Files
video-shader-toys/apps/LoopThroughWithOpenGLCompositing/videoio/VideoIOBackendFactory.cpp
2026-05-09 14:42:11 +10:00

76 lines
2.0 KiB
C++

#include "VideoIOBackendFactory.h"
#include "DeckLinkSession.h"
#include "VideoIOTypes.h"
#include <array>
namespace
{
struct VideoIOBackendRegistration
{
VideoIOBackendDescriptor descriptor;
VideoIODeviceFactory factory;
};
const std::array<VideoIOBackendRegistration, 1>& RegisteredBackends()
{
static const std::array<VideoIOBackendRegistration, 1> backends = { {
{
{
VideoIOBackendId::DeckLink,
"decklink",
"Blackmagic DeckLink",
"Please install the Blackmagic DeckLink drivers to use the features of this application.",
"This application requires the selected video I/O drivers installed."
},
[]() { return std::make_unique<DeckLinkSession>(); }
}
} };
return backends;
}
}
const VideoIOBackendDescriptor* GetVideoIOBackendDescriptor(VideoIOBackendId backendId)
{
for (const VideoIOBackendRegistration& registration : RegisteredBackends())
{
if (registration.descriptor.backendId == backendId)
return &registration.descriptor;
}
return nullptr;
}
std::vector<VideoIOBackendDescriptor> ListVideoIOBackendDescriptors()
{
std::vector<VideoIOBackendDescriptor> descriptors;
descriptors.reserve(RegisteredBackends().size());
for (const VideoIOBackendRegistration& registration : RegisteredBackends())
descriptors.push_back(registration.descriptor);
return descriptors;
}
std::unique_ptr<VideoIODevice> CreateVideoIODevice(VideoIOBackendId backendId, std::string& error)
{
for (const VideoIOBackendRegistration& registration : RegisteredBackends())
{
if (registration.descriptor.backendId != backendId)
continue;
error.clear();
return registration.factory ? registration.factory() : nullptr;
}
error = "Unsupported video I/O backend.";
return nullptr;
}
bool IsVideoIOBackendUnavailableError(VideoIOBackendId backendId, const std::string& error)
{
const VideoIOBackendDescriptor* descriptor = GetVideoIOBackendDescriptor(backendId);
return descriptor != nullptr &&
descriptor->unavailableMessage != nullptr &&
*descriptor->unavailableMessage != '\0' &&
error == descriptor->unavailableMessage;
}