streamtools/letterbox.c

   1 /*
   2     JPC-RR: A x86 PC Hardware Emulator
   3     Release 1
   4
   5     Copyright (C) 2009 H. Ilari Liusvaara
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License version 2 as published by
   9     the Free Software Foundation.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19
  20     Based on JPC x86 PC Hardware emulator,
  21     A project from the Physics Dept, The University of Oxford
  22
  23     Details about original JPC can be found at:
  24
  25     www-jpc.physics.ox.ac.uk
  26
  27 */
  28
  29 #include "frame.h"
  30 #include "stdio.h"
  31 #include <string.h>
  32 #include <stdlib.h>
  33
  34 void letterbox_frame(struct frame* n, struct frame* o)
  35 {
  36         unsigned scalefactor;
  37         unsigned src_left;
  38         unsigned dst_left;
  39         unsigned src_copyw;
  40         unsigned src_top;
  41         unsigned dst_top;
  42         unsigned src_copyh;
  43
  44         scalefactor = n->f_width / o->f_width;
  45         if(scalefactor > n->f_height / o->f_height)
  46                 scalefactor = n->f_height / o->f_height;
  47
  48         if(scalefactor == 0) {
  49                 src_left = o->f_width / 2 - n->f_width / 2;
  50                 src_top = o->f_height / 2 - n->f_height / 2;
  51                 dst_left = dst_top = 0;
  52                 src_copyw = n->f_width;
  53                 src_copyh = n->f_height;
  54                 scalefactor = 1;
  55         } else {
  56                 src_left = src_top = 0;
  57                 dst_left = n->f_width / 2 - scalefactor * o->f_width / 2;
  58                 dst_top = n->f_height / 2 - scalefactor * o->f_height / 2;
  59                 src_copyw = o->f_width;
  60                 src_copyh = o->f_height;
  61         }
  62
  63 /*
  64         fprintf(stderr, "Resize %u*%u -> %u*%u: src offset = %u*%u, dst offset = %u*%u "
  65                 "scale=%u.\n", o->f_width, o->f_height, n->f_width, n->f_height, src_left,
  66                 src_top, dst_left, dst_top, scalefactor);
  67 */
  68         for(unsigned y = 0; y < src_copyh; y++) {
  69                 for(unsigned i = 0; i < scalefactor; i++) {
  70                         unsigned dsty = y * scalefactor + i + dst_top;
  71                         for(unsigned x = 0; x < src_copyw; x++) {
  72                                 int px = o->f_framedata[(y + src_top) * o->f_width + (x + src_left)];
  73                                 for(unsigned j = 0; j < scalefactor; j++) {
  74                                         unsigned dstx = x * scalefactor + j + dst_left;
  75                                         n->f_framedata[dsty * n->f_width + dstx] = px;
  76                                 }
  77                         }
  78                 }
  79         }
  80 }
  81
  82 int main(int argc, char** argv)
  83 {
  84         unsigned long width, height;
  85         char* tmp;
  86
  87         if(argc < 5) {
  88                 fprintf(stderr, "usage: %s <in> <out> <width> <height>\n", argv[0]);
  89                 fprintf(stderr, "Letterbox the video stream read from <in> to be <width>x<height> and write the "
  90                         "resulting stream to <out>.\n");
  91                 return 1;
  92         }
  93         struct frame_input_stream* in = fis_open(argv[1]);
  94         struct frame_output_stream* out = fos_open(argv[2]);
  95         struct frame* frame;
  96         int num = 1;
  97
  98         width = strtoul(argv[3], &tmp, 10);
  99         if(*tmp) {
 100                 fprintf(stderr, "Bad width %s.\n", argv[3]);
 101                 return 1;
 102         }
 103         height = strtoul(argv[4], &tmp, 10);
 104         if(*tmp) {
 105                 fprintf(stderr, "Bad height %s.\n", argv[4]);
 106                 return 1;
 107         }
 108
 109         while(1) {
 110                 struct frame* newframe;
 111                 frame = fis_next_frame(in);
 112                 if(!frame)
 113                         break;
 114                 newframe = frame_create(width, height);
 115                 newframe->f_timeseq = frame->f_timeseq;
 116
 117                 letterbox_frame(newframe, frame);
 118
 119                 fos_save_frame(out, newframe);
 120                 frame_release(frame);
 121                 frame_release(newframe);
 122         }
 123
 124         fis_close(in);
 125         fos_close(out);
 126         return 0;
 127 }