gstreamer/ext/rsvg/gstrsvgdec.c
2021-03-23 14:19:17 +00:00

374 lines
11 KiB
C

/* GStreamer
* Copyright (C) <2009> Sebastian Dröge <sebastian.droege@collabora.co.uk>
* Copyright (C) <2013> Luciana Fujii <luciana.fujii@collabora.co.uk>
*
* 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.
*/
/**
* SECTION:element-rsvgdec
* @title: rsvgdec
*
* This elements renders SVG graphics.
*
* ## Example launch lines
* |[
* gst-launch-1.0 filesrc location=image.svg ! rsvgdec ! imagefreeze ! videoconvert ! autovideosink
* ]| render and show a svg image.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstrsvgdec.h"
#include <string.h>
GST_DEBUG_CATEGORY_STATIC (rsvgdec_debug);
#define GST_CAT_DEFAULT rsvgdec_debug
static GstStaticPadTemplate sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
GST_STATIC_CAPS ("image/svg+xml; image/svg"));
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define GST_RSVG_VIDEO_CAPS GST_VIDEO_CAPS_MAKE ("BGRA")
#define GST_RSVG_VIDEO_FORMAT GST_VIDEO_FORMAT_BGRA
#else
#define GST_RSVG_VIDEO_CAPS GST_VIDEO_CAPS_MAKE ("ARGB")
#define GST_RSVG_VIDEO_FORMAT GST_VIDEO_FORMAT_ARGB
#endif
static GstStaticPadTemplate src_factory =
GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_RSVG_VIDEO_CAPS));
#define gst_rsv_dec_parent_class parent_class
G_DEFINE_TYPE (GstRsvgDec, gst_rsvg_dec, GST_TYPE_VIDEO_DECODER);
GST_ELEMENT_REGISTER_DEFINE (rsvgdec, "rsvgdec", GST_RANK_PRIMARY,
GST_TYPE_RSVG_DEC);
static gboolean gst_rsvg_dec_stop (GstVideoDecoder * decoder);
static gboolean gst_rsvg_dec_set_format (GstVideoDecoder * decoder,
GstVideoCodecState * state);
static GstFlowReturn gst_rsvg_dec_parse (GstVideoDecoder * decoder,
GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos);
static GstFlowReturn gst_rsvg_dec_handle_frame (GstVideoDecoder * decoder,
GstVideoCodecFrame * frame);
static GstFlowReturn gst_rsvg_decode_image (GstRsvgDec * rsvg,
GstBuffer * buffer, GstVideoCodecFrame * frame);
static void gst_rsvg_dec_finalize (GObject * object);
static void
gst_rsvg_dec_class_init (GstRsvgDecClass * klass)
{
GstVideoDecoderClass *video_decoder_class = GST_VIDEO_DECODER_CLASS (klass);
GObjectClass *gobject_class = (GObjectClass *) klass;
GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
GST_DEBUG_CATEGORY_INIT (rsvgdec_debug, "rsvgdec", 0, "RSVG decoder");
gst_element_class_set_static_metadata (element_class,
"SVG image decoder", "Codec/Decoder/Image",
"Uses librsvg to decode SVG images",
"Sebastian Dröge <sebastian.droege@collabora.co.uk>");
gst_element_class_add_static_pad_template (element_class, &sink_factory);
gst_element_class_add_static_pad_template (element_class, &src_factory);
gobject_class->finalize = gst_rsvg_dec_finalize;
video_decoder_class->stop = GST_DEBUG_FUNCPTR (gst_rsvg_dec_stop);
video_decoder_class->set_format = GST_DEBUG_FUNCPTR (gst_rsvg_dec_set_format);
video_decoder_class->parse = GST_DEBUG_FUNCPTR (gst_rsvg_dec_parse);
video_decoder_class->handle_frame =
GST_DEBUG_FUNCPTR (gst_rsvg_dec_handle_frame);
}
static void
gst_rsvg_dec_init (GstRsvgDec * rsvg)
{
GstVideoDecoder *decoder = GST_VIDEO_DECODER (rsvg);
gst_video_decoder_set_packetized (decoder, FALSE);
gst_video_decoder_set_use_default_pad_acceptcaps (GST_VIDEO_DECODER_CAST
(rsvg), TRUE);
GST_PAD_SET_ACCEPT_TEMPLATE (GST_VIDEO_DECODER_SINK_PAD (rsvg));
}
static void
gst_rsvg_dec_finalize (GObject * object)
{
G_OBJECT_CLASS (gst_rsvg_dec_parent_class)->finalize (object);
}
#define CAIRO_UNPREMULTIPLY(a,r,g,b) G_STMT_START { \
b = (a > 0) ? MIN ((b * 255 + a / 2) / a, 255) : 0; \
g = (a > 0) ? MIN ((g * 255 + a / 2) / a, 255) : 0; \
r = (a > 0) ? MIN ((r * 255 + a / 2) / a, 255) : 0; \
} G_STMT_END
static void
gst_rsvg_decode_unpremultiply (guint8 * data, gint width, gint height)
{
gint i, j;
guint a;
for (i = 0; i < height; i++) {
for (j = 0; j < width; j++) {
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
a = data[3];
data[0] = (a > 0) ? MIN ((data[0] * 255 + a / 2) / a, 255) : 0;
data[1] = (a > 0) ? MIN ((data[1] * 255 + a / 2) / a, 255) : 0;
data[2] = (a > 0) ? MIN ((data[2] * 255 + a / 2) / a, 255) : 0;
#else
a = data[0];
data[1] = (a > 0) ? MIN ((data[1] * 255 + a / 2) / a, 255) : 0;
data[2] = (a > 0) ? MIN ((data[2] * 255 + a / 2) / a, 255) : 0;
data[3] = (a > 0) ? MIN ((data[3] * 255 + a / 2) / a, 255) : 0;
#endif
data += 4;
}
}
}
static GstFlowReturn
gst_rsvg_decode_image (GstRsvgDec * rsvg, GstBuffer * buffer,
GstVideoCodecFrame * frame)
{
GstVideoDecoder *decoder = GST_VIDEO_DECODER (rsvg);
GstFlowReturn ret = GST_FLOW_OK;
cairo_t *cr;
cairo_surface_t *surface;
RsvgHandle *handle;
GError *error = NULL;
RsvgDimensionData dimension;
gdouble scalex, scaley;
GstMapInfo minfo;
GstVideoFrame vframe;
GstVideoCodecState *output_state;
GST_LOG_OBJECT (rsvg, "parsing svg");
if (!gst_buffer_map (buffer, &minfo, GST_MAP_READ)) {
GST_ERROR_OBJECT (rsvg, "Failed to get SVG image");
return GST_FLOW_ERROR;
}
handle = rsvg_handle_new_from_data (minfo.data, minfo.size, &error);
if (!handle) {
GST_ERROR_OBJECT (rsvg, "Failed to parse SVG image: %s", error->message);
g_error_free (error);
return GST_FLOW_ERROR;
}
rsvg_handle_get_dimensions (handle, &dimension);
output_state = gst_video_decoder_get_output_state (decoder);
if ((output_state == NULL)
|| GST_VIDEO_INFO_WIDTH (&output_state->info) != dimension.width
|| GST_VIDEO_INFO_HEIGHT (&output_state->info) != dimension.height) {
/* Create the output state */
if (output_state)
gst_video_codec_state_unref (output_state);
output_state =
gst_video_decoder_set_output_state (decoder, GST_RSVG_VIDEO_FORMAT,
dimension.width, dimension.height, rsvg->input_state);
}
ret = gst_video_decoder_allocate_output_frame (decoder, frame);
if (ret != GST_FLOW_OK) {
g_object_unref (handle);
gst_video_codec_state_unref (output_state);
GST_ERROR_OBJECT (rsvg, "Buffer allocation failed %s",
gst_flow_get_name (ret));
return ret;
}
GST_LOG_OBJECT (rsvg, "render image at %d x %d",
GST_VIDEO_INFO_HEIGHT (&output_state->info),
GST_VIDEO_INFO_WIDTH (&output_state->info));
if (!gst_video_frame_map (&vframe,
&output_state->info, frame->output_buffer, GST_MAP_READWRITE)) {
GST_ERROR_OBJECT (rsvg, "Failed to get SVG image");
g_object_unref (handle);
gst_video_codec_state_unref (output_state);
return GST_FLOW_ERROR;
}
surface =
cairo_image_surface_create_for_data (GST_VIDEO_FRAME_PLANE_DATA (&vframe,
0), CAIRO_FORMAT_ARGB32, GST_VIDEO_FRAME_WIDTH (&vframe),
GST_VIDEO_FRAME_HEIGHT (&vframe), GST_VIDEO_FRAME_PLANE_STRIDE (&vframe,
0));
cr = cairo_create (surface);
cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
cairo_set_source_rgba (cr, 1.0, 1.0, 1.0, 0.0);
cairo_paint (cr);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_set_source_rgba (cr, 0.0, 0.0, 0.0, 1.0);
scalex = scaley = 1.0;
if (GST_VIDEO_INFO_WIDTH (&output_state->info) != dimension.width) {
scalex =
((gdouble) GST_VIDEO_INFO_WIDTH (&output_state->info)) /
((gdouble) dimension.width);
}
if (GST_VIDEO_INFO_HEIGHT (&output_state->info) != dimension.height) {
scaley =
((gdouble) GST_VIDEO_INFO_HEIGHT (&output_state->info)) /
((gdouble) dimension.height);
}
cairo_scale (cr, scalex, scaley);
rsvg_handle_render_cairo (handle, cr);
g_object_unref (handle);
cairo_destroy (cr);
cairo_surface_destroy (surface);
/* Now unpremultiply Cairo's ARGB to match GStreamer's */
gst_rsvg_decode_unpremultiply (GST_VIDEO_FRAME_PLANE_DATA (&vframe, 0),
GST_VIDEO_FRAME_WIDTH (&vframe), GST_VIDEO_FRAME_HEIGHT (&vframe));
gst_video_codec_state_unref (output_state);
gst_buffer_unmap (buffer, &minfo);
gst_video_frame_unmap (&vframe);
return ret;
}
static gboolean
gst_rsvg_dec_set_format (GstVideoDecoder * decoder, GstVideoCodecState * state)
{
GstRsvgDec *rsvg = GST_RSVG_DEC (decoder);
GstVideoInfo *info = &state->info;
if (rsvg->input_state)
gst_video_codec_state_unref (rsvg->input_state);
rsvg->input_state = gst_video_codec_state_ref (state);
/* Create the output state */
state = gst_video_decoder_set_output_state (decoder, GST_RSVG_VIDEO_FORMAT,
GST_VIDEO_INFO_WIDTH (info), GST_VIDEO_INFO_HEIGHT (info),
rsvg->input_state);
gst_video_codec_state_unref (state);
return TRUE;
}
static GstFlowReturn
gst_rsvg_dec_parse (GstVideoDecoder * decoder, GstVideoCodecFrame * frame,
GstAdapter * adapter, gboolean at_eos)
{
gboolean completed = FALSE;
const guint8 *data;
guint size;
guint i;
GST_LOG_OBJECT (decoder, "parse start");
size = gst_adapter_available (adapter);
/* "<svg></svg>" */
if (size < 5 + 6)
return GST_VIDEO_DECODER_FLOW_NEED_DATA;
data = gst_adapter_map (adapter, size);
if (data == NULL) {
GST_ERROR_OBJECT (decoder, "Unable to map memory");
return GST_FLOW_ERROR;
}
for (i = 0; i < size - 4; i++) {
if (memcmp (data + i, "<svg", 4) == 0) {
gst_adapter_flush (adapter, i);
size = gst_adapter_available (adapter);
if (size < 5 + 6)
return GST_VIDEO_DECODER_FLOW_NEED_DATA;
data = gst_adapter_map (adapter, size);
if (data == NULL) {
GST_ERROR_OBJECT (decoder, "Unable to map memory");
return GST_FLOW_ERROR;
}
break;
}
}
/* If start wasn't found: */
if (i == size - 4) {
gst_adapter_flush (adapter, size - 4);
return GST_VIDEO_DECODER_FLOW_NEED_DATA;
}
for (i = size - 6; i >= 5; i--) {
if (memcmp (data + i, "</svg>", 6) == 0) {
completed = TRUE;
size = i + 6;
break;
}
if (memcmp (data + i, "</svg:svg>", 10) == 0) {
completed = TRUE;
size = i + 10;
break;
}
}
if (completed) {
GST_LOG_OBJECT (decoder, "have complete svg of %u bytes", size);
gst_video_decoder_add_to_frame (decoder, size);
return gst_video_decoder_have_frame (decoder);
}
return GST_VIDEO_DECODER_FLOW_NEED_DATA;
}
static GstFlowReturn
gst_rsvg_dec_handle_frame (GstVideoDecoder * decoder,
GstVideoCodecFrame * frame)
{
GstRsvgDec *rsvg = GST_RSVG_DEC (decoder);
gboolean ret;
ret = gst_rsvg_decode_image (rsvg, frame->input_buffer, frame);
switch (ret) {
case GST_FLOW_OK:
ret = gst_video_decoder_finish_frame (decoder, frame);
break;
default:
gst_video_codec_frame_unref (frame);
break;
}
GST_LOG_OBJECT (rsvg, "Handle frame done");
return ret;
}
static gboolean
gst_rsvg_dec_stop (GstVideoDecoder * decoder)
{
GstRsvgDec *rsvg = GST_RSVG_DEC (decoder);
if (rsvg->input_state) {
gst_video_codec_state_unref (rsvg->input_state);
rsvg->input_state = NULL;
}
return TRUE;
}