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 UNUSED
  45 play_from_lut(GstSparrow *sparrow, guint8 *in, guint8 *out){
  46   sparrow_map_t *map = &sparrow->map;
  47   memset(out, 0, sparrow->out.size);
  48   int x, y;
  49   guint32 *line = (guint32 *)out;
  50   for (y = 0; y < sparrow->out.height; y++){
  51     sparrow_map_row_t *row = map->rows + y;
  52     for(x = row->start; x < row->end; x++){
  53       line[x] = ~0;
  54     }
  55     /*
  56     GST_DEBUG("row %p %d: s %d e%d line %d\n",
  57         row, y, row->start, row->end, line);
  58     */
  59     line += sparrow->out.width;
  60   }
  61 }
  62
  63 static void set_up_jpeg(GstSparrow *sparrow, sparrow_play_t *player){
  64   /*XXX pick a jpeg, somehow*/
  65   sparrow_frame_t *frame = &sparrow->shared->index[player->jpeg_index];
  66   GST_DEBUG("set up jpeg shared->index is %p, offset %d, frame %p\n",
  67       sparrow->shared->index, player->jpeg_index, frame);
  68   guint8 *src = sparrow->shared->jpeg_blob + frame->offset;
  69
  70   guint size = frame->jpeg_size;
  71   GST_DEBUG("blob is %p, offset %d, src %p, size %d\n",
  72       sparrow->shared->jpeg_blob, frame->offset, src, size);
  73
  74   begin_reading_jpeg(sparrow, src, size);
  75   player->jpeg_index++;
  76   if (player->jpeg_index == sparrow->shared->image_count){
  77     player->jpeg_index = 0;
  78   }
  79 }
  80
  81
  82 static inline guint8 one_subpixel(sparrow_play_t *player, guint8 inpix, guint8 jpegpix){
  83   /* simplest possible */
  84   guint sum = player->lut[inpix] + jpegpix;
  85   //int diff = jpegpix - inpix;
  86
  87
  88   return sum >> 1;
  89   //return jpegpix;
  90 }
  91
  92 static inline void
  93 do_one_pixel(GstSparrow *sparrow, guint8 *outpix, guint8 *inpix, guint8 *jpegpix){
  94   /* rather than cancel the whole other one, we need to calculate the
  95      difference from the desired image, and only compensate by that
  96      amount.  If a lot of negative compensation (i.e, trying to blacken)
  97      is needed, then it is time to raise the black level for the next
  98      round (otherwise, lower the black level). Use sum of
  99      compensations?, or count? or thresholded? or squared (via LUT)?
 100
 101      How are relative calculations calculated via LUT?
 102
 103      1. pre scale
 104      2. combine
 105      3. re scale
 106
 107   */
 108   sparrow_play_t *player = sparrow->helper_struct;
 109   //guint8 black = player->black_level;
 110   /*
 111     int r = ib[sparrow->in.rbyte];
 112     int g = ib[sparrow->in.gbyte];
 113     int b = ib[sparrow->in.bbyte];
 114   */
 115   //outpix[0] = player->lut[inpix[0]];
 116   //outpix[1] = player->lut[inpix[1]];
 117   //outpix[2] = player->lut[inpix[2]];
 118   //outpix[3] = player->lut[inpix[3]];
 119   outpix[0] = one_subpixel(player, inpix[0], jpegpix[0]);
 120   outpix[1] = one_subpixel(player, inpix[1], jpegpix[1]);
 121   outpix[2] = one_subpixel(player, inpix[2], jpegpix[2]);
 122   outpix[3] = one_subpixel(player, inpix[3], jpegpix[3]);
 123 }
 124
 125 static inline guint8* get_in_pixel(GstSparrow *sparrow, guint32 *in32, int x, int y){
 126   return (guint8 *)&in32[y * sparrow->in.width + x];
 127 };
 128
 129 static void
 130 play_from_full_lut(GstSparrow *sparrow, guint8 *in, guint8 *out){
 131   GST_DEBUG("play_from_full_lut\n");
 132   memset(out, 0, sparrow->out.size); /*is this necessary? (only for outside
 133                                        screen map, maybe in-loop might be
 134                                        quicker) */
 135   sparrow_play_t *player = sparrow->helper_struct;
 136   guint i;
 137   int ox, oy;
 138   //guint32 *out32 = (guint32 *)out;
 139   guint32 *in32 = (guint32 *)in;
 140   set_up_jpeg(sparrow, player);
 141   GST_DEBUG("in %p out %p", in, out);
 142
 143   guint8 *jpeg_row = player->image_row;
 144   i = 0;
 145   for (oy = 0; oy < sparrow->out.height; oy++){
 146     //GST_DEBUG("about to read line to %p", player->image_row);
 147     read_one_line(sparrow, player->image_row);
 148     for (ox = 0; ox < sparrow->out.width; ox++, i++){
 149       int x = sparrow->map_lut[i].x;
 150       int y = sparrow->map_lut[i].y;
 151       if (x || y){
 152         //GST_DEBUG("in %p x %d y %d", in, x, y);
 153         guint8 *inpix = get_in_pixel(sparrow, in32, x, y);
 154         do_one_pixel(sparrow,
 155             &out[i * PIXSIZE],
 156             inpix,
 157             &jpeg_row[ox * PIXSIZE]);
 158       }
 159     }
 160   }
 161   finish_reading_jpeg(sparrow);
 162
 163   if (DEBUG_PLAY && sparrow->debug){
 164     debug_frame(sparrow, out, sparrow->out.width, sparrow->out.height, PIXSIZE);
 165   }
 166 }
 167
 168
 169
 170 INVISIBLE sparrow_state
 171 mode_play(GstSparrow *sparrow, guint8 *in, guint8 *out){
 172 #if USE_FULL_LUT
 173   play_from_full_lut(sparrow, in, out);
 174 #else
 175   play_from_lut(sparrow, in, out);
 176 #endif
 177   return SPARROW_STATUS_QUO;
 178 }
 179
 180 static const double GAMMA = 1.5;
 181 static const double INV_GAMMA = 1.0 / 1.5;
 182 static const double FALSE_CEILING = 275;
 183
 184 static void
 185 init_gamma_lut(sparrow_play_t *player){
 186   for (int i = 0; i < 256; i++){
 187     /* for each colour:
 188        1. perform inverse gamma calculation (-> linear colour space)
 189        2. negate
 190        3 undo gamma.
 191      */
 192     double x;
 193     x = i / 255.01;
 194     x = 1 - pow(x, INV_GAMMA);
 195     x = pow(x, GAMMA) * FALSE_CEILING;
 196     if (x > 255){
 197       x = 255;
 198     }
 199     player->lut[i] = (guint8)x;
 200   }
 201 }
 202
 203 INVISIBLE void init_play(GstSparrow *sparrow){
 204   GST_DEBUG("starting play mode\n");
 205   init_jpeg_src(sparrow);
 206   sparrow_play_t *player = zalloc_aligned_or_die(sizeof(sparrow_play_t));
 207   player->image_row = zalloc_aligned_or_die(sparrow->out.width * PIXSIZE);
 208   player->black_level = INITIAL_BLACK;
 209   sparrow->helper_struct = player;
 210   init_gamma_lut(player);
 211   GST_DEBUG("finished init_play\n");
 212 }
 213
 214 INVISIBLE void finalise_play(GstSparrow *sparrow){
 215   GST_DEBUG("leaving play mode\n");
 216 }