1/*
2 * Copyright (C) 2010 Igalia S.L
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20#include "config.h"
21#include "ImageGStreamer.h"
22
23#if ENABLE(VIDEO) && USE(GSTREAMER)
24
25#include "GStreamerCommon.h"
26
27#include <cairo.h>
28#include <gst/gst.h>
29#include <gst/video/gstvideometa.h>
30
31
32namespace WebCore {
33
34ImageGStreamer::ImageGStreamer(GstSample* sample)
35{
36 GstCaps* caps = gst_sample_get_caps(sample);
37 GstVideoInfo videoInfo;
38 gst_video_info_init(&videoInfo);
39 if (!gst_video_info_from_caps(&videoInfo, caps))
40 return;
41
42 // Right now the TextureMapper only supports chromas with one plane
43 ASSERT(GST_VIDEO_INFO_N_PLANES(&videoInfo) == 1);
44
45 GstBuffer* buffer = gst_sample_get_buffer(sample);
46 if (UNLIKELY(!GST_IS_BUFFER(buffer)))
47 return;
48
49 m_frameMapped = gst_video_frame_map(&m_videoFrame, &videoInfo, buffer, GST_MAP_READ);
50 if (!m_frameMapped)
51 return;
52
53 unsigned char* bufferData = reinterpret_cast<unsigned char*>(GST_VIDEO_FRAME_PLANE_DATA(&m_videoFrame, 0));
54 int stride = GST_VIDEO_FRAME_PLANE_STRIDE(&m_videoFrame, 0);
55 int width = GST_VIDEO_FRAME_WIDTH(&m_videoFrame);
56 int height = GST_VIDEO_FRAME_HEIGHT(&m_videoFrame);
57
58 RefPtr<cairo_surface_t> surface;
59 cairo_format_t cairoFormat;
60#if G_BYTE_ORDER == G_LITTLE_ENDIAN
61 cairoFormat = (GST_VIDEO_FRAME_FORMAT(&m_videoFrame) == GST_VIDEO_FORMAT_BGRA) ? CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24;
62#else
63 cairoFormat = (GST_VIDEO_FRAME_FORMAT(&m_videoFrame) == GST_VIDEO_FORMAT_ARGB) ? CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24;
64#endif
65
66 // GStreamer doesn't use premultiplied alpha, but cairo does. So if the video format has an alpha component
67 // we need to premultiply it before passing the data to cairo. This needs to be both using gstreamer-gl and not
68 // using it.
69 //
70 // This method could be called several times for the same buffer, for example if we are rendering the video frames
71 // in several non accelerated canvases. Due to this, we cannot modify the buffer, so we need to create a copy.
72 if (cairoFormat == CAIRO_FORMAT_ARGB32) {
73 unsigned char* surfaceData = static_cast<unsigned char*>(fastMalloc(height * stride));
74 unsigned char* surfacePixel = surfaceData;
75
76 for (int x = 0; x < width; x++) {
77 for (int y = 0; y < height; y++) {
78#if G_BYTE_ORDER == G_LITTLE_ENDIAN
79 // Video frames use BGRA in little endian.
80 unsigned short alpha = bufferData[3];
81 surfacePixel[0] = (bufferData[0] * alpha + 128) / 255;
82 surfacePixel[1] = (bufferData[1] * alpha + 128) / 255;
83 surfacePixel[2] = (bufferData[2] * alpha + 128) / 255;
84 surfacePixel[3] = alpha;
85#else
86 // Video frames use ARGB in big endian.
87 unsigned short alpha = bufferData[0];
88 surfacePixel[0] = alpha;
89 surfacePixel[1] = (bufferData[1] * alpha + 128) / 255;
90 surfacePixel[2] = (bufferData[2] * alpha + 128) / 255;
91 surfacePixel[3] = (bufferData[3] * alpha + 128) / 255;
92#endif
93 bufferData += 4;
94 surfacePixel += 4;
95 }
96 }
97 surface = adoptRef(cairo_image_surface_create_for_data(surfaceData, cairoFormat, width, height, stride));
98 static cairo_user_data_key_t s_surfaceDataKey;
99 cairo_surface_set_user_data(surface.get(), &s_surfaceDataKey, surfaceData, [](void* data) { fastFree(data); });
100 } else
101 surface = adoptRef(cairo_image_surface_create_for_data(bufferData, cairoFormat, width, height, stride));
102
103 ASSERT(cairo_surface_status(surface.get()) == CAIRO_STATUS_SUCCESS);
104 m_image = BitmapImage::create(WTFMove(surface));
105
106 if (GstVideoCropMeta* cropMeta = gst_buffer_get_video_crop_meta(buffer))
107 setCropRect(FloatRect(cropMeta->x, cropMeta->y, cropMeta->width, cropMeta->height));
108}
109
110ImageGStreamer::~ImageGStreamer()
111{
112 if (m_image)
113 m_image = nullptr;
114
115 // We keep the buffer memory mapped until the image is destroyed because the internal
116 // cairo_surface_t was created using cairo_image_surface_create_for_data().
117 if (m_frameMapped)
118 gst_video_frame_unmap(&m_videoFrame);
119}
120
121} // namespace WebCore
122
123#endif // USE(GSTREAMER)
124