/* * GStreamer * Copyright (C) 2008 Filippo Argiolas * * 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. */ /** * SECTION:element-gloverlay * * Overlay GL video texture with a PNG image * * * Examples * |[ * gst-launch-1.0 videotestsrc ! gloverlay location=image.jpg ! glimagesink * ]| * FBO (Frame Buffer Object) is required. * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "gstgloverlay.h" #include "effects/gstgleffectssources.h" #include #include #include #include #if PNG_LIBPNG_VER >= 10400 #define int_p_NULL NULL #define png_infopp_NULL NULL #endif #define GST_CAT_DEFAULT gst_gl_overlay_debug GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT); #define DEBUG_INIT \ GST_DEBUG_CATEGORY_INIT (gst_gl_overlay_debug, "gloverlay", 0, "gloverlay element"); G_DEFINE_TYPE_WITH_CODE (GstGLOverlay, gst_gl_overlay, GST_TYPE_GL_FILTER, DEBUG_INIT); static gboolean gst_gl_overlay_set_caps (GstGLFilter * filter, GstCaps * incaps, GstCaps * outcaps); static void gst_gl_overlay_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_gl_overlay_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static void gst_gl_overlay_reset_resources (GstGLFilter * filter); static void gst_gl_overlay_before_transform (GstBaseTransform * trans, GstBuffer * outbuf); static gboolean gst_gl_overlay_filter_texture (GstGLFilter * filter, guint in_tex, guint out_tex); static gint gst_gl_overlay_load_png (GstGLFilter * filter); static gint gst_gl_overlay_load_jpeg (GstGLFilter * filter); enum { PROP_0, PROP_LOCATION, PROP_OFFSET_X, PROP_OFFSET_Y, PROP_RELATIVE_X, PROP_RELATIVE_Y, PROP_OVERLAY_WIDTH, PROP_OVERLAY_HEIGHT, PROP_ALPHA }; /* *INDENT-OFF* */ /* vertex source */ static const gchar *overlay_v_src = "attribute vec4 a_position;\n" "attribute vec2 a_texcoord;\n" "varying vec2 v_texcoord;\n" "void main()\n" "{\n" " gl_Position = a_position;\n" " v_texcoord = a_texcoord;\n" "}"; /* fragment source */ static const gchar *overlay_f_src = "#ifdef GL_ES\n" "precision mediump float;\n" "#endif\n" "uniform sampler2D texture;\n" "uniform float alpha;\n" "varying vec2 v_texcoord;\n" "void main()\n" "{\n" " vec4 rgba = texture2D( texture, v_texcoord );\n" " gl_FragColor = vec4(rgba.rgb, rgba.a * alpha);\n" "}\n"; /* *INDENT-ON* */ /* init resources that need a gl context */ static gboolean gst_gl_overlay_init_gl_resources (GstGLFilter * filter) { GstGLOverlay *overlay = GST_GL_OVERLAY (filter); if (overlay->shader) gst_gl_context_del_shader (filter->context, overlay->shader); return gst_gl_context_gen_shader (filter->context, overlay_v_src, overlay_f_src, &overlay->shader); } /* free resources that need a gl context */ static void gst_gl_overlay_reset_gl_resources (GstGLFilter * filter) { GstGLOverlay *overlay = GST_GL_OVERLAY (filter); const GstGLFuncs *gl = filter->context->gl_vtable; if (overlay->shader) { gst_gl_context_del_shader (filter->context, overlay->shader); overlay->shader = NULL; } if (overlay->image_memory) { gst_memory_unref ((GstMemory *) overlay->image_memory); overlay->image_memory = NULL; } if (overlay->vao) { gl->DeleteVertexArrays (1, &overlay->vao); overlay->vao = 0; } if (overlay->vbo) { gl->DeleteBuffers (1, &overlay->vbo); overlay->vbo = 0; } if (overlay->overlay_vao) { gl->DeleteVertexArrays (1, &overlay->overlay_vao); overlay->overlay_vao = 0; } if (overlay->overlay_vbo) { gl->DeleteBuffers (1, &overlay->overlay_vbo); overlay->overlay_vbo = 0; } } static void gst_gl_overlay_class_init (GstGLOverlayClass * klass) { GObjectClass *gobject_class; GstElementClass *element_class; gobject_class = (GObjectClass *) klass; element_class = GST_ELEMENT_CLASS (klass); gobject_class->set_property = gst_gl_overlay_set_property; gobject_class->get_property = gst_gl_overlay_get_property; GST_GL_FILTER_CLASS (klass)->set_caps = gst_gl_overlay_set_caps; GST_GL_FILTER_CLASS (klass)->filter_texture = gst_gl_overlay_filter_texture; GST_GL_FILTER_CLASS (klass)->display_reset_cb = gst_gl_overlay_reset_gl_resources; GST_GL_FILTER_CLASS (klass)->onStop = gst_gl_overlay_reset_resources; GST_GL_FILTER_CLASS (klass)->onInitFBO = gst_gl_overlay_init_gl_resources; GST_BASE_TRANSFORM_CLASS (klass)->before_transform = GST_DEBUG_FUNCPTR (gst_gl_overlay_before_transform); g_object_class_install_property (gobject_class, PROP_LOCATION, g_param_spec_string ("location", "location", "Location of image file to overlay", NULL, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_OFFSET_X, g_param_spec_int ("offset-x", "X Offset", "For positive value, horizontal offset of overlay image in pixels from" " left of video image. For negative value, horizontal offset of overlay" " image in pixels from right of video image", G_MININT, G_MAXINT, 0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_OFFSET_Y, g_param_spec_int ("offset-y", "Y Offset", "For positive value, vertical offset of overlay image in pixels from" " top of video image. For negative value, vertical offset of overlay" " image in pixels from bottom of video image", G_MININT, G_MAXINT, 0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_RELATIVE_X, g_param_spec_double ("relative-x", "Relative X Offset", "Horizontal offset of overlay image in fractions of video image " "width, from top-left corner of video image", 0.0, 1.0, 0.0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_RELATIVE_Y, g_param_spec_double ("relative-y", "Relative Y Offset", "Vertical offset of overlay image in fractions of video image " "height, from top-left corner of video image", 0.0, 1.0, 0.0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_OVERLAY_WIDTH, g_param_spec_int ("overlay-width", "Overlay Width", "Width of overlay image in pixels (0 = same as overlay image)", 0, G_MAXINT, 0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_OVERLAY_HEIGHT, g_param_spec_int ("overlay-height", "Overlay Height", "Height of overlay image in pixels (0 = same as overlay image)", 0, G_MAXINT, 0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_ALPHA, g_param_spec_double ("alpha", "Alpha", "Global alpha of overlay image", 0.0, 1.0, 1.0, GST_PARAM_CONTROLLABLE | GST_PARAM_MUTABLE_PLAYING | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); gst_element_class_set_metadata (element_class, "Gstreamer OpenGL Overlay", "Filter/Effect/Video", "Overlay GL video texture with a JPEG/PNG image", "Filippo Argiolas , " "Matthew Waters "); GST_GL_FILTER_CLASS (klass)->supported_gl_api = GST_GL_API_OPENGL | GST_GL_API_GLES2 | GST_GL_API_OPENGL3; } static void gst_gl_overlay_init (GstGLOverlay * overlay) { overlay->offset_x = 0; overlay->offset_y = 0; overlay->relative_x = 0.0; overlay->relative_y = 0.0; overlay->overlay_width = 0; overlay->overlay_height = 0; overlay->alpha = 1.0; } static void gst_gl_overlay_reset_resources (GstGLFilter * filter) { } static void gst_gl_overlay_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstGLOverlay *overlay = GST_GL_OVERLAY (object); switch (prop_id) { case PROP_LOCATION: if (overlay->location != NULL) g_free (overlay->location); overlay->location_has_changed = TRUE; overlay->location = g_value_dup_string (value); break; case PROP_OFFSET_X: overlay->offset_x = g_value_get_int (value); overlay->geometry_change = TRUE; break; case PROP_OFFSET_Y: overlay->offset_y = g_value_get_int (value); overlay->geometry_change = TRUE; break; case PROP_RELATIVE_X: overlay->relative_x = g_value_get_double (value); overlay->geometry_change = TRUE; break; case PROP_RELATIVE_Y: overlay->relative_y = g_value_get_double (value); overlay->geometry_change = TRUE; break; case PROP_OVERLAY_WIDTH: overlay->overlay_width = g_value_get_int (value); overlay->geometry_change = TRUE; break; case PROP_OVERLAY_HEIGHT: overlay->overlay_height = g_value_get_int (value); overlay->geometry_change = TRUE; break; case PROP_ALPHA: overlay->alpha = g_value_get_double (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_gl_overlay_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstGLOverlay *overlay = GST_GL_OVERLAY (object); switch (prop_id) { case PROP_LOCATION: g_value_set_string (value, overlay->location); break; case PROP_OFFSET_X: g_value_set_int (value, overlay->offset_x); break; case PROP_OFFSET_Y: g_value_set_int (value, overlay->offset_y); break; case PROP_RELATIVE_X: g_value_set_double (value, overlay->relative_x); break; case PROP_RELATIVE_Y: g_value_set_double (value, overlay->relative_y); break; case PROP_OVERLAY_WIDTH: g_value_set_int (value, overlay->overlay_width); break; case PROP_OVERLAY_HEIGHT: g_value_set_int (value, overlay->overlay_height); break; case PROP_ALPHA: g_value_set_double (value, overlay->alpha); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static gboolean gst_gl_overlay_set_caps (GstGLFilter * filter, GstCaps * incaps, GstCaps * outcaps) { GstGLOverlay *overlay = GST_GL_OVERLAY (filter); GstStructure *s = gst_caps_get_structure (incaps, 0); gint width = 0; gint height = 0; gst_structure_get_int (s, "width", &width); gst_structure_get_int (s, "height", &height); overlay->window_width = width; overlay->window_height = height; return TRUE; } static void _unbind_buffer (GstGLOverlay * overlay) { const GstGLFuncs *gl = GST_GL_FILTER (overlay)->context->gl_vtable; gl->BindBuffer (GL_ARRAY_BUFFER, 0); gl->DisableVertexAttribArray (overlay->attr_position); gl->DisableVertexAttribArray (overlay->attr_texture); } static void _bind_buffer (GstGLOverlay * overlay, GLuint vbo) { const GstGLFuncs *gl = GST_GL_FILTER (overlay)->context->gl_vtable; gl->BindBuffer (GL_ARRAY_BUFFER, vbo); gl->EnableVertexAttribArray (overlay->attr_position); gl->EnableVertexAttribArray (overlay->attr_texture); gl->VertexAttribPointer (overlay->attr_position, 3, GL_FLOAT, GL_FALSE, 5 * sizeof (GLfloat), (void *) 0); gl->VertexAttribPointer (overlay->attr_texture, 2, GL_FLOAT, GL_FALSE, 5 * sizeof (GLfloat), (void *) (3 * sizeof (GLfloat))); } /* *INDENT-OFF* */ float v_vertices[] = { /*| Vertex | TexCoord |*/ -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, }; /* *INDENT-ON* */ static void gst_gl_overlay_callback (gint width, gint height, guint texture, gpointer stuff) { GstGLOverlay *overlay = GST_GL_OVERLAY (stuff); GstGLFilter *filter = GST_GL_FILTER (overlay); GstMapInfo map_info; guint image_tex; gboolean memory_mapped = FALSE; const GstGLFuncs *gl = filter->context->gl_vtable; GLushort indices[] = { 0, 1, 2, 0, 2, 3, }; #if GST_GL_HAVE_OPENGL if (gst_gl_context_get_gl_api (filter->context) & GST_GL_API_OPENGL) { gl->MatrixMode (GL_PROJECTION); gl->LoadIdentity (); } #endif if (gst_gl_context_get_gl_api (filter->context) & GST_GL_API_OPENGL) gl->Enable (GL_TEXTURE_2D); gl->ActiveTexture (GL_TEXTURE0); gl->BindTexture (GL_TEXTURE_2D, texture); gst_gl_shader_use (overlay->shader); gst_gl_shader_set_uniform_1f (overlay->shader, "alpha", 1.0f); gst_gl_shader_set_uniform_1i (overlay->shader, "texture", 0); overlay->attr_position = gst_gl_shader_get_attribute_location (overlay->shader, "a_position"); overlay->attr_texture = gst_gl_shader_get_attribute_location (overlay->shader, "a_texcoord"); if (!overlay->vbo) { if (gl->GenVertexArrays) { gl->GenVertexArrays (1, &overlay->vao); gl->BindVertexArray (overlay->vao); } gl->GenBuffers (1, &overlay->vbo); gl->BindBuffer (GL_ARRAY_BUFFER, overlay->vbo); gl->BufferData (GL_ARRAY_BUFFER, 4 * 5 * sizeof (GLfloat), v_vertices, GL_STATIC_DRAW); if (gl->GenVertexArrays) _bind_buffer (overlay, overlay->vbo); } if (gl->GenVertexArrays) gl->BindVertexArray (overlay->vao); else _bind_buffer (overlay, overlay->vbo); gl->DrawElements (GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices); if (!overlay->image_memory) goto out; if (!gst_memory_map ((GstMemory *) overlay->image_memory, &map_info, GST_MAP_READ | GST_MAP_GL) || map_info.data == NULL) goto out; memory_mapped = TRUE; image_tex = *(guint *) map_info.data; if (!overlay->overlay_vbo) { if (gl->GenVertexArrays) { gl->GenVertexArrays (1, &overlay->overlay_vao); gl->BindVertexArray (overlay->overlay_vao); } gl->GenBuffers (1, &overlay->overlay_vbo); gl->BindBuffer (GL_ARRAY_BUFFER, overlay->overlay_vbo); overlay->geometry_change = TRUE; } if (overlay->geometry_change) { gint render_width, render_height; gfloat x, y, image_width, image_height; /* *INDENT-OFF* */ float vertices[] = { -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, -1.0f, 1.0f, 0.0f, 0.0, 1.0f, }; /* *INDENT-ON* */ /* scale from [0, 1] -> [-1, 1] */ x = ((gfloat) overlay->offset_x / (gfloat) overlay->window_width + overlay->relative_x) * 2.0f - 1.0; y = ((gfloat) overlay->offset_y / (gfloat) overlay->window_height + overlay->relative_y) * 2.0f - 1.0; /* scale from [0, 1] -> [0, 2] */ render_width = overlay->overlay_width > 0 ? overlay->overlay_width : overlay->image_width; render_height = overlay->overlay_height > 0 ? overlay->overlay_height : overlay->image_height; image_width = ((gfloat) render_width / (gfloat) overlay->window_width) * 2.0f; image_height = ((gfloat) render_height / (gfloat) overlay->window_height) * 2.0f; vertices[0] = vertices[15] = x; vertices[5] = vertices[10] = x + image_width; vertices[1] = vertices[6] = y; vertices[11] = vertices[16] = y + image_height; gl->BufferData (GL_ARRAY_BUFFER, 4 * 5 * sizeof (GLfloat), vertices, GL_STATIC_DRAW); } if (gl->GenVertexArrays) { if (overlay->geometry_change) _bind_buffer (overlay, overlay->overlay_vbo); gl->BindVertexArray (overlay->overlay_vao); gl->BindBuffer (GL_ARRAY_BUFFER, 0); } else { _bind_buffer (overlay, overlay->overlay_vbo); } gl->BindTexture (GL_TEXTURE_2D, image_tex); gst_gl_shader_set_uniform_1f (overlay->shader, "alpha", overlay->alpha); gl->DrawElements (GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, indices); out: if (gl->GenVertexArrays) { gl->BindVertexArray (0); } else { _unbind_buffer (overlay); } gst_gl_context_clear_shader (filter->context); if (memory_mapped) gst_memory_unmap ((GstMemory *) overlay->image_memory, &map_info); overlay->geometry_change = FALSE; } static gboolean gst_gl_overlay_filter_texture (GstGLFilter * filter, guint in_tex, guint out_tex) { GstGLOverlay *overlay = GST_GL_OVERLAY (filter); if (overlay->location_has_changed) { if (overlay->image_memory) { gst_memory_unref ((GstMemory *) overlay->image_memory); overlay->image_memory = NULL; } if (overlay->location != NULL) { if ((overlay->type_file = gst_gl_overlay_load_png (filter)) == 0) { if ((overlay->type_file = gst_gl_overlay_load_jpeg (filter)) == 0) { return FALSE; } } } overlay->location_has_changed = FALSE; } gst_gl_filter_render_to_target (filter, TRUE, in_tex, out_tex, gst_gl_overlay_callback, overlay); return TRUE; } static void gst_gl_overlay_before_transform (GstBaseTransform * trans, GstBuffer * outbuf) { GstClockTime stream_time; stream_time = gst_segment_to_stream_time (&trans->segment, GST_FORMAT_TIME, GST_BUFFER_TIMESTAMP (outbuf)); if (GST_CLOCK_TIME_IS_VALID (stream_time)) gst_object_sync_values (GST_OBJECT (trans), stream_time); } static void user_warning_fn (png_structp png_ptr, png_const_charp warning_msg) { g_warning ("%s\n", warning_msg); } #define LOAD_ERROR(msg) { GST_WARNING ("unable to load %s: %s", overlay->location, msg); return FALSE; } static gint gst_gl_overlay_load_jpeg (GstGLFilter * filter) { GstGLOverlay *overlay = GST_GL_OVERLAY (filter); GstVideoInfo v_info; GstMapInfo map_info; FILE *fp = NULL; struct jpeg_decompress_struct cinfo; struct jpeg_error_mgr jerr; JSAMPROW j; int i; fp = fopen (overlay->location, "rb"); if (!fp) { g_error ("error: couldn't open file!\n"); return 0; } jpeg_create_decompress (&cinfo); cinfo.err = jpeg_std_error (&jerr); jpeg_stdio_src (&cinfo, fp); jpeg_read_header (&cinfo, TRUE); jpeg_start_decompress (&cinfo); overlay->image_width = cinfo.image_width; overlay->image_height = cinfo.image_height; if (cinfo.num_components == 1) gst_video_info_set_format (&v_info, GST_VIDEO_FORMAT_Y444, overlay->image_width, overlay->image_height); else gst_video_info_set_format (&v_info, GST_VIDEO_FORMAT_RGB, overlay->image_width, overlay->image_height); overlay->image_memory = (GstGLMemory *) gst_gl_memory_alloc (filter->context, NULL, &v_info, 0, NULL); if (!gst_memory_map ((GstMemory *) overlay->image_memory, &map_info, GST_MAP_WRITE)) { LOAD_ERROR ("failed to map memory"); } for (i = 0; i < overlay->image_height; ++i) { j = (map_info.data + (((int) overlay->image_height - (i + 1)) * (int) overlay->image_width * cinfo.num_components)); jpeg_read_scanlines (&cinfo, &j, 1); } jpeg_finish_decompress (&cinfo); jpeg_destroy_decompress (&cinfo); gst_memory_unmap ((GstMemory *) overlay->image_memory, &map_info); fclose (fp); return 2; } static gint gst_gl_overlay_load_png (GstGLFilter * filter) { GstGLOverlay *overlay = GST_GL_OVERLAY (filter); GstVideoInfo v_info; GstMapInfo map_info; png_structp png_ptr; png_infop info_ptr; png_uint_32 width = 0; png_uint_32 height = 0; gint bit_depth = 0; gint color_type = 0; gint interlace_type = 0; png_FILE_p fp = NULL; guint y = 0; guchar **rows = NULL; gint filler; png_byte magic[8]; gint n_read; if (!filter->context) return 1; if ((fp = fopen (overlay->location, "rb")) == NULL) LOAD_ERROR ("file not found"); /* Read magic number */ n_read = fread (magic, 1, sizeof (magic), fp); if (n_read != sizeof (magic)) { fclose (fp); LOAD_ERROR ("can't read PNG magic number"); } /* Check for valid magic number */ if (png_sig_cmp (magic, 0, sizeof (magic))) { fclose (fp); LOAD_ERROR ("not a valid PNG image"); } png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (png_ptr == NULL) { fclose (fp); LOAD_ERROR ("failed to initialize the png_struct"); } png_set_error_fn (png_ptr, NULL, NULL, user_warning_fn); info_ptr = png_create_info_struct (png_ptr); if (info_ptr == NULL) { fclose (fp); png_destroy_read_struct (&png_ptr, png_infopp_NULL, png_infopp_NULL); LOAD_ERROR ("failed to initialize the memory for image information"); } png_init_io (png_ptr, fp); png_set_sig_bytes (png_ptr, sizeof (magic)); png_read_info (png_ptr, info_ptr); png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, int_p_NULL, int_p_NULL); if (color_type == PNG_COLOR_TYPE_RGB) { filler = 0xff; png_set_filler (png_ptr, filler, PNG_FILLER_AFTER); color_type = PNG_COLOR_TYPE_RGB_ALPHA; } if (color_type != PNG_COLOR_TYPE_RGB_ALPHA) { fclose (fp); png_destroy_read_struct (&png_ptr, png_infopp_NULL, png_infopp_NULL); LOAD_ERROR ("color type is not rgb"); } overlay->image_width = width; overlay->image_height = height; gst_video_info_set_format (&v_info, GST_VIDEO_FORMAT_RGBA, width, height); overlay->image_memory = (GstGLMemory *) gst_gl_memory_alloc (filter->context, NULL, &v_info, 0, NULL); if (!gst_memory_map ((GstMemory *) overlay->image_memory, &map_info, GST_MAP_WRITE)) { LOAD_ERROR ("failed to map memory"); } rows = (guchar **) malloc (sizeof (guchar *) * height); for (y = 0; y < height; ++y) rows[y] = (guchar *) (map_info.data + y * width * 4); png_read_image (png_ptr, rows); free (rows); gst_memory_unmap ((GstMemory *) overlay->image_memory, &map_info); png_read_end (png_ptr, info_ptr); png_destroy_read_struct (&png_ptr, &info_ptr, png_infopp_NULL); fclose (fp); return 1; }