/* GStreamer

 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>

 * Copyright (C) <2003> David Schleef <ds@schleef.org>

 * Copyright (C) <2006> Julien Moutte <julien@moutte.net>

 * Copyright (C) <2006> Tim-Philipp Müller <tim centricular net>

 *

 * 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-textoverlay

 * @see_also: #GstTextRender, #GstClockOverlay, #GstTimeOverlay, #GstSubParse

 *

 * <refsect2>

 * <para>

 * This plugin renders text on top of a video stream. This can be either

 * static text or text from buffers received on the text sink pad, e.g.

 * as produced by the subparse element. If the text sink pad is not linked,

 * the text set via the "text" property will be rendered. If the text sink

 * pad is linked, text will be rendered as it is received on that pad,

 * honouring and matching the buffer timestamps of both input streams.

 * </para>

 * <para>

 * The text can contain newline characters and text wrapping is enabled by

 * default.

 * </para>

 * <para>

 * Here is a simple pipeline that displays a static text in the top left

 * corner of the video picture:

 * <programlisting>

 * gst-launch -v videotestsrc ! textoverlay text="Room A" valign=top halign=left ! xvimagesink

 * </programlisting>

 * </para>

 * <para>

 * Here is another pipeline that displays subtitles from an .srt subtitle

 * file, centered at the bottom of the picture and with a rectangular shading

 * around the text in the background:

 * <programlisting>

 * gst-launch -v filesrc location=subtitles.srt ! subparse ! txt.   videotestsrc ! timeoverlay ! textoverlay name=txt shaded-background=yes ! xvimagesink

 * </programlisting>

 * If you do not have such a subtitle file, create one looking like this

 * in a text editor:

 * <programlisting>

 * 1

 * 00:00:03,000 --> 00:00:05,000

 * Hello? (3-5s)

 *  

 * 2

 * 00:00:08,000 --> 00:00:13,000

 * Yes, this is a subtitle. Don't

 * you like it? (8-13s)

 *  

 * 3

 * 00:00:18,826 --> 00:01:02,886

 * Uh? What are you talking about?

 * I don't understand  (18-62s)

 * </programlisting>

 * </para>

 * </refsect2>

 */

/* FIXME: alloc segment as part of instance struct */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <gst/video/video.h>

#include "gsttextoverlay.h"

#include "gsttimeoverlay.h"

#include "gstclockoverlay.h"

#include "gsttextrender.h"

/* FIXME:

 *  - use proper strides and offset for I420

 *  - if text is wider than the video picture, it does not get

 *    clipped properly during blitting (if wrapping is disabled)

 *  - make 'shading_value' a property (or enum:  light/normal/dark/verydark)?

 */

GST_DEBUG_CATEGORY (pango_debug);

#define GST_CAT_DEFAULT pango_debug

static const GstElementDetails text_overlay_details =

GST_ELEMENT_DETAILS ("Text overlay",

    "Filter/Editor/Video",

    "Adds text strings on top of a video buffer",

    "David Schleef <ds@schleef.org>");

#define DEFAULT_PROP_TEXT 	""

#define DEFAULT_PROP_SHADING	FALSE

#define DEFAULT_PROP_VALIGNMENT	GST_TEXT_OVERLAY_VALIGN_BASELINE

#define DEFAULT_PROP_HALIGNMENT	GST_TEXT_OVERLAY_HALIGN_CENTER

#define DEFAULT_PROP_VALIGN	"baseline"

#define DEFAULT_PROP_HALIGN	"center"

#define DEFAULT_PROP_XPAD	25

#define DEFAULT_PROP_YPAD	25

#define DEFAULT_PROP_DELTAX	0

#define DEFAULT_PROP_DELTAY	0

#define DEFAULT_PROP_WRAP_MODE  GST_TEXT_OVERLAY_WRAP_MODE_WORD_CHAR

#define DEFAULT_PROP_FONT_DESC	""

#define DEFAULT_PROP_SILENT	FALSE

#define DEFAULT_PROP_LINE_ALIGNMENT GST_TEXT_OVERLAY_LINE_ALIGN_CENTER

/* make a property of me */

#define DEFAULT_SHADING_VALUE    -80

enum

{

  PROP_0,

  PROP_TEXT,

  PROP_SHADING,

  PROP_VALIGN,                  /* deprecated */

  PROP_HALIGN,                  /* deprecated */

  PROP_HALIGNMENT,

  PROP_VALIGNMENT,

  PROP_XPAD,

  PROP_YPAD,

  PROP_DELTAX,

  PROP_DELTAY,

  PROP_WRAP_MODE,

  PROP_FONT_DESC,

  PROP_SILENT,

  PROP_LINE_ALIGNMENT

};

static GstStaticPadTemplate src_template_factory =

GST_STATIC_PAD_TEMPLATE ("src",

    GST_PAD_SRC,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))

    );

static GstStaticPadTemplate video_sink_template_factory =

GST_STATIC_PAD_TEMPLATE ("video_sink",

    GST_PAD_SINK,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))

    );

static GstStaticPadTemplate text_sink_template_factory =

    GST_STATIC_PAD_TEMPLATE ("text_sink",

    GST_PAD_SINK,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("text/x-pango-markup; text/plain")

    );

#define GST_TYPE_TEXT_OVERLAY_VALIGN (gst_text_overlay_valign_get_type())

static GType

gst_text_overlay_valign_get_type (void)

{

  static GType text_overlay_valign_type = 0;

  static const GEnumValue text_overlay_valign[] = {

    {GST_TEXT_OVERLAY_VALIGN_BASELINE, "baseline", "baseline"},

    {GST_TEXT_OVERLAY_VALIGN_BOTTOM, "bottom", "bottom"},

    {GST_TEXT_OVERLAY_VALIGN_TOP, "top", "top"},

    {0, NULL, NULL},

  };

  if (!text_overlay_valign_type) {

    text_overlay_valign_type =

        g_enum_register_static ("GstTextOverlayVAlign", text_overlay_valign);

  }

  return text_overlay_valign_type;

}

#define GST_TYPE_TEXT_OVERLAY_HALIGN (gst_text_overlay_halign_get_type())

static GType

gst_text_overlay_halign_get_type (void)

{

  static GType text_overlay_halign_type = 0;

  static const GEnumValue text_overlay_halign[] = {

    {GST_TEXT_OVERLAY_HALIGN_LEFT, "left", "left"},

    {GST_TEXT_OVERLAY_HALIGN_CENTER, "center", "center"},

    {GST_TEXT_OVERLAY_HALIGN_RIGHT, "right", "right"},

    {0, NULL, NULL},

  };

  if (!text_overlay_halign_type) {

    text_overlay_halign_type =

        g_enum_register_static ("GstTextOverlayHAlign", text_overlay_halign);

  }

  return text_overlay_halign_type;

}

#define GST_TYPE_TEXT_OVERLAY_WRAP_MODE (gst_text_overlay_wrap_mode_get_type())

static GType

gst_text_overlay_wrap_mode_get_type (void)

{

  static GType text_overlay_wrap_mode_type = 0;

  static const GEnumValue text_overlay_wrap_mode[] = {

    {GST_TEXT_OVERLAY_WRAP_MODE_NONE, "none", "none"},

    {GST_TEXT_OVERLAY_WRAP_MODE_WORD, "word", "word"},

    {GST_TEXT_OVERLAY_WRAP_MODE_CHAR, "char", "char"},

    {GST_TEXT_OVERLAY_WRAP_MODE_WORD_CHAR, "wordchar", "wordchar"},

    {0, NULL, NULL},

  };

  if (!text_overlay_wrap_mode_type) {

    text_overlay_wrap_mode_type =

        g_enum_register_static ("GstTextOverlayWrapMode",

        text_overlay_wrap_mode);

  }

  return text_overlay_wrap_mode_type;

}

#define GST_TYPE_TEXT_OVERLAY_LINE_ALIGN (gst_text_overlay_line_align_get_type())

static GType

gst_text_overlay_line_align_get_type (void)

{

  static GType text_overlay_line_align_type = 0;

  static const GEnumValue text_overlay_line_align[] = {

    {GST_TEXT_OVERLAY_LINE_ALIGN_LEFT, "left", "left"},

    {GST_TEXT_OVERLAY_LINE_ALIGN_CENTER, "center", "center"},

    {GST_TEXT_OVERLAY_LINE_ALIGN_RIGHT, "right", "right"},

    {0, NULL, NULL}

  };

  if (!text_overlay_line_align_type) {

    text_overlay_line_align_type =

        g_enum_register_static ("GstTextOverlayLineAlign",

        text_overlay_line_align);

  }

  return text_overlay_line_align_type;

}

/* These macros are adapted from videotestsrc.c */

#define I420_Y_ROWSTRIDE(width) (GST_ROUND_UP_4(width))

#define I420_U_ROWSTRIDE(width) (GST_ROUND_UP_8(width)/2)

#define I420_V_ROWSTRIDE(width) ((GST_ROUND_UP_8(I420_Y_ROWSTRIDE(width)))/2)

#define I420_Y_OFFSET(w,h) (0)

#define I420_U_OFFSET(w,h) (I420_Y_OFFSET(w,h)+(I420_Y_ROWSTRIDE(w)*GST_ROUND_UP_2(h)))

#define I420_V_OFFSET(w,h) (I420_U_OFFSET(w,h)+(I420_U_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))

#define I420_SIZE(w,h)     (I420_V_OFFSET(w,h)+(I420_V_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))

#define GST_TEXT_OVERLAY_GET_COND(ov) (((GstTextOverlay *)ov)->cond)

#define GST_TEXT_OVERLAY_WAIT(ov)     (g_cond_wait (GST_TEXT_OVERLAY_GET_COND (ov), GST_OBJECT_GET_LOCK (ov)))

#define GST_TEXT_OVERLAY_SIGNAL(ov)   (g_cond_signal (GST_TEXT_OVERLAY_GET_COND (ov)))

#define GST_TEXT_OVERLAY_BROADCAST(ov)(g_cond_broadcast (GST_TEXT_OVERLAY_GET_COND (ov)))

static GstStateChangeReturn gst_text_overlay_change_state (GstElement * element,

    GstStateChange transition);

static GstCaps *gst_text_overlay_getcaps (GstPad * pad);

static gboolean gst_text_overlay_setcaps (GstPad * pad, GstCaps * caps);

static gboolean gst_text_overlay_setcaps_txt (GstPad * pad, GstCaps * caps);

static gboolean gst_text_overlay_src_event (GstPad * pad, GstEvent * event);

static gboolean gst_text_overlay_video_event (GstPad * pad, GstEvent * event);

static GstFlowReturn gst_text_overlay_video_chain (GstPad * pad,

    GstBuffer * buffer);

static gboolean gst_text_overlay_text_event (GstPad * pad, GstEvent * event);

static GstFlowReturn gst_text_overlay_text_chain (GstPad * pad,

    GstBuffer * buffer);

static GstPadLinkReturn gst_text_overlay_text_pad_link (GstPad * pad,

    GstPad * peer);

static void gst_text_overlay_text_pad_unlink (GstPad * pad);

static void gst_text_overlay_pop_text (GstTextOverlay * overlay);

static void gst_text_overlay_finalize (GObject * object);

static void gst_text_overlay_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec);

static void gst_text_overlay_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec);

GST_BOILERPLATE (GstTextOverlay, gst_text_overlay, GstElement, GST_TYPE_ELEMENT)

     static void gst_text_overlay_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_template_factory));

  gst_element_class_add_pad_template (element_class,

      gst_static_pad_template_get (&video_sink_template_factory));

  /* ugh */

  if (!GST_IS_TIME_OVERLAY_CLASS (g_class) &&

      !GST_IS_CLOCK_OVERLAY_CLASS (g_class)) {

    gst_element_class_add_pad_template (element_class,

        gst_static_pad_template_get (&text_sink_template_factory));

  }

  gst_element_class_set_details (element_class, &text_overlay_details);

}

static gchar *

gst_text_overlay_get_text (GstTextOverlay * overlay, GstBuffer * video_frame)

{

  return g_strdup (overlay->default_text);

}

static void

gst_text_overlay_class_init (GstTextOverlayClass * klass)

{

  GObjectClass *gobject_class;

  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;

  gstelement_class = (GstElementClass *) klass;

  gobject_class->finalize = gst_text_overlay_finalize;

  gobject_class->set_property = gst_text_overlay_set_property;

  gobject_class->get_property = gst_text_overlay_get_property;

  gstelement_class->change_state =

      GST_DEBUG_FUNCPTR (gst_text_overlay_change_state);

  klass->get_text = gst_text_overlay_get_text;

  klass->pango_context = pango_ft2_get_context (72, 72);

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_TEXT,

      g_param_spec_string ("text", "text",

          "Text to be display.", DEFAULT_PROP_TEXT, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_SHADING,

      g_param_spec_boolean ("shaded-background", "shaded background",

          "Whether to shade the background under the text area",

          DEFAULT_PROP_SHADING, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_VALIGNMENT,

      g_param_spec_enum ("valignment", "vertical alignment",

          "Vertical alignment of the text",

          GST_TYPE_TEXT_OVERLAY_VALIGN, DEFAULT_PROP_VALIGNMENT,

          G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_HALIGNMENT,

      g_param_spec_enum ("halignment", "horizontal alignment",

          "Horizontal alignment of the text", GST_TYPE_TEXT_OVERLAY_HALIGN,

          DEFAULT_PROP_HALIGNMENT, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_VALIGN,

      g_param_spec_string ("valign", "vertical alignment",

          "Vertical alignment of the text (deprecated; use valignment)",

          DEFAULT_PROP_VALIGN, G_PARAM_WRITABLE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_HALIGN,

      g_param_spec_string ("halign", "horizontal alignment",

          "Horizontal alignment of the text (deprecated; use halignment)",

          DEFAULT_PROP_HALIGN, G_PARAM_WRITABLE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_XPAD,

      g_param_spec_int ("xpad", "horizontal paddding",

          "Horizontal paddding when using left/right alignment", 0, G_MAXINT,

          DEFAULT_PROP_XPAD, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_YPAD,

      g_param_spec_int ("ypad", "vertical padding",

          "Vertical padding when using top/bottom alignment", 0, G_MAXINT,

          DEFAULT_PROP_YPAD, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_DELTAX,

      g_param_spec_int ("deltax", "X position modifier",

          "Shift X position to the left or to the right. Unit is pixels.",

          G_MININT, G_MAXINT, DEFAULT_PROP_DELTAX, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_DELTAY,

      g_param_spec_int ("deltay", "Y position modifier",

          "Shift Y position up or down. Unit is pixels.", G_MININT, G_MAXINT,

          DEFAULT_PROP_DELTAY, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_WRAP_MODE,

      g_param_spec_enum ("wrap-mode", "wrap mode",

          "Whether to wrap the text and if so how.",

          GST_TYPE_TEXT_OVERLAY_WRAP_MODE, DEFAULT_PROP_WRAP_MODE,

          G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FONT_DESC,

      g_param_spec_string ("font-desc", "font description",

          "Pango font description of font to be used for rendering. "

          "See documentation of pango_font_description_from_string "

          "for syntax.", DEFAULT_PROP_FONT_DESC, G_PARAM_WRITABLE));

  /**

   * GstTextOverlay:line-alignment

   *

   * Alignment of text lines relative to each other (for multi-line text)

   *

   * Since: 0.10.15

   **/

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_LINE_ALIGNMENT,

      g_param_spec_enum ("line-alignment", "line alignment",

          "Alignment of text lines relative to each other.",

          GST_TYPE_TEXT_OVERLAY_LINE_ALIGN, DEFAULT_PROP_LINE_ALIGNMENT,

          G_PARAM_READWRITE));

  /**

   * GstTextOverlay:silent

   *

   * If set, no text is rendered. Useful to switch off text rendering

   * temporarily without removing the textoverlay element from the pipeline.

   *

   * Since: 0.10.15

   **/

  /* FIXME 0.11: rename to "visible" or "text-visible" or "render-text" */

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_SILENT,

      g_param_spec_boolean ("silent", "silent",

          "Whether to render the text string",

          DEFAULT_PROP_SILENT, G_PARAM_READWRITE));

}

static void

gst_text_overlay_finalize (GObject * object)

{

  GstTextOverlay *overlay = GST_TEXT_OVERLAY (object);

  g_free (overlay->default_text);

  g_free (overlay->bitmap.buffer);

  if (overlay->layout) {

    g_object_unref (overlay->layout);

    overlay->layout = NULL;

  }

  if (overlay->segment) {

    gst_segment_free (overlay->segment);

    overlay->segment = NULL;

  }

  if (overlay->text_buffer) {

    gst_buffer_unref (overlay->text_buffer);

    overlay->text_buffer = NULL;

  }

  if (overlay->cond) {

    g_cond_free (overlay->cond);

    overlay->cond = NULL;

  }

  G_OBJECT_CLASS (parent_class)->finalize (object);

}

static void

gst_text_overlay_init (GstTextOverlay * overlay, GstTextOverlayClass * klass)

{

  GstPadTemplate *template;

  /* video sink */

  template = gst_static_pad_template_get (&video_sink_template_factory);

  overlay->video_sinkpad = gst_pad_new_from_template (template, "video_sink");

  gst_object_unref (template);

  gst_pad_set_getcaps_function (overlay->video_sinkpad,

      GST_DEBUG_FUNCPTR (gst_text_overlay_getcaps));

  gst_pad_set_setcaps_function (overlay->video_sinkpad,

      GST_DEBUG_FUNCPTR (gst_text_overlay_setcaps));

  gst_pad_set_event_function (overlay->video_sinkpad,

      GST_DEBUG_FUNCPTR (gst_text_overlay_video_event));

  gst_pad_set_chain_function (overlay->video_sinkpad,

      GST_DEBUG_FUNCPTR (gst_text_overlay_video_chain));

  gst_element_add_pad (GST_ELEMENT (overlay), overlay->video_sinkpad);

  if (!GST_IS_TIME_OVERLAY_CLASS (klass) && !GST_IS_CLOCK_OVERLAY_CLASS (klass)) {

    /* text sink */

    template = gst_static_pad_template_get (&text_sink_template_factory);

    overlay->text_sinkpad = gst_pad_new_from_template (template, "text_sink");

    gst_object_unref (template);

    gst_pad_set_setcaps_function (overlay->text_sinkpad,

        GST_DEBUG_FUNCPTR (gst_text_overlay_setcaps_txt));

    gst_pad_set_event_function (overlay->text_sinkpad,

        GST_DEBUG_FUNCPTR (gst_text_overlay_text_event));

    gst_pad_set_chain_function (overlay->text_sinkpad,

        GST_DEBUG_FUNCPTR (gst_text_overlay_text_chain));

    gst_pad_set_link_function (overlay->text_sinkpad,

        GST_DEBUG_FUNCPTR (gst_text_overlay_text_pad_link));

    gst_pad_set_unlink_function (overlay->text_sinkpad,

        GST_DEBUG_FUNCPTR (gst_text_overlay_text_pad_unlink));

    gst_element_add_pad (GST_ELEMENT (overlay), overlay->text_sinkpad);

  }

  /* (video) source */

  template = gst_static_pad_template_get (&src_template_factory);

  overlay->srcpad = gst_pad_new_from_template (template, "src");

  gst_object_unref (template);

  gst_pad_set_getcaps_function (overlay->srcpad,

      GST_DEBUG_FUNCPTR (gst_text_overlay_getcaps));

  gst_pad_set_event_function (overlay->srcpad,

      GST_DEBUG_FUNCPTR (gst_text_overlay_src_event));

  gst_element_add_pad (GST_ELEMENT (overlay), overlay->srcpad);

  overlay->line_align = DEFAULT_PROP_LINE_ALIGNMENT;

  overlay->layout =

      pango_layout_new (GST_TEXT_OVERLAY_GET_CLASS (overlay)->pango_context);

  pango_layout_set_alignment (overlay->layout,

      (PangoAlignment) overlay->line_align);

  memset (&overlay->bitmap, 0, sizeof (overlay->bitmap));

  overlay->halign = DEFAULT_PROP_HALIGNMENT;

  overlay->valign = DEFAULT_PROP_VALIGNMENT;

  overlay->xpad = DEFAULT_PROP_XPAD;

  overlay->ypad = DEFAULT_PROP_YPAD;

  overlay->deltax = DEFAULT_PROP_DELTAX;

  overlay->deltay = DEFAULT_PROP_DELTAY;

  overlay->wrap_mode = DEFAULT_PROP_WRAP_MODE;

  overlay->want_shading = DEFAULT_PROP_SHADING;

  overlay->shading_value = DEFAULT_SHADING_VALUE;

  overlay->silent = DEFAULT_PROP_SILENT;

  overlay->default_text = g_strdup (DEFAULT_PROP_TEXT);

  overlay->need_render = TRUE;

  overlay->fps_n = 0;

  overlay->fps_d = 1;

  overlay->text_buffer = NULL;

  overlay->text_linked = FALSE;

  overlay->video_flushing = FALSE;

  overlay->text_flushing = FALSE;

  overlay->text_eos = FALSE;

  overlay->cond = g_cond_new ();

  overlay->segment = gst_segment_new ();

  if (overlay->segment) {

    gst_segment_init (overlay->segment, GST_FORMAT_TIME);

  } else {

    GST_WARNING_OBJECT (overlay, "segment creation failed");

    g_assert_not_reached ();

  }

}