gstreamer/ext/snapshot/gstsnapshot.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * 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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <inttypes.h>

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

#define MAX_HEIGHT      2048

static GstStaticPadTemplate snapshot_src_factory =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB)
    );

static GstStaticPadTemplate snapshot_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB)
    );

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

enum
{
  ARG_0,
  ARG_FRAME,
  ARG_LOCATION
};

static GType gst_snapshot_get_type (void);
static void gst_snapshot_base_init (gpointer g_class);
static void gst_snapshot_class_init (GstSnapshotClass * klass);
static void gst_snapshot_init (GstSnapshot * snapshot);

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

static void gst_snapshot_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_snapshot_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static void snapshot_handler (GstElement * element);

static GstElementClass *parent_class = NULL;
static guint gst_snapshot_signals[LAST_SIGNAL] = { 0 };


static void
user_error_fn (png_structp png_ptr, png_const_charp error_msg)
{
  g_warning ("%s", error_msg);
}

static void
user_warning_fn (png_structp png_ptr, png_const_charp warning_msg)
{
  g_warning ("%s", warning_msg);
}

GType
gst_snapshot_get_type (void)
{
  static GType snapshot_type = 0;

  if (!snapshot_type) {
    static const GTypeInfo snapshot_info = {
      sizeof (GstSnapshotClass),
      gst_snapshot_base_init,
      NULL,
      (GClassInitFunc) gst_snapshot_class_init,
      NULL,
      NULL,
      sizeof (GstSnapshot),
      0,
      (GInstanceInitFunc) gst_snapshot_init,
    };

    snapshot_type =
        g_type_register_static (GST_TYPE_ELEMENT, "GstSnapshot", &snapshot_info,
        0);
  }
  return snapshot_type;
}

static void
gst_snapshot_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 (&snapshot_sink_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&snapshot_src_factory));

  gst_element_class_set_static_metadata (element_class, "Snapshot",
      "Filter/Editor/Video",
      "Dump a frame to a png file", "Jeremy SIMON <jsimon13@yahoo.fr>");
}

static void
gst_snapshot_class_init (GstSnapshotClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

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

  parent_class = g_type_class_peek_parent (klass);

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_FRAME,
      g_param_spec_long ("frame", "frame", "frame",
          0, G_MAXLONG, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LOCATION,
      g_param_spec_string ("location", "location", "location",
          0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  gst_snapshot_signals[SNAPSHOT_SIGNAL] =
      g_signal_new ("snapshot", G_TYPE_FROM_CLASS (klass),
      G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstSnapshotClass, snapshot),
      NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);

  klass->snapshot = snapshot_handler;

  gobject_class->set_property = gst_snapshot_set_property;
  gobject_class->get_property = gst_snapshot_get_property;
}

static void
snapshot_handler (GstElement * element)
{
  GstSnapshot *snapshot;

  snapshot = GST_SNAPSHOT (element);
  snapshot->snapshot_asked = TRUE;
}

static gboolean
gst_snapshot_sinkconnect (GstPad * pad, const GstCaps * caps)
{
  GstSnapshot *filter;
  gdouble fps;
  GstStructure *structure;

  filter = GST_SNAPSHOT (gst_pad_get_parent (pad));

  structure = gst_caps_get_structure (caps, 0);
  gst_structure_get_int (structure, "width", &filter->width);
  gst_structure_get_int (structure, "height", &filter->height);
  gst_structure_get_double (structure, "framerate", &fps);
  gst_structure_get_fourcc (structure, "format", &filter->format);
  filter->to_bpp = 24;

  gst_pad_try_set_caps (filter->srcpad, caps);

  return GST_PAD_LINK_OK;
}

static void
gst_snapshot_init (GstSnapshot * snapshot)
{
  snapshot->sinkpad =
      gst_pad_new_from_static_template (&snapshot_sink_factory, "sink");
  gst_pad_set_link_function (snapshot->sinkpad, gst_snapshot_sinkconnect);
  gst_pad_set_chain_function (snapshot->sinkpad, gst_snapshot_chain);
  gst_element_add_pad (GST_ELEMENT (snapshot), snapshot->sinkpad);

  snapshot->srcpad =
      gst_pad_new_from_static_template (&snapshot_src_factory, "src");
  gst_element_add_pad (GST_ELEMENT (snapshot), snapshot->srcpad);

  snapshot->cur_frame = 0;
  snapshot->frame = -1;
  snapshot->snapshot_asked = FALSE;
}


static void
gst_snapshot_chain (GstPad * pad, GstData * _data)
{
  GstBuffer *buf = GST_BUFFER (_data);
  GstSnapshot *snapshot;
  guchar *data;
  gulong size;
  gint i;
  png_byte *row_pointers[MAX_HEIGHT];
  FILE *fp;

  g_return_if_fail (pad != NULL);
  g_return_if_fail (GST_IS_PAD (pad));
  g_return_if_fail (buf != NULL);

  snapshot = GST_SNAPSHOT (GST_OBJECT_PARENT (pad));

  data = GST_BUFFER_DATA (buf);
  size = GST_BUFFER_SIZE (buf);

  GST_DEBUG ("snapshot: have buffer of %d\n", GST_BUFFER_SIZE (buf));

  snapshot->cur_frame++;
  if (snapshot->cur_frame == snapshot->frame ||
      snapshot->snapshot_asked == TRUE) {
    snapshot->snapshot_asked = FALSE;

    GST_INFO ("dumpfile : %s\n", snapshot->location);
    fp = fopen (snapshot->location, "wb");
    if (fp == NULL)
      g_warning (" Can not open %s\n", snapshot->location);
    else {
      snapshot->png_struct_ptr =
          png_create_write_struct (PNG_LIBPNG_VER_STRING, (png_voidp) NULL,
          user_error_fn, user_warning_fn);
      if (snapshot->png_struct_ptr == NULL)
        g_warning ("Failed to initialize png structure");

      snapshot->png_info_ptr =
          png_create_info_struct (snapshot->png_struct_ptr);

      if (setjmp (snapshot->png_struct_ptr->jmpbuf))
        png_destroy_write_struct (&snapshot->png_struct_ptr,
            &snapshot->png_info_ptr);

      png_set_filter (snapshot->png_struct_ptr, 0,
          PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE);
      png_init_io (snapshot->png_struct_ptr, fp);
      png_set_compression_level (snapshot->png_struct_ptr, 9);
      png_set_IHDR (snapshot->png_struct_ptr,
          snapshot->png_info_ptr,
          snapshot->width,
          snapshot->height,
          snapshot->to_bpp / 3,
          PNG_COLOR_TYPE_RGB,
          PNG_INTERLACE_NONE,
          PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);

      for (i = 0; i < snapshot->height; i++)
        row_pointers[i] = data + (snapshot->width * i * snapshot->to_bpp / 8);

      png_write_info (snapshot->png_struct_ptr, snapshot->png_info_ptr);
      png_write_image (snapshot->png_struct_ptr, row_pointers);
      png_write_end (snapshot->png_struct_ptr, NULL);
      png_destroy_info_struct (snapshot->png_struct_ptr,
          &snapshot->png_info_ptr);
      png_destroy_write_struct (&snapshot->png_struct_ptr, (png_infopp) NULL);
      fclose (fp);
    }
  }

  gst_pad_push (snapshot->srcpad, GST_DATA (buf));
}

static void
gst_snapshot_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstSnapshot *snapshot;

  g_return_if_fail (GST_IS_SNAPSHOT (object));
  snapshot = GST_SNAPSHOT (object);

  switch (prop_id) {
    case ARG_LOCATION:
      snapshot->location = g_strdup (g_value_get_string (value));
      break;
    case ARG_FRAME:
      snapshot->frame = g_value_get_long (value);
      break;
    default:
      break;
  }
}

static void
gst_snapshot_get_property (GObject * object, guint prop_id, GValue * value,
    GParamSpec * pspec)
{
  GstSnapshot *snapshot;

  g_return_if_fail (GST_IS_SNAPSHOT (object));
  snapshot = GST_SNAPSHOT (object);

  switch (prop_id) {
    case ARG_LOCATION:
      g_value_set_string (value, snapshot->location);
      break;
    case ARG_FRAME:
      g_value_set_long (value, snapshot->frame);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}


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

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    snapshot,
    "Dump a frame to a png file",
    plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)