path: root/dom/media/webrtc/common/YuvStamper.cpp

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifdef HAVE_NETINET_IN_H
#  include <netinet/in.h>
#elif defined XP_WIN
#  include <winsock2.h>
#endif
#include <string.h>

#include "nspr.h"
#include "YuvStamper.h"
#include "mozilla/Sprintf.h"

typedef uint32_t UINT4;  // Needed for r_crc32() call
extern "C" {
#include "r_crc32.h"
}

namespace mozilla {

#define ON_5 0x20
#define ON_4 0x10
#define ON_3 0x08
#define ON_2 0x04
#define ON_1 0x02
#define ON_0 0x01

/*
  0, 0, 1, 1, 0, 0,
  0, 1, 0, 0, 1, 0,
  1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1,
  0, 1, 0, 0, 1, 0,
  0, 0, 1, 1, 0, 0
*/
static unsigned char DIGIT_0[] = {ON_3 | ON_2, ON_4 | ON_1, ON_5 | ON_0,
                                  ON_5 | ON_0, ON_5 | ON_0, ON_4 | ON_1,
                                  ON_3 | ON_2};

/*
  0, 0, 0, 1, 0, 0,
  0, 0, 0, 1, 0, 0,
  0, 0, 0, 1, 0, 0,
  0, 0, 0, 1, 0, 0,
  0, 0, 0, 1, 0, 0,
  0, 0, 0, 1, 0, 0,
  0, 0, 0, 1, 0, 0,
*/
static unsigned char DIGIT_1[] = {ON_2, ON_2, ON_2, ON_2, ON_2, ON_2, ON_2};

/*
  1, 1, 1, 1, 1, 0,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 0,
  1, 0, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0,
  0, 1, 1, 1, 1, 1,
*/
static unsigned char DIGIT_2[] = {
    ON_5 | ON_4 | ON_3 | ON_2 | ON_1, ON_0, ON_0,
    ON_4 | ON_3 | ON_2 | ON_1,        ON_5, ON_5,
    ON_4 | ON_3 | ON_2 | ON_1 | ON_0,
};

/*
  1, 1, 1, 1, 1, 0,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 1,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1,
  1, 1, 1, 1, 1, 0,
*/
static unsigned char DIGIT_3[] = {
    ON_5 | ON_4 | ON_3 | ON_2 | ON_1, ON_0, ON_0,
    ON_4 | ON_3 | ON_2 | ON_1 | ON_0, ON_0, ON_0,
    ON_5 | ON_4 | ON_3 | ON_2 | ON_1,
};

/*
  0, 1, 0, 0, 0, 1,
  0, 1, 0, 0, 0, 1,
  0, 1, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 1,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1
*/
static unsigned char DIGIT_4[] = {
    ON_4 | ON_0, ON_4 | ON_0, ON_4 | ON_0, ON_4 | ON_3 | ON_2 | ON_1 | ON_0,
    ON_0,        ON_0,        ON_0,
};

/*
  0, 1, 1, 1, 1, 1,
  1, 0, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0,
  0, 1, 1, 1, 1, 0,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1,
  1, 1, 1, 1, 1, 0,
*/
static unsigned char DIGIT_5[] = {
    ON_4 | ON_3 | ON_2 | ON_1 | ON_0, ON_5, ON_5,
    ON_4 | ON_3 | ON_2 | ON_1,        ON_0, ON_0,
    ON_5 | ON_4 | ON_3 | ON_2 | ON_1,
};

/*
  0, 1, 1, 1, 1, 1,
  1, 0, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0,
  1, 1, 1, 1, 1, 0,
  1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 0,
*/
static unsigned char DIGIT_6[] = {
    ON_4 | ON_3 | ON_2 | ON_1 | ON_0, ON_5,        ON_5,
    ON_4 | ON_3 | ON_2 | ON_1,        ON_5 | ON_0, ON_5 | ON_0,
    ON_4 | ON_3 | ON_2 | ON_1,
};

/*
  1, 1, 1, 1, 1, 1,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 1, 0,
  0, 0, 0, 1, 0, 0,
  0, 0, 1, 0, 0, 0,
  0, 1, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0
*/
static unsigned char DIGIT_7[] = {ON_5 | ON_4 | ON_3 | ON_2 | ON_1 | ON_0,
                                  ON_0,
                                  ON_1,
                                  ON_2,
                                  ON_3,
                                  ON_4,
                                  ON_5};

/*
  0, 1, 1, 1, 1, 1,
  1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 0,
  1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 0
*/
static unsigned char DIGIT_8[] = {
    ON_4 | ON_3 | ON_2 | ON_1, ON_5 | ON_0, ON_5 | ON_0,
    ON_4 | ON_3 | ON_2 | ON_1, ON_5 | ON_0, ON_5 | ON_0,
    ON_4 | ON_3 | ON_2 | ON_1,
};

/*
  0, 1, 1, 1, 1, 1,
  1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 1,
  0, 0, 0, 0, 0, 1,
  0, 0, 0, 0, 0, 1,
  0, 1, 1, 1, 1, 0
*/
static unsigned char DIGIT_9[] = {
    ON_4 | ON_3 | ON_2 | ON_1 | ON_0, ON_5 | ON_0, ON_5 | ON_0,
    ON_4 | ON_3 | ON_2 | ON_1 | ON_0, ON_0,        ON_0,
    ON_4 | ON_3 | ON_2 | ON_1,
};

static unsigned char* DIGITS[] = {DIGIT_0, DIGIT_1, DIGIT_2, DIGIT_3, DIGIT_4,
                                  DIGIT_5, DIGIT_6, DIGIT_7, DIGIT_8, DIGIT_9};

YuvStamper::YuvStamper(unsigned char* pYData, uint32_t width, uint32_t height,
                       uint32_t stride, uint32_t x, uint32_t y,
                       unsigned char symbol_width, unsigned char symbol_height)
    : pYData(pYData),
      mStride(stride),
      mWidth(width),
      mHeight(height),
      mSymbolWidth(symbol_width),
      mSymbolHeight(symbol_height),
      mCursor(x, y) {}

bool YuvStamper::Encode(uint32_t width, uint32_t height, uint32_t stride,
                        unsigned char* pYData, unsigned char* pMsg,
                        size_t msg_len, uint32_t x, uint32_t y) {
  YuvStamper stamper(pYData, width, height, stride, x, y, sBitSize, sBitSize);

  // Reserve space for a checksum.
  if (stamper.Capacity() < 8 * (msg_len + sizeof(uint32_t))) {
    return false;
  }

  bool ok = false;
  uint32_t crc;
  unsigned char* pCrc = reinterpret_cast<unsigned char*>(&crc);
  r_crc32(reinterpret_cast<char*>(pMsg), (int)msg_len, &crc);
  crc = htonl(crc);

  while (msg_len-- > 0) {
    if (!stamper.Write8(*pMsg++)) {
      return false;
    }
  }

  // Add checksum after the message.
  ok = stamper.Write8(*pCrc++) && stamper.Write8(*pCrc++) &&
       stamper.Write8(*pCrc++) && stamper.Write8(*pCrc++);

  return ok;
}

bool YuvStamper::Decode(uint32_t width, uint32_t height, uint32_t stride,
                        unsigned char* pYData, unsigned char* pMsg,
                        size_t msg_len, uint32_t x, uint32_t y) {
  YuvStamper stamper(pYData, width, height, stride, x, y, sBitSize, sBitSize);

  unsigned char* ptr = pMsg;
  size_t len = msg_len;
  uint32_t crc, msg_crc;
  unsigned char* pCrc = reinterpret_cast<unsigned char*>(&crc);

  // Account for space reserved for the checksum
  if (stamper.Capacity() < 8 * (len + sizeof(uint32_t))) {
    return false;
  }

  while (len-- > 0) {
    if (!stamper.Read8(*ptr++)) {
      return false;
    }
  }

  if (!(stamper.Read8(*pCrc++) && stamper.Read8(*pCrc++) &&
        stamper.Read8(*pCrc++) && stamper.Read8(*pCrc++))) {
    return false;
  }

  r_crc32(reinterpret_cast<char*>(pMsg), (int)msg_len, &msg_crc);
  return crc == htonl(msg_crc);
}

inline uint32_t YuvStamper::Capacity() {
  // Enforce at least a symbol width and height offset from outer edges.
  if (mCursor.y + mSymbolHeight > mHeight) {
    return 0;
  }

  if (mCursor.x + mSymbolWidth > mWidth && !AdvanceCursor()) {
    return 0;
  }

  // Normalize frame integral to mSymbolWidth x mSymbolHeight
  uint32_t width = mWidth / mSymbolWidth;
  uint32_t height = mHeight / mSymbolHeight;
  uint32_t x = mCursor.x / mSymbolWidth;
  uint32_t y = mCursor.y / mSymbolHeight;

  return (width * height - width * y) - x;
}

bool YuvStamper::Write8(unsigned char value) {
  // Encode MSB to LSB.
  unsigned char mask = 0x80;
  while (mask) {
    if (!WriteBit(!!(value & mask))) {
      return false;
    }
    mask >>= 1;
  }
  return true;
}

bool YuvStamper::WriteBit(bool one) {
  // A bit is mapped to a mSymbolWidth x mSymbolHeight square of luma data
  // points. Don't use ternary op.:
  // https://bugzilla.mozilla.org/show_bug.cgi?id=1001708
  unsigned char value;
  if (one)
    value = sYOn;
  else
    value = sYOff;

  for (uint32_t y = 0; y < mSymbolHeight; y++) {
    for (uint32_t x = 0; x < mSymbolWidth; x++) {
      *(pYData + (mCursor.x + x) + ((mCursor.y + y) * mStride)) = value;
    }
  }

  return AdvanceCursor();
}

bool YuvStamper::AdvanceCursor() {
  mCursor.x += mSymbolWidth;
  if (mCursor.x + mSymbolWidth > mWidth) {
    // move to the start of the next row if possible.
    mCursor.y += mSymbolHeight;
    if (mCursor.y + mSymbolHeight > mHeight) {
      // end of frame, do not advance
      mCursor.y -= mSymbolHeight;
      mCursor.x -= mSymbolWidth;
      return false;
    } else {
      mCursor.x = 0;
    }
  }

  return true;
}

bool YuvStamper::Read8(unsigned char& value) {
  unsigned char octet = 0;
  unsigned char bit = 0;

  for (int i = 8; i > 0; --i) {
    if (!ReadBit(bit)) {
      return false;
    }
    octet <<= 1;
    octet |= bit;
  }

  value = octet;
  return true;
}

bool YuvStamper::ReadBit(unsigned char& bit) {
  uint32_t sum = 0;
  for (uint32_t y = 0; y < mSymbolHeight; y++) {
    for (uint32_t x = 0; x < mSymbolWidth; x++) {
      sum += *(pYData + mStride * (mCursor.y + y) + mCursor.x + x);
    }
  }

  // apply threshold to collected bit square
  bit = (sum > (sBitThreshold * mSymbolWidth * mSymbolHeight)) ? 1 : 0;
  return AdvanceCursor();
}

bool YuvStamper::WriteDigits(uint32_t value) {
  char buf[20];
  SprintfLiteral(buf, "%.5u", value);
  size_t size = strlen(buf);

  if (Capacity() < size) {
    return false;
  }

  for (size_t i = 0; i < size; ++i) {
    if (!WriteDigit(buf[i] - '0')) return false;
    if (!AdvanceCursor()) {
      return false;
    }
  }

  return true;
}

bool YuvStamper::WriteDigit(unsigned char digit) {
  if (digit > sizeof(DIGITS) / sizeof(DIGITS[0])) return false;

  unsigned char* dig = DIGITS[digit];
  for (uint32_t row = 0; row < sDigitHeight; ++row) {
    unsigned char mask = 0x01 << (sDigitWidth - 1);
    for (uint32_t col = 0; col < sDigitWidth; ++col, mask >>= 1) {
      if (dig[row] & mask) {
        for (uint32_t xx = 0; xx < sPixelSize; ++xx) {
          for (uint32_t yy = 0; yy < sPixelSize; ++yy) {
            WritePixel(pYData, mCursor.x + (col * sPixelSize) + xx,
                       mCursor.y + (row * sPixelSize) + yy);
          }
        }
      }
    }
  }

  return true;
}

void YuvStamper::WritePixel(unsigned char* data, uint32_t x, uint32_t y) {
  unsigned char* ptr = &data[y * mStride + x];
  // Don't use ternary op.: https://bugzilla.mozilla.org/show_bug.cgi?id=1001708
  if (*ptr > sLumaThreshold)
    *ptr = sLumaMin;
  else
    *ptr = sLumaMax;
}

}  // namespace mozilla.