//    Copyright (C) 2010 Dirk Vanden Boer <dirk.vdb@gmail.com>
//
//    This program is free software; you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation; either version 2 of the License, or
//    (at your option) any later version.
//
//    This program 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 General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program; if not, write to the Free Software
//    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#include "filmstripfilter.h"
#include "filmstrip.h"

#include <cstddef>

namespace ffmpegthumbnailer
{

static const uint8_t* determineFilmStrip(uint32_t videoWidth, uint32_t& filmStripWidth, uint32_t& filmStripHeight)
{
    if (videoWidth <= SMALLEST_FILM_STRIP_WIDTH * 2)
    {
        return NULL;
    }
    
    if (videoWidth <= 96)
    {
        filmStripWidth = filmStripHeight = 4;
        return filmStrip4;
    }
    
    if (videoWidth <= 192)
    {
        filmStripWidth = filmStripHeight = 8;
        return filmStrip8;
    }
    
    if (videoWidth <= 384)
    {
        filmStripWidth = filmStripHeight = 16;
        return filmStrip16;
    }

    if (videoWidth <= 768)
    {
        filmStripWidth = filmStripHeight = 32;
        return filmStrip32;
    }
    
    filmStripWidth = filmStripHeight = 64;
    return filmStrip64;
}

void FilmStripFilter::process(VideoFrame& videoFrame)
{
    uint32_t filmStripWidth;
    uint32_t filmStripHeight;
    const uint8_t* filmHole = determineFilmStrip(videoFrame.width, filmStripWidth, filmStripHeight);

    if (!filmHole)
    {
        return;
    }

    int frameIndex = 0;
    int filmHoleIndex = 0;
    int offset = (videoFrame.width * 3) - 3;
 
    for (int32_t i = 0; i < videoFrame.height; ++i)
    {
        for (uint32_t j = 0; j < filmStripWidth * 3; j+=3)
        {
            int currentFilmHoleIndex = filmHoleIndex + j;

            videoFrame.frameData[frameIndex + j]     = filmHole[currentFilmHoleIndex];
            videoFrame.frameData[frameIndex + j + 1] = filmHole[currentFilmHoleIndex + 1];
            videoFrame.frameData[frameIndex + j + 2] = filmHole[currentFilmHoleIndex + 2];

            videoFrame.frameData[frameIndex + offset - j]     = filmHole[currentFilmHoleIndex];
            videoFrame.frameData[frameIndex + offset - j + 1] = filmHole[currentFilmHoleIndex + 1];
            videoFrame.frameData[frameIndex + offset - j + 2] = filmHole[currentFilmHoleIndex + 2];
        }
        frameIndex += videoFrame.lineSize;
        filmHoleIndex = (i % filmStripHeight) * filmStripWidth * 3;
    }
}

}
