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

/*
 *  Copyright (C) 2012, 2015, 2016 Igalia S.L
 *  Copyright (C) 2015, 2016 Metrological Group B.V.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */


#include "config.h"

#if USE(GSTREAMER)
#include "GStreamerUtilities.h"

#include "GRefPtrGStreamer.h"
#include "GstAllocatorFastMalloc.h"
#include "IntSize.h"
#include <gst/audio/audio-info.h>
#include <gst/gst.h>
#include <mutex>
#include <wtf/glib/GLibUtilities.h>
#include <wtf/glib/GUniquePtr.h>

#if ENABLE(VIDEO_TRACK) && USE(GSTREAMER_MPEGTS)
#define GST_USE_UNSTABLE_API
#include <gst/mpegts/mpegts.h>
#undef GST_USE_UNSTABLE_API
#endif

namespace WebCore {

const char* webkitGstMapInfoQuarkString = "webkit-gst-map-info";

GstPad* webkitGstGhostPadFromStaticTemplate(GstStaticPadTemplate* staticPadTemplate, const gchar* name, GstPad* target)
{
    GstPad* pad;
    GstPadTemplate* padTemplate = gst_static_pad_template_get(staticPadTemplate);

    if (target)
        pad = gst_ghost_pad_new_from_template(name, target, padTemplate);
    else
        pad = gst_ghost_pad_new_no_target_from_template(name, padTemplate);

    gst_object_unref(padTemplate);

    return pad;
}

#if ENABLE(VIDEO)
bool getVideoSizeAndFormatFromCaps(GstCaps* caps, WebCore::IntSize& size, GstVideoFormat& format, int& pixelAspectRatioNumerator, int& pixelAspectRatioDenominator, int& stride)
{
    if (!doCapsHaveType(caps, GST_VIDEO_CAPS_TYPE_PREFIX)) {
        GST_WARNING("Failed to get the video size and format, these are not a video caps");
        return false;
    }

    if (areEncryptedCaps(caps)) {
        GstStructure* structure = gst_caps_get_structure(caps, 0);
        format = GST_VIDEO_FORMAT_ENCODED;
        stride = 0;
        int width = 0, height = 0;
        gst_structure_get_int(structure, "width", &width);
        gst_structure_get_int(structure, "height", &height);
        if (!gst_structure_get_fraction(structure, "pixel-aspect-ratio", &pixelAspectRatioNumerator, &pixelAspectRatioDenominator)) {
            pixelAspectRatioNumerator = 1;
            pixelAspectRatioDenominator = 1;
        }

        size.setWidth(width);
        size.setHeight(height);
    } else {
        GstVideoInfo info;
        gst_video_info_init(&info);
        if (!gst_video_info_from_caps(&info, caps))
            return false;

        format = GST_VIDEO_INFO_FORMAT(&info);
        size.setWidth(GST_VIDEO_INFO_WIDTH(&info));
        size.setHeight(GST_VIDEO_INFO_HEIGHT(&info));
        pixelAspectRatioNumerator = GST_VIDEO_INFO_PAR_N(&info);
        pixelAspectRatioDenominator = GST_VIDEO_INFO_PAR_D(&info);
        stride = GST_VIDEO_INFO_PLANE_STRIDE(&info, 0);
    }

    return true;
}

std::optional<FloatSize> getVideoResolutionFromCaps(const GstCaps* caps)
{
    if (!doCapsHaveType(caps, GST_VIDEO_CAPS_TYPE_PREFIX)) {
        GST_WARNING("Failed to get the video resolution, these are not a video caps");
        return std::nullopt;
    }

    int width = 0, height = 0;
    int pixelAspectRatioNumerator = 1, pixelAspectRatioDenominator = 1;

    if (areEncryptedCaps(caps)) {
        GstStructure* structure = gst_caps_get_structure(caps, 0);
        gst_structure_get_int(structure, "width", &width);
        gst_structure_get_int(structure, "height", &height);
        gst_structure_get_fraction(structure, "pixel-aspect-ratio", &pixelAspectRatioNumerator, &pixelAspectRatioDenominator);
    } else {
        GstVideoInfo info;
        gst_video_info_init(&info);
        if (!gst_video_info_from_caps(&info, caps))
            return std::nullopt;

        width = GST_VIDEO_INFO_WIDTH(&info);
        height = GST_VIDEO_INFO_HEIGHT(&info);
        pixelAspectRatioNumerator = GST_VIDEO_INFO_PAR_N(&info);
        pixelAspectRatioDenominator = GST_VIDEO_INFO_PAR_D(&info);
    }

    return std::make_optional(FloatSize(width, height * (static_cast<float>(pixelAspectRatioNumerator) / static_cast<float>(pixelAspectRatioDenominator))));
}

bool getSampleVideoInfo(GstSample* sample, GstVideoInfo& videoInfo)
{
    if (!GST_IS_SAMPLE(sample))
        return false;

    GstCaps* caps = gst_sample_get_caps(sample);
    if (!caps)
        return false;

    gst_video_info_init(&videoInfo);
    if (!gst_video_info_from_caps(&videoInfo, caps))
        return false;

    return true;
}
#endif

GstBuffer* createGstBuffer(GstBuffer* buffer)
{
    gsize bufferSize = gst_buffer_get_size(buffer);
    GstBuffer* newBuffer = gst_buffer_new_and_alloc(bufferSize);

    if (!newBuffer)
        return 0;

    gst_buffer_copy_into(newBuffer, buffer, static_cast<GstBufferCopyFlags>(GST_BUFFER_COPY_METADATA), 0, bufferSize);
    return newBuffer;
}

GstBuffer* createGstBufferForData(const char* data, int length)
{
    GstBuffer* buffer = gst_buffer_new_and_alloc(length);

    gst_buffer_fill(buffer, 0, data, length);

    return buffer;
}

const char* capsMediaType(const GstCaps* caps)
{
    ASSERT(caps);
    GstStructure* structure = gst_caps_get_structure(caps, 0);
    if (!structure) {
        GST_WARNING("caps are empty");
        return nullptr;
    }
#if ENABLE(ENCRYPTED_MEDIA)
    if (gst_structure_has_name(structure, "application/x-cenc"))
        return gst_structure_get_string(structure, "original-media-type");
#endif
    return gst_structure_get_name(structure);
}

bool doCapsHaveType(const GstCaps* caps, const char* type)
{
    const char* mediaType = capsMediaType(caps);
    if (!mediaType) {
        GST_WARNING("Failed to get MediaType");
        return false;
    }
    return g_str_has_prefix(mediaType, type);
}

bool areEncryptedCaps(const GstCaps* caps)
{
    ASSERT(caps);
#if ENABLE(ENCRYPTED_MEDIA)
    GstStructure* structure = gst_caps_get_structure(caps, 0);
    if (!structure) {
        GST_WARNING("caps are empty");
        return false;
    }
    return gst_structure_has_name(structure, "application/x-cenc");
#else
    UNUSED_PARAM(caps);
    return false;
#endif
}

char* getGstBufferDataPointer(GstBuffer* buffer)
{
    GstMiniObject* miniObject = reinterpret_cast<GstMiniObject*>(buffer);
    GstMapInfo* mapInfo = static_cast<GstMapInfo*>(gst_mini_object_get_qdata(miniObject, g_quark_from_static_string(webkitGstMapInfoQuarkString)));
    return reinterpret_cast<char*>(mapInfo->data);
}

void mapGstBuffer(GstBuffer* buffer, uint32_t flags)
{
    GstMapInfo* mapInfo = static_cast<GstMapInfo*>(fastMalloc(sizeof(GstMapInfo)));
    if (!gst_buffer_map(buffer, mapInfo, static_cast<GstMapFlags>(flags))) {
        fastFree(mapInfo);
        gst_buffer_unref(buffer);
        return;
    }

    GstMiniObject* miniObject = reinterpret_cast<GstMiniObject*>(buffer);
    gst_mini_object_set_qdata(miniObject, g_quark_from_static_string(webkitGstMapInfoQuarkString), mapInfo, nullptr);
}

void unmapGstBuffer(GstBuffer* buffer)
{
    GstMiniObject* miniObject = reinterpret_cast<GstMiniObject*>(buffer);
    GstMapInfo* mapInfo = static_cast<GstMapInfo*>(gst_mini_object_steal_qdata(miniObject, g_quark_from_static_string(webkitGstMapInfoQuarkString)));

    if (!mapInfo)
        return;

    gst_buffer_unmap(buffer, mapInfo);
    fastFree(mapInfo);
}

Vector<String> extractGStreamerOptionsFromCommandLine()
{
    GUniqueOutPtr<char> contents;
    gsize length;
    if (!g_file_get_contents("/proc/self/cmdline", &contents.outPtr(), &length, nullptr))
        return { };

    Vector<String> options;
    auto optionsString = String::fromUTF8(contents.get(), length);
    optionsString.split('\0', false, [&options](StringView item) {
        if (item.startsWith("--gst"))
            options.append(item.toString());
    });
    return options;
}

bool initializeGStreamer(std::optional<Vector<String>>&& options)
{
    static std::once_flag onceFlag;
    static bool isGStreamerInitialized;
    std::call_once(onceFlag, [options = WTFMove(options)] {
        isGStreamerInitialized = false;

#if ENABLE(VIDEO) || ENABLE(WEB_AUDIO)
        Vector<String> parameters = options.value_or(extractGStreamerOptionsFromCommandLine());
        char** argv = g_new0(char*, parameters.size() + 2);
        int argc = parameters.size() + 1;
        argv[0] = g_strdup(getCurrentExecutableName().data());
        for (unsigned i = 0; i < parameters.size(); i++)
            argv[i + 1] = g_strdup(parameters[i].utf8().data());

        GUniqueOutPtr<GError> error;
        isGStreamerInitialized = gst_init_check(&argc, &argv, &error.outPtr());
        ASSERT_WITH_MESSAGE(isGStreamerInitialized, "GStreamer initialization failed: %s", error ? error->message : "unknown error occurred");
        g_strfreev(argv);

        if (isFastMallocEnabled()) {
            const char* disableFastMalloc = getenv("WEBKIT_GST_DISABLE_FAST_MALLOC");
            if (!disableFastMalloc || !strcmp(disableFastMalloc, "0"))
                gst_allocator_set_default(GST_ALLOCATOR(g_object_new(gst_allocator_fast_malloc_get_type(), nullptr)));
        }

#if ENABLE(VIDEO_TRACK) && USE(GSTREAMER_MPEGTS)
        if (isGStreamerInitialized)
            gst_mpegts_initialize();
#endif
#endif
    });
    return isGStreamerInitialized;
}

unsigned getGstPlayFlag(const char* nick)
{
    static GFlagsClass* flagsClass = static_cast<GFlagsClass*>(g_type_class_ref(g_type_from_name("GstPlayFlags")));
    ASSERT(flagsClass);

    GFlagsValue* flag = g_flags_get_value_by_nick(flagsClass, nick);
    if (!flag)
        return 0;

    return flag->value;
}

// Convert a MediaTime in seconds to a GstClockTime. Note that we can get MediaTime objects with a time scale that isn't a GST_SECOND, since they can come to
// us through the internal testing API, the DOM and internally. It would be nice to assert the format of the incoming time, but all the media APIs assume time
// is passed around in fractional seconds, so we'll just have to assume the same.
uint64_t toGstUnsigned64Time(const MediaTime& mediaTime)
{
    MediaTime time = mediaTime.toTimeScale(GST_SECOND);
    if (time.isInvalid())
        return GST_CLOCK_TIME_NONE;
    return time.timeValue();
}

bool gstRegistryHasElementForMediaType(GList* elementFactories, const char* capsString)
{
    GRefPtr<GstCaps> caps = adoptGRef(gst_caps_from_string(capsString));
    GList* candidates = gst_element_factory_list_filter(elementFactories, caps.get(), GST_PAD_SINK, false);
    bool result = candidates;

    gst_plugin_feature_list_free(candidates);
    return result;
}

}

#endif // USE(GSTREAMER)