3 files changed, 136 insertions, 12 deletions

diff --git a/kaldi_io/src/cwrapper_kaldi.cpp b/kaldi_io/src/cwrapper_kaldi.cpp
index f48d343..c19908b 100644
--- a/kaldi_io/src/cwrapper_kaldi.cpp
+++ b/kaldi_io/src/cwrapper_kaldi.cpp
@@ -1,9 +1,11 @@
 #include <string>
+#include <map>
 #include "base/kaldi-common.h"
 #include "hmm/posterior.h"
 #include "util/table-types.h"
 typedef kaldi::BaseFloat BaseFloat;
-
+typedef std::map<std::string, kaldi::Matrix<BaseFloat> > StringToMatrix_t;
+typedef std::map<std::string, std::string > StringToString_t;
 extern "C" {
 #include "cwrapper_kaldi.h"
 #include "string.h"
@@ -61,12 +63,80 @@ extern "C" {
         return repo->feature_reader->Done();
     }
 
+    const char *kaldi_feature_repo_key(KaldiFeatureRepo *repo) {
+        return repo->feature_reader->Key().c_str();
+    }
+
     void kaldi_feature_repo_destroy(KaldiFeatureRepo *repo) {
         if (repo->feature_reader)
             delete repo->feature_reader;
         delete repo;
     }
 
+    struct KaldiLookupFeatureRepo {
+        StringToMatrix_t key2mat;
+        StringToString_t map;
+    };
+
+    KaldiLookupFeatureRepo *kaldi_lookup_feature_repo_new(const char *feature_rspecifier, const char *map_rspecifier) {
+        KaldiLookupFeatureRepo *repo = new KaldiLookupFeatureRepo();
+        kaldi::SequentialBaseFloatMatrixReader feature_reader = kaldi::SequentialBaseFloatMatrixReader(string(feature_rspecifier));
+        for (; !feature_reader.Done(); feature_reader.Next())
+        {
+            const std::string &key = feature_reader.Key();
+            const kaldi::Matrix<BaseFloat> &feat = feature_reader.Value();
+            if (repo->key2mat.find(key) != repo->key2mat.end())
+                fprintf(stderr, "[kaldi] warning: lookup feature for key %s already exists", key.c_str());
+            repo->key2mat[key] = feat;
+        }
+        kaldi::SequentialTokenVectorReader map_reader = kaldi::SequentialTokenVectorReader(string(map_rspecifier));
+        for (; !map_reader.Done(); map_reader.Next())
+        {
+            const std::vector<std::string> target = map_reader.Value();
+            assert(target.size() >= 1);
+            repo->map[map_reader.Key()] = *target.begin();
+        }
+        return repo;
+    }
+
+    Matrix *kaldi_lookup_feature_repo_read_utterance(KaldiLookupFeatureRepo *repo, KaldiFeatureRepo *frepo, int nframes, lua_State *L, int debug) {
+        Matrix *mat;                    /* nerv implementation */
+        StringToString_t::iterator mit = repo->map.find(frepo->utt);
+        if (mit == repo->map.end())
+            nerv_error(L, "[kaldi] mapped key for key %s not found", frepo->utt.c_str());
+        const std::string &key = mit->second;
+        StringToMatrix_t::iterator it = repo->key2mat.find(key);
+        if (it == repo->key2mat.end())
+            nerv_error(L, "[kaldi] lookup feature for key %s not found", key.c_str());
+        const kaldi::Matrix<BaseFloat> &kmat = it->second;
+
+        int n = kmat.NumRows() < nframes ? kmat.NumRows() : nframes;
+        int m = kmat.NumCols();
+        Status status;
+        assert(sizeof(BaseFloat) == sizeof(float));
+        if(sizeof(BaseFloat) == sizeof(float))
+            mat = nerv_matrix_host_float_create(n, m, &status);
+        else if(sizeof(BaseFloat) == sizeof(double))
+            mat = nerv_matrix_host_double_create(n, m, &status);
+        NERV_LUA_CHECK_STATUS(L, status);
+        size_t stride = mat->stride;
+        if (debug)
+            fprintf(stderr, "[kaldi] lookup feature: %s %d %d\n", frepo->utt.c_str(), n, m);
+
+        for (int i = 0; i < n; i++)
+        {
+            const BaseFloat *row = kmat.RowData(i);
+            BaseFloat *nerv_row = (BaseFloat *)((char *)mat->data.f + i * stride);
+            /* use memmove to copy the row, since KaldiLib uses compact storage */
+            memmove(nerv_row, row, sizeof(BaseFloat) * m);
+        }
+        return mat;
+    }
+
+    void kaldi_lookup_feature_repo_destroy(KaldiLookupFeatureRepo *repo) {
+        delete repo;
+    }
+
     struct KaldiLabelRepo {
         kaldi::RandomAccessPosteriorReader *targets_reader;
     };
@@ -77,7 +147,7 @@ extern "C" {
         return repo;
     }
 
-    Matrix *kaldi_label_repo_read_utterance(KaldiLabelRepo *repo, KaldiFeatureRepo *frepo, int frm_ext, int nframes,
+    Matrix *kaldi_label_repo_read_utterance(KaldiLabelRepo *repo, KaldiFeatureRepo *frepo, int nframes,
                                             lua_State *L,
                                             int debug) {
         Matrix *mat;
@@ -94,7 +164,6 @@ extern "C" {
             mat = nerv_matrix_host_double_create(n, m, &status);
         NERV_LUA_CHECK_STATUS(L, status);
         size_t stride = mat->stride;
-
         if (debug)
             fprintf(stderr, "[kaldi] label: %s %d %d\n", frepo->utt.c_str(), n, m);
         for (int i = 0; i < n; i++)
diff --git a/kaldi_io/src/cwrapper_kaldi.h b/kaldi_io/src/cwrapper_kaldi.h
index e34cb5a..c8a7a25 100644
--- a/kaldi_io/src/cwrapper_kaldi.h
+++ b/kaldi_io/src/cwrapper_kaldi.h
@@ -12,17 +12,25 @@ extern "C" {
     Matrix *kaldi_feature_repo_read_utterance(KaldiFeatureRepo *repo, lua_State *L, int debug);
     void kaldi_feature_repo_next(KaldiFeatureRepo *repo);
     int kaldi_feature_repo_is_end(KaldiFeatureRepo *repo);
+    const char *kaldi_feature_repo_key(KaldiFeatureRepo *repo);
     void kaldi_feature_repo_destroy(KaldiFeatureRepo *repo);
 
     typedef struct KaldiLabelRepo KaldiLabelRepo;
 
     KaldiLabelRepo *kaldi_label_repo_new(const char *, const char *fmt);
 
-    Matrix *kaldi_label_repo_read_utterance(KaldiLabelRepo *repo, KaldiFeatureRepo *, int, int,
+    Matrix *kaldi_label_repo_read_utterance(KaldiLabelRepo *repo, KaldiFeatureRepo *, int,
                                             lua_State *L,
                                             int debug);
 
     void kaldi_label_repo_destroy(KaldiLabelRepo *repo);
+
+    typedef struct KaldiLookupFeatureRepo KaldiLookupFeatureRepo;
+
+    KaldiLookupFeatureRepo *kaldi_lookup_feature_repo_new(const char *, const char *);
+    Matrix *kaldi_lookup_feature_repo_read_utterance(KaldiLookupFeatureRepo *repo, KaldiFeatureRepo *frepo, int nframes, lua_State *L, int debug);
+    void kaldi_lookup_feature_repo_destroy(KaldiLookupFeatureRepo *repo);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/kaldi_io/src/init.c b/kaldi_io/src/init.c
index 413452c..529895b 100644
--- a/kaldi_io/src/init.c
+++ b/kaldi_io/src/init.c
@@ -3,6 +3,7 @@
 #include <stdio.h>
 
 const char *nerv_kaldi_feat_repo_tname = "nerv.KaldiFeatureRepo";
+const char *nerv_kaldi_lookup_feat_repo_tname = "nerv.KaldiLookupFeatureRepo";
 const char *nerv_kaldi_label_repo_tname = "nerv.KaldiLabelRepo";
 const char *nerv_matrix_host_float_tname = "nerv.MMatrixFloat";
 
@@ -42,10 +43,51 @@ static int feat_repo_is_end(lua_State *L) {
     return 1;
 }
 
+static int feat_repo_key(lua_State *L) {
+    KaldiFeatureRepo *repo = luaT_checkudata(L, 1, nerv_kaldi_feat_repo_tname);
+    lua_pushstring(L, kaldi_feature_repo_key(repo));
+    return 1;
+}
+
 static const luaL_Reg feat_repo_methods[] = {
     {"cur_utter", feat_repo_current_utterance},
     {"next", feat_repo_next},
     {"is_end", feat_repo_is_end},
+    {"key", feat_repo_key},
+    {NULL, NULL}
+};
+
+static int lookup_feat_repo_new(lua_State *L) {
+    const char *feature_rsepcifier = luaL_checkstring(L, 1);
+    const char *map_rspecifier = luaL_checkstring(L, 2);
+    KaldiLookupFeatureRepo *repo = kaldi_lookup_feature_repo_new(feature_rsepcifier, map_rspecifier);
+    luaT_pushudata(L, repo, nerv_kaldi_lookup_feat_repo_tname);
+    return 1;
+}
+
+static int lookup_feat_repo_destroy(lua_State *L) {
+    KaldiLookupFeatureRepo *repo = luaT_checkudata(L, 1, nerv_kaldi_lookup_feat_repo_tname);
+    kaldi_lookup_feature_repo_destroy(repo);
+    return 0;
+}
+
+static int lookup_feat_repo_read_utterance(lua_State *L) {
+    KaldiLookupFeatureRepo *repo = luaT_checkudata(L, 1, nerv_kaldi_lookup_feat_repo_tname);
+    KaldiFeatureRepo *feat_repo = luaT_checkudata(L, 2, nerv_kaldi_feat_repo_tname);
+    int nframes, debug;
+    if (!lua_isnumber(L, 3))
+        nerv_error(L, "nframes should be a number");
+    nframes = lua_tonumber(L, 3);
+    if (!lua_isboolean(L, 4))
+        nerv_error(L, "debug flag should be a boolean");
+    debug = lua_toboolean(L, 4);
+    Matrix *utter = kaldi_lookup_feature_repo_read_utterance(repo, feat_repo, nframes, L, debug);
+    luaT_pushudata(L, utter, nerv_matrix_host_float_tname);
+    return 1;
+}
+
+static const luaL_Reg lookup_feat_repo_methods[] = {
+    {"get_utter", lookup_feat_repo_read_utterance},
     {NULL, NULL}
 };
 
@@ -60,17 +102,14 @@ static int label_repo_new(lua_State *L) {
 static int label_repo_read_utterance(lua_State *L) {
     KaldiLabelRepo *repo = luaT_checkudata(L, 1, nerv_kaldi_label_repo_tname);
     KaldiFeatureRepo *feat_repo = luaT_checkudata(L, 2, nerv_kaldi_feat_repo_tname);
-    int frm_ext, nframes, debug;
+    int nframes, debug;
     if (!lua_isnumber(L, 3))
-        nerv_error(L, "frm_ext should be a number");
-    frm_ext = lua_tonumber(L, 3);
-    if (!lua_isnumber(L, 4))
         nerv_error(L, "nframes should be a number");
-    nframes = lua_tonumber(L, 4);
-    if (!lua_isboolean(L, 5))
+    nframes = lua_tonumber(L, 3);
+    if (!lua_isboolean(L, 4))
         nerv_error(L, "debug flag should be a boolean");
-    debug = lua_toboolean(L, 5);
-    Matrix *utter = kaldi_label_repo_read_utterance(repo, feat_repo, frm_ext, nframes, L, debug);
+    debug = lua_toboolean(L, 4);
+    Matrix *utter = kaldi_label_repo_read_utterance(repo, feat_repo, nframes, L, debug);
     luaT_pushudata(L, utter, nerv_matrix_host_float_tname);
     return 1;
 }
@@ -93,6 +132,13 @@ static void feat_repo_init(lua_State *L) {
     lua_pop(L, 1);
 }
 
+static void lookup_feat_repo_init(lua_State *L) {
+    luaT_newmetatable(L, nerv_kaldi_lookup_feat_repo_tname, NULL,
+                        lookup_feat_repo_new, lookup_feat_repo_destroy, NULL);
+    luaL_register(L, NULL, lookup_feat_repo_methods);
+    lua_pop(L, 1);
+}
+
 static void label_repo_init(lua_State *L) {
     luaT_newmetatable(L, nerv_kaldi_label_repo_tname, NULL,
                         label_repo_new, label_repo_destroy, NULL);
@@ -102,5 +148,6 @@ static void label_repo_init(lua_State *L) {
 
 void kaldi_io_init(lua_State *L) {
     feat_repo_init(L);
+    lookup_feat_repo_init(L);
     label_repo_init(L);
 }