From 1351f4c8ef33216e8a1b510aaec82b73d98e87bc Mon Sep 17 00:00:00 2001 From: Vladislav Vinogradov Date: Wed, 18 Apr 2012 12:46:56 +0000 Subject: [PATCH] added docs for VideoReader_GPU --- modules/gpu/doc/video.rst | 236 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 230 insertions(+), 6 deletions(-) diff --git a/modules/gpu/doc/video.rst b/modules/gpu/doc/video.rst index f491f04..944fbc3 100644 --- a/modules/gpu/doc/video.rst +++ b/modules/gpu/doc/video.rst @@ -328,7 +328,7 @@ Constructors. :param encoderCallback: Callbacks for video encoder. See :ocv:class:`gpu::VideoWriter_GPU::EncoderCallBack` . Use it if you want to work with raw video stream. -The constructors initialize video writers. FFMPEG is used to write videos. User can implement own multiplexing with ``EncoderCallBack`` . +The constructors initialize video writer. FFMPEG is used to write videos. User can implement own multiplexing with :ocv:class:`gpu::VideoWriter_GPU::EncoderCallBack` . @@ -446,10 +446,11 @@ Saves parameters to config file. gpu::VideoWriter_GPU::EncoderCallBack ------------------------------------ +------------------------------------- .. ocv:class:: gpu::VideoWriter_GPU::EncoderCallBack Callbacks for CUDA video encoder. :: + class EncoderCallBack { public: @@ -474,7 +475,7 @@ gpu::VideoWriter_GPU::EncoderCallBack::acquireBitStream ------------------------------------------------------- Callback function to signal the start of bitstream that is to be encoded. -.. ocv:function:: unsigned char* gpu::VideoWriter_GPU::EncoderCallBack::acquireBitStream(int* bufferSize); +.. ocv:function:: virtual unsigned char* gpu::VideoWriter_GPU::EncoderCallBack::acquireBitStream(int* bufferSize) = 0; Callback must allocate buffer for CUDA encoder and return pointer to it and it's size. @@ -484,7 +485,7 @@ gpu::VideoWriter_GPU::EncoderCallBack::releaseBitStream ------------------------------------------------------- Callback function to signal that the encoded bitstream is ready to be written to file. -.. ocv:function:: void gpu::VideoWriter_GPU::EncoderCallBack::releaseBitStream(unsigned char* data, int size); +.. ocv:function:: virtual void gpu::VideoWriter_GPU::EncoderCallBack::releaseBitStream(unsigned char* data, int size) = 0; @@ -492,7 +493,7 @@ gpu::VideoWriter_GPU::EncoderCallBack::onBeginFrame --------------------------------------------------- Callback function to signal that the encoding operation on the frame has started. -.. ocv:function:: void gpu::VideoWriter_GPU::EncoderCallBack::onBeginFrame(int frameNumber, PicType picType); +.. ocv:function:: virtual void gpu::VideoWriter_GPU::EncoderCallBack::onBeginFrame(int frameNumber, PicType picType) = 0; :param picType: Specify frame type (I-Frame, P-Frame or B-Frame). @@ -502,10 +503,233 @@ gpu::VideoWriter_GPU::EncoderCallBack::onEndFrame ------------------------------------------------- Callback function signals that the encoding operation on the frame has finished. -.. ocv:function:: void gpu::VideoWriter_GPU::EncoderCallBack::onEndFrame(int frameNumber, PicType picType); +.. ocv:function:: virtual void gpu::VideoWriter_GPU::EncoderCallBack::onEndFrame(int frameNumber, PicType picType) = 0; :param picType: Specify frame type (I-Frame, P-Frame or B-Frame). +gpu::VideoReader_GPU +-------------------- +Class for reading video from files. + +.. ocv:class:: gpu::VideoReader_GPU + + + +gpu::VideoReader_GPU::Codec +--------------------------- +.. ocv:class:: gpu::VideoReader_GPU::Codec + +Video codecs supported by ocv:class:`gpu::VideoReader_GPU` . :: + + enum Codec + { + MPEG1 = 0, + MPEG2, + MPEG4, + VC1, + H264, + JPEG, + H264_SVC, + H264_MVC, + + Uncompressed_YUV420 = (('I'<<24)|('Y'<<16)|('U'<<8)|('V')), // Y,U,V (4:2:0) + Uncompressed_YV12 = (('Y'<<24)|('V'<<16)|('1'<<8)|('2')), // Y,V,U (4:2:0) + Uncompressed_NV12 = (('N'<<24)|('V'<<16)|('1'<<8)|('2')), // Y,UV (4:2:0) + Uncompressed_YUYV = (('Y'<<24)|('U'<<16)|('Y'<<8)|('V')), // YUYV/YUY2 (4:2:2) + Uncompressed_UYVY = (('U'<<24)|('Y'<<16)|('V'<<8)|('Y')), // UYVY (4:2:2) + }; + + + +gpu::VideoReader_GPU::ChromaFormat +---------------------------------- +.. ocv:class:: gpu::VideoReader_GPU::ChromaFormat + +Chroma formats supported by ocv:class:`gpu::VideoReader_GPU` . :: + + enum ChromaFormat + { + Monochrome=0, + YUV420, + YUV422, + YUV444, + }; + + + +gpu::VideoReader_GPU::FormatInfo +-------------------------------- +.. ocv:class:: 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. + +.. ocv:function:: gpu::VideoReader_GPU::VideoReader_GPU(); +.. ocv:function:: gpu::VideoReader_GPU::VideoReader_GPU(const std::string& filename); +.. ocv:function:: gpu::VideoReader_GPU::VideoReader_GPU(const cv::Ptr& source); + + :param filename: Name of the input video file. + + :param source: Video file parser implemented by user. + +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. + +.. ocv:function:: void gpu::VideoReader_GPU::open(const std::string& filename); +.. ocv:function:: void gpu::VideoReader_GPU::open(const cv::Ptr& source); + +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. + +.. ocv:function:: bool gpu::VideoReader_GPU::isOpened() const; + + + +gpu::VideoReader_GPU::close +--------------------------- +Releases the video reader. + +.. ocv:function:: void gpu::VideoReader_GPU::close(); + + + +gpu::VideoReader_GPU::read +-------------------------- +Grabs, decodes and returns the next video frame. + +.. ocv:function:: bool gpu::VideoReader_GPU::read(GpuMat& image); + +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. + +.. ocv:function:: FormatInfo gpu::VideoReader_GPU::format() const; + +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. + +.. ocv:function:: void gpu::VideoReader_GPU::dumpFormat(std::ostream& st); + + :param st: Output stream. + +The method throws :ocv:class:`Exception` if video reader wasn't initialized. + + + +gpu::VideoReader_GPU::VideoSource +----------------------------------- +.. ocv:class:: 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. + +.. ocv:function:: virtual FormatInfo gpu::VideoReader_GPU::VideoSource::format() const = 0; + + + +gpu::VideoReader_GPU::VideoSource::start +---------------------------------------- +Starts processing. + +.. ocv:function:: virtual void gpu::VideoReader_GPU::VideoSource::start() = 0; + +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. + +.. ocv:function:: virtual void gpu::VideoReader_GPU::VideoSource::stop() = 0; + + + +gpu::VideoReader_GPU::VideoSource::isStarted +-------------------------------------------- +Returns ``true`` if processing was successfully started. + +.. ocv:function:: virtual bool gpu::VideoReader_GPU::VideoSource::isStarted() const = 0; + + + +gpu::VideoReader_GPU::VideoSource::hasError +------------------------------------------- +Returns ``true`` if error occured during processing. + +.. ocv:function:: virtual bool gpu::VideoReader_GPU::VideoSource::hasError() const = 0; + + + +gpu::VideoReader_GPU::VideoSource::parseVideoData +------------------------------------------------- +Parse next video frame. Implementation must call this method after new frame was grabbed. + +.. ocv:function:: bool gpu::VideoReader_GPU::VideoSource::parseVideoData(const unsigned char* data, size_t size, bool endOfStream = false); + + :param data: Pointer to frame data. Can be ``NULL`` if ``endOfStream`` if ``true`` . + + :param size: Size in bytes of current frame. + + :param endOfStream: Indicates that it is end of stream. + + + .. [Brox2004] T. Brox, A. Bruhn, N. Papenberg, J. Weickert. *High accuracy optical flow estimation based on a theory for warping*. ECCV 2004. -- 2.7.4