CameraCaptureReader.cpp

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// Copyright (c) 2008-2026 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later
 
#include "CameraCaptureReader.h"
 
#include <cstdlib>
#include <string>
 
#if defined(_WIN32)
    #define WIN32_LEAN_AND_MEAN
    #include <windows.h>
    #include <dshow.h>
    #include <oleauto.h>
#endif
 
extern "C" {
    #include <libavdevice/avdevice.h>
}
 
#include "Exceptions.h"
 
using namespace openshot;
 
#if defined(_WIN32)
namespace
{
    std::string WideToUtf8(const wchar_t* value)
    {
        if (!value || !*value) {
            return "";
        }
        const int length = WideCharToMultiByte(CP_UTF8, 0, value, -1, nullptr, 0, nullptr, nullptr);
        if (length <= 1) {
            return "";
        }
        std::string converted(static_cast<size_t>(length - 1), '\0');
        WideCharToMultiByte(CP_UTF8, 0, value, -1, &converted[0], length, nullptr, nullptr);
        return converted;
    }
 
    bool ContainsDeviceName(const AudioDeviceList& devices, const std::string& name)
    {
        for (const auto& device : devices) {
            if (device.second == name) {
                return true;
            }
        }
        return false;
    }
 
    AudioDeviceList GetWindowsDirectShowVideoDevices()
    {
        AudioDeviceList devices;
        const HRESULT init_result = CoInitializeEx(nullptr, COINIT_MULTITHREADED);
        const bool should_uninitialize = SUCCEEDED(init_result);
        if (FAILED(init_result) && init_result != RPC_E_CHANGED_MODE) {
            return devices;
        }
 
        ICreateDevEnum* device_enumerator = nullptr;
        HRESULT result = CoCreateInstance(
            CLSID_SystemDeviceEnum,
            nullptr,
            CLSCTX_INPROC_SERVER,
            IID_ICreateDevEnum,
            reinterpret_cast<void**>(&device_enumerator)
        );
        if (SUCCEEDED(result) && device_enumerator) {
            IEnumMoniker* moniker_enumerator = nullptr;
            result = device_enumerator->CreateClassEnumerator(
                CLSID_VideoInputDeviceCategory,
                &moniker_enumerator,
                0
            );
            if (result == S_OK && moniker_enumerator) {
                IMoniker* moniker = nullptr;
                while (moniker_enumerator->Next(1, &moniker, nullptr) == S_OK) {
                    IPropertyBag* property_bag = nullptr;
                    result = moniker->BindToStorage(
                        nullptr,
                        nullptr,
                        IID_IPropertyBag,
                        reinterpret_cast<void**>(&property_bag)
                    );
                    if (SUCCEEDED(result) && property_bag) {
                        VARIANT friendly_name;
                        VariantInit(&friendly_name);
                        result = property_bag->Read(L"FriendlyName", &friendly_name, nullptr);
                        if (SUCCEEDED(result) && friendly_name.vt == VT_BSTR) {
                            const std::string name = WideToUtf8(friendly_name.bstrVal);
                            if (!name.empty() && !ContainsDeviceName(devices, name)) {
                                devices.emplace_back(name, name);
                            }
                        }
                        VariantClear(&friendly_name);
                        property_bag->Release();
                    }
                    moniker->Release();
                    moniker = nullptr;
                }
                moniker_enumerator->Release();
            }
            device_enumerator->Release();
        }
        if (should_uninitialize) {
            CoUninitialize();
        }
        return devices;
    }
}
#endif
 
CameraCaptureReader::CameraCaptureReader(const CameraCaptureSettings& new_settings)
    : settings(new_settings)
    , reader(nullptr)
{
    if (settings.backend == CAMERA_CAPTURE_AUTO) {
        settings.backend = DefaultBackend();
    }
    ValidateSettings();
    RebuildReader();
}
 
CameraCaptureReader::~CameraCaptureReader()
{
    Close();
}
 
bool CameraCaptureReader::IsBackendSupported(CameraCaptureBackend backend)
{
#if defined(__linux__)
    return backend == CAMERA_CAPTURE_V4L2 || backend == CAMERA_CAPTURE_AUTO;
#elif defined(_WIN32)
    return backend == CAMERA_CAPTURE_WINDOWS_DSHOW || backend == CAMERA_CAPTURE_AUTO;
#elif defined(__APPLE__)
    return backend == CAMERA_CAPTURE_MAC_AVFOUNDATION || backend == CAMERA_CAPTURE_AUTO;
#else
    (void) backend;
    return false;
#endif
}
 
CameraCaptureBackend CameraCaptureReader::DefaultBackend()
{
#if defined(__linux__)
    return CAMERA_CAPTURE_V4L2;
#elif defined(_WIN32)
    return CAMERA_CAPTURE_WINDOWS_DSHOW;
#elif defined(__APPLE__)
    return CAMERA_CAPTURE_MAC_AVFOUNDATION;
#else
    return CAMERA_CAPTURE_AUTO;
#endif
}
 
AudioDeviceList CameraCaptureReader::GetDeviceNames(CameraCaptureBackend backend)
{
    if (backend == CAMERA_CAPTURE_AUTO) {
        backend = DefaultBackend();
    }
 
    AudioDeviceList devices;
    const char* input_format_name = nullptr;
#if defined(__linux__)
    if (backend == CAMERA_CAPTURE_V4L2) {
        input_format_name = "v4l2";
    }
#elif defined(_WIN32)
    if (backend == CAMERA_CAPTURE_WINDOWS_DSHOW) {
        return GetWindowsDirectShowVideoDevices();
    }
#elif defined(__APPLE__)
    if (backend == CAMERA_CAPTURE_MAC_AVFOUNDATION) {
        input_format_name = "avfoundation";
    }
#endif
    if (!input_format_name) {
        return devices;
    }
 
    avdevice_register_all();
    AVInputFormat* input_format = const_cast<AVInputFormat*>(av_find_input_format(input_format_name));
    if (!input_format) {
        return devices;
    }
 
    AVDeviceInfoList* device_list = nullptr;
    const int result = avdevice_list_input_sources(input_format, nullptr, nullptr, &device_list);
    if (result >= 0 && device_list) {
        for (int index = 0; index < device_list->nb_devices; ++index) {
            const AVDeviceInfo* device = device_list->devices[index];
            if (!device || !device->device_name) {
                continue;
            }
            const std::string name = device->device_name;
            const std::string label = device->device_description
                ? device->device_description
                : device->device_name;
        #if defined(__APPLE__)
            if (backend == CAMERA_CAPTURE_MAC_AVFOUNDATION && label.find("Capture screen") != std::string::npos) {
                continue;
            }
        #endif
            devices.emplace_back(label, name);
        }
    }
    avdevice_free_list_devices(&device_list);
    return devices;
}
 
void CameraCaptureReader::ValidateSettings() const
{
    if (!IsBackendSupported(settings.backend)) {
        throw InvalidOptions("Camera capture backend is not supported on this OS.");
    }
    if (settings.backend != CAMERA_CAPTURE_V4L2
        && settings.backend != CAMERA_CAPTURE_WINDOWS_DSHOW
        && settings.backend != CAMERA_CAPTURE_MAC_AVFOUNDATION) {
        throw InvalidOptions("Camera capture backend is not implemented in this build.");
    }
    if (settings.device.empty()) {
        throw InvalidOptions("Camera capture requires a device path.");
    }
    if (settings.width <= 0 || settings.height <= 0) {
        throw InvalidOptions("Camera capture requires a positive width and height.");
    }
    if (settings.fps.num <= 0 || settings.fps.den <= 0) {
        throw InvalidOptions("Camera capture requires a positive frame rate.");
    }
}
 
ScreenCaptureSettings CameraCaptureReader::ToDeviceSettings() const
{
    ScreenCaptureSettings converted;
    converted.display = settings.device;
    converted.width = settings.width;
    converted.height = settings.height;
    converted.fps = settings.fps;
    converted.options = settings.options;
    if (settings.backend == CAMERA_CAPTURE_WINDOWS_DSHOW) {
        converted.backend = SCREEN_CAPTURE_WINDOWS_GDI;
        converted.display = "video=" + settings.device;
        converted.options["input_format_name"] = "dshow";
    } else if (settings.backend == CAMERA_CAPTURE_MAC_AVFOUNDATION) {
        converted.backend = SCREEN_CAPTURE_MAC_AVFOUNDATION;
        converted.display = settings.device.find(':') == std::string::npos
            ? settings.device + ":none"
            : settings.device;
        converted.options["input_format_name"] = "avfoundation";
    } else {
        converted.backend = SCREEN_CAPTURE_X11;
        converted.options["input_format_name"] = "v4l2";
    }
    return converted;
}
 
void CameraCaptureReader::RebuildReader()
{
    reader = std::make_unique<ScreenCaptureReader>(ToDeviceSettings());
    info = reader->info;
    info.metadata["capture_type"] = "camera";
}
 
void CameraCaptureReader::Open()
{
    reader->Open();
    info = reader->info;
    info.metadata["capture_type"] = "camera";
}
 
void CameraCaptureReader::Close()
{
    if (reader) {
        reader->Close();
    }
}
 
openshot::CaptureReaderStats CameraCaptureReader::GetStats() const
{
    return reader ? reader->GetStats() : CaptureReaderStats();
}
 
std::shared_ptr<Frame> CameraCaptureReader::GetFrame(int64_t number)
{
    return reader->GetFrame(number);
}
 
std::string CameraCaptureReader::Json() const
{
    return JsonValue().toStyledString();
}
 
Json::Value CameraCaptureReader::JsonValue() const
{
    Json::Value root = ReaderBase::JsonValue();
    root["type"] = "CameraCaptureReader";
    root["backend"] = settings.backend;
    root["device"] = settings.device;
    root["width"] = settings.width;
    root["height"] = settings.height;
    root["fps"]["num"] = settings.fps.num;
    root["fps"]["den"] = settings.fps.den;
    root["options"] = Json::Value(Json::objectValue);
    for (const auto& option : settings.options) {
        root["options"][option.first] = option.second;
    }
    return root;
}
 
void CameraCaptureReader::SetJson(const std::string value)
{
    try {
        SetJsonValue(openshot::stringToJson(value));
    } catch (const std::exception&) {
        throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
    }
}
 
void CameraCaptureReader::SetJsonValue(const Json::Value root)
{
    if (!root["backend"].isNull())
        settings.backend = static_cast<CameraCaptureBackend>(root["backend"].asInt());
    if (!root["device"].isNull())
        settings.device = root["device"].asString();
    if (!root["width"].isNull())
        settings.width = root["width"].asInt();
    if (!root["height"].isNull())
        settings.height = root["height"].asInt();
    if (!root["fps"].isNull() && root["fps"].isObject()) {
        if (!root["fps"]["num"].isNull())
            settings.fps.num = root["fps"]["num"].asInt();
        if (!root["fps"]["den"].isNull())
            settings.fps.den = root["fps"]["den"].asInt();
    }
    if (!root["options"].isNull() && root["options"].isObject()) {
        settings.options.clear();
        for (const auto& key : root["options"].getMemberNames()) {
            settings.options[key] = root["options"][key].asString();
        }
    }
    if (settings.backend == CAMERA_CAPTURE_AUTO) {
        settings.backend = DefaultBackend();
    }
    ValidateSettings();
    RebuildReader();
}