From f792b466bfde6ccfe60cc27918628c5c31843798 Mon Sep 17 00:00:00 2001
From: Fangjun Kuang <csukuangfj@gmail.com>
Date: Mon, 13 Sep 2021 10:49:18 +0800
Subject: [PATCH] Change default value of lattice-score-scale from 1.0 to 0.5
 (#41)

* Change the default value of lattice-score-scale from 1.0 to 0.5

* Fix CI.
---
 .github/workflows/test.yml                  | 14 ++++++++++++++
 egs/librispeech/ASR/conformer_ctc/decode.py |  5 +++--
 egs/librispeech/ASR/tdnn_lstm_ctc/decode.py |  3 ++-
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c853e3de1..c3025d730 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -53,6 +53,20 @@ jobs:
           # icefall requirements
           pip install -r requirements.txt
 
+      - name: Install graphviz
+        if: startsWith(matrix.os, 'ubuntu')
+        shell: bash
+        run: |
+          python3 -m pip install -qq graphviz
+          sudo apt-get -qq install graphviz
+
+      - name: Install graphviz
+        if: startsWith(matrix.os, 'macos')
+        shell: bash
+        run: |
+          python3 -m pip install -qq graphviz
+          brew install -q graphviz
+
       - name: Run tests
         if: startsWith(matrix.os, 'ubuntu')
         run: |
diff --git a/egs/librispeech/ASR/conformer_ctc/decode.py b/egs/librispeech/ASR/conformer_ctc/decode.py
index cfdcff756..85161f737 100755
--- a/egs/librispeech/ASR/conformer_ctc/decode.py
+++ b/egs/librispeech/ASR/conformer_ctc/decode.py
@@ -108,7 +108,7 @@ def get_parser():
     parser.add_argument(
         "--lattice-score-scale",
         type=float,
-        default=1.0,
+        default=0.5,
         help="""The scale to be applied to `lattice.scores`.
         It's needed if you use any kinds of n-best based rescoring.
         Used only when "method" is one of the following values:
@@ -278,7 +278,8 @@ def decode_one_batch(
         "attention-decoder",
     ]
 
-    lm_scale_list = [0.8, 0.9, 1.0, 1.1, 1.2, 1.3]
+    lm_scale_list = [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7]
+    lm_scale_list += [0.8, 0.9, 1.0, 1.1, 1.2, 1.3]
     lm_scale_list += [1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0]
 
     if params.method == "nbest-rescoring":
diff --git a/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py b/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py
index 87e9cddb4..23b2e794c 100755
--- a/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py
+++ b/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py
@@ -206,7 +206,8 @@ def decode_one_batch(
 
     assert params.method in ["nbest-rescoring", "whole-lattice-rescoring"]
 
-    lm_scale_list = [0.8, 0.9, 1.0, 1.1, 1.2, 1.3]
+    lm_scale_list = [0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7]
+    lm_scale_list += [0.8, 0.9, 1.0, 1.1, 1.2, 1.3]
     lm_scale_list += [1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0]
 
     if params.method == "nbest-rescoring":