StatusCode execute(std::vector<Blob::Ptr>& inputs,
std::vector<Blob::Ptr>& outputs,
ResponseDesc *resp) noexcept override {
+ StatusCode returnCode = OK;
+
const float* logits = inputs[0]->cbuffer().as<const float*>() +
inputs[0]->getTensorDesc().getBlockingDesc().getOffsetPadding();
const int* logitsLength = inputs[1]->cbuffer().as<const int*>() +
outputs[0]->getTensorDesc().getBlockingDesc().getOffsetPadding();
const auto& logitsShape = inputs[0]->getTensorDesc().getDims();
- const auto batchNum = logitsShape[0];
- const auto maxTime = logitsShape[1];
- const auto classesNum = logitsShape[2];
+ const size_t batchNum = logitsShape[0];
+ const size_t maxTime = logitsShape[1];
+ const size_t classesNum = logitsShape[2];
int blankIndex = classesNum - 1;
if (inputs.size() > 4) {
blankIndex = inputs[4]->cbuffer().as<const int*>()[0];
}
- std::vector<int> targetD(maxTime);
-
- const size_t TC = maxTime * classesNum;
-
- for (size_t b = 0; b < batchNum; b++) {
- const int actualLogitLen = logitsLength[b];
- const int actualTargetLen = labelsLength[b];
- if (actualLogitLen < 0 || actualTargetLen < 0 || actualLogitLen > maxTime || actualTargetLen > maxTime
- || actualTargetLen > actualLogitLen) {
- std::string errorMsg = _logPrefix + ". Logit or label length cannot be greater than max sequence length. "
- + "Also a label length cannot be greater than a logit length"
- + " and both cannot be negative.\nMaxSeqLen: "
- + std::to_string(maxTime) + "; Logit len: " + std::to_string(actualLogitLen)
- + "; Label len: " + std::to_string(actualTargetLen);
- errorMsg.copy(resp->msg, sizeof(resp->msg) - 1);
- return GENERAL_ERROR;
- }
-
- const int* target = &labels[b * maxTime];
- // Decoding target: merge repeated characters if preprocess_collapse_repeated == True,
- // find unique elemnts if unique == True
- size_t decodedTargetLen = 0lu;
- if (_unique) {
- std::unordered_set<int> uniqVals;
- for (size_t t = 0lu; t < actualTargetLen; t++) {
- if (uniqVals.find(target[t]) != uniqVals.end()) {
- continue;
- }
- uniqVals.insert(target[t]);
- targetD[decodedTargetLen++] = target[t];
+ std::vector<int> decodedTargetLenB(batchNum, 0);
+ std::vector<std::vector<int>> targetDB(batchNum);
+ std::vector<std::vector<std::vector<float>>> logProbabilitiesB(batchNum);
+ size_t workAmount2 = 0lu;
+ std::vector<std::string> errorMsgB(parallel_get_max_threads());
+
+ auto threadBody_1 = [&](const int ithr, const int nthr) {
+ size_t start(0lu), end(0lu);
+ splitter(batchNum, nthr, ithr, start, end);
+ if (start >= end)
+ return;
+
+ for (size_t b = start; b < end; b++) {
+ if (logitsLength[b] < 0 || labelsLength[b] < 0 || logitsLength[b] > maxTime || labelsLength[b] > logitsLength[b]) {
+ errorMsgB[ithr] = _logPrefix + ". Logit length cannot be greater than max sequence length. "
+ + "Label length cannot be greater than a logit length"
+ + " and both cannot be negative.\nMaxSeqLen: "
+ + std::to_string(maxTime) + "; Logit len: " + std::to_string(logitsLength[b])
+ + "; Label len: " + std::to_string(labelsLength[b]);
+ returnCode = GENERAL_ERROR;
+ return;
}
- } else if (_preprocessCollapseRepeated) {
- int prevValue = target[0];
- targetD[decodedTargetLen++] = target[0];
- for (size_t t = 1lu; t < actualTargetLen; t++) {
- if (target[t] == prevValue) {
- continue;
+ const size_t actualLogitLen = logitsLength[b];
+ const size_t actualTargetLen = labelsLength[b];
+ size_t decodedTargetLen = 0lu;
+
+ // Decoding target: merge repeated characters if preprocess_collapse_repeated == True,
+ // find unique elemnts if unique == True.
+ // Inserts blanks before each index and a blank at the end.
+ const int* target = &labels[b * maxTime];
+ targetDB[b].resize(actualTargetLen * 2 + 1);
+ auto& targetD = targetDB[b];
+ if (_unique) {
+ std::unordered_set<int> uniqVals;
+ for (size_t t = 0lu; t < actualTargetLen; t++) {
+ if (uniqVals.find(target[t]) != uniqVals.end()) {
+ continue;
+ }
+ uniqVals.insert(target[t]);
+ targetD[decodedTargetLen++] = blankIndex;
+ targetD[decodedTargetLen++] = target[t];
+ }
+ targetD[decodedTargetLen++] = blankIndex;
+ } else if (_preprocessCollapseRepeated) {
+ auto prevValue = target[0];
+ targetD[decodedTargetLen++] = blankIndex;
+ targetD[decodedTargetLen++] = target[0];
+ for (size_t t = 1lu; t < actualTargetLen; t++) {
+ if (target[t] == prevValue) {
+ continue;
+ }
+ targetD[decodedTargetLen++] = blankIndex;
+ targetD[decodedTargetLen++] = prevValue = target[t];
}
- targetD[decodedTargetLen++] = target[t];
- prevValue = target[t];
+ targetD[decodedTargetLen++] = blankIndex;
+ } else {
+ for (size_t t = 0lu; t < actualTargetLen; t++) {
+ targetD[decodedTargetLen++] = blankIndex;
+ targetD[decodedTargetLen++] = target[t];
+ }
+ targetD[decodedTargetLen++] = blankIndex;
}
- } else {
- std::copy(target, target + actualTargetLen, targetD.data());
- decodedTargetLen = actualTargetLen;
- }
-
- const size_t BTC = b * TC;
+ decodedTargetLenB[b] = decodedTargetLen;
- std::vector<std::unordered_map<size_t, float>> logProbabilities(actualLogitLen);
- float logProb = 0.f, kExp = 0.f;
- for (size_t t = 0; t < actualLogitLen; t++) {
- kExp = 0.f;
- const size_t btcT = BTC + classesNum * t;
- for (size_t c = 0; c < classesNum; c++) {
- kExp += std::exp(logits[btcT + c]);
+ auto& logProbabilities = logProbabilitiesB[b];
+ logProbabilities.resize(actualLogitLen);
+ for (size_t ll = 0; ll < actualLogitLen; ll++) {
+ logProbabilities[ll].resize(decodedTargetLen);
}
- for (size_t s = 0; s < decodedTargetLen; s++) {
- logProb = logits[btcT + targetD[s]] - std::log(kExp);
- logProbabilities[t].insert({targetD[s], logProb});
- }
- logProb = logits[btcT + blankIndex] - std::log(kExp);
- logProbabilities[t].insert({blankIndex, logProb});
+ workAmount2 += actualLogitLen;
+ } // for batch
+ }; // threadBody_1
+
+ parallel_nt(0, threadBody_1);
+ if (returnCode != OK) {
+ std::string resErr("");
+ for (auto& err : errorMsgB) {
+ if (!err.empty())
+ resErr += err + "\n";
+ resErr.copy(resp->msg, sizeof(resp->msg) - 1);
}
+ return returnCode;
+ }
- const auto float_inf = std::numeric_limits<float>::infinity();
- size_t work_amount = actualLogitLen - decodedTargetLen + 1lu;
- std::vector<float> sumPerThread(parallel_get_max_threads(), -float_inf);
+ const size_t TC = maxTime * classesNum;
- // Looking for aligned paths
- auto thread_body = [&](const int ithr, const int nthr) {
- size_t start0(0lu), end0(0lu);
- splitter(work_amount, nthr, ithr, start0, end0);
- if (start0 >= end0)
- return;
- if (ithr >= sumPerThread.size())
- sumPerThread.push_back(-float_inf);
-
- std::function<void(size_t, size_t, size_t, float)> findPaths =
- [&](size_t targetIdx, size_t start, size_t end, float prevLogProb) {
- if (end > actualLogitLen) {
- if (sumPerThread[ithr] == -float_inf) {
- sumPerThread[ithr] = prevLogProb;
- } else if (prevLogProb != -float_inf) {
- if (sumPerThread[ithr] > prevLogProb)
- sumPerThread[ithr] = sumPerThread[ithr] + std::log1pf(std::exp(prevLogProb - sumPerThread[ithr]));
- else
- sumPerThread[ithr] = prevLogProb + std::log1pf(std::exp(sumPerThread[ithr] - prevLogProb));
- }
- return;
+ auto threadBody_2 = [&](const int ithr, const int nthr) {
+ size_t start(0lu), end(0lu);
+ size_t sB(0lu), sT(0lu);
+ splitter(workAmount2, nthr, ithr, start, end);
+ if (start >= end)
+ return;
+ int64_t cw = 0, st = start;
+ for (; sB < batchNum; sB++) {
+ cw += logitsLength[sB];
+ if (cw >= st) {
+ sT = logitsLength[sB] + st - cw;
+ break;
+ }
+ }
+ size_t workCounter = start;
+
+ for (size_t b = sB; b < batchNum; b++) {
+ const size_t actualLogitLen = logitsLength[b];
+ const size_t decodedTargetLen = decodedTargetLenB[b];
+ auto& logProbabilities = logProbabilitiesB[b];
+ auto& targetD = targetDB[b];
+
+ double expSum = 0.0;
+ size_t btcT = b * TC + sT * classesNum;
+ // logProbabilities = logSoftmax = logits[b][t][c] - ln(sum_c(exp(logits[b][t])))
+ for (size_t t = sT; t < actualLogitLen; t++) {
+ expSum = 0.0;
+ for (size_t c = 0lu; c < classesNum; c++) {
+ expSum += std::exp(logits[btcT + c]);
}
-
- size_t nextIdx = targetIdx + 1;
- int64_t st64 = start;
- float newLogProb = prevLogProb;
- if (!_ctcMergeRepeated) {
- for (size_t pos = start; pos < end; pos++) {
- newLogProb = prevLogProb;
- for (size_t bl = start; bl < pos; bl++) {
- auto lnProbIt = logProbabilities[bl].find(blankIndex);
- if (lnProbIt != logProbabilities[bl].end())
- newLogProb += lnProbIt->second;
- }
- auto lnProbIt = logProbabilities[pos].find(targetD[targetIdx]);
- if (lnProbIt != logProbabilities[pos].end())
- newLogProb += lnProbIt->second;
- if (end == actualLogitLen) {
- for (int64_t ble = pos + 1; ble < actualLogitLen; ble++) {
- auto lnProbIt = logProbabilities[ble].find(blankIndex);
- if (lnProbIt != logProbabilities[ble].end())
- newLogProb += lnProbIt->second;
- }
- }
- findPaths(nextIdx, pos + 1, end + 1, newLogProb);
- }
- } else {
- for (size_t pos = start; pos < end; pos++) {
- newLogProb = prevLogProb;
- size_t next_start = pos + 1;
- for (size_t bl = start; bl < pos; bl++) {
- auto lnProbIt = logProbabilities[bl].find(blankIndex);
- if (lnProbIt != logProbabilities[bl].end())
- newLogProb += lnProbIt->second;
- }
- if (end == actualLogitLen) {
- for (int64_t ble = pos + 1; ble < actualLogitLen; ble++) {
- auto lnProbIt = logProbabilities[ble].find(blankIndex);
- if (lnProbIt != logProbabilities[ble].end())
- newLogProb += lnProbIt->second;
- }
- }
- if (targetIdx < decodedTargetLen - 1
- && targetD[targetIdx] == targetD[targetIdx + 1]) {
- auto lnProbIt = logProbabilities[next_start++].find(blankIndex);
- if (lnProbIt != logProbabilities[next_start].end())
- newLogProb += lnProbIt->second;
- }
- for (int64_t bl = pos; bl >= st64; bl--) {
- newLogProb += logProbabilities[bl].find(targetD[targetIdx])->second;
- findPaths(nextIdx, next_start, end + 1, newLogProb);
- if (bl > 0) {
- auto lnProbIt = logProbabilities[bl - 1].find(blankIndex);
- if (lnProbIt != logProbabilities[bl - 1].end())
- newLogProb -= lnProbIt->second;
- }
- }
- }
+ for (size_t s = 0lu; s < decodedTargetLen; s++) {
+ logProbabilities[t][s] = logits[btcT + targetD[s]] - std::log(expSum);
}
- }; // findPaths
-
- // First tartget symbol
- int64_t st64 = start0;
- float newLogProb = 0.f;
- if (!_ctcMergeRepeated) {
- for (size_t pos = start0; pos < end0; pos++) {
- newLogProb = 0.f;
- for (size_t bl = 0; bl < pos; bl++) {
- auto lnProbIt = logProbabilities[bl].find(blankIndex);
- if (lnProbIt != logProbabilities[bl].end())
- newLogProb += lnProbIt->second;
- }
- auto lnProbIt = logProbabilities[pos].find(targetD[0]);
- if (lnProbIt != logProbabilities[pos].end())
- newLogProb += lnProbIt->second;
- if (work_amount == actualLogitLen) {
- for (int64_t ble = pos + 1; ble < actualLogitLen; ble++) {
- auto lnProbIt = logProbabilities[ble].find(blankIndex);
- if (lnProbIt != logProbabilities[ble].end())
- newLogProb += lnProbIt->second;
- }
- }
- if (decodedTargetLen > 1) {
- findPaths(1, pos + 1, work_amount + 1, newLogProb);
- } else {
- if (sumPerThread[ithr] == -float_inf)
- sumPerThread[ithr] = newLogProb;
- else if (newLogProb != -float_inf)
- sumPerThread[ithr] = sumPerThread[ithr] + std::log1pf(std::exp(newLogProb - sumPerThread[ithr]));
- }
+ btcT += classesNum;
+ if (++workCounter >= end) {
+ return;
}
- } else {
- for (size_t pos = start0; pos < end0; pos++) {
- newLogProb = 0.f;
- size_t next_start = pos + 1;
- for (size_t bl = 0; bl < pos; bl++) {
- auto lnProbIt = logProbabilities[bl].find(blankIndex);
- if (lnProbIt != logProbabilities[bl].end())
- newLogProb += lnProbIt->second;
- }
- if (work_amount == actualLogitLen) {
- for (int64_t ble = pos + 1; ble < actualLogitLen; ble++) {
- auto lnProbIt = logProbabilities[ble].find(blankIndex);
- if (lnProbIt != logProbabilities[ble].end())
- newLogProb += lnProbIt->second;
- }
+ }
+ sT = 0lu;
+ } // for batch
+ }; // threadBody_2
+
+ parallel_nt(0, threadBody_2);
+
+ const auto float_inf = std::numeric_limits<float>::infinity();
+
+ auto sumLogs = [&float_inf](float log1, float log2) {
+ if (log1 == -float_inf) {
+ return log2;
+ } else if (log2 == -float_inf) {
+ return log1;
+ } else {
+ if (log1 > log2)
+ return log1 + std::log1pf(std::exp(log2 - log1));
+ else
+ return log2 + std::log1pf(std::exp(log1 - log2));
+ }
+ };
+
+ auto threadBody_3 = [&](const int ithr, const int nthr) {
+ size_t start(0lu), end(0lu);
+ splitter(batchNum, nthr, ithr, start, end);
+ if (start >= end)
+ return;
+
+ // As per Connectionist Temporal Classification - Labeling Unsegmented Sequence Data with Recurrent Neural Networks:
+ // Graves et al., 2016, paragraph 4.1 (10)
+ for (size_t b = start; b < end; b++) {
+ auto& targetD = targetDB[b];
+ auto& logProbabilities = logProbabilitiesB[b];
+ const int actualLogitLen = logitsLength[b];
+ const int decodedTargetLen = decodedTargetLenB[b];
+ std::vector<std::vector<float>> logBwd(decodedTargetLen, std::vector<float>(actualLogitLen, -float_inf));
+ for (int s = decodedTargetLen - 2; s < decodedTargetLen; s++)
+ logBwd[s][actualLogitLen - 1] = 0.f;
+
+ for (int t = actualLogitLen - 2; t >= 0; t--) {
+ const int t_1 = t + 1;
+ for (int s = std::max(0, decodedTargetLen - (2 * (actualLogitLen - t)));
+ s < std::min(decodedTargetLen, 2 * (t_1)); s++) {
+ if (_ctcMergeRepeated || targetD[s] == blankIndex) {
+ logBwd[s][t] = sumLogs(logBwd[s][t],
+ logBwd[s][t_1] + logProbabilities[t_1][s]);
}
- if (decodedTargetLen > 1
- && targetD[0] == targetD[1]) {
- auto lnProbIt = logProbabilities[next_start++].find(blankIndex);
- if (lnProbIt != logProbabilities[next_start].end())
- newLogProb += lnProbIt->second;
+
+ if (s + 1 < decodedTargetLen) {
+ logBwd[s][t] = sumLogs(logBwd[s][t],
+ logBwd[s + 1][t_1] + logProbabilities[t_1][s + 1]);
}
- for (int64_t bl = pos; bl >= 0; bl--) {
- auto lnProbIt = logProbabilities[bl].find(targetD[0]);
- if (lnProbIt != logProbabilities[bl].end())
- newLogProb += lnProbIt->second;
- if (decodedTargetLen > 1) {
- findPaths(1, next_start, work_amount + 1, newLogProb);
- } else {
- if (sumPerThread[ithr] == -float_inf)
- sumPerThread[ithr] = newLogProb;
- else if (newLogProb != -float_inf)
- sumPerThread[ithr] = sumPerThread[ithr] + std::log1pf(std::exp(newLogProb - sumPerThread[ithr]));
- }
- if (bl > 0) {
- auto lnProbIt = logProbabilities[bl - 1].find(blankIndex);
- if (lnProbIt != logProbabilities[bl - 1].end())
- newLogProb -= lnProbIt->second;
+
+ if (s + 2 < decodedTargetLen) {
+ if (targetD[s] != blankIndex && (!_ctcMergeRepeated || (targetD[s] != targetD[s + 2]))) {
+ logBwd[s][t] = sumLogs(logBwd[s][t],
+ logBwd[s + 2][t_1] + logProbabilities[t_1][s + 2]);
}
}
}
}
- }; // thread_body
-
- parallel_nt(0, thread_body);
- float res = -float_inf;
+ logBwd[0][0] += logProbabilities[0][0];
+ logBwd[1][0] += logProbabilities[0][(decodedTargetLen > 1) ? 1 : 0];
- for (auto sum : sumPerThread) {
- if (res == -float_inf) {
- res = sum;
- } else if (sum != -float_inf) {
- if (res > sum)
- res = res + std::log1pf(std::exp(sum - res));
- else
- res = sum + std::log1pf(std::exp(res - sum));
- }
- }
+ dstData[b] = -sumLogs(logBwd[0][0], logBwd[1][0]);
+ } // for batch
+ }; // threadBody_3
- dstData[b] = -res;
- } // for (size_t b = 0; b < batchNum; b++)
+ parallel_nt(0, threadBody_3);
- return OK;
+ return returnCode;
} // execute
protected:
};
REG_FACTORY_FOR(CTCLossImpl, CTCLoss);
-
} // namespace Cpu
} // namespace Extensions
} // namespace InferenceEngine
-