Source/WebCore/platform/graphics/gstreamer/ImageGStreamerCairo.cpp

/*
 * Copyright (C) 2010 Igalia S.L
 *
 * 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; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "ImageGStreamer.h"

#if ENABLE(VIDEO) && USE(GSTREAMER)

#include "GStreamerUtilities.h"

#include <cairo.h>
#include <gst/gst.h>
#include <gst/video/gstvideometa.h>


using namespace std;
using namespace WebCore;

ImageGStreamer::ImageGStreamer(GstSample* sample)
{
    GstCaps* caps = gst_sample_get_caps(sample);
    GstVideoInfo videoInfo;
    gst_video_info_init(&videoInfo);
    if (!gst_video_info_from_caps(&videoInfo, caps))
        return;

    // Right now the TextureMapper only supports chromas with one plane
    ASSERT(GST_VIDEO_INFO_N_PLANES(&videoInfo) == 1);

    GstBuffer* buffer = gst_sample_get_buffer(sample);
    if (!gst_video_frame_map(&m_videoFrame, &videoInfo, buffer, GST_MAP_READ))
        return;

    unsigned char* bufferData = reinterpret_cast<unsigned char*>(GST_VIDEO_FRAME_PLANE_DATA(&m_videoFrame, 0));

    cairo_format_t cairoFormat;
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
    cairoFormat = (GST_VIDEO_FRAME_FORMAT(&m_videoFrame) == GST_VIDEO_FORMAT_BGRA) ? CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24;
#else
    cairoFormat = (GST_VIDEO_FRAME_FORMAT(&m_videoFrame) == GST_VIDEO_FORMAT_ARGB) ? CAIRO_FORMAT_ARGB32 : CAIRO_FORMAT_RGB24;
#endif

    int stride = GST_VIDEO_FRAME_PLANE_STRIDE(&m_videoFrame, 0);
    int width = GST_VIDEO_FRAME_WIDTH(&m_videoFrame);
    int height = GST_VIDEO_FRAME_HEIGHT(&m_videoFrame);

    RefPtr<cairo_surface_t> surface = adoptRef(cairo_image_surface_create_for_data(bufferData, cairoFormat, width, height, stride));
    ASSERT(cairo_surface_status(surface.get()) == CAIRO_STATUS_SUCCESS);
    m_image = BitmapImage::create(surface.release());

    if (GstVideoCropMeta* cropMeta = gst_buffer_get_video_crop_meta(buffer))
        setCropRect(FloatRect(cropMeta->x, cropMeta->y, cropMeta->width, cropMeta->height));
}

ImageGStreamer::~ImageGStreamer()
{
    if (m_image)
        m_image = nullptr;

    // We keep the buffer memory mapped until the image is destroyed because the internal
    // cairo_surface_t was created using cairo_image_surface_create_for_data().
    gst_video_frame_unmap(&m_videoFrame);
}
#endif // USE(GSTREAMER)