diff options
Diffstat (limited to 'gst/videoparsers/gstpngparse.c')
| -rw-r--r-- | gst/videoparsers/gstpngparse.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/gst/videoparsers/gstpngparse.c b/gst/videoparsers/gstpngparse.c new file mode 100644 index 000000000..f4fa84efe --- /dev/null +++ b/gst/videoparsers/gstpngparse.c @@ -0,0 +1,192 @@ +/* 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; +} |