gstreamer/gst/audiovisualizers/gstwavescope.c
2011-11-10 23:20:32 +02:00

134 lines
3.9 KiB
C

/* GStreamer
* Copyright (C) <2011> Stefan Kost <ensonic@users.sf.net>
*
* gstwavescope.c: simple oscilloscope
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-wavescope
* @see_also: goom
*
* Wavescope is a simple audio visualisation element. It renders the waveforms
* like on an oscilloscope.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch audiotestsrc ! audioconvert ! wavescope ! ximagesink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstwavescope.h"
static GstStaticPadTemplate gst_wave_scope_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
#if G_BYTE_ORDER == G_BIG_ENDIAN
GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("xRGB"))
#else
GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("BGRx"))
#endif
);
static GstStaticPadTemplate gst_wave_scope_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw, "
"format = (string) " GST_AUDIO_NE (S16) ", "
"rate = (int) [ 8000, 96000 ], " "channels = (int) 2")
);
GST_DEBUG_CATEGORY_STATIC (wave_scope_debug);
#define GST_CAT_DEFAULT wave_scope_debug
static gboolean gst_wave_scope_render (GstBaseAudioVisualizer * scope,
GstBuffer * audio, GstBuffer * video);
G_DEFINE_TYPE (GstWaveScope, gst_wave_scope, GST_TYPE_BASE_AUDIO_VISUALIZER);
static void
gst_wave_scope_class_init (GstWaveScopeClass * g_class)
{
GstElementClass *element_class = (GstElementClass *) g_class;
GstBaseAudioVisualizerClass *scope_class =
(GstBaseAudioVisualizerClass *) g_class;
gst_element_class_set_details_simple (element_class, "Waveform oscilloscope",
"Visualization",
"Simple waveform oscilloscope", "Stefan Kost <ensonic@users.sf.net>");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_wave_scope_src_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_wave_scope_sink_template));
scope_class->render = GST_DEBUG_FUNCPTR (gst_wave_scope_render);
}
static void
gst_wave_scope_init (GstWaveScope * scope)
{
/* do nothing */
}
static gboolean
gst_wave_scope_render (GstBaseAudioVisualizer * scope, GstBuffer * audio,
GstBuffer * video)
{
gsize asize;
guint32 *vdata =
(guint32 *) gst_buffer_map (video, NULL, NULL, GST_MAP_WRITE);
gint16 *adata = (gint16 *) gst_buffer_map (audio, &asize, NULL, GST_MAP_READ);
guint i, c, s, x, y, off, oy;
guint num_samples;
gfloat dx, dy;
guint w = scope->width;
/* draw dots */
num_samples = asize / (scope->channels * sizeof (gint16));
dx = (gfloat) scope->width / (gfloat) num_samples;
dy = scope->height / 65536.0;
oy = scope->height / 2;
s = 0;
for (i = 0; i < num_samples; i++) {
x = (guint) ((gfloat) i * dx);
for (c = 0; c < scope->channels; c++) {
y = (guint) (oy + (gfloat) adata[s++] * dy);
off = (y * w) + x;
vdata[off] = 0x00FFFFFF;
}
}
gst_buffer_unmap (video, vdata, -1);
gst_buffer_unmap (audio, adata, -1);
return TRUE;
}
gboolean
gst_wave_scope_plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (wave_scope_debug, "wavescope", 0, "wavescope");
return gst_element_register (plugin, "wavescope", GST_RANK_NONE,
GST_TYPE_WAVE_SCOPE);
}