Video Decoding

gpu::VideoReader_GPU

Video reader class.

gpu::VideoReader_GPU::Codec

Video codecs supported by :ocv:class:`gpu::VideoReader_GPU` .

gpu::VideoReader_GPU::ChromaFormat

Chroma formats supported by :ocv:class:`gpu::VideoReader_GPU` .

gpu::VideoReader_GPU::FormatInfo

Struct providing information about video file format.

struct FormatInfo
{
    Codec codec;
    ChromaFormat chromaFormat;
    int width;
    int height;
};

gpu::VideoReader_GPU::VideoReader_GPU

Constructors.

The constructors initialize video reader. FFMPEG is used to read videos. User can implement own demultiplexing with :ocv:class:`gpu::VideoReader_GPU::VideoSource` .

gpu::VideoReader_GPU::open

Initializes or reinitializes video reader.

The method opens video reader. Parameters are the same as in the constructor :ocv:func:`gpu::VideoReader_GPU::VideoReader_GPU` . The method throws :ocv:class:`Exception` if error occurs.

gpu::VideoReader_GPU::isOpened

Returns true if video reader has been successfully initialized.

gpu::VideoReader_GPU::close

Releases the video reader.

gpu::VideoReader_GPU::read

Grabs, decodes and returns the next video frame.

If no frames has been grabbed (there are no more frames in video file), the methods return false . The method throws :ocv:class:`Exception` if error occurs.

gpu::VideoReader_GPU::format

Returns information about video file format.

The method throws :ocv:class:`Exception` if video reader wasn't initialized.

gpu::VideoReader_GPU::dumpFormat

Dump information about video file format to specified stream.

The method throws :ocv:class:`Exception` if video reader wasn't initialized.

gpu::VideoReader_GPU::VideoSource

Interface for video demultiplexing.

class VideoSource
{
public:
    VideoSource();
    virtual ~VideoSource() {}

    virtual FormatInfo format() const = 0;
    virtual void start() = 0;
    virtual void stop() = 0;
    virtual bool isStarted() const = 0;
    virtual bool hasError() const = 0;

protected:
    bool parseVideoData(const unsigned char* data, size_t size, bool endOfStream = false);
};

User can implement own demultiplexing by implementing this interface.

gpu::VideoReader_GPU::VideoSource::format

Returns information about video file format.

gpu::VideoReader_GPU::VideoSource::start

Starts processing.

Implementation must create own thread with video processing and call periodic :ocv:func:`gpu::VideoReader_GPU::VideoSource::parseVideoData` .

gpu::VideoReader_GPU::VideoSource::stop

Stops processing.

gpu::VideoReader_GPU::VideoSource::isStarted

Returns true if processing was successfully started.

gpu::VideoReader_GPU::VideoSource::hasError

Returns true if error occured during processing.

gpu::VideoReader_GPU::VideoSource::parseVideoData

Parse next video frame. Implementation must call this method after new frame was grabbed.