icefall_librispeech_streaming_pruned_transducer_stateless5_20220729

See https://github.com/k2-fsa/icefall/pull/454

training command:

./pruned_transducer_stateless5/train.py \
  --exp-dir pruned_transducer_stateless5/exp \
  --num-encoder-layers 18 \
  --dim-feedforward 2048 \
  --nhead 8 \
  --encoder-dim 512 \
  --decoder-dim 512 \
  --joiner-dim 512 \
  --full-libri 1 \
  --dynamic-chunk-training 1 \
  --causal-convolution 1 \
  --short-chunk-size 20 \
  --num-left-chunks 4 \
  --max-duration 300 \
  --world-size 4 \
  --start-epoch 1 \
  --num-epochs 25

You can find the tensorboard log here https://tensorboard.dev/experiment/rO04h6vjTLyw0qSxjp4m4Q

The decoding command is:

decoding_method="greedy_search"  # "fast_beam_search", "modified_beam_search"
for chunk in 2 4 8 16; do
  for left in 32 64; do
    ./pruned_transducer_stateless5/decode.py \
            --num-encoder-layers 18 \
            --dim-feedforward 2048 \
            --nhead 8 \
            --encoder-dim 512 \
            --decoder-dim 512 \
            --joiner-dim 512 \
            --simulate-streaming 1 \
            --decode-chunk-size ${chunk} \
            --left-context ${left} \
            --causal-convolution 1 \
            --epoch 25 \
            --avg 5 \
            --exp-dir ./pruned_transducer_stateless5/exp \
            --max-sym-per-frame 1 \
            --max-duration 1000 \
            --decoding-method ${decoding_method}
  done
done

export command is:

./pruned_transducer_stateless5/export.py \
        --streaming-model 1 \
        --causal-convolution 1 \
        --num-encoder-layers 18 \
        --dim-feedforward 2048 \
        --nhead 8 \
        --encoder-dim 512 \
        --decoder-dim 512 \
        --joiner-dim 512 \
        --epoch 25 \
        --avg 5 \
        --exp-dir ./pruned_transducer_stateless5/exp

./pruned_transducer_stateless5/export.py \
        --streaming-model 1 \
        --causal-convolution 1 \
        --num-encoder-layers 18 \
        --dim-feedforward 2048 \
        --nhead 8 \
        --encoder-dim 512 \
        --decoder-dim 512 \
        --joiner-dim 512 \
        --epoch 25 \
        --avg 5 \
        --exp-dir ./pruned_transducer_stateless5/exp \
        --jit 1