cairo: Add cairo-based PDF/PS/SVG encoder element

Fixes bug #331420.

ext/cairo/Makefile.am

@@ -1,11 +1,12 @@
 plugin_LTLIBRARIES = libgstcairo.la
 
-noinst_HEADERS = gsttimeoverlay.h gsttextoverlay.h
+noinst_HEADERS = gsttimeoverlay.h gsttextoverlay.h gstcairorender.h
 
 libgstcairo_la_SOURCES = \
 	gstcairo.c \
 	gsttimeoverlay.c \
-	gsttextoverlay.c
+	gsttextoverlay.c \
+	gstcairorender.c
 
 libgstcairo_la_CFLAGS = \
         $(GST_PLUGINS_BASE_CFLAGS) \

ext/cairo/gstcairo.c

@@ -24,6 +24,7 @@
 
 #include <gsttimeoverlay.h>
 #include <gsttextoverlay.h>
+#include <gstcairorender.h>
 #include <string.h>
 #include <math.h>
 
@@ -36,6 +37,8 @@ plugin_init (GstPlugin * plugin)
       GST_TYPE_CAIRO_TEXT_OVERLAY);
   gst_element_register (plugin, "cairotimeoverlay", GST_RANK_NONE,
       GST_TYPE_CAIRO_TIME_OVERLAY);
+  gst_element_register (plugin, "cairorender", GST_RANK_SECONDARY,
+      GST_TYPE_CAIRO_RENDER);
 
   GST_DEBUG_CATEGORY_INIT (cairo_debug, "cairo", 0, "Cairo elements");
 
@@ -43,5 +46,5 @@ plugin_init (GstPlugin * plugin)
 }
 
 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR, "cairo",
-    "Cairo-based overlaying", plugin_init, VERSION,
+    "Cairo-based elements", plugin_init, VERSION,
     GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);

ext/cairo/gstcairorender.c

@@ -0,0 +1,419 @@
+/* GStreamer
+ *
+ * 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.
+ */
+#include "gstcairorender.h"
+
+#include <cairo.h>
+#include <cairo-features.h>
+#ifdef CAIRO_HAS_PS_SURFACE
+#include <cairo-ps.h>
+#endif
+#ifdef CAIRO_HAS_PDF_SURFACE
+#include <cairo-pdf.h>
+#endif
+#ifdef CAIRO_HAS_SVG_SURFACE
+#include <cairo-svg.h>
+#endif
+
+#include <gst/video/video.h>
+
+#include <string.h>
+
+struct _GstCairoRender
+{
+  GstElement parent;
+
+  GstPad *snk, *src;
+
+  /* Source */
+  cairo_surface_t *surface;
+  guint width, height;
+
+  /* Sink */
+  gint64 offset, duration;
+  gboolean png;
+  cairo_format_t format;
+};
+
+struct _GstCairoRenderClass
+{
+  GstElementClass parent_class;
+};
+
+GST_DEBUG_CATEGORY_STATIC (cairo_render_debug);
+#define GST_CAT_DEFAULT cairo_render_debug
+
+static gboolean
+gst_cairo_render_event (GstPad * pad, GstEvent * e)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (GST_PAD_PARENT (pad));
+
+  switch (GST_EVENT_TYPE (e)) {
+    case GST_EVENT_EOS:
+      if (c->surface)
+        cairo_surface_finish (c->surface);
+      break;
+    default:
+      break;
+  }
+  return gst_pad_event_default (pad, e);
+}
+
+static cairo_status_t
+write_func (void *closure, const unsigned char *data, unsigned int length)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (closure);
+  GstBuffer *buf;
+  GstFlowReturn r;
+
+  buf = gst_buffer_new ();
+  gst_buffer_set_data (buf, (guint8 *) data, length);
+  gst_buffer_set_caps (buf, GST_PAD_CAPS (c->src));
+  if ((r = gst_pad_push (c->src, buf)) != GST_FLOW_OK) {
+    GST_DEBUG_OBJECT (c, "Could not pass on buffer: %s.",
+        gst_flow_get_name (r));
+    return CAIRO_STATUS_WRITE_ERROR;
+  }
+  return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+read_func (void *closure, unsigned char *data, unsigned int length)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (closure);
+  GstBuffer *buf;
+
+  if (gst_pad_pull_range (c->snk, c->offset, length, &buf) != GST_FLOW_OK)
+    return CAIRO_STATUS_READ_ERROR;
+  c->offset += GST_BUFFER_SIZE (buf);
+  memcpy (data, GST_BUFFER_DATA (buf), length);
+  gst_buffer_unref (buf);
+  return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+read_buffer (void *closure, unsigned char *data, unsigned int length)
+{
+  GstBuffer *buf = GST_BUFFER (closure);
+
+  if (GST_BUFFER_OFFSET (buf) + length > GST_BUFFER_SIZE (buf))
+    return CAIRO_STATUS_READ_ERROR;
+  memcpy (data, GST_BUFFER_DATA (buf) + GST_BUFFER_OFFSET (buf), length);
+  GST_BUFFER_OFFSET (buf) += length;
+  return CAIRO_STATUS_SUCCESS;
+}
+
+static gboolean
+gst_cairo_render_push_surface (GstCairoRender * c, cairo_surface_t * surface)
+{
+  cairo_status_t s = 0;
+  cairo_t *cr;
+
+  if (!c->surface) {
+    s = cairo_surface_write_to_png_stream (surface, write_func, c);
+    cairo_surface_destroy (surface);
+    if (s != CAIRO_STATUS_SUCCESS) {
+      GST_DEBUG_OBJECT (c, "Could not create PNG stream: %s.",
+          cairo_status_to_string (s));
+      return FALSE;
+    }
+    return TRUE;
+  }
+
+  cr = cairo_create (c->surface);
+  cairo_set_source_surface (cr, surface, 0, 0);
+  cairo_paint (cr);
+  cairo_show_page (cr);
+  cairo_destroy (cr);
+  cairo_surface_destroy (surface);
+  return (TRUE);
+}
+
+static GstFlowReturn
+gst_cairo_render_chain (GstPad * pad, GstBuffer * buf)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (GST_PAD_PARENT (pad));
+  cairo_surface_t *s;
+  gboolean success;
+
+  if (c->png) {
+    GST_BUFFER_OFFSET (buf) = 0;
+    s = cairo_image_surface_create_from_png_stream (read_buffer, buf);
+  } else
+    s = cairo_image_surface_create_for_data (GST_BUFFER_DATA (buf),
+        c->format, c->width, c->height, c->width);
+  success = gst_cairo_render_push_surface (c, s);
+  gst_buffer_unref (buf);
+  return success ? GST_FLOW_OK : GST_FLOW_ERROR;
+}
+
+static gboolean
+gst_cairo_render_activate_sink (GstPad * pad)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (GST_PAD_PARENT (pad));
+  GstFormat format = GST_FORMAT_BYTES;
+
+  if (c->png) {
+    if (!gst_pad_check_pull_range (pad)) {
+      GST_DEBUG_OBJECT (c, "We do not have random access. "
+          "Let's hope each buffer we receive contains a whole png image.");
+      return gst_pad_activate_push (pad, TRUE);
+    }
+    if (!gst_pad_query_peer_duration (c->snk, &format, &c->duration)) {
+      GST_DEBUG_OBJECT (c, "Could not query duration. "
+          "Let's hope each buffer we receive contains a whole png image.");
+      return gst_pad_activate_push (pad, TRUE);
+    }
+    return gst_pad_activate_pull (pad, TRUE);
+  }
+  return gst_pad_activate_push (pad, TRUE);
+}
+
+static gboolean
+gst_cairo_render_setcaps_sink (GstPad * pad, GstCaps * caps)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (GST_PAD_PARENT (pad));
+  const GValue *value;
+  GstStructure *s = gst_caps_get_structure (caps, 0);
+  const gchar *mime = gst_structure_get_name (s);
+
+  GST_DEBUG_OBJECT (c, "Got caps (%s).", mime);
+  if ((c->png = !strcmp (mime, "image/png")))
+    return TRUE;
+
+  /* Width and height */
+  value = gst_structure_get_value (s, "width");
+  if (!value || !G_VALUE_HOLDS_INT (value)) {
+    GST_DEBUG_OBJECT (c, "Width is missing.");
+    return FALSE;
+  }
+  c->width = g_value_get_int (value);
+  value = gst_structure_get_value (s, "height");
+  if (!value || !G_VALUE_HOLDS_INT (value)) {
+    GST_DEBUG_OBJECT (c, "Height is missing.");
+    return FALSE;
+  }
+  c->height = g_value_get_int (value);
+
+  /* Colorspace
+   * FIXME: I couldn't figure out the right caps. The solution below
+   * results in a black and white result which is better than nothing.
+   * If you know how to fix this, please do it. */
+  if (!strcmp (mime, "video/x-raw-yuv"))
+    c->format = CAIRO_FORMAT_A8;
+  else if (!strcmp (mime, "video/x-raw-rgb"))
+    c->format = CAIRO_FORMAT_RGB24;
+  else {
+    GST_DEBUG_OBJECT (c, "Unknown mime type '%s'.", mime);
+    return FALSE;
+  }
+
+  /* Framerate */
+  value = gst_structure_get_value (s, "framerate");
+  if (value && GST_VALUE_HOLDS_FRACTION (value)) {
+    caps = gst_pad_get_allowed_caps (c->src);
+    s = gst_caps_get_structure (caps, 0);
+    gst_structure_set_value (s, "framerate", value);
+    gst_pad_set_caps (c->src, caps);
+    gst_caps_unref (caps);
+  }
+  return TRUE;
+}
+
+static void
+gst_cairo_render_loop (gpointer data)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (data);
+
+  if (c->offset >= c->duration) {
+    gst_pad_pause_task (c->snk);
+    gst_pad_send_event (c->snk, gst_event_new_eos ());
+    return;
+  }
+
+  if (!gst_cairo_render_push_surface (c,
+          cairo_image_surface_create_from_png_stream (read_func, c))) {
+    GST_DEBUG_OBJECT (c, "Could not push image.");
+    gst_pad_pause_task (c->snk);
+    gst_pad_send_event (c->snk, gst_event_new_eos ());
+  }
+}
+
+static gboolean
+gst_cairo_render_activatepull_sink (GstPad * pad, gboolean active)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (GST_PAD_PARENT (pad));
+
+  if (active) {
+    c->offset = 0;
+    return gst_pad_start_task (pad, gst_cairo_render_loop, c);
+  } else
+    return gst_pad_stop_task (pad);
+}
+
+static gboolean
+gst_cairo_render_setcaps_src (GstPad * pad, GstCaps * caps)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (GST_PAD_PARENT (pad));
+  const GValue *value;
+  GstStructure *s = gst_caps_get_structure (caps, 0);
+  const gchar *mime = gst_structure_get_name (s);
+  gdouble w = 256, h = 256;
+
+  if (c->surface) {
+    cairo_surface_destroy (c->surface);
+    c->surface = NULL;
+  }
+#if CAIRO_HAS_PNG_FUNCTIONS
+  if (!strcmp (mime, "image/png"))
+    return TRUE;
+#endif
+  value = gst_structure_get_value (s, "width");
+  if (!value || !G_VALUE_HOLDS_INT (value)) {
+    GST_DEBUG_OBJECT (c, "Width is missing.");
+    return FALSE;
+  }
+  w = g_value_get_int (value);
+  value = gst_structure_get_value (s, "height");
+  if (!value || !G_VALUE_HOLDS_INT (value)) {
+    GST_DEBUG_OBJECT (c, "Height is missing.");
+    return FALSE;
+  }
+  h = g_value_get_int (value);
+
+#if CAIRO_HAS_PS_SURFACE
+  if (!strcmp (mime, "application/postscript")) {
+    c->surface = cairo_ps_surface_create_for_stream (write_func, c, w, h);
+    return TRUE;
+  }
+#endif
+#if CAIRO_HAS_PDF_SURFACE
+  if (!strcmp (mime, "application/x-pdf")) {
+    c->surface = cairo_pdf_surface_create_for_stream (write_func, c, w, h);
+    return TRUE;
+  }
+#endif
+#if CAIRO_HAS_SVG_SURFACE
+  if (!strcmp (mime, "image/svg")) {
+    c->surface = cairo_svg_surface_create_for_stream (write_func, c, w, h);
+    return TRUE;
+  }
+#endif
+  return FALSE;
+}
+
+static GstElementDetails cairo_render_details =
+GST_ELEMENT_DETAILS ("CAIRO encoder",
+    "Codec/Encoder", "Encodes streams using CAIRO",
+    "Lutz Mueller <lutz@topfrose.de>");
+
+static GstStaticPadTemplate t_src = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS (
+#if CAIRO_HAS_PDF_SURFACE
+        "application/x-pdf, "
+        "width = (int) [ 1, MAX], " "height = (int) [ 1, MAX] "
+#endif
+#if CAIRO_HAS_PDF_SURFACE && (CAIRO_HAS_PS_SURFACE || CAIRO_HAS_SVG_SURFACE || CAIRO_HAS_PNG_FUNCTIONS)
+        ";"
+#endif
+#if CAIRO_HAS_PS_SURFACE
+        "application/postscript, "
+        "width = (int) [ 1, MAX], " "height = (int) [ 1, MAX] "
+#endif
+#if (CAIRO_HAS_PDF_SURFACE || CAIRO_HAS_PS_SURFACE) && (CAIRO_HAS_SVG_SURFACE || CAIRO_HAS_PNG_FUNCTIONS)
+        ";"
+#endif
+#if CAIRO_HAS_SVG_SURFACE
+        "application/svg, "
+        "width = (int) [ 1, MAX], " "height = (int) [ 1, MAX] "
+#endif
+#if (CAIRO_HAS_PDF_SURFACE || CAIRO_HAS_PS_SURFACE || CAIRO_HAS_SVG_SURFACE) && CAIRO_HAS_PNG_FUNCTIONS
+        ";"
+#endif
+#if CAIRO_HAS_PNG_FUNCTIONS
+        "image/png"
+#endif
+    ));
+static GstStaticPadTemplate t_snk = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420")
+#if CAIRO_HAS_PNG_FUNCTIONS
+        ";image/png"
+#endif
+    ));
+
+GST_BOILERPLATE (GstCairoRender, gst_cairo_render, GstElement,
+    GST_TYPE_ELEMENT);
+
+static void
+gst_cairo_render_init (GstCairoRender * c, GstCairoRenderClass * klass)
+{
+  /* The sink */
+  c->snk =
+      gst_pad_new_from_template (gst_static_pad_template_get (&t_snk), "sink");
+  gst_pad_set_event_function (c->snk, gst_cairo_render_event);
+  gst_pad_set_chain_function (c->snk, gst_cairo_render_chain);
+  gst_pad_set_activate_function (c->snk, gst_cairo_render_activate_sink);
+  gst_pad_set_activatepull_function (c->snk,
+      gst_cairo_render_activatepull_sink);
+  gst_pad_set_setcaps_function (c->snk, gst_cairo_render_setcaps_sink);
+  gst_pad_use_fixed_caps (c->snk);
+  gst_element_add_pad (GST_ELEMENT (c), c->snk);
+
+  /* The source */
+  c->src =
+      gst_pad_new_from_template (gst_static_pad_template_get (&t_src), "src");
+  gst_pad_set_setcaps_function (c->src, gst_cairo_render_setcaps_src);
+  gst_pad_use_fixed_caps (c->src);
+  gst_element_add_pad (GST_ELEMENT (c), c->src);
+
+  c->width = 256;
+  c->height = 256;
+}
+
+static void
+gst_cairo_render_base_init (gpointer g_class)
+{
+  GstElementClass *ec = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details (ec, &cairo_render_details);
+  gst_element_class_add_pad_template (ec, gst_static_pad_template_get (&t_snk));
+  gst_element_class_add_pad_template (ec, gst_static_pad_template_get (&t_src));
+}
+
+static void
+gst_cairo_render_finalize (GObject * object)
+{
+  GstCairoRender *c = GST_CAIRO_RENDER (object);
+
+  if (c->surface) {
+    cairo_surface_destroy (c->surface);
+    c->surface = NULL;
+  }
+
+  G_OBJECT_CLASS (parent_class)->finalize (object);
+}
+
+static void
+gst_cairo_render_class_init (GstCairoRenderClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  gobject_class->finalize = gst_cairo_render_finalize;
+
+  GST_DEBUG_CATEGORY_INIT (cairo_render_debug, "cairo_render", 0,
+      "CAIRO encoder");
+}

ext/cairo/gstcairorender.h

@@ -0,0 +1,37 @@
+/* cairorender: CAIRO plugin for GStreamer
+ *
+ * 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.
+ */
+
+#ifndef __GST_CAIRO_RENDER_H_
+#define __GST_CAIRO_RENDER_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_CAIRO_RENDER         (gst_cairo_render_get_type())
+#define GST_CAIRO_RENDER(obj)         (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CAIRO_RENDER,GstCairoRender))
+#define GST_CAIRO_RENDER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CAIRO_RENDER,GstCairoRenderClass))
+
+typedef struct _GstCairoRender      GstCairoRender;
+typedef struct _GstCairoRenderClass GstCairoRenderClass;
+
+GType gst_cairo_render_get_type (void) G_GNUC_CONST;
+
+G_END_DECLS
+
+#endif /* __GST_CAIRO_RENDER_H__ */