OctoWS2811 - troubleshooting offset diff btwn image on screen and LEDs

/*  OctoWS2811 VideoDisplay.ino - Video on LEDs, from a PC, Mac, Raspberry Pi
    http://www.pjrc.com/teensy/td_libs_OctoWS2811.html
    Copyright (c) 2013 Paul Stoffregen, PJRC.COM, LLC
*/

#include <OctoWS2811.h>

#define LED_WIDTH      25   // number of LEDs horizontally
#define LED_HEIGHT     32   // number of LEDs vertically (must be multiple of 8)
#define LED_LAYOUT     0    // 0 = even rows left->right, 1 = even rows right->left

#define VIDEO_XOFFSET  0
#define VIDEO_YOFFSET  0       // display entire image
#define VIDEO_WIDTH    100
#define VIDEO_HEIGHT   100

const int ledsPerStrip = LED_WIDTH * LED_HEIGHT / 8;

DMAMEM int displayMemory[ledsPerStrip*6];
int drawingMemory[ledsPerStrip*6];
elapsedMicros elapsedUsecSinceLastFrameSync = 0;

const int config = WS2811_800kHz; // color config is on the PC side

OctoWS2811 leds(ledsPerStrip, displayMemory, drawingMemory, config);

void setup() {
  pinMode(12, INPUT_PULLUP); // Frame Sync
  Serial.setTimeout(50);
  leds.begin();
  leds.show();
}

void loop() {
  int startChar = Serial.read();

  if (startChar == '*') {
    // receive a "master" frame - we send the frame sync to other boards
    // the sender is controlling the video pace.  The 16 bit number is
    // how far into this frame to send the sync to other boards.
    unsigned int startAt = micros();
    unsigned int usecUntilFrameSync = 0;
    int count = Serial.readBytes((char *)&usecUntilFrameSync, 2);
    if (count != 2) return;
    count = Serial.readBytes((char *)drawingMemory, sizeof(drawingMemory));
    if (count == sizeof(drawingMemory)) {
      unsigned int endAt = micros();
      unsigned int usToWaitBeforeSyncOutput = 100;
      if (endAt - startAt < usecUntilFrameSync) {
        usToWaitBeforeSyncOutput = usecUntilFrameSync - (endAt - startAt);
      }
      digitalWrite(12, HIGH);
      pinMode(12, OUTPUT);
      delayMicroseconds(usToWaitBeforeSyncOutput);
      digitalWrite(12, LOW);
      // WS2811 update begins immediately after falling edge of frame sync
      digitalWrite(13, HIGH);
      leds.show();
      digitalWrite(13, LOW);
    }

  } else if (startChar == '$') {
    // receive a "master" frame - we send the frame sync to other boards
    // we are controlling the video pace.  The 16 bit number is how long
    // after the prior frame sync to wait until showing this frame
    unsigned int usecUntilFrameSync = 0;
    int count = Serial.readBytes((char *)&usecUntilFrameSync, 2);
    if (count != 2) return;
    count = Serial.readBytes((char *)drawingMemory, sizeof(drawingMemory));
    if (count == sizeof(drawingMemory)) {
      digitalWrite(12, HIGH);
      pinMode(12, OUTPUT);
      while (elapsedUsecSinceLastFrameSync < usecUntilFrameSync) /* wait */ ;
      elapsedUsecSinceLastFrameSync -= usecUntilFrameSync;
      digitalWrite(12, LOW);
      // WS2811 update begins immediately after falling edge of frame sync
      digitalWrite(13, HIGH);
      leds.show();
      digitalWrite(13, LOW);
    }

  } else if (startChar == '%') {
    // receive a "slave" frame - wait to show it until the frame sync arrives
    pinMode(12, INPUT_PULLUP);
    unsigned int unusedField = 0;
    int count = Serial.readBytes((char *)&unusedField, 2);
    if (count != 2) return;
    count = Serial.readBytes((char *)drawingMemory, sizeof(drawingMemory));
    if (count == sizeof(drawingMemory)) {
      elapsedMillis wait = 0;
      while (digitalRead(12) != HIGH && wait < 30) ; // wait for sync high
      while (digitalRead(12) != LOW && wait < 30) ;  // wait for sync high->low
      // WS2811 update begins immediately after falling edge of frame sync
      if (wait < 30) {
        digitalWrite(13, HIGH);
        leds.show();
        digitalWrite(13, LOW);
      }
    }

  } else if (startChar == '@') {
    // reset the elapsed frame time, for startup of '$' message playing
    elapsedUsecSinceLastFrameSync = 0;

  } else if (startChar == '?') {
    // when the video application asks, give it all our info
    // for easy and automatic configuration
    Serial.print(LED_WIDTH);
    Serial.write(',');
    Serial.print(LED_HEIGHT);
    Serial.write(',');
    Serial.print(LED_LAYOUT);
    Serial.write(',');
    Serial.print(0);
    Serial.write(',');
    Serial.print(0);
    Serial.write(',');
    Serial.print(VIDEO_XOFFSET);
    Serial.write(',');
    Serial.print(VIDEO_YOFFSET);
    Serial.write(',');
    Serial.print(VIDEO_WIDTH);
    Serial.write(',');
    Serial.print(VIDEO_HEIGHT);
    Serial.write(',');
    Serial.print(0);
    Serial.write(',');
    Serial.print(0);
    Serial.write(',');
    Serial.print(0);
    Serial.println();

  } else if (startChar >= 0) {
    // discard unknown characters
  }
}

/*  OctoWS2811 movie2serial.pde - Transmit video data to 1 or more
      Teensy 3.0 boards running OctoWS2811 VideoDisplay.ino
    http://www.pjrc.com/teensy/td_libs_OctoWS2811.html
    Copyright (c) 2013 Paul Stoffregen, PJRC.COM, LLC
*/

import processing.video.*;
import processing.serial.*;
import java.awt.Rectangle;

Movie myMovie;

float gamma = 1.7;

int numPorts=0;  // the number of serial ports in use
int maxPorts=24; // maximum number of serial ports

Serial[] ledSerial = new Serial[maxPorts];     // each port's actual Serial port
Rectangle[] ledArea = new Rectangle[maxPorts]; // the area of the movie each port gets, in % (0-100)
boolean[] ledLayout = new boolean[maxPorts];   // layout of rows, true = even is left->right
PImage[] ledImage = new PImage[maxPorts];      // image sent to each port
int[] gammatable = new int[256];
int errorCount=0;
float framerate=0;

void setup() {
  String[] list = Serial.list();
  delay(20);
  println("Serial Ports List:");
  println(list);
  serialConfigure("/dev/tty.usbmodem509331");  // change these to your port names
  if (errorCount > 0) exit();
  for (int i=0; i < 256; i++) {
    gammatable[i] = (int)(pow((float)i / 255.0, gamma) * 255.0 + 0.5);
  }
  
  myMovie = new Movie(this, "moon_4x_480.mov");
  myMovie.loop();  // start the movie :-)
  size(myMovie.width, myMovie.height + 100);  // create the w indow
}

 
// movieEvent runs for each new frame of movie data
void movieEvent(Movie m) {
  // read the movie's next frame
  m.read();
  
  //if (framerate == 0) framerate = m.getSourceFrameRate();
  framerate = 30.0; // TODO, how to read the frame rate???
  
  for (int i=0; i < numPorts; i++) {    
    // copy a portion of the movie's image to the LED image
    int xoffset = percentage(m.width, ledArea[i].x);
    int yoffset = percentage(m.height, ledArea[i].y);
    int xwidth =  percentage(m.width, ledArea[i].width);
    int yheight = percentage(m.height, ledArea[i].height);
    ledImage[i].copy(m, xoffset, yoffset, xwidth, yheight,
                     0, 0, ledImage[i].width, ledImage[i].height);
                     
    // convert the LED image to raw data
    byte[] ledData =  new byte[(ledImage[i].width * ledImage[i].height * 3) + 3];
    image2data(ledImage[i], ledData, ledLayout[i]);
    if (i == 0) {
      ledData[0] = '*';  // first Teensy is the frame sync master
      int usec = (int)((1000000.0 / framerate) * 0.75);
      ledData[1] = (byte)(usec);   // request the frame sync pulse
      ledData[2] = (byte)(usec >> 8); // at 75% of the frame time
    } else {
      ledData[0] = '%';  // others sync to the master board
      ledData[1] = 0;
      ledData[2] = 0;
    }
    // send the raw data to the LEDs  :-)
    ledSerial[i].write(ledData); 
  }
}

// image2data converts an image to OctoWS2811's raw data format.
// The number of vertical pixels in the image must be a multiple
// of 8.  The data array must be the proper size for the image.
void image2data(PImage image, byte[] data, boolean layout) {
  int offset = 3;
  int x, y, xbegin, xend, xinc, mask;
  int linesPerPin = image.height / 8;
  println("linesPerPin = " + linesPerPin);  
  int pixel[] = new int[8];
  
  for (y = 0; y < linesPerPin; y++) {
    if ((y & 1) == (layout ? 0 : 1)) {
      // even numbered rows are left to right
      xbegin = 0;
      xend = image.width;
      xinc = 1;
    } else {
      // odd numbered rows are right to left
      xbegin = image.width - 1;
      xend = -1;
      xinc = -1;
    }
    for (x = xbegin; x != xend; x += xinc) {
      for (int i=0; i < 8; i++) {
        // fetch 8 pixels from the image, 1 for each pin
        pixel[i] = image.pixels[x + (y + linesPerPin * i) * image.width];
        pixel[i] = colorWiring(pixel[i]);
      }
      // convert 8 pixels to 24 bytes
      for (mask = 0x800000; mask != 0; mask >>= 1) {
        byte b = 0;
        for (int i=0; i < 8; i++) {
          if ((pixel[i] & mask) != 0) b |= (1 << i);
        }
        data[offset++] = b;
      }
    }
  } 
}

// translate the 24 bit color from RGB to the actual
// order used by the LED wiring.  GRB is the most common.
int colorWiring(int c) {
  int red = (c & 0xFF0000) >> 16;
  int green = (c & 0x00FF00) >> 8;
  int blue = (c & 0x0000FF);
  red = gammatable[red];
  green = gammatable[green];
  blue = gammatable[blue];
  return (green << 16) | (red << 8) | (blue); // GRB - most common wiring
}

// ask a Teensy board for its LED configuration, and set up the info for it.
void serialConfigure(String portName) {
  if (numPorts >= maxPorts) {
    println("too many serial ports, please increase maxPorts");
    errorCount++;
    return;
  }
  try {
    ledSerial[numPorts] = new Serial(this, portName);
    if (ledSerial[numPorts] == null) throw new NullPointerException();
    ledSerial[numPorts].write('?');
  } catch (Throwable e) {
    println("Serial port " + portName + " does not exist or is non-functional");
    errorCount++;
    return;
  }
  delay(50);
  String line = ledSerial[numPorts].readStringUntil(10);
  if (line == null) {
    println("Serial port " + portName + " is not responding.");
    println("Is it really a Teensy 3.0 running VideoDisplay?");
    errorCount++;
    return;
  }
  String param[] = line.split(",");
  if (param.length != 12) {
    println("Error: port " + portName + " did not respond to LED config query");
    errorCount++;
    return;
  }
  // only store the info and increase numPorts if Teensy responds properly
  ledImage[numPorts] = new PImage(Integer.parseInt(param[0]), Integer.parseInt(param[1]), RGB);
  ledArea[numPorts] = new Rectangle(Integer.parseInt(param[5]), Integer.parseInt(param[6]),
                     Integer.parseInt(param[7]), Integer.parseInt(param[8]));
  ledLayout[numPorts] = (Integer.parseInt(param[5]) == 0);
  numPorts++;
}

// draw runs every time the screen is redrawn - show the movie...
void draw() {
  // show the original video
  image(myMovie, 0, 80);
  
  // then try to show what was most recently sent to the LEDs
  // by displaying all the images for each port.
  for (int i=0; i < numPorts; i++) {
    // compute the intended size of the entire LED array
    int xsize = percentageInverse(ledImage[i].width, ledArea[i].width);
    int ysize = percentageInverse(ledImage[i].height, ledArea[i].height);
    // computer this image's position within it
    int xloc =  percentage(xsize, ledArea[i].x);
    int yloc =  percentage(ysize, ledArea[i].y);
    // show what should appear on the LEDs
    image(ledImage[i], 240 - xsize / 2 + xloc, 10 + yloc);
  } 
}

// respond to mouse clicks as pause/play
boolean isPlaying = true;
void mousePressed() {
  if (isPlaying) {
    myMovie.pause();
    isPlaying = false;
  } else {
    myMovie.play();
    isPlaying = true;
  }
}

// scale a number by a percentage, from 0 to 100
int percentage(int num, int percent) {
  double mult = percentageFloat(percent);
  double output = num * mult;
  return (int)output;
}

// scale a number by the inverse of a percentage, from 0 to 100
int percentageInverse(int num, int percent) {
  double div = percentageFloat(percent);
  double output = num / div;
  return (int)output;
}

// convert an integer from 0 to 100 to a float percentage
// from 0.0 to 1.0.  Special cases for 1/3, 1/6, 1/7, etc
// are handled automatically to fix integer rounding.
double percentageFloat(int percent) {
  if (percent == 33) return 1.0 / 3.0;
  if (percent == 17) return 1.0 / 6.0;
  if (percent == 14) return 1.0 / 7.0;
  if (percent == 13) return 1.0 / 8.0;
  if (percent == 11) return 1.0 / 9.0;
  if (percent ==  9) return 1.0 / 11.0;
  if (percent ==  8) return 1.0 / 12.0;
  return (double)percent / 100.0;
}

#define LED_WIDTH      25   // number of LEDs horizontally
#define LED_HEIGHT     32   // number of LEDs vertically (must be multiple of 8)
#define LED_LAYOUT     0    // 0 = even rows left->right, 1 = even rows right->left

const int ledsPerStrip = LED_WIDTH * LED_HEIGHT / 8;