gstreamer/ext/qroverlay/gstqroverlay.c

/*
 * GStreamer
 * Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>
 * Copyright (c) 2020 Anthony Violo <anthony.violo@ubicast.eu>
 *
 * 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.
 */

/**
 * SECTION:element-qroverlay
 *
 * This element will build a Json string that contains a description of the
 * buffer and will convert the string to a QRcode. The QRcode contains a
 * timestamp, a buffer number, a framerate and some custom extra-data. Each
 * frame will have a Qrcode overlaid in the video stream. Some properties are
 * available to set the position and to define its size. You can add custom data
 * with the properties #qroverlay:extra-data-name and
 * #qroverlay:extra-data-array. You can also define the quality of the Qrcode
 * with #qroverlay:qrcode-error-correction. You can also define interval and
 * span of #qrovlerlay:extra-data-name #qrovlerlay:extra-data-array
 *
 * ## Example launch line
 *
 * ``` bash
 * gst-launch -v -m videotestsrc ! qroverlay ! fakesink silent=TRUE
 * ```
 *
 * Since: 1.20
 */

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

#include <gst/gst.h>
#include <gst/base/gstbasetransform.h>
#include <json-glib/json-glib.h>

#include <qrencode.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#include "gstqroverlay.h"

GST_DEBUG_CATEGORY_STATIC (gst_qr_overlay_debug);
#define GST_CAT_DEFAULT gst_qr_overlay_debug

static gchar *get_qrcode_content (GstBaseQROverlay * filter,
    GstVideoFrame * frame);

enum
{
  PROP_0,
  PROP_DATA_INTERVAL_BUFFERS,
  PROP_DATA_SPAN_BUFFERS,
  PROP_EXTRA_DATA_NAME,
  PROP_EXTRA_DATA_ARRAY,
};

typedef struct _GstQROverlayPrivate GstQROverlayPrivate;
struct _GstQROverlayPrivate
{
  guint32 frame_number;
  guint array_counter;
  guint array_size;
  guint span_frame;
  guint64 extra_data_interval_buffers;
  guint64 extra_data_span_buffers;
  gchar *extra_data_name;
  gchar *extra_data_str;
  gchar **extra_data_array;
  gfloat x_percent;
  gfloat y_percent;
  gboolean silent;
  gboolean extra_data_enabled;
};

#define PRIV(s) gst_qr_overlay_get_instance_private (GST_QR_OVERLAY (s))

#define DEFAULT_PROP_QUALITY    1
#define DEFAULT_PROP_PIXEL_SIZE    3

#define gst_qr_overlay_parent_class parent_class
G_DEFINE_TYPE_WITH_PRIVATE (GstQROverlay, gst_qr_overlay,
    GST_TYPE_BASE_QR_OVERLAY);

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

/* GObject vmethod implementations */

/* initialize the qroverlay's class */
static void
gst_qr_overlay_class_init (GstQROverlayClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

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

  gobject_class->set_property = gst_qr_overlay_set_property;
  gobject_class->get_property = gst_qr_overlay_get_property;

  g_object_class_install_property (gobject_class,
      PROP_DATA_INTERVAL_BUFFERS,
      g_param_spec_int64 ("extra-data-interval-buffers",
          "extra-data-interval-buffers",
          "Extra data append into the Qrcode at the first buffer of each "
          " interval", 0, G_MAXINT64, 60, G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class,
      PROP_DATA_SPAN_BUFFERS, g_param_spec_int64 ("extra-data-span-buffers",
          "extra-data-span-buffers",
          "Numbers of consecutive buffers that the extra data will be inserted "
          " (counting the first buffer)", 0, G_MAXINT64, 1, G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class,
      PROP_EXTRA_DATA_NAME, g_param_spec_string ("extra-data-name",
          "Extra data name",
          "Json key name for extra append data", NULL, G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class,
      PROP_EXTRA_DATA_ARRAY, g_param_spec_string ("extra-data-array",
          "Extra data array",
          "List of comma separated values that the extra data value will be "
          " cycled from at each interval, example array structure :"
          " \"240,480,720,960,1200,1440,1680,1920\"", NULL, G_PARAM_READWRITE));


  gst_element_class_set_details_simple (gstelement_class,
      "qroverlay",
      "Qrcode overlay containing buffer information",
      "Overlay Qrcodes over each buffer with buffer information and custom data",
      "Anthony Violo <anthony.violo@ubicast.eu>");

  gst_type_mark_as_plugin_api (GST_TYPE_BASE_QR_OVERLAY, 0);

  GST_BASE_QR_OVERLAY_CLASS (klass)->get_content =
      GST_DEBUG_FUNCPTR (get_qrcode_content);
}

/* initialize the new element
 * initialize instance structure
 */
static void
gst_qr_overlay_init (GstQROverlay * filter)
{
  GstQROverlayPrivate *priv = PRIV (filter);

  priv->frame_number = 1;
  priv->x_percent = 50.0;
  priv->y_percent = 50.0;
  priv->array_counter = 0;
  priv->array_size = 0;
  priv->extra_data_interval_buffers = 60;
  priv->extra_data_span_buffers = 1;
  priv->span_frame = 0;
}

static void
gst_qr_overlay_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstQROverlayPrivate *priv = PRIV (object);

  switch (prop_id) {
    case PROP_DATA_INTERVAL_BUFFERS:
      priv->extra_data_interval_buffers = g_value_get_int64 (value);
      break;
    case PROP_DATA_SPAN_BUFFERS:
      priv->extra_data_span_buffers = g_value_get_int64 (value);
      break;
    case PROP_EXTRA_DATA_NAME:
      priv->extra_data_name = g_value_dup_string (value);
      break;
    case PROP_EXTRA_DATA_ARRAY:
    {
      g_clear_pointer (&priv->extra_data_str, g_free);
      g_clear_pointer (&priv->extra_data_array, g_strfreev);
      priv->extra_data_str = g_value_dup_string (value);
      if (priv->extra_data_str) {
        priv->extra_data_array = g_strsplit (priv->extra_data_str, ",", -1);
        priv->array_size = g_strv_length (priv->extra_data_array);
      }
      break;
    }
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_qr_overlay_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstQROverlayPrivate *priv = PRIV (object);

  switch (prop_id) {
    case PROP_DATA_INTERVAL_BUFFERS:
      g_value_set_int64 (value, priv->extra_data_interval_buffers);
      break;
    case PROP_DATA_SPAN_BUFFERS:
      g_value_set_int64 (value, priv->extra_data_span_buffers);
      break;
    case PROP_EXTRA_DATA_NAME:
      g_value_set_string (value, priv->extra_data_name);
      break;
    case PROP_EXTRA_DATA_ARRAY:
      g_value_set_string (value, priv->extra_data_str);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static gchar *
get_qrcode_content (GstBaseQROverlay * filter, GstVideoFrame * frame)
{
  GstQROverlayPrivate *priv = PRIV (filter);
  GstBuffer *buf = frame->buffer;
  GString *res = g_string_new (NULL);
  JsonGenerator *jgen;
  gchar *framerate_string =
      g_strdup_printf ("%d/%d", frame->info.fps_n, frame->info.fps_d);

  JsonObject *jobj = json_object_new ();
  JsonNode *root = json_node_new (JSON_NODE_OBJECT);

  json_object_set_int_member (jobj, "TIMESTAMP",
      (gint64) GST_BUFFER_TIMESTAMP (buf));
  json_object_set_int_member (jobj, "BUFFERCOUNT", (gint64) priv->frame_number);
  json_object_set_string_member (jobj, "FRAMERATE", framerate_string);
  json_object_set_string_member (jobj, "NAME", GST_ELEMENT_NAME (filter));
  g_free (framerate_string);

  if (priv->extra_data_array && priv->extra_data_name &&
      (priv->frame_number == 1
          || priv->frame_number % priv->extra_data_interval_buffers == 1
          || (priv->span_frame > 0
              && priv->span_frame < priv->extra_data_span_buffers))) {
    json_object_set_string_member (jobj, priv->extra_data_name,
        priv->extra_data_array[priv->array_counter]);

    priv->span_frame++;
    if (priv->span_frame == priv->extra_data_span_buffers) {
      priv->array_counter++;
      priv->span_frame = 0;
      if (priv->array_counter >= priv->array_size)
        priv->array_counter = 0;
    }
  }

  jgen = json_generator_new ();
  json_node_set_object (root, jobj);
  json_generator_set_root (jgen, root);
  res = json_generator_to_gstring (jgen, res);
  g_object_unref (jgen);
  priv->frame_number++;

  return g_strdup (g_string_free (res, FALSE));
}

static gboolean
qroverlay_init (GstPlugin * qroverlay)
{
  GST_DEBUG_CATEGORY_INIT (gst_qr_overlay_debug, "qroverlay", 0,
      "Qrcode overlay element");

  return gst_element_register (qroverlay, "qroverlay", GST_RANK_NONE,
      GST_TYPE_QR_OVERLAY);
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    qroverlay,
    "libqrencode qroverlay plugin",
    qroverlay_init, VERSION, "LGPL", PACKAGE_NAME, GST_PACKAGE_ORIGIN)