play.c

   1 /* Copyright (C) <2010> Douglas Bagnall <douglas@halo.gen.nz>
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Library General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Library General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Library General Public
  14  * License along with this library; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 02111-1307, USA.
  17  */
  18
  19 #include "sparrow.h"
  20 #include "gstsparrow.h"
  21
  22 #include <string.h>
  23 #include <math.h>
  24
  25 #define DEBUG_PLAY 0
  26 #define INITIAL_BLACK 32
  27 #define MIN_BLACK 0
  28 #define MAX_BLACK 160
  29
  30
  31 typedef struct sparrow_play_s{
  32   guint8 lut[256];
  33   guint8 *image_row;
  34   guint8 black_level;
  35   guint jpeg_index;
  36 } sparrow_play_t;
  37
  38
  39 static inline guint8
  40 negate(sparrow_play_t *player, guint8 in){
  41   return player->lut[in];
  42 }
  43
  44 static void set_up_jpeg(GstSparrow *sparrow, sparrow_play_t *player){
  45   /*XXX pick a jpeg, somehow*/
  46   sparrow_frame_t *frame = &sparrow->shared->index[player->jpeg_index];
  47   GST_DEBUG("set up jpeg shared->index is %p, offset %d, frame %p\n",
  48       sparrow->shared->index, player->jpeg_index, frame);
  49   guint8 *src = sparrow->shared->jpeg_blob + frame->offset;
  50
  51   guint size = frame->jpeg_size;
  52   GST_DEBUG("blob is %p, offset %d, src %p, size %d\n",
  53       sparrow->shared->jpeg_blob, frame->offset, src, size);
  54
  55   begin_reading_jpeg(sparrow, src, size);
  56   player->jpeg_index++;
  57   if (player->jpeg_index == sparrow->shared->image_count){
  58     player->jpeg_index = 0;
  59   }
  60 }
  61
  62
  63 static inline guint8 one_subpixel(sparrow_play_t *player, guint8 inpix, guint8 jpegpix){
  64   /* simplest possible */
  65   guint sum = player->lut[inpix] + jpegpix;
  66   //int diff = jpegpix - inpix;
  67
  68
  69   return sum >> 1;
  70   //return jpegpix;
  71 }
  72
  73 static inline void
  74 do_one_pixel(GstSparrow *sparrow, guint8 *outpix, guint8 *inpix, guint8 *jpegpix){
  75   /* rather than cancel the whole other one, we need to calculate the
  76      difference from the desired image, and only compensate by that
  77      amount.  If a lot of negative compensation (i.e, trying to blacken)
  78      is needed, then it is time to raise the black level for the next
  79      round (otherwise, lower the black level). Use sum of
  80      compensations?, or count? or thresholded? or squared (via LUT)?
  81
  82      How are relative calculations calculated via LUT?
  83
  84      1. pre scale
  85      2. combine
  86      3. re scale
  87
  88   */
  89   sparrow_play_t *player = sparrow->helper_struct;
  90   //guint8 black = player->black_level;
  91   /*
  92     int r = ib[sparrow->in.rbyte];
  93     int g = ib[sparrow->in.gbyte];
  94     int b = ib[sparrow->in.bbyte];
  95   */
  96   //outpix[0] = player->lut[inpix[0]];
  97   //outpix[1] = player->lut[inpix[1]];
  98   //outpix[2] = player->lut[inpix[2]];
  99   //outpix[3] = player->lut[inpix[3]];
 100   outpix[0] = one_subpixel(player, inpix[0], jpegpix[0]);
 101   outpix[1] = one_subpixel(player, inpix[1], jpegpix[1]);
 102   outpix[2] = one_subpixel(player, inpix[2], jpegpix[2]);
 103   outpix[3] = one_subpixel(player, inpix[3], jpegpix[3]);
 104 }
 105
 106
 107 static void
 108 play_from_full_lut(GstSparrow *sparrow, guint8 *in, guint8 *out){
 109   GST_DEBUG("play_from_full_lut\n");
 110 #if 0
 111   memset(out, 0, sparrow->out.size); /*is this necessary? (only for outside
 112                                        screen map, maybe in-loop might be
 113                                        quicker) */
 114 #endif
 115   sparrow_play_t *player = sparrow->helper_struct;
 116   guint i;
 117   int ox, oy;
 118   guint32 *out32 = (guint32 *)out;
 119   guint32 *in32 = (guint32 *)in;
 120   set_up_jpeg(sparrow, player);
 121   GST_DEBUG("in %p out %p", in, out);
 122
 123   guint8 *jpeg_row = player->image_row;
 124   i = 0;
 125   for (oy = 0; oy < sparrow->out.height; oy++){
 126     //GST_DEBUG("about to read line to %p", jpeg_row);
 127     read_one_line(sparrow, jpeg_row);
 128     for (ox = 0; ox < sparrow->out.width; ox++, i++){
 129       int x = sparrow->map_lut[i].x;
 130       int y = sparrow->map_lut[i].y;
 131       if (x || y){
 132         guint8 *inpix = (guint8*)&in32[y * sparrow->in.width + x];
 133         do_one_pixel(sparrow,
 134             &out[i * PIXSIZE],
 135             inpix,
 136             &jpeg_row[ox * PIXSIZE]);
 137       }
 138       else {
 139         out32[i] = 0;
 140       }
 141     }
 142   }
 143   finish_reading_jpeg(sparrow);
 144
 145   if (DEBUG_PLAY && sparrow->debug){
 146     debug_frame(sparrow, out, sparrow->out.width, sparrow->out.height, PIXSIZE);
 147   }
 148 }
 149
 150
 151 INVISIBLE sparrow_state
 152 mode_play(GstSparrow *sparrow, guint8 *in, guint8 *out){
 153   play_from_full_lut(sparrow, in, out);
 154   return SPARROW_STATUS_QUO;
 155 }
 156
 157 static const double GAMMA = 1.5;
 158 static const double INV_GAMMA = 1.0 / 1.5;
 159 static const double FALSE_CEILING = 275;
 160
 161 static void
 162 init_gamma_lut(sparrow_play_t *player){
 163   for (int i = 0; i < 256; i++){
 164     /* for each colour:
 165        1. perform inverse gamma calculation (-> linear colour space)
 166        2. negate
 167        3 undo gamma.
 168      */
 169     double x;
 170     x = i / 255.01;
 171     x = 1 - pow(x, INV_GAMMA);
 172     x = pow(x, GAMMA) * FALSE_CEILING;
 173     if (x > 255){
 174       x = 255;
 175     }
 176     player->lut[i] = (guint8)x;
 177   }
 178 }
 179
 180 INVISIBLE void init_play(GstSparrow *sparrow){
 181   GST_DEBUG("starting play mode\n");
 182   init_jpeg_src(sparrow);
 183   sparrow_play_t *player = zalloc_aligned_or_die(sizeof(sparrow_play_t));
 184   player->image_row = zalloc_aligned_or_die(sparrow->out.width * PIXSIZE);
 185   player->black_level = INITIAL_BLACK;
 186   sparrow->helper_struct = player;
 187   init_gamma_lut(player);
 188   GST_DEBUG("finished init_play\n");
 189 }
 190
 191 INVISIBLE void finalise_play(GstSparrow *sparrow){
 192   GST_DEBUG("leaving play mode\n");
 193 }