audiofxbasefirfilter: property for not draining on changes

Adds a new property for not draining the buffers when the
kernel changes

1 files changed, 59 insertions, 7 deletions

diff --git a/gst/audiofx/audiofxbasefirfilter.c b/gst/audiofx/audiofxbasefirfilter.c
index 37fa639cf..61aa8c62e 100644
--- a/gst/audiofx/audiofxbasefirfilter.c
+++ b/gst/audiofx/audiofxbasefirfilter.c
@@ -582,9 +582,6 @@ gst_audio_fx_base_fir_filter_class_init (GstAudioFXBaseFIRFilterClass * klass)
    *
    * Whether the filter should be drained when its coeficients change
    *
-   * Note: Currently this only works if the kernel size is not changed!
-   * Support for drainless kernel size changes will be added in the future.
-   *
    * Since: 0.10.18
    */
   g_object_class_install_property (gobject_class, PROP_DRAIN_ON_CHANGES,
@@ -1030,10 +1027,59 @@ gst_audio_fx_base_fir_filter_event (GstBaseTransform * base, GstEvent * event)
 }
 
 void
+gst_audio_fx_base_fir_filter_update_buffer_size (GstAudioFXBaseFIRFilter * self,
+    guint channels, guint old_kernel_length, guint old_real_buffer_length)
+{
+  gdouble *old_buffer = self->buffer;
+  guint size = 0;
+  gint c;
+
+  if (!self->fft) {
+    size = channels * self->kernel_length;
+    self->buffer_length = size;
+    self->buffer = g_new0 (gdouble, self->buffer_length);
+    if (old_buffer) {
+      memcpy (self->buffer, old_buffer,
+          sizeof (gdouble) * MIN (self->buffer_fill, size));
+      g_free (old_buffer);
+    }
+  } else {
+    guint real_buffer_length = self->block_length + self->kernel_length - 1;
+    size = channels * real_buffer_length;
+
+    self->buffer = g_new0 (gdouble, size);
+    self->buffer_length = self->block_length;
+
+    for (c = 0; c < channels; c++) {
+      /* copy the kernel */
+      memcpy (self->buffer + c * real_buffer_length,
+          old_buffer + c * (old_real_buffer_length),
+          sizeof (gdouble) * MIN (old_kernel_length - 1,
+              self->kernel_length - 1));
+      /* copy the channel residue */
+      memcpy (self->buffer + c * real_buffer_length + self->kernel_length - 1,
+          old_buffer + c * old_real_buffer_length + old_kernel_length - 1,
+          sizeof (gdouble) *
+          MIN ((old_real_buffer_length - (old_kernel_length - 1)),
+              real_buffer_length - (self->kernel_length - 1)));
+    }
+    self->buffer_length = self->block_length;
+    if (self->buffer_fill < self->kernel_length - 1) {
+      self->buffer_fill = self->kernel_length - 1;
+    }
+  }
+
+  /* FIXME check what would happen if the new buffer is too short
+   * and if that is possible at all */
+}
+
+void
 gst_audio_fx_base_fir_filter_set_kernel (GstAudioFXBaseFIRFilter * self,
     gdouble * kernel, guint kernel_length, guint64 latency)
 {
   gboolean latency_changed;
+  guint old_kernel_length;
+  guint old_buffer_length;
 
   g_return_if_fail (kernel != NULL);
   g_return_if_fail (self != NULL);
@@ -1046,9 +1092,7 @@ gst_audio_fx_base_fir_filter_set_kernel (GstAudioFXBaseFIRFilter * self,
       || (!self->low_latency && self->kernel_length >= FFT_THRESHOLD
           && kernel_length < FFT_THRESHOLD));
 
-  /* FIXME: If the latency changes, the buffer size changes too and we
-   * have to drain in any case until this is fixed in the future */
-  if (self->buffer && (!self->drain_on_changes || latency_changed)) {
+  if (self->buffer && !self->drain_on_changes) {
     gst_audio_fx_base_fir_filter_push_residue (self);
     self->start_ts = GST_CLOCK_TIME_NONE;
     self->start_off = GST_BUFFER_OFFSET_NONE;
@@ -1058,13 +1102,16 @@ gst_audio_fx_base_fir_filter_set_kernel (GstAudioFXBaseFIRFilter * self,
   }
 
   g_free (self->kernel);
-  if (!self->drain_on_changes || latency_changed) {
+
+  if (!self->drain_on_changes) {
     g_free (self->buffer);
     self->buffer = NULL;
     self->buffer_fill = 0;
     self->buffer_length = 0;
   }
 
+  old_buffer_length = self->buffer_length;
+  old_kernel_length = self->kernel_length;
   self->kernel = kernel;
   self->kernel_length = kernel_length;
 
@@ -1072,6 +1119,11 @@ gst_audio_fx_base_fir_filter_set_kernel (GstAudioFXBaseFIRFilter * self,
   gst_audio_fx_base_fir_filter_select_process_function (self,
       GST_AUDIO_FILTER_CAST (self)->format.width,
       GST_AUDIO_FILTER_CAST (self)->format.channels);
+  if (!self->drain_on_changes) {
+    gst_audio_fx_base_fir_filter_update_buffer_size (self,
+        GST_AUDIO_FILTER_CAST (self)->format.channels, old_kernel_length,
+        old_buffer_length + old_kernel_length - 1);
+  }
 
   if (latency_changed) {
     self->latency = latency;