1/*
2 * Librsvg rasterization wrapper
3 * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "avcodec.h"
23#include "codec_internal.h"
24#include "internal.h"
25#include "libavutil/opt.h"
26#include "librsvg-2.0/librsvg/rsvg.h"
27
28typedef struct LibRSVGContext {
29    AVClass *class;
30
31    int width;
32    int height;
33    int keep_ar;
34} LibRSVGContext;
35
36static int librsvg_decode_frame(AVCodecContext *avctx, AVFrame *frame,
37                                int *got_frame, AVPacket *pkt)
38{
39    int ret;
40    LibRSVGContext *s = avctx->priv_data;
41
42    RsvgHandle *handle;
43    RsvgDimensionData unscaled_dimensions, dimensions;
44    cairo_surface_t *image;
45    cairo_t *crender = NULL;
46    GError *error = NULL;
47
48    *got_frame = 0;
49
50    handle = rsvg_handle_new_from_data(pkt->data, pkt->size, &error);
51    if (error) {
52        av_log(avctx, AV_LOG_ERROR, "Error parsing svg!\n");
53        g_error_free(error);
54        return AVERROR_INVALIDDATA;
55    }
56
57    rsvg_handle_get_dimensions(handle, &dimensions);
58    rsvg_handle_get_dimensions(handle, &unscaled_dimensions);
59    dimensions.width  = s->width  ? s->width  : dimensions.width;
60    dimensions.height = s->height ? s->height : dimensions.height;
61    if (s->keep_ar && (s->width || s->height)) {
62        double default_ar = unscaled_dimensions.width/(double)unscaled_dimensions.height;
63        if (!s->width)
64            dimensions.width  = lrintf(dimensions.height * default_ar);
65        else
66            dimensions.height = lrintf(dimensions.width  / default_ar);
67    }
68
69    if ((ret = ff_set_dimensions(avctx, dimensions.width, dimensions.height)))
70        return ret;
71    avctx->pix_fmt = AV_PIX_FMT_RGB32;
72
73    if ((ret = ff_get_buffer(avctx, frame, 0)))
74        return ret;
75    frame->pict_type = AV_PICTURE_TYPE_I;
76    frame->key_frame = 1;
77
78    image = cairo_image_surface_create_for_data(frame->data[0], CAIRO_FORMAT_ARGB32,
79                                                frame->width, frame->height,
80                                                frame->linesize[0]);
81    if (cairo_surface_status(image) != CAIRO_STATUS_SUCCESS)
82        return AVERROR_INVALIDDATA;
83
84    crender = cairo_create(image);
85
86    cairo_save(crender);
87    cairo_set_operator(crender, CAIRO_OPERATOR_CLEAR);
88    cairo_paint(crender);
89    cairo_restore(crender);
90
91    cairo_scale(crender, dimensions.width / (double)unscaled_dimensions.width,
92                dimensions.height / (double)unscaled_dimensions.height);
93
94    rsvg_handle_render_cairo(handle, crender);
95
96    cairo_destroy(crender);
97    cairo_surface_destroy(image);
98    g_object_unref(handle);
99
100    *got_frame = 1;
101
102    return 0;
103}
104
105#define OFFSET(x) offsetof(LibRSVGContext, x)
106#define DEC (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
107static const AVOption options[] = {
108    { "width", "Width to render to (0 for default)", OFFSET(width), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, DEC },
109    { "height", "Height to render to (0 for default)", OFFSET(height), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, DEC },
110    { "keep_ar", "Keep aspect ratio with custom width/height", OFFSET(keep_ar), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, DEC },
111    { NULL },
112};
113
114static const AVClass librsvg_decoder_class = {
115    .class_name = "Librsvg",
116    .item_name  = av_default_item_name,
117    .option     = options,
118    .version    = LIBAVUTIL_VERSION_INT,
119};
120
121const FFCodec ff_librsvg_decoder = {
122    .p.name         = "librsvg",
123    .p.long_name    = NULL_IF_CONFIG_SMALL("Librsvg rasterizer"),
124    .p.priv_class   = &librsvg_decoder_class,
125    .p.type         = AVMEDIA_TYPE_VIDEO,
126    .p.id           = AV_CODEC_ID_SVG,
127    .p.capabilities = AV_CODEC_CAP_DR1,
128    .p.wrapper_name = "librsvg",
129    FF_CODEC_DECODE_CB(librsvg_decode_frame),
130    .priv_data_size = sizeof(LibRSVGContext),
131};
132