ImfDeepScanLineInputFile.h

Go to the documentation of this file.

//
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) Contributors to the OpenEXR Project.
//

#ifndef INCLUDED_IMF_DEEP_SCAN_LINE_INPUT_FILE_H
#define INCLUDED_IMF_DEEP_SCAN_LINE_INPUT_FILE_H

//-----------------------------------------------------------------------------
//
//      class DeepScanLineInputFile
//
//-----------------------------------------------------------------------------

#include "ImfForward.h"

#include "ImfContext.h"

#include "ImfDeepScanLineOutputFile.h"

#include "ImfThreading.h"

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER

class IMF_EXPORT_TYPE DeepScanLineInputFile
{
public:
    //------------
    // Constructor
    //------------

    IMF_EXPORT
    DeepScanLineInputFile (
        const char*               filename,
        const ContextInitializer& ctxtinit,
        int                       numThreads = globalThreadCount ());

    IMF_EXPORT
    DeepScanLineInputFile (
        const char fileName[], int numThreads = globalThreadCount ());

    IMF_EXPORT
    DeepScanLineInputFile (
        OPENEXR_IMF_INTERNAL_NAMESPACE::IStream& is,
        int numThreads = globalThreadCount ());

    IMF_EXPORT
    DeepScanLineInputFile (
        const Header&                            header,
        OPENEXR_IMF_INTERNAL_NAMESPACE::IStream* is,
        int version, /*version field from file*/
        int numThreads = globalThreadCount ());

    //------------------------
    // Access to the file name
    //------------------------

    IMF_EXPORT
    const char* fileName () const;

    //--------------------------
    // Access to the file header
    //--------------------------

    IMF_EXPORT
    const Header& header () const;

    //----------------------------------
    // Access to the file format version
    //----------------------------------

    IMF_EXPORT
    int version () const;

    //-----------------------------------------------------------
    // Set the current frame buffer -- copies the FrameBuffer
    // object into the InputFile object.
    //
    // The current frame buffer is the destination for the pixel
    // data read from the file.  The current frame buffer must be
    // set at least once before readPixels() is called.
    // The current frame buffer can be changed after each call
    // to readPixels().
    //-----------------------------------------------------------

    IMF_EXPORT
    void setFrameBuffer (const DeepFrameBuffer& frameBuffer);

    //-----------------------------------
    // Access to the current frame buffer
    //-----------------------------------

    IMF_EXPORT
    const DeepFrameBuffer& frameBuffer () const;

    //---------------------------------------------------------------
    // Check if the file is complete:
    //
    // isComplete() returns true if all pixels in the data window are
    // present in the input file, or false if any pixels are missing.
    // (Another program may still be busy writing the file, or file
    // writing may have been aborted prematurely.)
    //---------------------------------------------------------------

    IMF_EXPORT
    bool isComplete () const;

    //---------------------------------------------------------------
    // Read pixel data:
    //
    // readPixels(s1,s2) reads all scan lines with y coordinates
    // in the interval [min (s1, s2), max (s1, s2)] from the file,
    // and stores them in the current frame buffer.
    //
    // Both s1 and s2 must be within the interval
    // [header().dataWindow().min.y, header.dataWindow().max.y]
    //
    // The scan lines can be read from the file in random order, and
    // individual scan lines may be skipped or read multiple times.
    // For maximum efficiency, the scan lines should be read in the
    // order in which they were written to the file.
    //
    // readPixels(s) calls readPixels(s,s).
    //
    // If threading is enabled, readPixels (s1, s2) tries to perform
    // decopmression of multiple scanlines in parallel.
    //
    //---------------------------------------------------------------

    IMF_EXPORT
    void readPixels (int scanLine1, int scanLine2);
    IMF_EXPORT
    void readPixels (int scanLine);

    //---------------------------------------------------------------
    // Extract pixel data from pre-read block
    //
    // readPixels(rawPixelData,frameBuffer,s1,s2) reads all scan lines with y coordinates
    // in the interval [min (s1, s2), max (s1, s2)] from the data provided and
    // stores them in the provided frameBuffer.
    // the data can be obtained from a call to rawPixelData()
    //
    //
    // Both s1 and s2 must be within the data specified
    //
    // you must provide a frameBuffer with a samplecountslice, which must have been read
    // and the data valid - readPixels uses your sample count buffer to compute
    // offsets to the data it needs
    //
    // This call does not block, and is thread safe for clients with an existing
    // threading model. The InputFile's frameBuffer is not used in this call.
    //
    // This call is only provided for clients which have an existing threading model in place
    // and unpredictable access patterns to the data.
    // The fastest way to read an entire image is to enable threading,use setFrameBuffer then
    // readPixels(header().dataWindow().min.y, header.dataWindow().max.y)
    //
    //---------------------------------------------------------------

    IMF_EXPORT
    void readPixels (
        const char*            rawPixelData,
        const DeepFrameBuffer& frameBuffer,
        int                    scanLine1,
        int                    scanLine2) const;

    //----------------------------------------------
    // Read a block of raw pixel data from the file,
    // without uncompressing it (this function is
    // used to implement OutputFile::copyPixels()).
    // note: returns the entire payload of the relevant chunk of data, not including part number
    // including compressed and uncompressed sizes
    // on entry, if pixelDataSize is insufficiently large, no bytes are read (pixelData can safely be NULL)
    // on exit, pixelDataSize is the number of bytes required to read the chunk
    //
    //----------------------------------------------

    IMF_EXPORT
    void
    rawPixelData (int firstScanLine, char* pixelData, uint64_t& pixelDataSize);

    //-------------------------------------------------
    // firstScanLineInChunk() returns the row number of the first row that's stored in the
    // same chunk as scanline y. Depending on the compression mode, this may not be the same as y
    //
    // lastScanLineInChunk() returns the row number of the last row that's stored in the same
    // chunk as scanline y.  Depending on the compression mode, this may not be the same as y.
    // The last chunk in the file may be smaller than all the others
    //
    //------------------------------------------------
    IMF_EXPORT
    int firstScanLineInChunk (int y) const;
    IMF_EXPORT
    int lastScanLineInChunk (int y) const;

    //-----------------------------------------------------------
    // Read pixel sample counts into a slice in the frame buffer.
    //
    // readPixelSampleCounts(s1, s2) reads all the counts of
    // pixel samples with y coordinates in the interval
    // [min (s1, s2), max (s1, s2)] from the file, and stores
    // them in the slice naming "sample count".
    //
    // Both s1 and s2 must be within the interval
    // [header().dataWindow().min.y, header.dataWindow().max.y]
    //
    // readPixelSampleCounts(s) calls readPixelSampleCounts(s,s).
    //
    //-----------------------------------------------------------

    IMF_EXPORT
    void readPixelSampleCounts (int scanline1, int scanline2);
    IMF_EXPORT
    void readPixelSampleCounts (int scanline);

    //----------------------------------------------------------
    // Read pixel sample counts into the provided frameBuffer
    // using a block read of data read by rawPixelData
    // for multi-scanline compression schemes, you must decode the entire block
    // so scanline1=firstScanLineInChunk(y) and scanline2=lastScanLineInChunk(y)
    //
    // This call does not block, and is thread safe for clients with an existing
    // threading model. The InputFile's frameBuffer is not used in this call.
    //
    // The fastest way to read an entire image is to enable threading in OpenEXR, use setFrameBuffer then
    // readPixelSampleCounts(header().dataWindow().min.y, header.dataWindow().max.y)
    //
    //----------------------------------------------------------
    IMF_EXPORT
    void readPixelSampleCounts (
        const char*            rawdata,
        const DeepFrameBuffer& frameBuffer,
        int                    scanLine1,
        int                    scanLine2) const;

private:
    Context _ctxt;
    struct IMF_HIDDEN Data;
    std::shared_ptr<Data> _data;

    IMF_HIDDEN DeepScanLineInputFile (InputPartData* part);

    friend class MultiPartInputFile;
    friend class InputFile;

    friend void DeepScanLineOutputFile::copyPixels (DeepScanLineInputFile&);
};

OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT

#endif