gstreamer/gst/chart/gstchart.c

/* gstchart.c: implementation of chart drawing element
 * Copyright (C) <2001> Richard Boulton <richard@tartarus.org>
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gst/gst.h>
#include <gst/video/video.h>

#define GST_TYPE_CHART (gst_chart_get_type())
#define GST_CHART(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CHART,GstChart))
#define GST_CHART_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CHART,GstChart))
#define GST_IS_CHART(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_CHART))
#define GST_IS_CHART_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_CHART))

typedef struct _GstChart GstChart;
typedef struct _GstChartClass GstChartClass;

struct _GstChart
{
  GstElement element;

  /* pads */
  GstPad *sinkpad, *srcpad;

  /* the timestamp of the next frame */
  guint64 next_time;

  /* video state */
  gint bpp;
  gint depth;
  gint width;
  gint height;

  gint samplerate;
  gdouble framerate;            /* desired frame rate */
  gint samples_between_frames;  /* number of samples between start of successive frames */
  gint samples_since_last_frame;        /* number of samples between start of successive frames */
};

struct _GstChartClass
{
  GstElementClass parent_class;
};

GType gst_chart_get_type (void);

/* signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  /* FILL ME */
};

static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB_16)
    );

static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("audio/x-raw-int, "
        "endianness = (int) BYTE_ORDER, "
        "signed = (boolean) TRUE, "
        "width = (int) 16, "
        "depth = (int) 16, "
        "rate = (int) [ 8000, 96000 ], " "channels = (int) 1")
    );

static void gst_chart_base_init (gpointer g_class);
static void gst_chart_class_init (GstChartClass * klass);
static void gst_chart_init (GstChart * chart);

static void gst_chart_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_chart_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static void gst_chart_chain (GstPad * pad, GstData * _data);

static GstPadLinkReturn
gst_chart_sinkconnect (GstPad * pad, const GstCaps * caps);
static GstPadLinkReturn
gst_chart_srcconnect (GstPad * pad, const GstCaps * caps);

static GstElementClass *parent_class = NULL;

GType
gst_chart_get_type (void)
{
  static GType type = 0;

  if (!type) {
    static const GTypeInfo info = {
      sizeof (GstChartClass),
      gst_chart_base_init,
      NULL,
      (GClassInitFunc) gst_chart_class_init,
      NULL,
      NULL,
      sizeof (GstChart),
      0,
      (GInstanceInitFunc) gst_chart_init,
    };

    type = g_type_register_static (GST_TYPE_ELEMENT, "GstChart", &info, 0);
  }
  return type;
}

static void
gst_chart_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_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_simple (element_class, "Chart drawer",
      "Visualization",
      "Takes frames of data and outputs video frames of a chart of data",
      "Richard Boulton <richard@tartarus.org>");
}

static void
gst_chart_class_init (GstChartClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->set_property = gst_chart_set_property;
  gobject_class->get_property = gst_chart_get_property;
}

static void
gst_chart_init (GstChart * chart)
{
  /* create the sink and src pads */
  chart->sinkpad = gst_pad_new_from_static_template (&sink_factory, "sink");
  chart->srcpad = gst_pad_new_from_static_template (&src_factory, "src");
  gst_element_add_pad (GST_ELEMENT (chart), chart->sinkpad);
  gst_element_add_pad (GST_ELEMENT (chart), chart->srcpad);

  gst_pad_set_chain_function (chart->sinkpad, gst_chart_chain);
  gst_pad_set_link_function (chart->sinkpad, gst_chart_sinkconnect);
  gst_pad_set_link_function (chart->srcpad, gst_chart_srcconnect);

  chart->next_time = 0;

  /* reset the initial video state */
  chart->bpp = 16;
  chart->depth = 16;
  chart->width = 256;
  chart->height = 128;

  chart->samplerate = -1;
  chart->framerate = 25;        /* desired frame rate */
  chart->samples_between_frames = 0;    /* number of samples between start of successive frames */
  chart->samples_since_last_frame = 0;
}

static GstPadLinkReturn
gst_chart_sinkconnect (GstPad * pad, const GstCaps * caps)
{
  GstChart *chart;
  GstStructure *structure;

  chart = GST_CHART (gst_pad_get_parent (pad));

  structure = gst_caps_get_structure (caps, 0);

  gst_structure_get_int (structure, "rate", &chart->samplerate);
  chart->samples_between_frames = chart->samplerate / chart->framerate;

  GST_DEBUG ("CHART: new sink caps: rate %d", chart->samplerate);
  /*gst_chart_sync_parms (chart); */
  /* */
  return GST_PAD_LINK_OK;
}

static GstPadLinkReturn
gst_chart_srcconnect (GstPad * pad, const GstCaps * caps)
{
  GstChart *chart;
  GstStructure *structure;

  chart = GST_CHART (gst_pad_get_parent (pad));

  structure = gst_caps_get_structure (caps, 0);

  if (!gst_structure_get_double (structure, "framerate", &chart->framerate) ||
      !gst_structure_get_int (structure, "width", &chart->width) ||
      !gst_structure_get_int (structure, "height", &chart->height))
    return GST_PAD_LINK_REFUSED;

  chart->samples_between_frames = chart->samplerate / chart->framerate;
  GST_DEBUG ("CHART: new src caps: framerate %f, %dx%d",
      chart->framerate, chart->width, chart->height);

  return GST_PAD_LINK_OK;
}

static void
draw_chart_16bpp (guchar * output, gint width, gint height,
    gint16 * src_data, gint src_size)
{
  gint i;
  guint16 *colstart;
  gint16 *in;

  GST_DEBUG
      ("CHART: drawing frame to %p, width = %d, height = %d, src_data = %p, src_size = %d",
      output, width, height, src_data, src_size);

  for (colstart = (guint16 *) output, in = (gint16 *) src_data, i = 0;
      i < width; colstart++, in++, i++) {
    guint16 *pos = colstart;
    gint h1;

    h1 = (((gint) (*in)) * height / (1 << 16)) + height / 2;
    if (h1 >= height)
      h1 = height;

    if (h1 < height / 2) {
      while (pos < colstart + h1 * width) {
        *pos = 0x0000;
        pos += width;
      }
      while (pos < colstart + height / 2 * width) {
        *pos = 0x07e0;
        pos += width;
      }
      while (pos < colstart + height * width) {
        *pos = 0x0000;
        pos += width;
      }
    } else {
      while (pos < colstart + height / 2 * width) {
        *pos = 0x0000;
        pos += width;
      }
      while (pos < colstart + h1 * width) {
        *pos = 0x07e0;
        pos += width;
      }
      while (pos < colstart + height * width) {
        *pos = 0x0000;
        pos += width;
      }
    }
  }
}

static void
gst_chart_chain (GstPad * pad, GstData * _data)
{
  GstBuffer *bufin = GST_BUFFER (_data);
  GstChart *chart;
  GstBuffer *bufout;
  guint32 samples_in;
  guint32 sizeout;
  gint16 *datain;
  guchar *dataout;

  g_return_if_fail (bufin != NULL);
  g_return_if_fail (pad != NULL);
  g_return_if_fail (GST_IS_PAD (pad));
  g_return_if_fail (GST_IS_CHART (GST_OBJECT_PARENT (pad)));
  chart = GST_CHART (GST_OBJECT_PARENT (pad));
  g_return_if_fail (chart != NULL);

  GST_DEBUG ("CHART: chainfunc called");

  samples_in = GST_BUFFER_SIZE (bufin) / sizeof (gint16);
  datain = (gint16 *) (GST_BUFFER_DATA (bufin));
  GST_DEBUG ("input buffer has %d samples", samples_in);
  if (chart->next_time <= GST_BUFFER_TIMESTAMP (bufin)) {
    chart->next_time = GST_BUFFER_TIMESTAMP (bufin);
    GST_DEBUG ("in:  %" G_GINT64_FORMAT, GST_BUFFER_TIMESTAMP (bufin));
  }

  chart->samples_since_last_frame += samples_in;
  if (chart->samples_between_frames <= chart->samples_since_last_frame) {
    chart->samples_since_last_frame = 0;

    /* get data to draw into buffer */
    if (samples_in >= chart->width) {
      /* make a new buffer for the output */
      bufout = gst_buffer_new ();
      sizeout = chart->bpp / 8 * chart->width * chart->height;
      dataout = g_malloc (sizeout);
      GST_BUFFER_SIZE (bufout) = sizeout;
      GST_BUFFER_DATA (bufout) = dataout;
      GST_DEBUG ("CHART: made new buffer: size %d, width %d, height %d",
          sizeout, chart->width, chart->height);

      /* take data and draw to new buffer */
      /* FIXME: call different routines for different properties */
      draw_chart_16bpp (dataout, chart->width, chart->height, (gint16 *) datain,
          samples_in);

      gst_buffer_unref (bufin);

      /* set timestamp */
      GST_BUFFER_TIMESTAMP (bufout) = chart->next_time;

      GST_DEBUG ("CHART: outputting buffer");
      /* output buffer */
      GST_BUFFER_FLAG_SET (bufout, GST_BUFFER_READONLY);
      gst_pad_push (chart->srcpad, GST_DATA (bufout));
    }
  } else {
    GST_DEBUG ("CHART: skipping buffer");
    gst_buffer_unref (bufin);
  }

  GST_DEBUG ("CHART: exiting chainfunc");
}

static void
gst_chart_set_property (GObject * object, guint prop_id, const GValue * value,
    GParamSpec * pspec)
{
  GstChart *chart;

  g_return_if_fail (GST_IS_CHART (object));
  chart = GST_CHART (object);

  switch (prop_id) {
    default:
      break;
  }
}

static void
gst_chart_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstChart *chart;

  g_return_if_fail (GST_IS_CHART (object));
  chart = GST_CHART (object);

  switch (prop_id) {
    default:
      break;
  }
}

static gboolean
plugin_init (GstPlugin * plugin)
{
  if (!gst_element_register (plugin, "chart", GST_RANK_NONE, GST_TYPE_CHART))
    return FALSE;

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    chart,
    "Takes frames of data and outputs video frames of a chart of data",
    plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)