gstreamer/ext/libpng/gstpngdec.c

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/* 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 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_BGRA ";" GST_VIDEO_CAPS_BGR)
);
static GstStaticPadTemplate gst_pngdec_sink_pad_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("image/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_use_explicit_caps (pngdec->srcpad);
pngdec->png = NULL;
pngdec->info = NULL;
pngdec->color_type = -1;
pngdec->width = -1;
pngdec->height = -1;
pngdec->fps = -1;
}
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);
if (pngdec->png == NULL) {
gst_buffer_unref (buf);
GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL),
("Failed to initialize png structure"));
return;
}
pngdec->info = png_create_info_struct (pngdec->png);
if (pngdec->info == NULL) {
gst_buffer_unref (buf);
png_destroy_read_struct (&(pngdec->png), (png_infopp) NULL,
(png_infopp) NULL);
GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL),
("Failed to initialize info structure"));
return;
}
pngdec->endinfo = png_create_info_struct (pngdec->png);
if (pngdec->endinfo == NULL) {
gst_buffer_unref (buf);
png_destroy_read_struct (&pngdec->png, &pngdec->info, (png_infopp) NULL);
GST_ELEMENT_ERROR (pngdec, LIBRARY, INIT, (NULL),
("Failed to initialize endinfo structure"));
return;
}
/* non-0 return is from a longjmp inside of libpng */
if (setjmp (pngdec->png->jmpbuf) != 0) {
gst_buffer_unref (buf);
png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo);
GST_ELEMENT_ERROR (pngdec, LIBRARY, FAILED, (NULL),
("returning from longjmp"));
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);
if (pngdec->info->bit_depth != 8) {
gst_buffer_unref (buf);
png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo);
GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL),
("pngdec only supports 8 bit images for now"));
return;
}
if (pngdec->width != width ||
pngdec->height != height ||
pngdec->color_type != pngdec->info->color_type) {
GstCaps *caps, *templ, *res;
gboolean ret;
gint bpp;
pngdec->width = width;
pngdec->height = height;
pngdec->color_type = pngdec->info->color_type;
templ = gst_caps_copy (gst_pad_template_get_caps
(gst_static_pad_template_get (&gst_pngdec_src_pad_template)));
switch (pngdec->color_type) {
case PNG_COLOR_TYPE_RGB:
bpp = 24;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
bpp = 32;
break;
default:
GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL),
("pngdec does not support grayscale or paletted data yet"));
return;
}
caps = gst_caps_new_simple ("video/x-raw-rgb",
"width", G_TYPE_INT, width,
"height", G_TYPE_INT, height,
"bpp", G_TYPE_INT, bpp, "framerate", G_TYPE_DOUBLE, pngdec->fps, NULL);
res = gst_caps_intersect (templ, caps);
gst_caps_free (caps);
gst_caps_free (templ);
ret = gst_pad_set_explicit_caps (pngdec->srcpad, res);
gst_caps_free (res);
if (!ret) {
gst_buffer_unref (buf);
png_destroy_read_struct (&pngdec->png, &pngdec->info, &pngdec->endinfo);
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,
height * pngdec->info->rowbytes);
inp = GST_BUFFER_DATA (out);
for (i = 0; i < height; i++) {
rows[i] = inp;
inp += pngdec->info->rowbytes;
}
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));
}