bool Example1Tx::makeFecBlocks(SuperBlock *txBlocks, uint16_t frameIndex)
{
if (m_params.RecoveryCount > 0)
{
for (int i = 0; i < m_params.OriginalCount; i++)
{
m_txDescriptorBlocks[i].Block = (void *) &txBlocks[i].protectedBlock;
m_txDescriptorBlocks[i].Index = i;
}
if (m_cm256_OK)
{
if (cm256_encode(m_params, m_txDescriptorBlocks, m_txRecovery))
{
std::cerr << "example2: encode failed" << std::endl;
return false;
}
for (int i = 0; i < m_params.RecoveryCount; i++)
{
txBlocks[i + m_params.OriginalCount].header.blockIndex = i + m_params.OriginalCount;
txBlocks[i + m_params.OriginalCount].header.frameIndex = frameIndex;
txBlocks[i + m_params.OriginalCount].protectedBlock = m_txRecovery[i];
}
}
}
return true;
}
/**
* This is a more realistic example with separation of received data creation (mocking) and its processing
*/
bool example3()
{
#pragma pack(push, 1)
struct Sample
{
uint16_t i;
uint16_t q;
};
struct Header
{
uint16_t frameIndex;
uint8_t blockIndex;
uint8_t filler;
};
static const int samplesPerBlock = (512 - sizeof(Header)) / sizeof(Sample);
struct ProtectedBlock
{
Sample samples[samplesPerBlock];
};
struct SuperBlock
{
Header header;
ProtectedBlock protectedBlock;
};
#pragma pack(pop)
if (cm256_init())
{
return false;
}
cm256_encoder_params params;
// Number of bytes per file block
params.BlockBytes = sizeof(ProtectedBlock);
// Number of blocks
params.OriginalCount = 128; // Superframe = set of protected frames
// Number of additional recovery blocks generated by encoder
params.RecoveryCount = 32;
SuperBlock* txBuffer = new SuperBlock[params.OriginalCount+params.RecoveryCount];
ProtectedBlock* txRecovery = new ProtectedBlock[params.RecoveryCount];
cm256_block txDescriptorBlocks[params.OriginalCount+params.RecoveryCount];
int frameCount = 0;
// Fill original data
for (int i = 0; i < params.OriginalCount+params.RecoveryCount; ++i)
{
txBuffer[i].header.frameIndex = frameCount;
txBuffer[i].header.blockIndex = i;
if (i < params.OriginalCount)
{
txBuffer[i].protectedBlock.samples[0].i = i; // marker
}
else
{
memset((void *) &txBuffer[i].protectedBlock, 0, sizeof(ProtectedBlock));
}
txDescriptorBlocks[i].Block = (void *) &txBuffer[i].protectedBlock;
txDescriptorBlocks[i].Index = txBuffer[i].header.blockIndex;
}
// Generate recovery data
long long ts = getUSecs();
if (cm256_encode(params, txDescriptorBlocks, txRecovery))
{
std::cerr << "example2: encode failed" << std::endl;
delete[] txBuffer;
delete[] txRecovery;
return false;
}
long long usecs = getUSecs() - ts;
std::cerr << "Encoded in " << usecs << " microseconds" << std::endl;
// insert recovery data in sent data
for (int i = 0; i < params.RecoveryCount; i++)
{
txBuffer[params.OriginalCount+i].protectedBlock = txRecovery[i];
}
SuperBlock* rxBuffer = new SuperBlock[params.OriginalCount + params.RecoveryCount]; // received blocks
int k = 0;
for (int i = 0; i < params.OriginalCount+params.RecoveryCount; i++)
{
if (i % 5 != 4)
{
rxBuffer[k] = txBuffer[i];
k++;
}
}
Sample *samplesBuffer = new Sample[samplesPerBlock * params.OriginalCount];
ProtectedBlock* retrievedDataBuffer = (ProtectedBlock *) samplesBuffer;
ProtectedBlock* recoveryBuffer = new ProtectedBlock[params.OriginalCount]; // recovery blocks with maximum size
cm256_block rxDescriptorBlocks[params.OriginalCount];
int recoveryStartIndex;
k = 0;
for (int i = 0; i < params.OriginalCount; i++)
{
int blockIndex = rxBuffer[i].header.blockIndex;
if (blockIndex < params.OriginalCount) // it's an original block
{
retrievedDataBuffer[blockIndex] = rxBuffer[i].protectedBlock;
rxDescriptorBlocks[i].Block = (void *) &retrievedDataBuffer[blockIndex];
rxDescriptorBlocks[i].Index = blockIndex;
}
else // it's a recovery block
{
if (k == 0)
{
recoveryStartIndex = i;
}
recoveryBuffer[k] = rxBuffer[i].protectedBlock;
rxDescriptorBlocks[i].Block = (void *) &recoveryBuffer[k];
rxDescriptorBlocks[i].Index = blockIndex;
k++;
}
}
ts = getUSecs();
if (cm256_decode(params, rxDescriptorBlocks))
{
delete[] txBuffer;
delete[] txRecovery;
delete[] rxBuffer;
delete[] samplesBuffer;
delete[] recoveryBuffer;
return false;
}
usecs = getUSecs() - ts;
for (int i = 0; i < k; i++) // recover missing blocks
{
int blockIndex = rxDescriptorBlocks[recoveryStartIndex+i].Index;
retrievedDataBuffer[blockIndex] = recoveryBuffer[i];
}
for (int i = 0; i < params.OriginalCount; i++)
{
std::cerr << i << ":"
<< (unsigned int) rxDescriptorBlocks[i].Index << ":"
<< (unsigned int) retrievedDataBuffer[i].samples[0].i << std::endl;
}
std::cerr << "Decoded in " << usecs << " microseconds" << std::endl;
delete[] txBuffer;
delete[] txRecovery;
delete[] rxBuffer;
delete[] samplesBuffer;
delete[] recoveryBuffer;
return true;
}
bool ExampleFileUsage()
{
if (cm256_init())
{
return false;
}
cm256_encoder_params params;
// Number of bytes per file block
params.BlockBytes = 1296;
// Number of blocks
params.OriginalCount = 100;
// Number of additional recovery blocks generated by encoder
params.RecoveryCount = 30;
// Size of the original file
static const int OriginalFileBytes = params.OriginalCount * params.BlockBytes;
// Allocate and fill the original file data
uint8_t* originalFileData = new uint8_t[OriginalFileBytes];
for (int i = 0; i < OriginalFileBytes; ++i)
{
originalFileData[i] = (uint8_t)i;
}
// Pointers to data
cm256_block blocks[256];
for (int i = 0; i < params.OriginalCount; ++i)
{
blocks[i].Block = originalFileData + i * params.BlockBytes;
}
// Recovery data
uint8_t* recoveryBlocks = new uint8_t[params.RecoveryCount * params.BlockBytes];
// Generate recovery data
if (cm256_encode(params, blocks, recoveryBlocks))
{
delete[] originalFileData;
delete[] recoveryBlocks;
return false;
}
// Initialize the indices
for (int i = 0; i < params.OriginalCount; ++i)
{
blocks[i].Index = cm256_get_original_block_index(params, i);
}
//// Simulate loss of data, substituting a recovery block in its place ////
for (int i = 0; i < params.RecoveryCount && i < params.OriginalCount; ++i)
{
blocks[i].Block = recoveryBlocks + params.BlockBytes * i; // First recovery block
blocks[i].Index = cm256_get_recovery_block_index(params, i); // First recovery block index
}
//// Simulate loss of data, substituting a recovery block in its place ////
if (cm256_decode(params, blocks))
{
delete[] originalFileData;
delete[] recoveryBlocks;
return false;
}
for (int i = 0; i < params.RecoveryCount && i < params.OriginalCount; ++i)
{
uint8_t* block = (uint8_t*)blocks[i].Block;
int index = blocks[i].Index;
for (int j = 0; j < params.BlockBytes; ++j)
{
const uint8_t expected = (uint8_t)(j + index * params.BlockBytes);
if (block[j] != expected)
{
delete[] originalFileData;
delete[] recoveryBlocks;
return false;
}
}
}
delete[] originalFileData;
delete[] recoveryBlocks;
return true;
}
bool example2()
{
static const int payloadSize = 256; // represents 4 subframes of 64 bytes
#pragma pack(push, 1)
struct ProtectedBlock
{
uint8_t blockIndex;
uint8_t data[payloadSize];
};
struct SuperBlock
{
uint8_t frameIndex;
uint8_t blockIndex;
ProtectedBlock protectedBlock;
};
#pragma pack(pop)
if (cm256_init())
{
return false;
}
cm256_encoder_params params;
// Number of bytes per file block
params.BlockBytes = sizeof(ProtectedBlock);
// Number of blocks
params.OriginalCount = 128; // Superframe = set of protected frames
// Number of additional recovery blocks generated by encoder
params.RecoveryCount = 32;
SuperBlock* txBuffer = new SuperBlock[params.OriginalCount+params.RecoveryCount];
ProtectedBlock* txRecovery = new ProtectedBlock[params.RecoveryCount];
cm256_block txDescriptorBlocks[params.OriginalCount+params.RecoveryCount];
int frameCount = 0;
// Fill original data
for (int i = 0; i < params.OriginalCount+params.RecoveryCount; ++i)
{
txBuffer[i].frameIndex = frameCount;
txBuffer[i].blockIndex = i;
if (i < params.OriginalCount)
{
txBuffer[i].protectedBlock.blockIndex = i;
for (int j = 0; j < payloadSize; ++j)
{
txBuffer[i].protectedBlock.data[j] = i;
}
txDescriptorBlocks[i].Block = (void *) &txBuffer[i].protectedBlock;
txDescriptorBlocks[i].Index = txBuffer[i].blockIndex;
}
else
{
memset((void *) &txBuffer[i].protectedBlock, 0, sizeof(ProtectedBlock));
txDescriptorBlocks[i].Block = (void *) &txBuffer[i].protectedBlock;
txDescriptorBlocks[i].Index = i;
}
}
// Generate recovery data
long long ts = getUSecs();
if (cm256_encode(params, txDescriptorBlocks, txRecovery))
{
std::cerr << "example2: encode failed" << std::endl;
delete[] txBuffer;
delete[] txRecovery;
return false;
}
long long usecs = getUSecs() - ts;
std::cerr << "Encoded in " << usecs << " microseconds" << std::endl;
// insert recovery data in sent data
for (int i = 0; i < params.RecoveryCount; i++)
{
txBuffer[params.OriginalCount+i].protectedBlock = txRecovery[i];
}
SuperBlock* rxBuffer = new SuperBlock[params.OriginalCount];
cm256_block rxDescriptorBlocks[params.OriginalCount];
int k = 0;
for (int i = 0; i < params.OriginalCount+params.RecoveryCount; i++)
{
if (k < params.OriginalCount)
{
if (i % 5 != 4)
{
rxBuffer[k] = txBuffer[i];
rxDescriptorBlocks[k].Block = (void *) &rxBuffer[k].protectedBlock;
rxDescriptorBlocks[k].Index = rxBuffer[k].blockIndex;
k++;
}
}
}
ts = getUSecs();
if (cm256_decode(params, rxDescriptorBlocks))
{
delete[] txBuffer;
delete[] txRecovery;
delete[] rxBuffer;
return false;
}
usecs = getUSecs() - ts;
for (int i = 0; i < params.OriginalCount; i++)
{
std::cerr << i << ":"
<< (unsigned int) rxBuffer[i].blockIndex << ":"
<< (unsigned int) rxBuffer[i].protectedBlock.blockIndex << ":"
<< (unsigned int) rxBuffer[i].protectedBlock.data[0] << std::endl;
}
std::cerr << "Decoded in " << usecs << " microseconds" << std::endl;
delete[] txBuffer;
delete[] txRecovery;
delete[] rxBuffer;
return true;
}
