--- /dev/null
+/* GStreamer PNG Parser
+ * Copyright (C) <2013> Collabora Ltd
+ * @author Olivier Crete <olivier.crete@collabora.com>
+ *
+ * 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 "gstpngparse.h"
+
+#include <gst/base/gstbytereader.h>
+
+#define PNG_SIGNATURE G_GUINT64_CONSTANT (0x89504E470D0A1A0A)
+
+GST_DEBUG_CATEGORY (png_parse_debug);
+#define GST_CAT_DEFAULT png_parse_debug
+
+static GstStaticPadTemplate srctemplate =
+GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("image/png, width = (int)[1, MAX], height = (int)[1, MAX],"
+ "parsed = (boolean) true")
+ );
+
+static GstStaticPadTemplate sinktemplate =
+GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS ("image/png")
+ );
+
+#define parent_class gst_png_parse_parent_class
+G_DEFINE_TYPE (GstPngParse, gst_png_parse, GST_TYPE_BASE_PARSE);
+
+static gboolean gst_png_parse_start (GstBaseParse * parse);
+static GstFlowReturn gst_png_parse_handle_frame (GstBaseParse * parse,
+ GstBaseParseFrame * frame, gint * skipsize);
+
+static void
+gst_png_parse_class_init (GstPngParseClass * klass)
+{
+ GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
+ GstBaseParseClass *parse_class = GST_BASE_PARSE_CLASS (klass);
+
+ GST_DEBUG_CATEGORY_INIT (png_parse_debug, "pngparse", 0, "png parser");
+
+ gst_element_class_add_pad_template (gstelement_class,
+ gst_static_pad_template_get (&srctemplate));
+ gst_element_class_add_pad_template (gstelement_class,
+ gst_static_pad_template_get (&sinktemplate));
+ gst_element_class_set_static_metadata (gstelement_class, "PNG parser",
+ "Codec/Parser/Video/Image",
+ "Parses PNG files", "Olivier Crete <olivier.crete@collabora.com>");
+
+ /* Override BaseParse vfuncs */
+ parse_class->start = GST_DEBUG_FUNCPTR (gst_png_parse_start);
+ parse_class->handle_frame = GST_DEBUG_FUNCPTR (gst_png_parse_handle_frame);
+}
+
+static void
+gst_png_parse_init (GstPngParse * pngparse)
+{
+}
+
+static gboolean
+gst_png_parse_start (GstBaseParse * parse)
+{
+ GstPngParse *pngparse = GST_PNG_PARSE (parse);
+
+ GST_DEBUG_OBJECT (pngparse, "start");
+
+ /* the start code and at least 2 empty frames (IHDR and IEND) */
+ gst_base_parse_set_min_frame_size (parse, 8 + 12 + 12);
+
+ pngparse->width = 0;
+ pngparse->height = 0;
+
+ return TRUE;
+}
+
+
+static GstFlowReturn
+gst_png_parse_handle_frame (GstBaseParse * parse,
+ GstBaseParseFrame * frame, gint * skipsize)
+{
+ GstPngParse *pngparse = GST_PNG_PARSE (parse);
+ GstMapInfo map;
+ GstByteReader reader;
+ GstFlowReturn ret = GST_FLOW_OK;
+ guint64 signature;
+
+ gst_buffer_map (frame->buffer, &map, GST_MAP_READ);
+ gst_byte_reader_init (&reader, map.data, map.size);
+
+ if (!gst_byte_reader_peek_uint64_be (&reader, &signature))
+ goto beach;
+
+ if (signature != PNG_SIGNATURE) {
+ for (;;) {
+ guint offset;
+
+ offset = gst_byte_reader_masked_scan_uint32 (&reader, 0xffffffff,
+ 0x89504E47, 0, gst_byte_reader_get_remaining (&reader));
+
+ if (offset == -1) {
+ *skipsize = gst_byte_reader_get_remaining (&reader) - 4;
+ goto beach;
+ }
+
+ gst_byte_reader_skip (&reader, offset);
+
+ if (!gst_byte_reader_peek_uint64_be (&reader, &signature))
+ goto beach;
+
+ if (signature == PNG_SIGNATURE) {
+ /* We're skipping, go out, we'll be back */
+ *skipsize = gst_byte_reader_get_pos (&reader);
+ goto beach;
+ }
+ gst_byte_reader_skip (&reader, 4);
+ }
+ }
+
+ gst_byte_reader_skip (&reader, 8);
+
+ for (;;) {
+ guint32 length;
+ guint32 code;
+ guint width, height;
+
+ if (!gst_byte_reader_get_uint32_be (&reader, &length))
+ goto beach;
+ if (!gst_byte_reader_get_uint32_le (&reader, &code))
+ goto beach;
+
+ if (code == GST_MAKE_FOURCC ('I', 'H', 'D', 'R')) {
+ if (!gst_byte_reader_get_uint32_be (&reader, &width))
+ goto beach;
+ if (!gst_byte_reader_get_uint32_be (&reader, &height))
+ goto beach;
+ length -= 8;
+ }
+
+ if (!gst_byte_reader_skip (&reader, length + 4))
+ goto beach;
+
+ if (code == GST_MAKE_FOURCC ('I', 'E', 'N', 'D')) {
+ if (pngparse->width != width || pngparse->height != height) {
+ GstCaps *caps;
+
+ pngparse->height = height;
+ pngparse->width = width;
+
+ caps = gst_caps_new_simple ("image/png",
+ "width", G_TYPE_INT, width, "height", G_TYPE_INT, height, NULL);
+ if (!gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (parse), caps)) {
+ ret = GST_FLOW_NOT_NEGOTIATED;
+ }
+ gst_caps_unref (caps);
+
+ if (ret != GST_FLOW_OK)
+ goto beach;
+ }
+
+
+ gst_buffer_unmap (frame->buffer, &map);
+ return gst_base_parse_finish_frame (parse, frame,
+ gst_byte_reader_get_pos (&reader));
+ }
+ }
+
+beach:
+
+ gst_buffer_unmap (frame->buffer, &map);
+
+ return ret;
+}
--- /dev/null
+/* GStreamer PNG Parser
+ * Copyright (C) <2013> Collabora Ltd
+ * @author Olivier Crete <olivier.crete@collabora.com>
+ *
+ * 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.
+ */
+
+#ifndef __GST_PNG_PARSE_H__
+#define __GST_PNG_PARSE_H__
+
+#include <gst/gst.h>
+#include <gst/base/gstadapter.h>
+#include <gst/base/gstbaseparse.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_PNG_PARSE \
+ (gst_png_parse_get_type())
+#define GST_PNG_PARSE(obj) \
+ (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_PNG_PARSE,GstPngParse))
+#define GST_PNG_PARSE_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_PNG_PARSE,GstPngParseClass))
+#define GST_IS_PNG_PARSE(obj) \
+ (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_PNG_PARSE))
+#define GST_IS_PNG_PARSE_CLASS(klass) \
+ (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_PNG_PARSE))
+
+GType gst_png_parse_get_type (void);
+
+typedef struct _GstPngParse GstPngParse;
+typedef struct _GstPngParseClass GstPngParseClass;
+
+struct _GstPngParse
+{
+ GstBaseParse baseparse;
+
+ guint width;
+ guint height;
+};
+
+struct _GstPngParseClass
+{
+ GstBaseParseClass parent_class;
+};
+
+G_END_DECLS
+
+#endif