let HTK I/O implementation be a single package

1 files changed, 62 insertions, 0 deletions

diff --git a/htk_io/init.lua b/htk_io/init.lua
new file mode 100644
index 0000000..27ece6e
--- /dev/null
+++ b/htk_io/init.lua
@@ -0,0 +1,62 @@
+require 'libhtkio'
+local TNetReader = nerv.class("nerv.TNetReader", "nerv.DataReader")
+
+function TNetReader:__init(global_conf, reader_conf)
+    self.feat_id = reader_conf.id
+    self.frm_ext = reader_conf.frm_ext
+    self.gconf = global_conf
+    self.global_transf = reader_conf.global_transf
+    self.debug = global_conf.debug
+    if self.debug == nil then
+        self.debug = false
+    end
+    self.feat_repo = nerv.TNetFeatureRepo(reader_conf.scp_file,
+                                          reader_conf.conf_file,
+                                          reader_conf.frm_ext)
+    self.lab_repo = {}
+    for id, mlf_spec in pairs(reader_conf.mlfs) do
+        self.lab_repo[id] = nerv.TNetLabelRepo(mlf_spec.file,
+                                            mlf_spec.format,
+                                            mlf_spec.format_arg,
+                                            mlf_spec.dir,
+                                            mlf_spec.ext)
+    end
+end
+
+function TNetReader:get_data()
+    if self.feat_repo:is_end() then
+        return nil
+    end
+    local res = {}
+    local frm_ext = self.frm_ext
+    local step = frm_ext * 2 + 1
+    -- read HTK feature
+    local feat_utter = self.feat_repo:cur_utter(self.debug)
+    -- expand the feature
+    local expanded = self.gconf.cumat_type(feat_utter:nrow(), feat_utter:ncol() * step)
+    expanded:expand_frm(self.gconf.cumat_type.new_from_host(feat_utter), frm_ext)
+    -- rearrange the feature (``transpose'' operation in TNet)
+    local rearranged = expanded:create()
+    rearranged:rearrange_frm(expanded, step)
+    -- prepare for transf
+    local input = {rearranged}
+    local output = {rearranged:create()}
+    -- do transf
+    self.global_transf:init(input[1]:nrow())
+    self.global_transf:propagate(input, output)
+    -- trim frames
+    expanded = self.gconf.mmat_type(output[1]:nrow() - frm_ext * 2, output[1]:ncol())
+    output[1]:copy_toh(expanded, frm_ext, feat_utter:nrow() - frm_ext)
+    res[self.feat_id] = expanded
+    -- add corresponding labels
+    for id, repo in pairs(self.lab_repo) do
+        local lab_utter = repo:get_utter(self.feat_repo,
+                                        expanded:nrow(),
+                                        self.debug)
+        res[id] = lab_utter
+    end
+    -- move the pointer to next
+    self.feat_repo:next()
+    collectgarbage("collect")
+    return res
+end