File indexing completed on 2024-04-21 04:49:03 

0001 /*
0002     SPDX-FileCopyrightText: 2010 Dirk Vanden Boer <dirk.vdb@gmail.com>
0003 
0004     SPDX-License-Identifier: GPL-2.0-or-later
0005 */
0006 
0007 #include "filmstripfilter.h"
0008 #include "filmstrip.h"
0009 
0010 namespace ffmpegthumbnailer
0011 {
0012 
0013 static const int FILMHOLE_WIDTH = 12;
0014 static const int FILMHOLE_HEIGHT = 10;
0015 
0016 static const quint8* determineFilmStrip(quint32 videoWidth, quint32& filmStripWidth, quint32& filmStripHeight)
0017 {
0018     if (videoWidth <= SMALLEST_FILM_STRIP_WIDTH * 2)
0019     {
0020         return nullptr;
0021     }
0022     
0023     if (videoWidth <= 96)
0024     {
0025         filmStripWidth = filmStripHeight = 4;
0026         return filmStrip4;
0027     }
0028 
0029     if (videoWidth <= 192)
0030     {
0031         filmStripWidth = filmStripHeight = 8;
0032         return filmStrip8;
0033     }
0034 
0035     if (videoWidth <= 384)
0036     {
0037         filmStripWidth = filmStripHeight = 16;
0038         return filmStrip16;
0039     }
0040 
0041     if (videoWidth <= 768)
0042     {
0043         filmStripWidth = filmStripHeight = 32;
0044         return filmStrip32;
0045     }
0046 
0047     filmStripWidth = filmStripHeight = 64;
0048     return filmStrip64;
0049 }
0050 
0051 
0052 
0053 void FilmStripFilter::process(VideoFrame& videoFrame)
0054 {
0055     quint32 filmStripWidth;
0056     quint32 filmStripHeight;
0057     const quint8* filmHole = determineFilmStrip(videoFrame.width, filmStripWidth, filmStripHeight);
0058     
0059     if (!filmHole)
0060     {
0061         return;
0062     }
0063     
0064     int frameIndex = 0;
0065     int filmHoleIndex = 0;
0066     int offset = (videoFrame.width * 3) - 3;
0067 
0068     for (quint32 i = 0; i < videoFrame.height; ++i)
0069     {
0070         for (quint32 j = 0; j < filmStripWidth * 3; j+=3)
0071         {
0072             int currentFilmHoleIndex = filmHoleIndex + j;
0073 
0074             videoFrame.frameData[frameIndex + j]     = filmHole[currentFilmHoleIndex];
0075             videoFrame.frameData[frameIndex + j + 1] = filmHole[currentFilmHoleIndex + 1];
0076             videoFrame.frameData[frameIndex + j + 2] = filmHole[currentFilmHoleIndex + 2];
0077 
0078             videoFrame.frameData[frameIndex + offset - j]     = filmHole[currentFilmHoleIndex];
0079             videoFrame.frameData[frameIndex + offset - j + 1] = filmHole[currentFilmHoleIndex + 1];
0080             videoFrame.frameData[frameIndex + offset - j + 2] = filmHole[currentFilmHoleIndex + 2];
0081         }
0082         frameIndex += videoFrame.lineSize;
0083         filmHoleIndex = (i % filmStripHeight) * filmStripWidth * 3;
0084     }   
0085 }
0086 
0087 }