void histogram_process()
{
static unsigned char *img;
static int viewport_size, viewport_width, viewport_row_offset;
register int x, i, hi;
int y, v, u, c;
float (*histogram_transform)(float);
unsigned int histo_fill[5];
int histo_main;
long exposition_thresh = camera_screen.size / 500;
// Select transform function
switch (conf.histo_mode)
{
case HISTO_MODE_LOG:
histogram_transform = logarithmic;
break;
case HISTO_MODE_LINEAR:
default:
histogram_transform = identity;
break;
}
// Select which calculated histogram channel determines magnification / scaling
if (conf.histo_layout == OSD_HISTO_LAYOUT_Y || conf.histo_layout == OSD_HISTO_LAYOUT_Y_argb)
histo_main = HISTO_Y;
else
histo_main = HISTO_RGB;
histogram_alloc();
// This function is called in the main spytask loop roughly every 20msec
// To avoid hogging all the CPU it performs it's work in stages controlled by histogram-stage
// Stage Function
// 0 Initialize global variables used in next stages
// 1,2,3 Count number of values for a third of the viewport image at each stage
// 4 Calculate max values, over and under exposure setting
// 5 Calculate the histogram display values
switch (histogram_stage)
{
case 0:
img=vid_get_viewport_active_buffer();
if (!img) return;
img += vid_get_viewport_image_offset(); // offset into viewport for when image size != viewport size (e.g. 16:9 image on 4:3 LCD)
viewport_size = vid_get_viewport_height() * vid_get_viewport_byte_width() * vid_get_viewport_yscale();
viewport_width = vid_get_viewport_width();
viewport_row_offset = vid_get_viewport_row_offset();
for (c=0; c<5; ++c) {
memset(histogram_proc[c],0,256*sizeof(unsigned short));
histo_max[c] = histo_max_center[c] = 0;
}
histogram_stage=1;
break;
case 1:
case 2:
case 3:
x = 0; // count how many blocks we have done on the current row (to skip unused buffer space at end of each row)
for (i=(histogram_stage-1)*6; i<viewport_size; i+=HISTO_STEP_SIZE*6) {
y = img[i+1];
u = *(signed char*)(&img[i]);
//if (u&0x00000080) u|=0xFFFFFF00; // Compiler should handle the unsigned -> signed conversion
v = *(signed char*)(&img[i+2]);
//if (v&0x00000080) v|=0xFFFFFF00; // Compiler should handle the unsigned -> signed conversion
++histogram_proc[HISTO_Y][y]; // Y
hi = clip(((y<<12) + v*5743 + 2048)>>12); // R
++histogram_proc[HISTO_R][hi];
hi = clip(((y<<12) - u*1411 - v*2925 + 2048)>>12); // G
++histogram_proc[HISTO_G][hi];
hi = clip(((y<<12) + u*7258 + 2048)>>12); // B
++histogram_proc[HISTO_B][hi];
// Handle case where viewport memory buffer is wider than the actual buffer.
x += HISTO_STEP_SIZE * 2; // viewport width is measured in blocks of three bytes each even though the data is stored in six byte chunks !
if (x == viewport_width)
{
i += viewport_row_offset;
x = 0;
}
}
++histogram_stage;
break;
case 4:
for (i=0, c=0; i<HISTO_WIDTH; ++i, c+=2) { // G
// Merge each pair of values into a single value (for width = 128)
// Warning: this is optimised for HISTO_WIDTH = 128, don't change the width unless you re-write this code as well.
histogram_proc[HISTO_Y][i] = histogram_proc[HISTO_Y][c] + histogram_proc[HISTO_Y][c+1];
histogram_proc[HISTO_R][i] = histogram_proc[HISTO_R][c] + histogram_proc[HISTO_R][c+1];
histogram_proc[HISTO_G][i] = histogram_proc[HISTO_G][c] + histogram_proc[HISTO_G][c+1];
histogram_proc[HISTO_B][i] = histogram_proc[HISTO_B][c] + histogram_proc[HISTO_B][c+1];
// Calc combined RGB totals
histogram_proc[HISTO_RGB][i] = histogram_proc[HISTO_R][i] + histogram_proc[HISTO_G][i] + histogram_proc[HISTO_B][i];
}
// calculate maximums
for (c=0; c<5; ++c) {
for (i=0; i<HISTO_WIDTH; ++i) {
if (histo_max[c]<histogram_proc[c][i])
histo_max[c]=histogram_proc[c][i];
if (histo_max_center[c]<histogram_proc[c][i] && i>=conf.histo_ignore_boundary && i<HISTO_WIDTH-conf.histo_ignore_boundary)
histo_max_center[c]=histogram_proc[c][i];
}
if (histo_max_center[c] > 0) {
histo_max_center_invw[c] = ((float)HISTO_HEIGHT)/histogram_transform((float)histo_max_center[c]);
} else if (histo_max[c] > 0) {
histo_max_center_invw[c] = ((float)HISTO_HEIGHT)/histogram_transform((float)histo_max[c]);
} else {
histo_max_center_invw[c] = 0.0f;
}
}
if (histo_max[HISTO_RGB] > 0) { // over- / under- expos
under_exposed = (histogram_proc[HISTO_RGB][0]*8
+histogram_proc[HISTO_RGB][1]*4
+histogram_proc[HISTO_RGB][2]) > exposition_thresh;
over_exposed = (histogram_proc[HISTO_RGB][HISTO_WIDTH-3]
+histogram_proc[HISTO_RGB][HISTO_WIDTH-2]*4
+histogram_proc[HISTO_RGB][HISTO_WIDTH-1]*8) > exposition_thresh;
} else {
over_exposed = 0;
under_exposed = 1;
}
histogram_stage=5;
break;
case 5:
for (c=0; c<5; ++c) {
histo_fill[c]=0;
for (i=0; i<HISTO_WIDTH; ++i) {
histogram[c][i] = (histogram_transform((float)histogram_proc[c][i]))*histo_max_center_invw[c];
if (histogram[c][i] > HISTO_HEIGHT)
histogram[c][i] = HISTO_HEIGHT;
histo_fill[c]+=histogram[c][i];
}
}
histo_magnification = 0;
if (conf.histo_auto_ajust) {
if (histo_fill[histo_main] < (HISTO_HEIGHT*HISTO_WIDTH)/5) { // try to ajust if average level is less than 20%
histo_magnification = (20*HISTO_HEIGHT*HISTO_WIDTH) / histo_fill[histo_main];
for (c=0; c<5; ++c) {
for (i=0;i<HISTO_WIDTH;i++) {
histogram[c][i] = histogram[c][i] * histo_magnification / 100;
if (histogram[c][i] > HISTO_HEIGHT)
histogram[c][i] = HISTO_HEIGHT;
}
}
}
}
histogram_stage=0;
break;
}
}
void histogram_process()
{
static unsigned char *img;
int i, hi, c;
int y, v, u;
static int x;
static int viewport_size;
unsigned int histo_fill[5];
switch (histogram_stage) {
case 0:
img=((mode_get()&MODE_MASK) == MODE_PLAY)?vid_get_viewport_fb_d():((kbd_is_key_pressed(KEY_SHOOT_HALF))?vid_get_viewport_fb():vid_get_viewport_live_fb());
if (img==NULL){
img = vid_get_viewport_fb();
}
img += vid_get_viewport_image_offset(); // offset into viewport for when image size != viewport size (e.g. 16:9 image on 4:3 LCD)
viewport_size = vid_get_viewport_height() * vid_get_viewport_buffer_width();
for (c=0; c<5; ++c) {
for (i=0; i<HISTO_WIDTH; ++i) {
histogram_proc[c][i]=0;
}
histo_max[c] = histo_max_center[c] = 0;
}
histogram_stage=1;
break;
case 1:
case 2:
case 3:
x = 0; // count how many blocks we have done on the current row (to skip unused buffer space at end of each row)
for (i=(histogram_stage-1)*6; i<viewport_size*3; i+=HISTO_STEP_SIZE*6) {
y = img[i+1];
u = *(signed char*)(&img[i]);
if (u&0x00000080) u|=0xFFFFFF00;
v = *(signed char*)(&img[i+2]);
if (v&0x00000080) v|=0xFFFFFF00;
hi = y*HISTO_WIDTH/256; // Y
++histogram_proc[HISTO_Y][hi];
hi = clip(((y<<12) + v*5743 + 2048)/4096)*HISTO_WIDTH/256; // R
++histogram_proc[HISTO_R][hi];
hi = clip(((y<<12) - u*1411 - v*2925 + 2048)/4096)*HISTO_WIDTH/256; // G
++histogram_proc[HISTO_G][hi];
hi = clip(((y<<12) + u*7258 + 2048)/4096)*HISTO_WIDTH/256; // B
++histogram_proc[HISTO_B][hi];
// Handle case where viewport memory buffer is wider than the actual buffer.
x += HISTO_STEP_SIZE * 2; // viewport width is measured in blocks of three bytes each even though the data is stored in six byte chunks !
if (x == vid_get_viewport_width())
{
i += vid_get_viewport_row_offset();
x = 0;
}
}
++histogram_stage;
break;
case 4:
for (i=0; i<HISTO_WIDTH; ++i) { // G
histogram_proc[HISTO_RGB][i]=histogram_proc[HISTO_R][i]+histogram_proc[HISTO_G][i]+histogram_proc[HISTO_B][i];
}
for (c=0; c<5; ++c) { // calculate maximums
for (i=0; i<HISTO_WIDTH; ++i) {
if (histo_max[c]<histogram_proc[c][i])
histo_max[c]=histogram_proc[c][i];
if (histo_max_center[c]<histogram_proc[c][i] && i>=conf.histo_ignore_boundary && i<HISTO_WIDTH-conf.histo_ignore_boundary)
histo_max_center[c]=histogram_proc[c][i];
}
if (histo_max[c] > 0) {
histo_max_invw[c] = ((float)HISTO_HEIGHT)/histogram_transform((float)histo_max[c]);
} else {
histo_max_invw[c] = 0.0f;
}
if (histo_max_center[c] > 0) {
histo_max_center_invw[c] = ((float)HISTO_HEIGHT)/histogram_transform((float)histo_max_center[c]);
} else {
histo_max_center_invw[c] = 0.0f;
}
}
if (histo_max[HISTO_RGB] > 0) { // over- / under- expos
under_exposed = (histogram_proc[HISTO_RGB][0]*8
+histogram_proc[HISTO_RGB][1]*4
+histogram_proc[HISTO_RGB][2]) > exposition_thresh;
over_exposed = (histogram_proc[HISTO_RGB][HISTO_WIDTH-3]
+histogram_proc[HISTO_RGB][HISTO_WIDTH-2]*4
+histogram_proc[HISTO_RGB][HISTO_WIDTH-1]*8) > exposition_thresh;
} else {
over_exposed = 0;
under_exposed = 1;
}
histogram_stage=5;
state_expos_recalculated = 1;
break;
case 5:
for (c=0; c<5; ++c) {
histo_fill[c]=0;
for (i=0; i<HISTO_WIDTH; ++i) {
histogram[c][i] = (histogram_transform((float)histogram_proc[c][i]))*histo_max_center_invw[c];
if (histogram[c][i] > HISTO_HEIGHT)
histogram[c][i] = HISTO_HEIGHT;
histo_fill[c]+=histogram[c][i];
}
}
if (conf.histo_auto_ajust) {
histo_magnification = histo_fill[histo_main]*1000/(HISTO_HEIGHT*HISTO_WIDTH);
if (histo_magnification<200) { // try to ajust if average level is less than 20%
histo_magnification=200*1000/histo_magnification;
for (c=0; c<5; ++c) {
for (i=0;i<HISTO_WIDTH;i++) {
histogram[c][i] = (histogram_transform((float)histogram_proc[c][i]))*histo_max_center_invw[c]*histo_magnification/1000;
if (histogram[c][i] > HISTO_HEIGHT)
histogram[c][i] = HISTO_HEIGHT;
}
}
} else
histo_magnification=0;
} else {
histo_magnification=0;
}
histogram_stage=0;
break;
case HISTOGRAM_IDLE_STAGE:
break;
}
}
