Fix linux uvc source #72

vshcryabets · 2025-12-30T07:18:12Z

No description provided.

Copilot

Pull request overview

This PR refactors the Linux UVC camera implementation with major API changes and modernizations:

Renames UvcCamera to UvcSource for consistency
Migrates to std::expected for better error handling (C++23)
Updates all implementations to return ExpectedFrame/ExpectedResolutions
Adds command-line argument support to GTK preview app
Improves error messages and exception handling

Key Changes

Adopted C++23 and std::expected for improved error handling across all source implementations
Refactored UvcSource with std::string/std::vector instead of raw pointers for better memory safety
Enhanced GTK preview app with runtime source selection via command-line arguments

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 17 comments.

Show a summary per file

File	Description
linux/apps/sdl_preview/uvccapture.cpp	Updated to use renamed UvcSource class
linux/apps/gtk_preview/gtk_preview.cpp	Major refactoring: added command-line argument parsing for source selection, removed preprocessor conditionals, made RGBA conversion dynamic
linux/CMakeLists.txt	Updated C++ standard to C++23, enabled V4L2 module by default, updated comments
libausbc/src/main/jni/modules/sources/test/*.cpp	Updated tests to handle ExpectedFrame/ExpectedResolutions return types
libausbc/src/main/jni/modules/sources/src/jni/*.cpp	Updated JNI wrappers to handle std::expected and convert errors to Java exceptions
libausbc/src/main/jni/modules/sources/src/UvcSource.cpp	New implementation replacing UvcCamera with improved C++ memory management
libausbc/src/main/jni/modules/sources/src/UvcCamera.cpp	Deleted old implementation
libausbc/src/main/jni/modules/sources/src/*.cpp	Updated all source implementations to return std::expected types
libausbc/src/main/jni/modules/sources/include/*.h	Updated headers with new API signatures using ExpectedFrame/ExpectedResolutions
libausbc/src/main/jni/modules/images/src/ImageUseCases.cpp	Added buffer size validation for YUYV conversion
libausbc/src/main/jni/modules/encoders/*.cpp	Updated encoder to use new ExpectedResolutions type
libausbc/src/main/jni/modules/sources/CMakeLists.txt	Updated source file from UvcCamera.cpp to UvcSource.cpp

Comments suppressed due to low confidence (1)

libausbc/src/main/jni/modules/sources/include/UvcSource.h:22

The header now uses std::string (line 22, 31) and std::vector (line 42, 47) but relies on transitive includes from Source.h. For better header independence and to avoid potential issues if Source.h changes its includes, consider explicitly including <string> and <vector> in this header file.

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Copilot · 2025-12-30T07:25:56Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+    if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
+        fprintf(stderr, "%s is no video capture device\n",
+            this->uvcConfig.dev_name);
+        exit(EXIT_FAILURE);


Using exit(EXIT_FAILURE) in library code prevents proper error handling and resource cleanup. Consider throwing a UvcException instead, which allows callers to handle the error appropriately and ensures that destructors are called for stack-allocated objects.

Copilot · 2025-12-30T07:25:56Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+            fprintf(stderr, "%s is no V4L2 device\n", this->uvcConfig.dev_name);
+            exit(EXIT_FAILURE);
+        } else {
+            throw UvcException(UvcException::Type::IoCtlError, "VIDIOC_QUERYCAP");
+        }
+    }
+
+    if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
+        fprintf(stderr, "%s is no video capture device\n",
+            this->uvcConfig.dev_name);
+        exit(EXIT_FAILURE);
+    }
+    switch (io) {
+        case IO_METHOD_READ:
+            if (!(cap.capabilities & V4L2_CAP_READWRITE)) {
+                fprintf(stderr, "%s does not support read i/o\n",
+                    this->uvcConfig.dev_name);
+                exit(EXIT_FAILURE);
+            }
+            break;
+
+        case IO_METHOD_MMAP:
+        case IO_METHOD_USERPTR:
+            if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
+                fprintf(stderr, "%s does not support streaming i/o\n",
+                    this->uvcConfig.dev_name);
+                exit(EXIT_FAILURE);


Using exit(EXIT_FAILURE) in library code prevents proper error handling and resource cleanup. Consider throwing a UvcException instead, which allows callers to handle the error appropriately and ensures that destructors are called for stack-allocated objects.

Suggested change

fprintf(stderr, "%s is no V4L2 device\n", this->uvcConfig.dev_name);

exit(EXIT_FAILURE);

} else {

throw UvcException(UvcException::Type::IoCtlError, "VIDIOC_QUERYCAP");

}

}

if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {

fprintf(stderr, "%s is no video capture device\n",

this->uvcConfig.dev_name);

exit(EXIT_FAILURE);

}

switch (io) {

case IO_METHOD_READ:

if (!(cap.capabilities & V4L2_CAP_READWRITE)) {

fprintf(stderr, "%s does not support read i/o\n",

this->uvcConfig.dev_name);

exit(EXIT_FAILURE);

}

break;

case IO_METHOD_MMAP:

case IO_METHOD_USERPTR:

if (!(cap.capabilities & V4L2_CAP_STREAMING)) {

fprintf(stderr, "%s does not support streaming i/o\n",

this->uvcConfig.dev_name);

exit(EXIT_FAILURE);

throw UvcException(

UvcException::Type::WrongDevice,

std::string(this->uvcConfig.dev_name) + " is no V4L2 device");

} else {

throw UvcException(UvcException::Type::IoCtlError, "VIDIOC_QUERYCAP");

}

}

if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {

throw UvcException(

UvcException::Type::WrongDevice,

std::string(this->uvcConfig.dev_name) + " is no video capture device");

}

switch (io) {

case IO_METHOD_READ:

if (!(cap.capabilities & V4L2_CAP_READWRITE)) {

throw UvcException(

UvcException::Type::WrongDevice,

std::string(this->uvcConfig.dev_name) + " does not support read i/o");

}

break;

case IO_METHOD_MMAP:

case IO_METHOD_USERPTR:

if (!(cap.capabilities & V4L2_CAP_STREAMING)) {

throw UvcException(

UvcException::Type::WrongDevice,

std::string(this->uvcConfig.dev_name) + " does not support streaming i/o");

Copilot · 2025-12-30T07:25:56Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+
+std::future<void> UvcSource::startProducing(const Source::ProducingConfiguration &config)
+{    
+    return std::async(std::launch::async, [this,&config]() {


Capturing 'config' by reference in an asynchronous lambda is dangerous because the config parameter may go out of scope before the lambda executes. The lambda should capture 'config' by value instead to avoid potential use-after-free bugs.

Suggested change

return std::async(std::launch::async, [this,&config]() {

return std::async(std::launch::async, [this, config]() {

Copilot · 2025-12-30T07:25:56Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+
+    if (req.count < 2) {
+        fprintf(stderr, "Insufficient buffer memory on %s\n",
+            this->uvcConfig.dev_name);


Using std::string directly with fprintf's %s format specifier is undefined behavior. Since dev_name is now a std::string instead of const char*, you must call .c_str() on it when passing to fprintf.

Suggested change

this->uvcConfig.dev_name);

this->uvcConfig.dev_name.c_str());

Copilot · 2025-12-30T07:25:57Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+                fprintf(stderr, "%s does not support read i/o\n",
+                    this->uvcConfig.dev_name);


Using std::string directly with fprintf's %s format specifier is undefined behavior. Since dev_name is now a std::string instead of const char*, you must call .c_str() on it when passing to fprintf.

Copilot · 2025-12-30T07:25:59Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+            if (!(cap.capabilities & V4L2_CAP_READWRITE)) {
+                fprintf(stderr, "%s does not support read i/o\n",
+                    this->uvcConfig.dev_name);
+                exit(EXIT_FAILURE);


Using exit(EXIT_FAILURE) in library code prevents proper error handling and resource cleanup. Consider throwing a UvcException instead, which allows callers to handle the error appropriately and ensures that destructors are called for stack-allocated objects.

Copilot · 2025-12-30T07:25:59Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+            fprintf(stderr, "%s does not support "
+                            "user pointer i/o\n", this->uvcConfig.dev_name);


Using std::string directly with fprintf's %s format specifier is undefined behavior. Since dev_name is now a std::string instead of const char*, you must call .c_str() on it when passing to fprintf.

Copilot · 2025-12-30T07:25:59Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+
+    if (-1 == xioctl(deviceFd, VIDIOC_QUERYCAP, &cap)) {
+        if (EINVAL == errno) {
+            fprintf(stderr, "%s is no V4L2 device\n", this->uvcConfig.dev_name);


Using std::string directly with fprintf's %s format specifier is undefined behavior. Since dev_name is now a std::string instead of const char*, you must call .c_str() on it when passing to fprintf.

Copilot · 2025-12-30T07:25:59Z

linux/apps/gtk_preview/gtk_preview.cpp

+
+        // Filter out our custom options before passing to GTK
+        int gtk_argc = 1;
+        char *gtk_argv[argc];


Variable-length arrays (VLAs) are not standard C++ and may not be supported by all compilers. The size 'argc' is not a compile-time constant. Consider using std::vector instead to ensure portability and standard compliance.

Copilot · 2025-12-30T07:25:59Z

linux/apps/gtk_preview/gtk_preview.cpp

+                .height = 480};
+        }
+        if (testSource == nullptr) {
+            std::cerr << "No test source specified. Use --testSourceYUV420 or --testSourceRGB, --uvcSource" << std::endl;


The error message format is inconsistent. Consider changing to: "No test source specified. Use --testSourceYUV420, --testSourceRGB, or --uvcSource" for better clarity and consistency with the option names.

Suggested change

std::cerr << "No test source specified. Use --testSourceYUV420 or --testSourceRGB, --uvcSource" << std::endl;

std::cerr << "No test source specified. Use --testSourceYUV420, --testSourceRGB, or --uvcSource" << std::endl;

…d improve error handling

Copilot

Pull request overview

Copilot reviewed 33 out of 33 changed files in this pull request and generated 11 comments.

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Copilot · 2025-12-30T19:25:25Z

linux/apps/sdl_preview/uvccapture.cpp

    const char *videodevice = "/dev/video0";

-    UvcCamera::Configuration deviceConfig = {
+    UvcSource::Configuration deviceConfig = {


The type name should be UvcSource::OpenConfiguration instead of UvcSource::Configuration. The UvcSource class defines an OpenConfiguration struct (as seen in UvcSource.h line 30), not a Configuration struct.

Copilot · 2025-12-30T19:25:26Z

linux/apps/gtk_preview/gtk_preview.cpp

+            gtk_argv.push_back(argv[i]);
+            }


Inconsistent indentation: the closing brace and the gtk_argv.push_back statement should be indented at the same level as the if statement. Currently the gtk_argv.push_back is indented incorrectly.

Copilot · 2025-12-30T19:25:26Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+                throw UvcException(UvcException::Type::ReadError, "Doesn't support read i/o" + this->uvcConfig.dev_name);
+            }
+            break;
+
+        case IO_METHOD_MMAP:
+        case IO_METHOD_USERPTR:
+            if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
+                throw UvcException(UvcException::Type::MmapError, "Doesn't support streaming i/o" + this->uvcConfig.dev_name);


Missing space in error message concatenation. The error message will read "Doesn't support streaming i/o/dev/video0" instead of "Doesn't support streaming i/o /dev/video0". Add a space before concatenating the device name.

Suggested change

throw UvcException(UvcException::Type::ReadError, "Doesn't support read i/o" + this->uvcConfig.dev_name);

}

break;

case IO_METHOD_MMAP:

case IO_METHOD_USERPTR:

if (!(cap.capabilities & V4L2_CAP_STREAMING)) {

throw UvcException(UvcException::Type::MmapError, "Doesn't support streaming i/o" + this->uvcConfig.dev_name);

throw UvcException(UvcException::Type::ReadError, "Doesn't support read i/o " + this->uvcConfig.dev_name);

}

break;

case IO_METHOD_MMAP:

case IO_METHOD_USERPTR:

if (!(cap.capabilities & V4L2_CAP_STREAMING)) {

throw UvcException(UvcException::Type::MmapError, "Doesn't support streaming i/o " + this->uvcConfig.dev_name);

Copilot · 2025-12-30T19:25:26Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+}
+
+UvcSource::~UvcSource() {
+    close().get();


Calling .get() on a future in a destructor can be problematic. If the async operation throws an exception, .get() will rethrow it in the destructor, which will call std::terminate() if the destructor itself is called during stack unwinding. Consider handling exceptions or using a non-throwing cleanup approach in the destructor.

Suggested change

close().get();

try {

close().get();

} catch (...) {

// Suppress all exceptions in destructor to avoid std::terminate during stack unwinding.

}

Copilot · 2025-12-30T19:25:27Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+
+        buffers.clear();
+
+        if (deviceFd > 0) {


The condition deviceFd > 0 is incorrect for file descriptor validation. File descriptor 0 (stdin) is valid. The check should be deviceFd >= 0 to properly handle all valid file descriptors, or compare against -1 which is the error value returned by open().

Suggested change

if (deviceFd > 0) {

if (deviceFd >= 0) {

Copilot · 2025-12-30T19:25:27Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+                resolutions.emplace_back(frmsize.discrete.width, frmsize.discrete.height);
+            } else if (frmsize.type == V4L2_FRMSIZE_TYPE_STEPWISE) {
+                for (uint32_t w = frmsize.stepwise.min_width; w <= frmsize.stepwise.max_width; w += frmsize.stepwise.step_width) {
+                    for (uint32_t h = frmsize.stepwise.min_height; h <= frmsize.stepwise.max_height; h += frmsize.stepwise.step_height) {
+                        resolutions.emplace_back(w, h);


Incomplete initialization of Resolution struct. The Resolution struct has 4 fields (id, width, height, fps), but only width and height are being provided to emplace_back. The id and fps fields will be default-initialized (id=0, fps=empty vector), which may not be the intended behavior. Consider explicitly initializing all fields or documenting the expected default values.

Suggested change

resolutions.emplace_back(frmsize.discrete.width, frmsize.discrete.height);

} else if (frmsize.type == V4L2_FRMSIZE_TYPE_STEPWISE) {

for (uint32_t w = frmsize.stepwise.min_width; w <= frmsize.stepwise.max_width; w += frmsize.stepwise.step_width) {

for (uint32_t h = frmsize.stepwise.min_height; h <= frmsize.stepwise.max_height; h += frmsize.stepwise.step_height) {

resolutions.emplace_back(w, h);

resolutions.emplace_back(auvc::Resolution{0, frmsize.discrete.width, frmsize.discrete.height, {}});

} else if (frmsize.type == V4L2_FRMSIZE_TYPE_STEPWISE) {

for (uint32_t w = frmsize.stepwise.min_width; w <= frmsize.stepwise.max_width; w += frmsize.stepwise.step_width) {

for (uint32_t h = frmsize.stepwise.min_height; h <= frmsize.stepwise.max_height; h += frmsize.stepwise.step_height) {

resolutions.emplace_back(auvc::Resolution{0, w, h, {}});

Copilot · 2025-12-30T19:25:27Z

linux/apps/gtk_preview/gtk_preview.cpp

+        int gtk_argc = 1;
+        std::vector<char*> gtk_argv;
+        gtk_argv.push_back(argv[0]);
+        for (int i = 1; i < argc; ++i) {
+            if (strcmp(argv[i], "--testSourceYUV420") != 0 && 
+                strcmp(argv[i], "--testSourceRGB") != 0 &&
+                strcmp(argv[i], "--uvcSource") != 0) {
+            gtk_argv.push_back(argv[i]);
+            }
+        }
+        status = g_application_run(G_APPLICATION(app), gtk_argc, gtk_argv.data());


The gtk_argc variable is incremented incorrectly. It's initialized to 1 (for argv[0]) but never incremented when custom arguments are filtered out. This will cause gtk_argc to not match the actual size of gtk_argv. You should either increment gtk_argc when pushing arguments to gtk_argv, or use gtk_argv.size() instead of gtk_argc.

Copilot · 2025-12-30T19:25:27Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+                throw UvcException(UvcException::Type::ReadError, "Doesn't support read i/o" + this->uvcConfig.dev_name);
+            }
+            break;
+
+        case IO_METHOD_MMAP:
+        case IO_METHOD_USERPTR:
+            if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
+                throw UvcException(UvcException::Type::MmapError, "Doesn't support streaming i/o" + this->uvcConfig.dev_name);


Missing space in error message concatenation. The error message will read "Doesn't support read i/o/dev/video0" instead of "Doesn't support read i/o /dev/video0". Add a space before concatenating the device name.

Suggested change

throw UvcException(UvcException::Type::ReadError, "Doesn't support read i/o" + this->uvcConfig.dev_name);

}

break;

case IO_METHOD_MMAP:

case IO_METHOD_USERPTR:

if (!(cap.capabilities & V4L2_CAP_STREAMING)) {

throw UvcException(UvcException::Type::MmapError, "Doesn't support streaming i/o" + this->uvcConfig.dev_name);

throw UvcException(UvcException::Type::ReadError, "Doesn't support read i/o " + this->uvcConfig.dev_name);

}

break;

case IO_METHOD_MMAP:

case IO_METHOD_USERPTR:

if (!(cap.capabilities & V4L2_CAP_STREAMING)) {

throw UvcException(UvcException::Type::MmapError, "Doesn't support streaming i/o " + this->uvcConfig.dev_name);

Copilot · 2025-12-30T19:25:28Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+
+        while (ioctl(deviceFd, VIDIOC_ENUM_FRAMESIZES, &frmsize) == 0) {
+            if (frmsize.type == V4L2_FRMSIZE_TYPE_DISCRETE) {
+                resolutions.emplace_back(frmsize.discrete.width, frmsize.discrete.height);


Incomplete initialization of Resolution struct. The Resolution struct has 4 fields (id, width, height, fps), but only width and height are being provided to emplace_back. The id and fps fields will be default-initialized (id=0, fps=empty vector), which may not be the intended behavior. Consider explicitly initializing all fields or documenting the expected default values.

Copilot · 2025-12-30T19:25:28Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+                for (uint32_t w = frmsize.stepwise.min_width; w <= frmsize.stepwise.max_width; w += frmsize.stepwise.step_width) {
+                    for (uint32_t h = frmsize.stepwise.min_height; h <= frmsize.stepwise.max_height; h += frmsize.stepwise.step_height) {
+                        resolutions.emplace_back(w, h);


Potential infinite loop if step_width or step_height is zero. The V4L2 API might return zero for step values in some cases, which would cause an infinite loop here. Add validation to ensure step values are greater than zero before entering the loop, or handle the zero case appropriately.

Suggested change

for (uint32_t w = frmsize.stepwise.min_width; w <= frmsize.stepwise.max_width; w += frmsize.stepwise.step_width) {

for (uint32_t h = frmsize.stepwise.min_height; h <= frmsize.stepwise.max_height; h += frmsize.stepwise.step_height) {

resolutions.emplace_back(w, h);

// Guard against zero step values to avoid potential infinite loops.

if (frmsize.stepwise.step_width == 0 || frmsize.stepwise.step_height == 0) {

// Fallback: at least record the minimum resolution rather than looping indefinitely.

resolutions.emplace_back(frmsize.stepwise.min_width, frmsize.stepwise.min_height);

} else {

for (uint32_t w = frmsize.stepwise.min_width; w <= frmsize.stepwise.max_width; w += frmsize.stepwise.step_width) {

for (uint32_t h = frmsize.stepwise.min_height; h <= frmsize.stepwise.max_height; h += frmsize.stepwise.step_height) {

resolutions.emplace_back(w, h);

}

Copilot

Pull request overview

Copilot reviewed 35 out of 35 changed files in this pull request and generated 8 comments.

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Copilot · 2026-01-02T20:11:34Z

libausbc/src/main/jni/modules/sources/src/UvcSource.cpp

+                if (frmsize.stepwise.step_width == 0 || frmsize.stepwise.step_height == 0) {
+                    resolutions.emplace_back(
+                        auvc::Resolution {
+                            .id = frmsize.index,
+                            .width = static_cast<uint16_t>(frmsize.stepwise.min_width),
+                            .height = static_cast<uint16_t>(frmsize.stepwise.min_height),
+                            .fps = {}
+                        });
+                    continue;


In the STEPWISE frame size handling, when step_width or step_height is 0, the code adds only the minimum resolution and then continues to the next iteration. However, according to V4L2 documentation, a step of 0 typically means any value is supported between min and max. The current implementation might miss valid resolutions. Consider handling this case more comprehensively or adding a comment explaining why only the minimum is added.

Copilot · 2026-01-02T20:11:34Z

libausbc/src/main/jni/modules/sources/include/Source.h

+
+class Source {
+public:
+    struct OpenConfiguration {


A 'tag' field was added to OpenConfiguration but it's not clear what this field is used for. Consider adding documentation to explain the purpose and expected usage of this field, especially since it's part of the public API.

Suggested change

struct OpenConfiguration {

struct OpenConfiguration {

/**

* Optional user-defined identifier for this source instance.

*

* The library does not interpret this value; it is provided so callers

* can attach an opaque tag (for example, for logging, debugging, or

* distinguishing between multiple open sources).

*/

Copilot · 2026-01-02T20:11:34Z

libausbc/src/main/jni/modules/sources/include/Source.h

+    [[nodiscard]] virtual std::future<void> stopProducing() {
+        this->captureConfiguration = ProducingConfiguration();
+        return auvc::completed();
+    };


The stopProducing method was changed from pure virtual to have a default implementation that resets captureConfiguration. This is a good improvement that reduces boilerplate in derived classes, but ensure all existing implementations are reviewed to verify they don't rely on being forced to override this method.

Copilot · 2026-01-02T20:11:35Z

libausbc/src/main/jni/modules/sources/include/UvcSource.h

+class UvcException : public std::exception {
+    public:
+    enum Type {
+        Other,
+        WrongDevice,
+        CantOpenDevice,
+        CantCloseDevice,
+        IoCtlError,
+        MmapError,
+        ReadError,
+        FrameTimeout,
+        DeviceNotOpened
+    };
+    private:
+        Type errorType;
+        std::string errorMessage;
+    public:
+    UvcException(Type type, const std::string& message);
+    const char* what() const noexcept override;
+};


UvcException is defined outside the SUPPORT_V4L2 conditional compilation guard, but it's only used within UvcSource which is inside the guard. Consider moving the UvcException class definition inside the #ifdef SUPPORT_V4L2 block to avoid defining it when it won't be used.

Copilot · 2026-01-02T20:11:35Z

linux/apps/gtk_preview/gtk_preview.cpp

+        int gtk_argc = 1;
+        std::vector<char*> gtk_argv;
+        gtk_argv.push_back(argv[0]);
+        for (int i = 1; i < argc; ++i) {
+            if (strcmp(argv[i], "--testSourceYUV420") != 0 && 
+                strcmp(argv[i], "--testSourceRGB") != 0 &&
+                strcmp(argv[i], "--uvcSource") != 0) {
+                gtk_argv.push_back(argv[i]);
+            }
+        }
+        status = g_application_run(G_APPLICATION(app), gtk_argc, gtk_argv.data());


The gtk_argc variable is hardcoded to 1 but should reflect the actual size of the gtk_argv vector. After filtering out custom options, gtk_argc should be set to gtk_argv.size() instead of being fixed at 1. This would cause GTK to not receive any of its own command-line arguments that might be passed.

Copilot · 2026-01-02T20:11:35Z

linux/CMakeLists.txt

 include(CTest)

-set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD 23)


The upgrade to C++23 is necessary because std::expected was introduced in C++23. However, note that this requires compiler support for C++23, which may not be available on all platforms. Consider documenting this requirement or checking if C++23 is widely supported in your target environments.

Copilot · 2026-01-02T20:11:35Z

libausbc/src/main/jni/modules/sources/include/Source.h

+        uint8_t id;
+        uint16_t width;
+        uint16_t height;


The const qualifiers were removed from the Resolution struct members (id, width, height). While this makes the struct more flexible for assignments, it may break existing code that relied on these members being immutable. Consider whether this breaking change is intentional and necessary.

Suggested change

uint8_t id;

uint16_t width;

uint16_t height;

const uint8_t id{0};

const uint16_t width{0};

const uint16_t height{0};

Copilot · 2026-01-02T20:11:36Z

libausbc/src/main/jni/modules/sources/src/PullToPushSource.cpp

    }
    if (consumer == nullptr) {
-        throw SourceError(SourceError::SOURCE_ERROR_WRONG_CONFIG, "No consumer or frame callback set");
+        throw auvc::SourceError(auvc::SourceErrorCode::SOURCE_ERROR_WRONG_CONFIG, "No consumer");


The error message was changed from "No consumer or frame callback set" to just "No consumer". If there was previously support for both consumer and frame callback options, this message change might be misleading. Verify that frame callback support has been removed or clarify the message.

Suggested change

throw auvc::SourceError(auvc::SourceErrorCode::SOURCE_ERROR_WRONG_CONFIG, "No consumer");

throw auvc::SourceError(auvc::SourceErrorCode::SOURCE_ERROR_WRONG_CONFIG, "No consumer or frame callback set");

V.Shkriabets added 3 commits December 30, 2025 08:38

Update UvcSource

23a3bf9

Fix UvcSource

0b3bb24

Fix memory management in UvcSource

d8b42cf

vshcryabets requested a review from Copilot December 30, 2025 07:18

vshcryabets self-assigned this Dec 30, 2025

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Update UvcSource and related files to use ExpectedResolutions type an…

1e0d3cf

…d improve error handling

vshcryabets requested a review from Copilot December 30, 2025 19:18

Copilot started reviewing on behalf of vshcryabets December 30, 2025 19:19 View session

Copilot AI reviewed Dec 30, 2025

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Fix comments

feef638

vshcryabets requested a review from Copilot January 2, 2026 20:07

Copilot started reviewing on behalf of vshcryabets January 2, 2026 20:07 View session

Copilot AI reviewed Jan 2, 2026

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vshcryabets merged commit c14b345 into master Jan 3, 2026
7 checks passed

vshcryabets deleted the fix/linux-uvc-source branch January 3, 2026 07:20

	return std::async(std::launch::async, [this,&config]() {
	return std::async(std::launch::async, [this, config]() {

	this->uvcConfig.dev_name);
	this->uvcConfig.dev_name.c_str());

		fprintf(stderr, "%s does not support read i/o\n",
		this->uvcConfig.dev_name);

		fprintf(stderr, "%s does not support "
		"user pointer i/o\n", this->uvcConfig.dev_name);

	std::cerr << "No test source specified. Use --testSourceYUV420 or --testSourceRGB, --uvcSource" << std::endl;
	std::cerr << "No test source specified. Use --testSourceYUV420, --testSourceRGB, or --uvcSource" << std::endl;

-    struct OpenConfiguration {
+    struct OpenConfiguration {
+        /**
+         * Optional user-defined identifier for this source instance.
+         *
+         * The library does not interpret this value; it is provided so callers
+         * can attach an opaque tag (for example, for logging, debugging, or
+         * distinguishing between multiple open sources).
+         */

	throw auvc::SourceError(auvc::SourceErrorCode::SOURCE_ERROR_WRONG_CONFIG, "No consumer");
	throw auvc::SourceError(auvc::SourceErrorCode::SOURCE_ERROR_WRONG_CONFIG, "No consumer or frame callback set");

Fix linux uvc source #72

Fix linux uvc source #72

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