org.libav.swscale.bridge.ISWScaleLibrary Maven / Gradle / Ivy

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/*
 * Copyright (C) 2012 Ondrej Perutka
 *
 * This program is free software: you can redistribute it and/or 
 * modify it under the terms of the GNU Lesser General Public 
 * License as published by the Free Software Foundation, either 
 * version 3 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library. If not, see 
 * .
 */
package org.libav.swscale.bridge;

import com.sun.jna.Library;
import com.sun.jna.Pointer;

/**
 * Interface to provide access to the native swscale library. The methods'
 * documentation has been taken from the original Libav documentation.
 * 
 * @author Ondrej Perutka
 */
public interface ISWScaleLibrary extends Library {
    
    public static final int SWS_FAST_BILINEAR = 1;
    public static final int SWS_BILINEAR = 2;
    public static final int SWS_BICUBIC = 4;
    public static final int SWS_X = 8;
    public static final int SWS_POINT = 0x10;
    public static final int SWS_AREA = 0x20;
    public static final int SWS_BICUBLIN = 0x40;
    public static final int SWS_GAUSS = 0x80;
    public static final int SWS_SINC = 0x100;
    public static final int SWS_LANCZOS = 0x200;
    public static final int SWS_SPLINE = 0x400;
    
    /**
     * Get version of the swscale library. Bits 23 to 16 represents major
     * version, bits 15 to 8 are for minor version and bits 7 to 0 are for
     * micro version.
     * 
     * @return version of the swscale library
     */
    int swscale_version();
    
    /**
     * Checks if context can be reused, otherwise reallocates a new one. 
     * If context is NULL, just calls sws_getContext() to get a new context. 
     * 
     * Otherwise, checks if the parameters are the ones already saved in 
     * context. If that is the case, returns the current context. Otherwise, 
     * frees context and gets a new context with the new parameters.
     * 
     * Be warned that srcFilter and dstFilter are not checked, they are assumed 
     * to remain the same.
     * 
     * @param context existing context or null
     * @param srcW the width of the source image
     * @param srcH the height of the source image
     * @param srcFormat the source image PixelFormat
     * @param dstW the width of the destination image
     * @param dstH the height of the destination image
     * @param dstFormat the destination image PixelFormat
     * @param flags specify which algorithm and options to use for rescaling
     * @param srcFilter 
     * @param dstFilter 
     * @param param 
     * @return a pointer to an allocated context, or NULL in case of error
     */
    Pointer sws_getCachedContext(Pointer context, int srcW, int srcH, int srcFormat, int dstW, int dstH, int dstFormat, int flags, Pointer srcFilter, Pointer dstFilter, Pointer param);
    
    /**
     * Frees the swscaler context swsContext. 
     * 
     * If swsContext is NULL, then does nothing.
     * 
     * @param swsContext 
     */
    void sws_freeContext(Pointer swsContext);
    
    /**
     * Scales the image slice in srcSlice and puts the resulting scaled slice in 
     * the image in dst. 
     * 
     * A slice is a sequence of consecutive rows in an image.
     * 
     * Slices have to be provided in sequential order, either in top-bottom or 
     * bottom-top order. If slices are provided in non-sequential order the 
     * behavior of the function is undefined.
     * 
     * Assumes planar YUV to be in YUV order instead of YVU.
     * 
     * @param context the scaling context previously created with 
     * sws_getContext()
     * @param srcSlice the array containing the pointers to the planes of the 
     * source slice
     * @param srcStride the array containing the strides for each plane of the 
     * source image
     * @param srcSliceY the position in the source image of the slice to 
     * process, that is the number (counted starting from zero) in the image of 
     * the first row of the slice
     * @param srcSliceH the height of the source slice, that is the number of 
     * rows in the slice
     * @param dst the array containing the pointers to the planes of the 
     * destination image
     * @param dstStride the array containing the strides for each plane of the 
     * destination image
     * @return the height of the output slice
     */
    int sws_scale(Pointer context, Pointer[] srcSlice, int[] srcStride, int srcSliceY, int srcSliceH, Pointer[] dst, int[] dstStride);
}