Upload the language model

deep_speech_2/README.md

@@ -66,12 +66,31 @@ More help for arguments:
 python train.py --help
 ```
 
-### Inferencing
+### Preparing language model
+
+The following steps, inference, parameters tuning and evaluating, will require a language model during decoding.
+A compressed language model is provided and can be accessed by
+
+```
+cd ./lm
+sh run.sh
+cd ..
+```
+
+### Inference
+
+For GPU inference
 
 ```
 CUDA_VISIBLE_DEVICES=0 python infer.py
 ```
 
+For CPU inference
+
+```
+python infer.py --use_gpu=False
+```
+
 More help for arguments:
 
 ```
@@ -92,14 +111,24 @@ python evaluate.py --help
 
 ### Parameters tuning
 
-Parameters tuning for the CTC beam search decoder
+Usually, the parameters $\alpha$ and $\beta$ for the CTC [prefix beam search](https://arxiv.org/abs/1408.2873) decoder need to be tuned after retraining the acoustic model.
+
+For GPU tuning
 
 ```
 CUDA_VISIBLE_DEVICES=0 python tune.py
 ```
 
+For CPU tuning
+
+```
+python tune.py --use_gpu=False
+```
+
 More help for arguments:
 
 ```
 python tune.py --help
 ```
+
+Then reset parameters with the tuning result before inference or evaluating.

deep_speech_2/evaluate.py

@@ -62,7 +62,7 @@
 )
 parser.add_argument(
     "--language_model_path",
-    default="lm/data/1Billion.klm",
+    default="lm/data/common_crawl_00.prune01111.trie.klm",
     type=str,
     help="Path for language model. (default: %(default)s)")
 parser.add_argument(
@@ -139,6 +139,7 @@ def evaluate():
     batch_reader = data_generator.batch_reader_creator(
         manifest_path=args.decode_manifest_path,
         batch_size=args.batch_size,
+        min_batch_size=1,
         sortagrad=False,
         shuffle_method=None)
 

deep_speech_2/infer.py

@@ -89,7 +89,7 @@
     help="Number of output per sample in beam search. (default: %(default)d)")
 parser.add_argument(
     "--language_model_path",
-    default="lm/data/1Billion.klm",
+    default="lm/data/common_crawl_00.prune01111.trie.klm",
     type=str,
     help="Path for language model. (default: %(default)s)")
 parser.add_argument(

deep_speech_2/lm/run.sh

@@ -1,3 +1,19 @@
-echo "Downloading language model."
+echo "Downloading language model ..."
+
+mkdir data
+
+LM=common_crawl_00.prune01111.trie.klm
+MD5="099a601759d467cd0a8523ff939819c5"
+
+wget -c http://paddlepaddle.bj.bcebos.com/model_zoo/speech/$LM -P ./data
+
+echo "Checking md5sum ..."
+md5_tmp=`md5sum ./data/$LM | awk -F[' '] '{print $1}'`
+
+if [ $MD5 != $md5_tmp ]; then
+    echo "Fail to download the language model!"
+    exit 1
+fi
+
+
 
-wget -c ftp://xxx/xxx/en.00.UNKNOWN.klm -P ./data

deep_speech_2/tune.py

@@ -77,7 +77,7 @@
     help="Width for beam search decoding. (default: %(default)d)")
 parser.add_argument(
     "--language_model_path",
-    default="lm/data/1Billion.klm",
+    default="lm/data/common_crawl_00.prune01111.trie.klm",
     type=str,
     help="Path for language model. (default: %(default)s)")
 parser.add_argument(