += interval; values++; } g_mutex_unlock (&self->lock); return ret; } /* cubic interpolation */ /* The following functions implement a natural cubic spline interpolator. * For details look at http://en.wikipedia.org/wiki/Spline_interpolation * * Instead of using a real matrix with n^2 elements for the linear system * of equations we use three arrays o, p, q to hold the tridiagonal matrix * as following to save memory: * * p[0] q[0] 0 0 0 * o[1] p[1] q[1] 0 0 * 0 o[2] p[2] q[2] . * . . . . . */ static void _interpolate_cubic_update_cache (GstTimedValueControlSource * self) { gint i, n = self->nvalues; gdouble *o = g_new0 (gdouble, n); gdouble *p = g_new0 (gdouble, n); gdouble *q = g_new0 (gdouble, n); gdouble *h = g_new0 (gdouble, n); gdouble *b = g_new0 (gdouble, n); gdouble *z = g_new0 (gdouble, n); GSequenceIter *iter; GstControlPoint *cp; GstClockTime x, x_next; gdouble y_prev, y, y_next; /* Fill linear system of equations */ iter = g_sequence_get_begin_iter (self->values); cp = g_sequence_get (iter); x = cp->timestamp; y = cp->value; p[0] = 1.0; iter = g_sequence_iter_next (iter); cp = g_sequence_get (iter); x_next = cp->timestamp; y_next = cp->value; h[0] = gst_guint64_to_gdouble (x_next - x); for (i = 1; i < n - 1; i++) { /* Shuffle x and y values */ y_prev = y; x = x_next; y = y_next; iter = g_sequence_iter_next (iter); cp = g_sequence_get (iter); x_next = cp->timestamp; y_next = cp->value; h[i] = gst_guint64_to_gdouble (x_next - x); o[i] = h[i - 1]; p[i] = 2.0 * (h[i - 1] + h[i]); q[i] = h[i]; b[i] = (y_next - y) / h[i] - (y - y_prev) / h[i - 1]; } p[n - 1] = 1.0; /* Use Gauss elimination to set everything below the diagonal to zero */ for (i = 1; i < n - 1; i++) { gdouble a = o[i] / p[i - 1]; p[i] -= a * q[i - 1]; b[i] -= a * b[i - 1]; } /* Solve everything else from bottom to top */ for (i = n - 2; i > 0; i--) z[i] = (b[i] - q[i] * z[i + 1]) / p[i]; /* Save cache next in the GstControlPoint */ iter = g_sequence_get_begin_iter (self->values); for (i = 0; i < n; i++) { cp = g_sequence_get (iter); cp->cache.cubic.h = h[i]; cp->cache.cubic.z = z[i]; iter = g_sequence_iter_next (iter); } /* Free our temporary arrays */ g_free (o); g_free (p); g_free (q); g_free (h); g_free (b); g_free (z); } static inline gdouble _interpolate_cubic (GstTimedValueControlSource * self, GstControlPoint * cp1, gdouble value1, GstControlPoint * cp2, gdouble value2, GstClockTime timestamp) { if (!self->valid_cache) { _interpolate_cubic_update_cache (self); self->valid_cache = TRUE; } if (cp2) { gdouble diff1, diff2; gdouble out; diff1 = gst_guint64_to_gdouble (timestamp - cp1->timestamp); diff2 = gst_guint64_to_gdouble (cp2->timestamp - timestamp); out = (cp2->cache.cubic.z * diff1 * diff1 * diff1 + cp1->cache.cubic.z * diff2 * diff2 * diff2) / cp1->cache.cubic.h; out += (value2 / cp1->cache.cubic.h - cp1->cache.cubic.h * cp2->cache.cubic.z) * diff1; out += (value1 / cp1->cache.cubic.h - cp1->cache.cubic.h * cp1->cache.cubic.z) * diff2; return out; } else { return value1; } } static gboolean interpolate_cubic_get (GstTimedValueControlSource * self, GstClockTime timestamp, gdouble * value) { gboolean ret = FALSE; GstControlPoint *cp1, *cp2 = NULL; if (self->nvalues <= 2) return interpolate_linear_get (self, timestamp, value); g_mutex_lock (&self->lock); if (_get_nearest_control_points (self, timestamp, &cp1, &cp2)) { *value = _interpolate_cubic (self, cp1, cp1->value, cp2, (cp2 ? cp2->value : 0.0), timestamp); ret = TRUE; } g_mutex_unlock (&self->lock); return ret; } static gboolean interpolate_cubic_get_value_array (GstTimedValueControlSource * self, GstClockTime timestamp, GstClockTime interval, guint n_values, gdouble * values) { gboolean ret = FALSE; guint i; GstClockTime ts = timestamp; GstClockTime next_ts = 0; GstControlPoint *cp1 = NULL, *cp2 = NULL; if (self->nvalues <= 2) return interpolate_linear_get_value_array (self, timestamp, interval, n_values, values); g_mutex_lock (&self->lock); for (i = 0; i < n_values; i++) { GST_LOG ("values[%3d] : ts=%" GST_TIME_FORMAT ", next_ts=%" GST_TIME_FORMAT, i, GST_TIME_ARGS (ts), GST_TIME_ARGS (next_ts)); if (ts >= next_ts) { _get_nearest_control_points2 (self, ts, &cp1, &cp2, &next_ts); } if (cp1) { *values = _interpolate_cubic (self, cp1, cp1->value, cp2, (cp2 ? cp2->value : 0.0), ts); ret = TRUE; GST_LOG ("values[%3d]=%lf", i, *values); } else { *values = NAN; GST_LOG ("values[%3d]=-", i); } ts += interval; values++; } g_mutex_unlock (&self->lock); return ret; } /* monotonic cubic interpolation */ /* the following functions implement monotonic cubic spline interpolation. * For details: http://en.wikipedia.org/wiki/Monotone_cubic_interpolation * * In contrast to the previous cubic mode, the values won't overshoot. */ static void _interpolate_cubic_monotonic_update_cache (GstTimedValueControlSource * self) { gint i, n = self->nvalues; gdouble *dxs = g_new0 (gdouble, n); gdouble *dys = g_new0 (gdouble, n); gdouble *ms = g_new0 (gdouble, n); gdouble *c1s = g_new0 (gdouble, n); GSequenceIter *iter; GstControlPoint *cp; GstClockTime x, x_next, dx; gdouble y, y_next, dy; /* Get consecutive differences and slopes */ iter = g_sequence_get_begin_iter (self->values); cp = g_sequence_get (iter); x_next = cp->timestamp; y_next = cp->value; for (i = 0; i < n - 1; i++) { x = x_next; y = y_next; iter = g_sequence_iter_next (iter); cp = g_sequence_get (iter); x_next = cp->timestamp; y_next = cp->value; dx = gst_guint64_to_gdouble (x_next - x); dy = y_next - y; dxs[i] = dx; dys[i] = dy; ms[i] = dy / dx; } /* Get degree-1 coefficients */ c1s[0] = ms[0]; for (i = 1; i < n; i++) { gdouble m = ms[i - 1]; gdouble m_next = ms[i]; if (m * m_next <= 0) { c1s[i] = 0.0; } else { gdouble dx_next, dx_sum; dx = dxs[i], dx_next = dxs[i + 1], dx_sum = dx + dx_next; c1s[i] = 3.0 * dx_sum / ((dx_sum + dx_next) / m + (dx_sum + dx) / m_next); } } c1s[n - 1] = ms[n - 1]; /* Get degree-2 and degree-3 coefficients */ iter = g_sequence_get_begin_iter (self->values); for (i = 0; i < n - 1; i++) { gdouble c1, m, inv_dx, common; cp = g_sequence_get (iter); c1 = c1s[i]; m = ms[i]; inv_dx = 1.0 / dxs[i]; common = c1 + c1s[i + 1] - m - m; cp->cache.cubic_monotonic.c1s = c1; cp->cache.cubic_monotonic.c2s = (m - c1 - common) * inv_dx; cp->cache.cubic_monotonic.c3s = common * inv_dx * inv_dx; iter = g_sequence_iter_next (iter); } /* Free our temporary arrays */ g_free (dxs); g_free (dys); g_free (ms); g_free (c1s); } static inline gdouble _interpolate_cubic_monotonic (GstTimedValueControlSource * self, GstControlPoint * cp1, gdouble value1, GstControlPoint * cp2, gdouble value2, GstClockTime timestamp) { if (!self->valid_cache) { _interpolate_cubic_monotonic_update_cache (self); self->valid_cache = TRUE; } if (cp2) { gdouble diff = gst_guint64_to_gdouble (timestamp - cp1->timestamp); gdouble diff2 = diff * diff; gdouble out; out = value1 + cp1->cache.cubic_monotonic.c1s * diff; out += cp1->cache.cubic_monotonic.c2s * diff2; out += cp1->cache.cubic_monotonic.c3s * diff * diff2; return out; } else { return value1; } } static gboolean interpolate_cubic_monotonic_get (GstTimedValueControlSource * self, GstClockTime timestamp, gdouble * value) { gboolean ret = FALSE; GstControlPoint *cp1, *cp2 = NULL; if (self->nvalues <= 2) return interpolate_linear_get (self, timestamp, value); g_mutex_lock (&self->lock); if (_get_nearest_control_points (self, timestamp, &cp1, &cp2)) { *value = _interpolate_cubic_monotonic (self, cp1, cp1->value, cp2, (cp2 ? cp2->value : 0.0), timestamp); ret = TRUE; } g_mutex_unlock (&self->lock); return ret; } static gboolean interpolate_cubic_monotonic_get_value_array (GstTimedValueControlSource * self, GstClockTime timestamp, GstClockTime interval, guint n_values, gdouble * values) { gboolean ret = FALSE; guint i; GstClockTime ts = timestamp; GstClockTime next_ts = 0; GstControlPoint *cp1 = NULL, *cp2 = NULL; if (self->nvalues <= 2) return interpolate_linear_get_value_array (self, timestamp, interval, n_values, values); g_mutex_lock (&self->lock); for (i = 0; i < n_values; i++) { GST_LOG ("values[%3d] : ts=%" GST_TIME_FORMAT ", next_ts=%" GST_TIME_FORMAT, i, GST_TIME_ARGS (ts), GST_TIME_ARGS (next_ts)); if (ts >= next_ts) { _get_nearest_control_points2 (self, ts, &cp1, &cp2, &next_ts); } if (cp1) { *values = _interpolate_cubic_monotonic (self, cp1, cp1->value, cp2, (cp2 ? cp2->value : 0.0), ts); ret = TRUE; GST_LOG ("values[%3d]=%lf", i, *values); } else { *values = NAN; GST_LOG ("values[%3d]=-", i); } ts += interval; values++; } g_mutex_unlock (&self->lock); return ret; } static struct { GstControlSourceGetValue get; GstControlSourceGetValueArray get_value_array; } interpolation_modes[] = { { (GstControlSourceGetValue) interpolate_none_get, (GstControlSourceGetValueArray) interpolate_none_get_value_array}, { (GstControlSourceGetValue) interpolate_linear_get, (GstControlSourceGetValueArray) interpolate_linear_get_value_array}, { (GstControlSourceGetValue) interpolate_cubic_get, (GstControlSourceGetValueArray) interpolate_cubic_get_value_array}, { (GstControlSourceGetValue) interpolate_cubic_monotonic_get, (GstControlSourceGetValueArray) interpolate_cubic_monotonic_get_value_array}}; static const guint num_interpolation_modes = G_N_ELEMENTS (interpolation_modes); enum { PROP_MODE = 1 }; #define _do_init \ GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "interpolation control source", 0, \ "timeline value interpolating control source") G_DEFINE_TYPE_WITH_CODE (GstInterpolationControlSource, gst_interpolation_control_source, GST_TYPE_TIMED_VALUE_CONTROL_SOURCE, _do_init); struct _GstInterpolationControlSourcePrivate { GstInterpolationMode interpolation_mode; }; /** * gst_interpolation_control_source_new: * * This returns a new, unbound #GstInterpolationControlSource. * * Returns: (transfer full): a new, unbound #GstInterpolationControlSource. */ GstControlSource * gst_interpolation_control_source_new (void) { GstControlSource *csource = g_object_new (GST_TYPE_INTERPOLATION_CONTROL_SOURCE, NULL); /* Clear floating flag */ gst_object_ref_sink (csource); return csource; } static gboolean gst_interpolation_control_source_set_interpolation_mode (GstInterpolationControlSource * self, GstInterpolationMode mode) { GstControlSource *csource = GST_CONTROL_SOURCE (self); if (mode >= num_interpolation_modes || (int) mode < 0) { GST_WARNING ("interpolation mode %d invalid or not implemented yet", mode); return FALSE; } GST_TIMED_VALUE_CONTROL_SOURCE_LOCK (self); csource->get_value = interpolation_modes[mode].get; csource->get_value_array = interpolation_modes[mode].get_value_array; gst_timed_value_control_invalidate_cache ((GstTimedValueControlSource *) csource); self->priv->interpolation_mode = mode; GST_TIMED_VALUE_CONTROL_SOURCE_UNLOCK (self); return TRUE; } static void gst_interpolation_control_source_init (GstInterpolationControlSource * self) { self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, GST_TYPE_INTERPOLATION_CONTROL_SOURCE, GstInterpolationControlSourcePrivate); gst_interpolation_control_source_set_interpolation_mode (self, GST_INTERPOLATION_MODE_NONE); } static void gst_interpolation_control_source_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstInterpolationControlSource *self = GST_INTERPOLATION_CONTROL_SOURCE (object); switch (prop_id) { case PROP_MODE: gst_interpolation_control_source_set_interpolation_mode (self, (GstInterpolationMode) g_value_get_enum (value)); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_interpolation_control_source_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstInterpolationControlSource *self = GST_INTERPOLATION_CONTROL_SOURCE (object); switch (prop_id) { case PROP_MODE: g_value_set_enum (value, self->priv->interpolation_mode); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_interpolation_control_source_class_init (GstInterpolationControlSourceClass * klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); //GstControlSourceClass *csource_class = GST_CONTROL_SOURCE_CLASS (klass); g_type_class_add_private (klass, sizeof (GstInterpolationControlSourcePrivate)); gobject_class->set_property = gst_interpolation_control_source_set_property; gobject_class->get_property = gst_interpolation_control_source_get_property; g_object_class_install_property (gobject_class, PROP_MODE, g_param_spec_enum ("mode", "Mode", "Interpolation mode", GST_TYPE_INTERPOLATION_MODE, GST_INTERPOLATION_MODE_NONE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); }