ext/libpng/: Added png decoder.

Original commit message from CVS:
* ext/libpng/Makefile.am:
* ext/libpng/gstpng.c: (plugin_init):
* ext/libpng/gstpngdec.c: (user_error_fn), (user_warning_fn),
(gst_pngdec_get_type), (gst_pngdec_base_init),
(gst_pngdec_class_init), (gst_pngdec_sinklink), (gst_pngdec_init),
(gst_pngdec_src_getcaps), (user_read_data), (gst_pngdec_chain):
* ext/libpng/gstpngdec.h:
Added png decoder.

1 files changed, 342 insertions, 0 deletions

diff --git a/ext/libpng/gstpngdec.c b/ext/libpng/gstpngdec.c
new file mode 100644
index 00000000..0916d237
--- /dev/null
+++ b/ext/libpng/gstpngdec.c
@@ -0,0 +1,342 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * 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 <string.h>
+#include <gst/gst.h>
+#include "gstpngdec.h"
+#include <gst/video/video.h>
+
+static GstElementDetails gst_pngdec_details = {
+  "PNG decoder",
+  "Codec/Decoder/Image",
+  "Decode a png video frame to a raw image",
+  "Wim Taymans <wim@fluendo.com>",
+};
+
+
+/* Filter signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum
+{
+  ARG_0
+};
+
+static void gst_pngdec_base_init (gpointer g_class);
+static void gst_pngdec_class_init (GstPngDecClass * klass);
+static void gst_pngdec_init (GstPngDec * pngdec);
+
+static void gst_pngdec_chain (GstPad * pad, GstData * _data);
+
+static GstCaps *gst_pngdec_src_getcaps (GstPad * pad);
+
+static GstElementClass *parent_class = NULL;
+
+
+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_pngdec_get_type (void)
+{
+  static GType pngdec_type = 0;
+
+  if (!pngdec_type) {
+    static const GTypeInfo pngdec_info = {
+      sizeof (GstPngDecClass),
+      gst_pngdec_base_init,
+      NULL,
+      (GClassInitFunc) gst_pngdec_class_init,
+      NULL,
+      NULL,
+      sizeof (GstPngDec),
+      0,
+      (GInstanceInitFunc) gst_pngdec_init,
+    };
+
+    pngdec_type = g_type_register_static (GST_TYPE_ELEMENT, "GstPngDec",
+        &pngdec_info, 0);
+  }
+  return pngdec_type;
+}
+
+static GstStaticPadTemplate gst_pngdec_src_pad_template =
+    GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_RGBA ";" GST_VIDEO_CAPS_RGB)
+    );
+
+static GstStaticPadTemplate gst_pngdec_sink_pad_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("video/x-png, "
+        "width = (int) [ 16, 4096 ], "
+        "height = (int) [ 16, 4096 ], " "framerate = (double) [ 0.0, MAX ]")
+    );
+
+static void
+gst_pngdec_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 (&gst_pngdec_src_pad_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_pngdec_sink_pad_template));
+  gst_element_class_set_details (element_class, &gst_pngdec_details);
+}
+
+static void
+gst_pngdec_class_init (GstPngDecClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
+}
+
+
+static GstPadLinkReturn
+gst_pngdec_sinklink (GstPad * pad, const GstCaps * caps)
+{
+  GstPngDec *pngdec;
+  GstStructure *structure;
+
+  pngdec = GST_PNGDEC (gst_pad_get_parent (pad));
+
+  structure = gst_caps_get_structure (caps, 0);
+  gst_structure_get_double (structure, "framerate", &pngdec->fps);
+
+  return TRUE;
+}
+
+static void
+gst_pngdec_init (GstPngDec * pngdec)
+{
+  pngdec->sinkpad = gst_pad_new_from_template (gst_static_pad_template_get
+      (&gst_pngdec_sink_pad_template), "sink");
+  gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->sinkpad);
+
+  pngdec->srcpad = gst_pad_new_from_template (gst_static_pad_template_get
+      (&gst_pngdec_src_pad_template), "src");
+  gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->srcpad);
+
+  gst_pad_set_chain_function (pngdec->sinkpad, gst_pngdec_chain);
+  gst_pad_set_link_function (pngdec->sinkpad, gst_pngdec_sinklink);
+
+  gst_pad_set_getcaps_function (pngdec->srcpad, gst_pngdec_src_getcaps);
+
+  pngdec->png = NULL;
+  pngdec->info = NULL;
+
+  pngdec->color_type = -1;
+  pngdec->width = -1;
+  pngdec->height = -1;
+  pngdec->fps = -1;
+}
+
+static GstCaps *
+gst_pngdec_src_getcaps (GstPad * pad)
+{
+  GstPngDec *pngdec;
+  GstCaps *caps;
+  gint i;
+  GstPadTemplate *templ;
+  GstCaps *inter;
+
+  pngdec = GST_PNGDEC (gst_pad_get_parent (pad));
+  templ = gst_static_pad_template_get (&gst_pngdec_src_pad_template);
+  caps = gst_caps_copy (gst_pad_template_get_caps (templ));
+
+  if (pngdec->color_type != -1) {
+    GstCaps *to_inter = NULL;
+
+    switch (pngdec->color_type) {
+      case PNG_COLOR_TYPE_RGB:
+        to_inter = gst_caps_new_simple ("video/x-raw-rgb",
+            "bpp", G_TYPE_INT, 24, NULL);
+        break;
+      case PNG_COLOR_TYPE_RGB_ALPHA:
+        to_inter = gst_caps_new_simple ("video/x-raw-rgb",
+            "bpp", G_TYPE_INT, 32, NULL);
+        break;
+      case PNG_COLOR_TYPE_GRAY:
+      case PNG_COLOR_TYPE_PALETTE:
+      case PNG_COLOR_TYPE_GRAY_ALPHA:
+      default:
+        g_warning ("unsupported colortype");
+        break;
+    }
+    inter = gst_caps_intersect (caps, to_inter);
+    gst_caps_free (caps);
+    gst_caps_free (to_inter);
+    caps = inter;
+  }
+
+  for (i = 0; i < gst_caps_get_size (caps); i++) {
+    GstStructure *structure = gst_caps_get_structure (caps, i);
+
+    g_print ("%d %d\n", pngdec->width, pngdec->height);
+    if (pngdec->width != -1) {
+      gst_structure_set (structure, "width", G_TYPE_INT, pngdec->width, NULL);
+    }
+
+    if (pngdec->height != -1) {
+      gst_structure_set (structure, "height", G_TYPE_INT, pngdec->height, NULL);
+    }
+
+    if (pngdec->fps != -1) {
+      gst_structure_set (structure,
+          "framerate", G_TYPE_DOUBLE, pngdec->fps, NULL);
+    }
+  }
+
+  return caps;
+}
+
+static void
+user_read_data (png_structp png_ptr, png_bytep data, png_size_t length)
+{
+  GstPngDec *dec;
+
+  dec = GST_PNGDEC (png_ptr->io_ptr);
+
+  if (GST_BUFFER_SIZE (dec->buffer_in) < dec->offset + length) {
+    g_warning ("reading past end of buffer");
+  }
+
+  memcpy (data, GST_BUFFER_DATA (dec->buffer_in) + dec->offset, length);
+
+  dec->offset += length;
+}
+
+static void
+gst_pngdec_chain (GstPad * pad, GstData * _data)
+{
+  GstBuffer *buf = GST_BUFFER (_data);
+  GstPngDec *pngdec;
+  png_uint_32 width, height;
+  gint depth, color;
+  png_bytep *rows, inp;
+  GstBuffer *out;
+  gint i;
+
+  pngdec = GST_PNGDEC (gst_pad_get_parent (pad));
+
+  if (!GST_PAD_IS_USABLE (pngdec->srcpad)) {
+    gst_buffer_unref (buf);
+    return;
+  }
+
+  pngdec->buffer_in = buf;
+  pngdec->offset = 0;
+
+  /* initialize png struct stuff */
+  pngdec->png = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+      (png_voidp) NULL, user_error_fn, user_warning_fn);
+
+  /* FIXME: better error handling */
+  if (pngdec->png == NULL) {
+    g_warning ("Failed to initialize png structure");
+    return;
+  }
+
+  pngdec->info = png_create_info_struct (pngdec->png);
+  if (pngdec->info == NULL) {
+    g_warning ("Failed to initialize info structure");
+    png_destroy_read_struct (&(pngdec->png), (png_infopp) NULL,
+        (png_infopp) NULL);
+    return;
+  }
+
+  pngdec->endinfo = png_create_info_struct (pngdec->png);
+  if (pngdec->endinfo == NULL) {
+    g_warning ("Failed to initialize endinfo structure");
+    return;
+  }
+
+  /* non-0 return is from a longjmp inside of libpng */
+  if (setjmp (pngdec->png->jmpbuf) != 0) {
+    GST_DEBUG ("returning from longjmp");
+    png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo);
+    return;
+  }
+
+  png_set_read_fn (pngdec->png, pngdec, user_read_data);
+
+  png_read_info (pngdec->png, pngdec->info);
+  png_get_IHDR (pngdec->png, pngdec->info, &width, &height,
+      &depth, &color, NULL, NULL, NULL);
+
+  GST_LOG ("color type: %d\n", pngdec->info->color_type);
+
+  if (pngdec->width != width ||
+      pngdec->height != height ||
+      pngdec->color_type != pngdec->info->color_type) {
+    pngdec->width = width;
+    pngdec->height = height;
+    pngdec->color_type = pngdec->info->color_type;
+
+    if (GST_PAD_LINK_FAILED (gst_pad_renegotiate (pngdec->srcpad))) {
+      GST_ELEMENT_ERROR (pngdec, CORE, NEGOTIATION, (NULL), (NULL));
+      return;
+    }
+  }
+
+  rows = (png_bytep *) g_malloc (sizeof (png_bytep) * height);
+
+  out =
+      gst_pad_alloc_buffer (pngdec->srcpad, GST_BUFFER_OFFSET_NONE,
+      width * height * 4);
+
+  inp = GST_BUFFER_DATA (out);
+  for (i = 0; i < height; i++) {
+    rows[i] = inp;
+    inp += width * 4;
+  }
+
+  png_read_image (pngdec->png, rows);
+  free (rows);
+
+  png_destroy_info_struct (pngdec->png, &pngdec->info);
+  png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo);
+
+  pngdec->buffer_in = NULL;
+  gst_buffer_unref (buf);
+
+  gst_pad_push (pngdec->srcpad, GST_DATA (out));
+}