157 lines
3.7 KiB
ReStructuredText
157 lines
3.7 KiB
ReStructuredText
Video Decoding
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==============
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.. highlight:: cpp
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cudacodec::VideoReader
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----------------------
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Video reader interface.
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.. ocv:class:: cudacodec::VideoReader
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.. note::
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* An example on how to use the videoReader class can be found at opencv_source_code/samples/gpu/video_reader.cpp
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cudacodec::VideoReader::nextFrame
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---------------------------------
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Grabs, decodes and returns the next video frame.
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.. ocv:function:: bool cudacodec::VideoReader::nextFrame(OutputArray frame)
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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.
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cudacodec::VideoReader::format
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------------------------------
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Returns information about video file format.
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.. ocv:function:: FormatInfo cudacodec::VideoReader::format() const
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cudacodec::Codec
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----------------
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Video codecs supported by :ocv:class:`cudacodec::VideoReader` .
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.. ocv:enum:: cudacodec::Codec
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.. ocv:emember:: MPEG1 = 0
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.. ocv:emember:: MPEG2
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.. ocv:emember:: MPEG4
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.. ocv:emember:: VC1
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.. ocv:emember:: H264
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.. ocv:emember:: JPEG
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.. ocv:emember:: H264_SVC
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.. ocv:emember:: H264_MVC
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.. ocv:emember:: Uncompressed_YUV420 = (('I'<<24)|('Y'<<16)|('U'<<8)|('V'))
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Y,U,V (4:2:0)
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.. ocv:emember:: Uncompressed_YV12 = (('Y'<<24)|('V'<<16)|('1'<<8)|('2'))
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Y,V,U (4:2:0)
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.. ocv:emember:: Uncompressed_NV12 = (('N'<<24)|('V'<<16)|('1'<<8)|('2'))
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Y,UV (4:2:0)
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.. ocv:emember:: Uncompressed_YUYV = (('Y'<<24)|('U'<<16)|('Y'<<8)|('V'))
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YUYV/YUY2 (4:2:2)
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.. ocv:emember:: Uncompressed_UYVY = (('U'<<24)|('Y'<<16)|('V'<<8)|('Y'))
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UYVY (4:2:2)
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cudacodec::ChromaFormat
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-----------------------
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Chroma formats supported by :ocv:class:`cudacodec::VideoReader` .
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.. ocv:enum:: cudacodec::ChromaFormat
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.. ocv:emember:: Monochrome = 0
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.. ocv:emember:: YUV420
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.. ocv:emember:: YUV422
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.. ocv:emember:: YUV444
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cudacodec::FormatInfo
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---------------------
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.. ocv:struct:: cudacodec::FormatInfo
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Struct providing information about video file format. ::
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struct FormatInfo
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{
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Codec codec;
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ChromaFormat chromaFormat;
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int width;
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int height;
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};
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cudacodec::createVideoReader
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----------------------------
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Creates video reader.
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.. ocv:function:: Ptr<VideoReader> cudacodec::createVideoReader(const String& filename)
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.. ocv:function:: Ptr<VideoReader> cudacodec::createVideoReader(const Ptr<RawVideoSource>& source)
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:param filename: Name of the input video file.
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:param source: RAW video source implemented by user.
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FFMPEG is used to read videos. User can implement own demultiplexing with :ocv:class:`cudacodec::RawVideoSource` .
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cudacodec::RawVideoSource
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-------------------------
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.. ocv:class:: cudacodec::RawVideoSource
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Interface for video demultiplexing. ::
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class RawVideoSource
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{
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public:
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virtual ~RawVideoSource() {}
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virtual bool getNextPacket(unsigned char** data, int* size, bool* endOfFile) = 0;
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virtual FormatInfo format() const = 0;
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};
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User can implement own demultiplexing by implementing this interface.
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cudacodec::RawVideoSource::getNextPacket
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----------------------------------------
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Returns next packet with RAW video frame.
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.. ocv:function:: bool cudacodec::VideoSource::getNextPacket(unsigned char** data, int* size, bool* endOfFile) = 0
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:param data: Pointer to frame data.
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:param size: Size in bytes of current frame.
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:param endOfStream: Indicates that it is end of stream.
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cudacodec::RawVideoSource::format
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---------------------------------
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Returns information about video file format.
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.. ocv:function:: virtual FormatInfo cudacodec::RawVideoSource::format() const = 0
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