1 /* GStreamer
2 * Copyright (C) <2011> Stefan Kost <ensonic@users.sf.net>
3 *
4 * gstspectrascope.c: frequency spectrum scope
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20
21 */
22 /**
23 * SECTION:element-spectrascope
24 * @title: spectrascope
25 * @see_also: goom
26 *
27 * Spectrascope is a simple spectrum visualisation element. It renders the
28 * frequency spectrum as a series of bars.
29 *
30 * ## Example launch line
31 * |[
32 * gst-launch-1.0 audiotestsrc ! audioconvert ! spectrascope ! ximagesink
33 * ]|
34 *
35 */
36 #ifdef HAVE_CONFIG_H
37 #include "config.h"
38 #endif
39 #include <stdlib.h>
40
41 #include "gstspectrascope.h"
42
43 #if G_BYTE_ORDER == G_BIG_ENDIAN
44 #define RGB_ORDER "xRGB"
45 #else
46 #define RGB_ORDER "BGRx"
47 #endif
48
49 static GstStaticPadTemplate gst_spectra_scope_src_template =
50 GST_STATIC_PAD_TEMPLATE ("src",
51 GST_PAD_SRC,
52 GST_PAD_ALWAYS,
53 GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE (RGB_ORDER))
54 );
55
56 static GstStaticPadTemplate gst_spectra_scope_sink_template =
57 GST_STATIC_PAD_TEMPLATE ("sink",
58 GST_PAD_SINK,
59 GST_PAD_ALWAYS,
60 GST_STATIC_CAPS ("audio/x-raw, "
61 "format = (string) " GST_AUDIO_NE (S16) ", "
62 "layout = (string) interleaved, "
63 "rate = (int) [ 8000, 96000 ], "
64 "channels = (int) 2, " "channel-mask = (bitmask) 0x3")
65 );
66
67
68 GST_DEBUG_CATEGORY_STATIC (spectra_scope_debug);
69 #define GST_CAT_DEFAULT spectra_scope_debug
70
71 static void gst_spectra_scope_finalize (GObject * object);
72
73 static gboolean gst_spectra_scope_setup (GstAudioVisualizer * scope);
74 static gboolean gst_spectra_scope_render (GstAudioVisualizer * scope,
75 GstBuffer * audio, GstVideoFrame * video);
76
77
78 G_DEFINE_TYPE (GstSpectraScope, gst_spectra_scope, GST_TYPE_AUDIO_VISUALIZER);
79
80 static void
gst_spectra_scope_class_init(GstSpectraScopeClass * g_class)81 gst_spectra_scope_class_init (GstSpectraScopeClass * g_class)
82 {
83 GObjectClass *gobject_class = (GObjectClass *) g_class;
84 GstElementClass *element_class = (GstElementClass *) g_class;
85 GstAudioVisualizerClass *scope_class = (GstAudioVisualizerClass *) g_class;
86
87 gobject_class->finalize = gst_spectra_scope_finalize;
88
89 gst_element_class_set_static_metadata (element_class,
90 "Frequency spectrum scope", "Visualization",
91 "Simple frequency spectrum scope", "Stefan Kost <ensonic@users.sf.net>");
92
93 gst_element_class_add_static_pad_template (element_class,
94 &gst_spectra_scope_src_template);
95 gst_element_class_add_static_pad_template (element_class,
96 &gst_spectra_scope_sink_template);
97
98 scope_class->setup = GST_DEBUG_FUNCPTR (gst_spectra_scope_setup);
99 scope_class->render = GST_DEBUG_FUNCPTR (gst_spectra_scope_render);
100 }
101
102 static void
gst_spectra_scope_init(GstSpectraScope * scope)103 gst_spectra_scope_init (GstSpectraScope * scope)
104 {
105 /* do nothing */
106 }
107
108 static void
gst_spectra_scope_finalize(GObject * object)109 gst_spectra_scope_finalize (GObject * object)
110 {
111 GstSpectraScope *scope = GST_SPECTRA_SCOPE (object);
112
113 if (scope->fft_ctx) {
114 gst_fft_s16_free (scope->fft_ctx);
115 scope->fft_ctx = NULL;
116 }
117 if (scope->freq_data) {
118 g_free (scope->freq_data);
119 scope->freq_data = NULL;
120 }
121
122 G_OBJECT_CLASS (gst_spectra_scope_parent_class)->finalize (object);
123 }
124
125 static gboolean
gst_spectra_scope_setup(GstAudioVisualizer * bscope)126 gst_spectra_scope_setup (GstAudioVisualizer * bscope)
127 {
128 GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
129 guint num_freq = GST_VIDEO_INFO_WIDTH (&bscope->vinfo) + 1;
130
131 if (scope->fft_ctx)
132 gst_fft_s16_free (scope->fft_ctx);
133 g_free (scope->freq_data);
134
135 /* we'd need this amount of samples per render() call */
136 bscope->req_spf = num_freq * 2 - 2;
137 scope->fft_ctx = gst_fft_s16_new (bscope->req_spf, FALSE);
138 scope->freq_data = g_new (GstFFTS16Complex, num_freq);
139
140 return TRUE;
141 }
142
143 static inline void
add_pixel(guint32 * _p,guint32 _c)144 add_pixel (guint32 * _p, guint32 _c)
145 {
146 guint8 *p = (guint8 *) _p;
147 guint8 *c = (guint8 *) & _c;
148
149 if (p[0] < 255 - c[0])
150 p[0] += c[0];
151 else
152 p[0] = 255;
153 if (p[1] < 255 - c[1])
154 p[1] += c[1];
155 else
156 p[1] = 255;
157 if (p[2] < 255 - c[2])
158 p[2] += c[2];
159 else
160 p[2] = 255;
161 if (p[3] < 255 - c[3])
162 p[3] += c[3];
163 else
164 p[3] = 255;
165 }
166
167 static gboolean
gst_spectra_scope_render(GstAudioVisualizer * bscope,GstBuffer * audio,GstVideoFrame * video)168 gst_spectra_scope_render (GstAudioVisualizer * bscope, GstBuffer * audio,
169 GstVideoFrame * video)
170 {
171 GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
172 gint16 *mono_adata;
173 GstFFTS16Complex *fdata = scope->freq_data;
174 guint x, y, off, l;
175 guint w = GST_VIDEO_INFO_WIDTH (&bscope->vinfo);
176 guint h = GST_VIDEO_INFO_HEIGHT (&bscope->vinfo) - 1;
177 gfloat fr, fi;
178 GstMapInfo amap;
179 guint32 *vdata;
180 gint channels;
181
182 gst_buffer_map (audio, &amap, GST_MAP_READ);
183 vdata = (guint32 *) GST_VIDEO_FRAME_PLANE_DATA (video, 0);
184
185 channels = GST_AUDIO_INFO_CHANNELS (&bscope->ainfo);
186
187 mono_adata = (gint16 *) g_memdup (amap.data, amap.size);
188
189 if (channels > 1) {
190 guint ch = channels;
191 guint num_samples = amap.size / (ch * sizeof (gint16));
192 guint i, c, v, s = 0;
193
194 /* deinterleave and mixdown adata */
195 for (i = 0; i < num_samples; i++) {
196 v = 0;
197 for (c = 0; c < ch; c++) {
198 v += mono_adata[s++];
199 }
200 mono_adata[i] = v / ch;
201 }
202 }
203
204 /* run fft */
205 gst_fft_s16_window (scope->fft_ctx, mono_adata, GST_FFT_WINDOW_HAMMING);
206 gst_fft_s16_fft (scope->fft_ctx, mono_adata, fdata);
207 g_free (mono_adata);
208
209 /* draw lines */
210 for (x = 0; x < w; x++) {
211 /* figure out the range so that we don't need to clip,
212 * or even better do a log mapping? */
213 fr = (gfloat) fdata[1 + x].r / 512.0;
214 fi = (gfloat) fdata[1 + x].i / 512.0;
215 y = (guint) (h * sqrt (fr * fr + fi * fi));
216 if (y > h)
217 y = h;
218 y = h - y;
219 off = (y * w) + x;
220 vdata[off] = 0x00FFFFFF;
221 for (l = y; l < h; l++) {
222 off += w;
223 add_pixel (&vdata[off], 0x007F7F7F);
224 }
225 /* ensure bottom line is full bright (especially in move-up mode) */
226 add_pixel (&vdata[off], 0x007F7F7F);
227 }
228 gst_buffer_unmap (audio, &amap);
229 return TRUE;
230 }
231
232 gboolean
gst_spectra_scope_plugin_init(GstPlugin * plugin)233 gst_spectra_scope_plugin_init (GstPlugin * plugin)
234 {
235 GST_DEBUG_CATEGORY_INIT (spectra_scope_debug, "spectrascope", 0,
236 "spectrascope");
237
238 return gst_element_register (plugin, "spectrascope", GST_RANK_NONE,
239 GST_TYPE_SPECTRA_SCOPE);
240 }
241