diff options
Diffstat (limited to 'gst/replaygain/gstrglimiter.c')
| -rw-r--r-- | gst/replaygain/gstrglimiter.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/gst/replaygain/gstrglimiter.c b/gst/replaygain/gstrglimiter.c new file mode 100644 index 00000000..609db3d7 --- /dev/null +++ b/gst/replaygain/gstrglimiter.c @@ -0,0 +1,197 @@ +/* GStreamer ReplayGain limiter + * + * Copyright (C) 2007 Rene Stadler <mail@renestadler.de> + * + * gstrglimiter.c: Element to apply signal compression to raw audio data + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * as published by the Free Software Foundation; either version 2.1 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +/** + * SECTION:element-rglimiter + * @see_also: <link linkend="GstRgVolume">rgvolume</link> + * + * <refsect2> + * <para> + * This element applies signal compression/limiting to raw audio data. It + * performs strict hard limiting with soft-knee characteristics, using a + * threshold of -6 dB. This type of filter is mentioned in the proposed <ulink + * url="http://replaygain.org">ReplayGain standard</ulink>. + * </para> + * <title>Example launch line</title> + * <para>Playback of a file:</para> + * <programlisting> + * gst-launch filesrc location="Filename.ext" ! decodebin ! audioconvert \ + * ! rgvolume pre-amp=6.0 headroom=10.0 ! rglimiter \ + * ! audioconvert ! audioresample ! alsasink + * </programlisting> + * </refsect2> + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <gst/gst.h> +#include <math.h> + +#include "gstrglimiter.h" + +GST_DEBUG_CATEGORY_STATIC (gst_rg_limiter_debug); +#define GST_CAT_DEFAULT gst_rg_limiter_debug + +enum +{ + PROP_0, + PROP_ENABLED, +}; + +static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink", + GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw-float, " + "width = (int) 32, channels = (int) [1, MAX], " + "rate = (int) [1, MAX], endianness = (int) BYTE_ORDER")); + +static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src", + GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw-float, " + "width = (int) 32, channels = (int) [1, MAX], " + "rate = (int) [1, MAX], endianness = (int) BYTE_ORDER")); + +GST_BOILERPLATE (GstRgLimiter, gst_rg_limiter, GstBaseTransform, + GST_TYPE_BASE_TRANSFORM); + +static void gst_rg_limiter_class_init (GstRgLimiterClass * klass); +static void gst_rg_limiter_init (GstRgLimiter * filter, + GstRgLimiterClass * gclass); + +static void gst_rg_limiter_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec); +static void gst_rg_limiter_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec); + +static GstFlowReturn gst_rg_limiter_transform_ip (GstBaseTransform * base, + GstBuffer * buf); + +static const GstElementDetails element_details = { + "ReplayGain limiter", + "Filter/Effect/Audio", + "Apply signal compression to raw audio data", + "Ren\xc3\xa9 Stadler <mail@renestadler.de>" +}; + +static void +gst_rg_limiter_base_init (gpointer g_class) +{ + GstElementClass *element_class = g_class; + + gst_element_class_add_pad_template (element_class, + gst_static_pad_template_get (&src_factory)); + gst_element_class_add_pad_template (element_class, + gst_static_pad_template_get (&sink_factory)); + gst_element_class_set_details (element_class, &element_details); + + GST_DEBUG_CATEGORY_INIT (gst_rg_limiter_debug, "rglimiter", 0, + "ReplayGain limiter element"); +} + +static void +gst_rg_limiter_class_init (GstRgLimiterClass * klass) +{ + GObjectClass *gobject_class; + GstBaseTransformClass *trans_class; + + gobject_class = (GObjectClass *) klass; + + gobject_class->set_property = gst_rg_limiter_set_property; + gobject_class->get_property = gst_rg_limiter_get_property; + + g_object_class_install_property (gobject_class, PROP_ENABLED, + g_param_spec_boolean ("enabled", "Enabled", "Enable processing", TRUE, + G_PARAM_READWRITE)); + + trans_class = GST_BASE_TRANSFORM_CLASS (klass); + trans_class->transform_ip = GST_DEBUG_FUNCPTR (gst_rg_limiter_transform_ip); + trans_class->passthrough_on_same_caps = FALSE; +} + +static void +gst_rg_limiter_init (GstRgLimiter * filter, GstRgLimiterClass * gclass) +{ + filter->enabled = TRUE; + gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (filter), FALSE); +} + +static void +gst_rg_limiter_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec) +{ + GstRgLimiter *filter = GST_RG_LIMITER (object); + + switch (prop_id) { + case PROP_ENABLED: + filter->enabled = g_value_get_boolean (value); + gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (filter), + !filter->enabled); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +gst_rg_limiter_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec) +{ + GstRgLimiter *filter = GST_RG_LIMITER (object); + + switch (prop_id) { + case PROP_ENABLED: + g_value_set_boolean (value, filter->enabled); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +#define LIMIT 1.0 +#define THRES 0.5 /* ca. -6 dB */ +#define COMPL 0.5 /* LIMIT - THRESH */ + +static GstFlowReturn +gst_rg_limiter_transform_ip (GstBaseTransform * base, GstBuffer * buf) +{ + GstRgLimiter *filter = GST_RG_LIMITER (base); + gfloat *input; + guint count; + guint i; + + if (!filter->enabled) + return GST_FLOW_OK; + + input = (gfloat *) GST_BUFFER_DATA (buf); + count = GST_BUFFER_SIZE (buf) / sizeof (gfloat); + + for (i = count; i--;) { + if (*input > THRES) + *input = tanhf ((*input - THRES) / COMPL) * COMPL + THRES; + else if (*input < -THRES) + *input = tanhf ((*input + THRES) / COMPL) * COMPL - THRES; + input++; + } + + return GST_FLOW_OK; +} |