gstreamer/subprojects/gst-plugins-bad/ext/qroverlay/gstbaseqroverlay.c

/*
 * GStreamer
 * Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>
 * Copyright (c) 2020 Anthony Violo <anthony.violo@ubicast.eu>
 * Copyright (c) 2020 Thibault Saunier <tsaunier@igalia.com>
 *
 * 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/base/gstbasetransform.h>
#include <json-glib/json-glib.h>

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

#include "gstbaseqroverlay.h"

GST_DEBUG_CATEGORY_STATIC (gst_base_qr_overlay_debug);
#define GST_CAT_DEFAULT gst_base_qr_overlay_debug

enum
{
  PROP_0,
  PROP_X_AXIS,
  PROP_Y_AXIS,
  PROP_SIZE,
  PROP_QRCODE_ERROR_CORRECTION,
  PROP_CASE_SENSITIVE,
};

typedef struct _GstBaseQROverlayPrivate GstBaseQROverlayPrivate;
struct _GstBaseQROverlayPrivate
{
  guint qrcode_quality;
  guint span_frame;
  QRecLevel level;
  gfloat x_percent;
  gfloat y_percent;
  gfloat size_percent;
  GstElement *overlaycomposition;
  GstVideoInfo info;
  gboolean valid;
  gboolean case_sensitive;
  gint window_width;
  gint window_height;

  GstPad *sinkpad, *srcpad;
  GstVideoOverlayComposition *prev_overlay;
};

#define PRIV(s) gst_base_qr_overlay_get_instance_private (GST_BASE_QR_OVERLAY (s))

#define OVERLAY_COMPOSITION_CAPS GST_VIDEO_CAPS_MAKE (GST_VIDEO_OVERLAY_COMPOSITION_BLEND_FORMATS)

#define ALL_CAPS OVERLAY_COMPOSITION_CAPS ";" \
    GST_VIDEO_CAPS_MAKE_WITH_FEATURES ("ANY", GST_VIDEO_FORMATS_ANY)

static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (ALL_CAPS)
    );

static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (ALL_CAPS)
    );

#define DEFAULT_PROP_QUALITY    1
#define DEFAULT_PROP_X 50
#define DEFAULT_PROP_Y 50
#define DEFAULT_PROP_SIZE 33
#define DEFAULT_PROP_CASE_SENSITIVE FALSE

#define GST_TYPE_QRCODE_QUALITY (gst_qrcode_quality_get_type())
static GType
gst_qrcode_quality_get_type (void)
{
  static GType qrcode_quality_type = 0;

  static const GEnumValue qrcode_quality[] = {
    {0, "Level L", "Approx 7%"},
    {1, "Level M", "Approx 15%"},
    {2, "Level Q", "Approx 25%"},
    {3, "Level H", "Approx 30%"},
    {0, NULL, NULL},
  };

  if (!qrcode_quality_type) {
    qrcode_quality_type =
        g_enum_register_static ("GstQrcodeOverlayCorrection", qrcode_quality);
  }
  return qrcode_quality_type;
}

#define gst_base_qr_overlay_parent_class parent_class
G_DEFINE_TYPE_WITH_PRIVATE (GstBaseQROverlay, gst_base_qr_overlay,
    GST_TYPE_BIN);

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

static void
gst_base_qr_overlay_caps_changed_cb (GstBaseQROverlay * self, GstCaps * caps,
    gint window_width, gint window_height, GstElement * overlay)
{
  GstBaseQROverlayPrivate *priv = PRIV (self);

  priv->window_width = window_width;
  priv->window_height = window_height;

  GST_DEBUG_OBJECT (self, "%" GST_PTR_FORMAT, caps);

  if (gst_video_info_from_caps (&priv->info, caps))
    priv->valid = TRUE;
  else
    priv->valid = FALSE;

  /* needs to redraw the overlay as its position depends of the video size */
  gst_mini_object_replace (((GstMiniObject **) & priv->prev_overlay), NULL);
}

static void
render_size (GstBaseQROverlay * self, int *width, int *height)
{
  GstBaseQROverlayPrivate *priv = PRIV (self);
  gdouble video_aspect =
      (gdouble) priv->info.width / (gdouble) priv->info.height;
  gdouble window_aspect =
      (gdouble) priv->window_width / (gdouble) priv->window_height;

  /* Render size within the window */
  if (video_aspect >= window_aspect) {
    *width = priv->window_width;
    *height = window_aspect * priv->window_height / video_aspect;
  } else {
    *width = video_aspect * priv->window_width / window_aspect;
    *height = priv->window_height;
  }
}

static GstVideoOverlayComposition *
draw_overlay (GstBaseQROverlay * self, QRcode * qrcode)
{
  guint8 *qr_data, *pixels;
  gint stride, pstride, y, x, yy;
  gsize offset, line_offset;
  GstVideoInfo info;
  GstVideoOverlayRectangle *rect;
  GstVideoOverlayComposition *comp;
  GstBuffer *buf;
  GstBaseQROverlayPrivate *priv = PRIV (self);

  gst_video_info_init (&info);

  int render_width, render_height;
  render_size (self, &render_width, &render_height);

  // Total size in pixels of the qrcode.
  gdouble size_scale = priv->size_percent / 100;
  int square_size =
      render_width < render_height
      ? render_width * size_scale : render_height * size_scale;
  // Size in pixels of 1 qrcode block (1 block margin on each side).
  int qrcode_size = square_size / (qrcode->width + 2);
  // Update square_size for a round number of blocks.
  square_size = qrcode_size * (qrcode->width + 2);
  // Margin in pixels in each side to center the qrcode.
  int margin = qrcode_size;

  gst_video_info_set_format (&info, GST_VIDEO_FORMAT_ARGB, square_size,
      square_size);

  pixels = g_malloc ((size_t) info.size);
  stride = info.stride[0];
  pstride = info.finfo->pixel_stride[0];

  /* White background */
  memset (pixels, 0xff, info.size);

  /* Draw the black QR code blocks */
  line_offset = margin * stride;
  qr_data = qrcode->data;
  for (y = 0; y < qrcode->width; y++) {
    for (x = 0; x < (qrcode->width); x++) {
      for (yy = 0; yy < qrcode_size * pstride; yy += pstride) {
        if (!(*qr_data & 1))
          continue;

        offset = line_offset + stride * (yy / pstride) +
            x * qrcode_size * pstride + margin * pstride;

        for (gint i = 0; i < qrcode_size * pstride; i += pstride) {
          pixels[offset + i] = 0x00;
          pixels[offset + i + 1] = 0x00;
          pixels[offset + i + 2] = 0x00;
        }
      }
      qr_data++;
    }
    line_offset += stride * qrcode_size;
  }

  buf = gst_buffer_new_wrapped (pixels, info.size);
  gst_buffer_add_video_meta (buf, GST_VIDEO_FRAME_FLAG_NONE,
      GST_VIDEO_OVERLAY_COMPOSITION_FORMAT_RGB, info.width, info.height);

  square_size =
      priv->info.width < priv->info.height
      ? priv->info.width * size_scale : priv->info.height * size_scale;

  x = (int) (priv->info.width - square_size) * (priv->x_percent / 100);
  x = GST_ROUND_DOWN_2 (x);
  y = (int) (priv->info.height - square_size) * (priv->y_percent / 100);
  y = GST_ROUND_DOWN_4 (y);

  GST_DEBUG_OBJECT (self, "draw overlay at (%d,%d) size: %dx%d", x, y,
      square_size, square_size);

  rect =
      gst_video_overlay_rectangle_new_raw (buf, x, y, square_size, square_size,
      GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);
  comp = gst_video_overlay_composition_new (rect);
  gst_video_overlay_rectangle_unref (rect);

  return comp;
}

static GstVideoOverlayComposition *
gst_base_qr_overlay_draw_cb (GstBaseQROverlay * self, GstSample * sample,
    GstElement * _)
{
  GstBaseQROverlayPrivate *priv = PRIV (self);
  QRcode *qrcode;
  gchar *content;
  gboolean reuse_previous = FALSE;
  GstVideoOverlayComposition *overlay = NULL;
  GstBuffer *buffer = gst_sample_get_buffer (sample);
  GstSegment *segment = gst_sample_get_segment (sample);
  GstClockTime rtime = gst_segment_to_running_time (segment, GST_FORMAT_TIME,
      GST_BUFFER_PTS (buffer));

  if (!priv->valid) {
    GST_ERROR_OBJECT (self, "Trying to draw before negotiation?");

    return NULL;
  }

  if (GST_CLOCK_TIME_IS_VALID (rtime))
    gst_object_sync_values (GST_OBJECT (self), rtime);

  content =
      GST_BASE_QR_OVERLAY_GET_CLASS (self)->get_content (GST_BASE_QR_OVERLAY
      (self), buffer, &priv->info, &reuse_previous);
  if (reuse_previous && priv->prev_overlay) {
    overlay = gst_video_overlay_composition_ref (priv->prev_overlay);
  } else if (content) {
    GST_INFO_OBJECT (self, "String will be encoded : %s", content);
    qrcode =
        QRcode_encodeString (content, 0, priv->qrcode_quality, QR_MODE_8,
        priv->case_sensitive);

    if (qrcode) {
      GST_DEBUG_OBJECT (self, "String encoded");
      overlay = draw_overlay (GST_BASE_QR_OVERLAY (self), qrcode);
      gst_mini_object_replace (((GstMiniObject **) & priv->prev_overlay),
          (GstMiniObject *) overlay);
    } else {
      GST_WARNING_OBJECT (self, "Could not encode content: %s", content);
    }
  }
  g_free (content);

  return overlay;
}

/* GObject vmethod implementations */

static void
gst_base_qr_overlay_dispose (GObject * object)
{
  GstBaseQROverlayPrivate *priv = PRIV (object);

  gst_mini_object_replace (((GstMiniObject **) & priv->prev_overlay), NULL);
}

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

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

  gobject_class->set_property = gst_base_qr_overlay_set_property;
  gobject_class->get_property = gst_base_qr_overlay_get_property;
  gobject_class->dispose = gst_base_qr_overlay_dispose;

  GST_DEBUG_CATEGORY_INIT (gst_base_qr_overlay_debug, "qroverlay", 0,
      "Qrcode overlay base class");

  g_object_class_install_property (gobject_class, PROP_X_AXIS,
      g_param_spec_float ("x", "X position (in percent of the width)",
          "X position (in percent of the width)", 0.0, 100.0, DEFAULT_PROP_X,
          G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class, PROP_Y_AXIS,
      g_param_spec_float ("y", "Y position (in percent of the height)",
          "Y position (in percent of the height)", 0.0, 100.0, DEFAULT_PROP_Y,
          G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class, PROP_SIZE,
      g_param_spec_float ("size",
          "Size of the square (in percent of the smallest of width and height)",
          "Size of the square (in percent of the smallest of width and height)",
          0.0, 100.0, DEFAULT_PROP_SIZE, G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class, PROP_QRCODE_ERROR_CORRECTION,
      g_param_spec_enum ("qrcode-error-correction", "qrcode-error-correction",
          "qrcode-error-correction", GST_TYPE_QRCODE_QUALITY,
          DEFAULT_PROP_QUALITY, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  /**
   * GstBaseQROverlay::case-sensitive:
   *
   * Strings to encode are case sensitive (e.g. passwords or SSIDs).
   *
   * Since: 1.22
   */
  g_object_class_install_property (gobject_class, PROP_CASE_SENSITIVE,
      g_param_spec_boolean ("case-sensitive", "Case Sensitive",
          "Strings to encode are case sensitive (e.g. passwords or SSIDs)",
          DEFAULT_PROP_CASE_SENSITIVE,
          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&src_template));
  gst_element_class_add_pad_template (gstelement_class,
      gst_static_pad_template_get (&sink_template));

  gst_type_mark_as_plugin_api (GST_TYPE_QRCODE_QUALITY, 0);
  gst_type_mark_as_plugin_api (GST_TYPE_QRCODE_QUALITY, 0);
}

/* initialize the new element
 * initialize instance structure
 */
static void
gst_base_qr_overlay_init (GstBaseQROverlay * self)
{
  GstBaseQROverlayPrivate *priv = PRIV (self);

  priv->x_percent = DEFAULT_PROP_X;
  priv->y_percent = DEFAULT_PROP_X;
  priv->size_percent = DEFAULT_PROP_SIZE;
  priv->qrcode_quality = DEFAULT_PROP_QUALITY;
  priv->case_sensitive = DEFAULT_PROP_CASE_SENSITIVE;
  priv->span_frame = 0;
  priv->overlaycomposition =
      gst_element_factory_make ("overlaycomposition", NULL);
  gst_video_info_init (&priv->info);

  if (priv->overlaycomposition) {
    GstPadTemplate *sink_tmpl = gst_static_pad_template_get (&sink_template);
    GstPadTemplate *src_tmpl = gst_static_pad_template_get (&src_template);

    gst_bin_add (GST_BIN (self), priv->overlaycomposition);

    gst_element_add_pad (GST_ELEMENT_CAST (self),
        gst_ghost_pad_new_from_template ("sink",
            priv->overlaycomposition->sinkpads->data, sink_tmpl));
    gst_element_add_pad (GST_ELEMENT_CAST (self),
        gst_ghost_pad_new_from_template ("src",
            priv->overlaycomposition->srcpads->data, src_tmpl));
    gst_object_unref (sink_tmpl);
    gst_object_unref (src_tmpl);

    g_signal_connect_swapped (priv->overlaycomposition, "draw",
        G_CALLBACK (gst_base_qr_overlay_draw_cb), self);
    g_signal_connect_swapped (priv->overlaycomposition, "caps-changed",
        G_CALLBACK (gst_base_qr_overlay_caps_changed_cb), self);
  }
}

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

  switch (prop_id) {
    case PROP_X_AXIS:
      priv->x_percent = g_value_get_float (value);
      break;
    case PROP_Y_AXIS:
      priv->y_percent = g_value_get_float (value);
      break;
    case PROP_SIZE:
      priv->size_percent = g_value_get_float (value);
      break;
    case PROP_QRCODE_ERROR_CORRECTION:
      priv->qrcode_quality = g_value_get_enum (value);
      break;
    case PROP_CASE_SENSITIVE:
      priv->case_sensitive = g_value_get_boolean (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

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

  switch (prop_id) {
    case PROP_X_AXIS:
      g_value_set_float (value, priv->x_percent);
      break;
    case PROP_Y_AXIS:
      g_value_set_float (value, priv->y_percent);
      break;
    case PROP_SIZE:
      g_value_set_float (value, priv->size_percent);
      break;
    case PROP_QRCODE_ERROR_CORRECTION:
      g_value_set_enum (value, priv->qrcode_quality);
      break;
    case PROP_CASE_SENSITIVE:
      g_value_set_boolean (value, priv->case_sensitive);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}