train.py draft..

egs/librispeech/ASR/conformer_ctc_bn_2d/train.py

@@ -17,18 +17,21 @@
 
 
 import argparse
+import collections
 import logging
 from pathlib import Path
+import random # temp..
 from shutil import copyfile
-from typing import Optional
+from typing import Optional, Tuple
 
 import k2
 import torch
+from torch import Tensor
 import torch.distributed as dist
 import torch.multiprocessing as mp
 import torch.nn as nn
 from asr_datamodule import LibriSpeechAsrDataModule
-from conformer import DiscreteBottleneckConformer
+from conformer import BidirectionalConformer
 from lhotse.utils import fix_random_seed
 from torch.nn.parallel import DistributedDataParallel as DDP
 from torch.nn.utils import clip_grad_norm_
@@ -153,7 +156,7 @@ def get_params() -> AttributeDict:
             "exp_dir": Path("conformer_ctc_bn/exp_gloam_5e-4_0.85_discrete8"),
             "lang_dir": Path("data/lang_bpe"),
             "feature_dim": 80,
-            "subsampling_factor": 4,
+            "subsampling_factor": 4,  # can't be changed
             "best_train_loss": float("inf"),
             "best_valid_loss": float("inf"),
             "best_train_epoch": -1,
@@ -166,12 +169,18 @@ def get_params() -> AttributeDict:
             "reduction": "sum",
             "use_double_scores": True,
             "accum_grad": 1,
-            "att_rate": 0.7,
+            "att_scale": 0.4,
+            "reverse_att_scale": 0.4,  # ctc_scale == 1.0 - att_scale - reverse_att_scale
             "attention_dim": 512,
             "nhead": 8,
+            "num_trunk_encoder_layers": 12,
             "num_decoder_layers": 6,
-            "is_espnet_structure": True,
+            "num_reverse_encoder_layers": 4,
-            "mmi_loss": False,
+            "num_reverse_decoder_layers": 4,
+            "num_self_predictor_layers": 2,
+            "discretization_tot_classes": 512,
+            "discretization_num_groups": 8,
+            "is_bpe": True,
             "use_feat_batchnorm": True,
             "max_lrate": 5.0e-04,
             "first_decay_epoch": 1,
@@ -270,15 +279,83 @@ def save_checkpoint(
         copyfile(src=filename, dst=best_valid_filename)
 
 
+class LossRecord(collections.defaultdict):
+    def __init__(self):
+        # Passing the type 'int' to the base-class constructor
+        # makes undefined items default to int() which is zero.
+        super(LossRecord, self).__init__(int)
+
+    def __add__(self, other: LossRecord) -> LossRecord:
+        ans = LossRecord()
+        for k, v in self.items():
+            ans[k] = v
+        for k, v in other.items():
+            ans[k] = ans[k] + v
+        return ans
+
+    def __mul__(self, alpha: float) -> LossRecord:
+        ans = LossRecord()
+        for k, v in self.items():
+            ans[k] = v * alpha
+        return ans
+
+
+    def __str__(self) -> str:
+        ans = ''
+        for k, v in self.norm_items():
+            norm_value = '%.2g' % v
+            ans += (str(k) + '=' + str(norm_value) + ', ')
+        frames = str(self['frames'])
+        ans += 'over ' + frames + ' frames.'
+        return ans
+
+    def norm_items(self) -> List[Tuple[string, float]]
+        """
+        Returns a list of pairs, like:
+          [('ctc_loss', 0.1), ('att_loss', 0.07)]
+        """
+        num_frames = self['frames'] if 'frames' in self else 1
+        ans = []
+        for k, v in self.items():
+            if k != 'frames':
+                norm_value = float(v) / num_frames
+                ans.append((k, norm_value))
+
+
+    def reduce(self, device):
+        """
+        Reduce using torch.distributed, which I believe ensures that
+        all processes get the total.
+        """
+        keys = sorted(self.keys())
+        s = torch.tensor([ float(self[k]) for k in keys ],
+                         device=device)
+        dist.all_reduce(s, op=dist.ReduceOp.SUM)
+        for k, v in zip(keys, s.cpu().tolist()):
+            self[k] = v
+
+    def write_summary(self, tb_writer: SummaryWriter, prefix: str, batch_idx: int) -> None:
+        """
+        Add logging information to a TensorBoard writer.
+                tb_writer: a TensorBoard writer
+                  prefix: a prefix for the name of the loss, e.g. "train/valid_",
+                              or "train/current_"
+               batch_idx: The current batch index, used as the x-axis of the plot.
+        """
+        for k, v in self.norm_items():
+            tb_writer.add_scalar(prefix + k, v, batch_idx)
+
+
+
 def compute_loss(
     params: AttributeDict,
     model: nn.Module,
     batch: dict,
     graph_compiler: BpeCtcTrainingGraphCompiler,
     is_training: bool,
-):
+) -> Tuple[Tensor, LossRecord]
     """
-    Compute CTC loss given the model and its inputs.
+    Compute loss function (including CTC, attention, and reverse-attention terms).
 
     Args:
       params:
@@ -306,9 +383,16 @@ def compute_loss(
 
         supervisions = batch["supervisions"]
 
+        mmodel = model.module if hasattr(model, "module") else model
+
         with torch.set_grad_enabled(is_training):
-            nnet_output, encoder_memory, memory_mask = model(feature, supervisions)
+            memory, position_embedding, memory_mask = model(feature, supervisions)
-            # nnet_output is [N, T, C]
+            # memory's shape is (N, T, C)
+
+            ctc_output = mmodel.ctc_encoder_forward(memory,
+                                                   position_embedding,
+                                                   memory_mask)
+
 
         # NOTE: We need `encode_supervisions` to sort sequences with
         # different duration in decreasing order, required by
@@ -322,7 +406,7 @@ def compute_loss(
         decoding_graph = graph_compiler.compile(token_ids)
 
         dense_fsa_vec = k2.DenseFsaVec(
-            nnet_output,
+            ctc_output,
             supervision_segments,
             allow_truncate=params.subsampling_factor - 1,
         )
@@ -335,38 +419,71 @@ def compute_loss(
             use_double_scores=params.use_double_scores,
         )
 
-        if params.att_rate != 0.0:
+        if params.att_scale != 0.0:
             with torch.set_grad_enabled(is_training):
-                if hasattr(model, "module"):
+                att_loss = mmodel.decoder_forward(
-                    att_loss = model.module.decoder_forward(
+                    memory,
-                        encoder_memory,
+                    memory_mask,
-                        memory_mask,
+                    token_ids=token_ids,
-                        token_ids=token_ids,
+                    sos_id=graph_compiler.sos_id,
-                        sos_id=graph_compiler.sos_id,
+                    eos_id=graph_compiler.eos_id,
-                        eos_id=graph_compiler.eos_id,
+                )
-                    )
-                else:
-                    att_loss = model.decoder_forward(
-                        encoder_memory,
-                        memory_mask,
-                        token_ids=token_ids,
-                        sos_id=graph_compiler.sos_id,
-                        eos_id=graph_compiler.eos_id,
-                    )
-                loss = (1.0 - params.att_rate) * ctc_loss + params.att_rate * att_loss
         else:
-            loss = ctc_loss
+            att_loss = torch.tensor([0.0]).to(device)
-            att_loss = torch.tensor([0])
 
-        # train_frames and valid_frames are used for printing.
+        if params.reverse_att_scale != 0.0:
-        if is_training:
+            with torch.set_grad_enabled(is_training):
-            params.train_frames = supervision_segments[:, 2].sum().item()
+                (sampled, softmax,
+                 positive_embed_shifted,
+                 negative_embed_shifted) = mmodel.sample_forward(memory)
+
+                reverse_decoder_logprob = mmodel.reverse_decoder_forward(
+                    positive_embed_shifted,
+                    memory_mask,
+                    sampled, softmax,
+                    token_ids,
+                    sos_id=graph_compiler.sos_id,
+                    eos_id=graph_compiler.eos_id,
+                    padding_id=0)
+
+                self_prediction_logprob = mmodel.self_prediction_forward(
+                    negative_embed_shifted,
+                    memory_mask,
+                    sampled, softmax)
+
+                # Note: reverse_att_loss is the mutual information between
+                # the word sequence and the frames; it will generally be negative,
+                # and is to be minimized (i.e. it goes away from zero as we train,
+                # it does not approach zero).
+                reverse_att_loss = self_prediction_logprob - reverse_decoder_logprob
+
+                if random.random() < 0.01:
+                    # Will eventually remove this block..
+                    num_frames = supervision_segments[:, 2].sum().item()
+                    print(f"Self-prediction logprob = {self_prediction_logprob/num_frames}, "
+                          f"reverse-decoder logprob = {reverse_decoder_logprob/num_frames}"
+                          f"reverse_att_loss = {reverse_att_loss/num_frames}")
         else:
-            params.valid_frames = supervision_segments[:, 2].sum().item()
+            reverse_att_loss = torch.tensor([0.0]).to(device)
 
+        ctc_scale = 1.0 - params.att_scale - params.reverse_att_scale
+        loss = (ctc_scale * ctc_loss +
+                params.att_scale * att_loss +
+                params.reverse_att_scale * reverse_att_loss)
         assert loss.requires_grad == is_training
 
-        return loss, ctc_loss.detach(), att_loss.detach()
+        info = LossRecord()
+        # TODO: there are many GPU->CPU transfers here, maybe combine them into one.
+        info['frames'] = supervision_segments[:, 2].sum().item()
+        info['ctc_loss'] = ctc_loss.detach().cpu().item()
+        if params.att_scale != 0.0:
+            info['att_loss'] = att_loss.detach().cpu().item()
+        if params.reverse_att_scale != 0.0:
+            info['reverse_att_loss'] = reverse_att_loss.detach().cpu().item()
+        info['loss'] = loss.detach().cpu().item()
+
+
+        return loss, info
     except RuntimeError as e:
         print(f"Runtime error.  feature.shape = {feature.shape}, supervisions = {supervisions}")
         raise e
@@ -381,18 +498,13 @@ def compute_validation_loss(
     graph_compiler: BpeCtcTrainingGraphCompiler,
     valid_dl: torch.utils.data.DataLoader,
     world_size: int = 1,
-) -> None:
+) -> LossRecord:
-    """Run the validation process. The validation loss
+    """Run the validation process. """
-    is saved in `params.valid_loss`.
-    """
     model.eval()
 
-    tot_loss = 0.0
+    tot_loss = LossRecord()
-    tot_ctc_loss = 0.0
-    tot_att_loss = 0.0
-    tot_frames = 0.0
     for batch_idx, batch in enumerate(valid_dl):
-        loss, ctc_loss, att_loss = compute_loss(
+        loss, loss_info = compute_loss(
             params=params,
             model=model,
             batch=batch,
@@ -400,36 +512,18 @@ def compute_validation_loss(
             is_training=False,
         )
         assert loss.requires_grad is False
-        assert ctc_loss.requires_grad is False
+        tot_loss = tot_loss + loss_info
-        assert att_loss.requires_grad is False
-
-        loss_cpu = loss.detach().cpu().item()
-        tot_loss += loss_cpu
-
-        tot_ctc_loss += ctc_loss.detach().cpu().item()
-        tot_att_loss += att_loss.detach().cpu().item()
-
-        tot_frames += params.valid_frames
 
     if world_size > 1:
-        s = torch.tensor(
+        tot_loss.reduce(loss.device)
-            [tot_loss, tot_ctc_loss, tot_att_loss, tot_frames],
-            device=loss.device,
-        )
-        dist.all_reduce(s, op=dist.ReduceOp.SUM)
-        s = s.cpu().tolist()
-        tot_loss = s[0]
-        tot_ctc_loss = s[1]
-        tot_att_loss = s[2]
-        tot_frames = s[3]
 
-    params.valid_loss = tot_loss / tot_frames
+    loss_value = tot_loss['loss'] / tot_loss['frames']
-    params.valid_ctc_loss = tot_ctc_loss / tot_frames
+    if loss_value < params.best_valid_loss:
-    params.valid_att_loss = tot_att_loss / tot_frames
-
-    if params.valid_loss < params.best_valid_loss:
         params.best_valid_epoch = params.cur_epoch
-        params.best_valid_loss = params.valid_loss
+        params.best_valid_loss = loss_value
+
+    return tot_loss
+
 
 
 def train_one_epoch(
@@ -468,24 +562,20 @@ def train_one_epoch(
     """
     model.train()
 
-    tot_loss = 0.0  # sum of losses over all batches
+    tot_loss = LossInfo()
-    tot_ctc_loss = 0.0
-    tot_att_loss = 0.0
 
-    tot_frames = 0.0  # sum of frames over all batches
-    params.tot_loss = 0.0
-    params.tot_frames = 0.0
     for batch_idx, batch in enumerate(train_dl):
         params.batch_idx_train += 1
         batch_size = len(batch["supervisions"]["text"])
 
-        loss, ctc_loss, att_loss = compute_loss(
+        loss, loss_info = compute_loss(
             params=params,
             model=model,
             batch=batch,
             graph_compiler=graph_compiler,
             is_training=True,
         )
+        tot_loss = (tot_loss * (1 + 1 / params.reset_interval)) + loss_info  # summary stats.
 
         # NOTE: We use reduction==sum and loss is computed over utterances
         # in the batch and there is no normalization to it so far.
@@ -495,75 +585,22 @@ def train_one_epoch(
         clip_grad_norm_(model.parameters(), 5.0, 2.0)
         optimizer.step()
 
-        loss_cpu = loss.detach().cpu().item()
+        if batch_idx % 10 == 0:
-        ctc_loss_cpu = ctc_loss.detach().cpu().item()
-        att_loss_cpu = att_loss.detach().cpu().item()
 
-        tot_frames += params.train_frames
+            if tb_writer is not None:
-        tot_loss += loss_cpu
+                loss_info.write_summary(tb_writer, "train/current_", params.batch_idx_train)
-        tot_ctc_loss += ctc_loss_cpu
+                tot_loss.write_summary(tb_writer, "train/tot_", params.batch_idx_train)
-        tot_att_loss += att_loss_cpu
-
-        params.tot_frames += params.train_frames
-        params.tot_loss += loss_cpu
-
-        tot_avg_loss = tot_loss / tot_frames
-        tot_avg_ctc_loss = tot_ctc_loss / tot_frames
-        tot_avg_att_loss = tot_att_loss / tot_frames
 
         if batch_idx % params.log_interval == 0:
             logging.info(
-                f"Epoch {params.cur_epoch}, batch {batch_idx}, "
+                f"Epoch {params.cur_epoch}, batch {batch_idx}, loss[{loss_info}], "
-                f"batch avg ctc loss {ctc_loss_cpu/params.train_frames:.4f}, "
+                f"tot_loss[{tot_loss}], batch size: {batch_size}"
-                f"batch avg att loss {att_loss_cpu/params.train_frames:.4f}, "
-                f"batch avg loss {loss_cpu/params.train_frames:.4f}, "
-                f"total avg ctc loss: {tot_avg_ctc_loss:.4f}, "
-                f"total avg att loss: {tot_avg_att_loss:.4f}, "
-                f"total avg loss: {tot_avg_loss:.4f}, "
-                f"batch size: {batch_size}"
             )
 
-            if tb_writer is not None:
-                tb_writer.add_scalar(
-                    "train/current_ctc_loss",
-                    ctc_loss_cpu / params.train_frames,
-                    params.batch_idx_train,
-                )
-                tb_writer.add_scalar(
-                    "train/current_att_loss",
-                    att_loss_cpu / params.train_frames,
-                    params.batch_idx_train,
-                )
-                tb_writer.add_scalar(
-                    "train/current_loss",
-                    loss_cpu / params.train_frames,
-                    params.batch_idx_train,
-                )
-                tb_writer.add_scalar(
-                    "train/tot_avg_ctc_loss",
-                    tot_avg_ctc_loss,
-                    params.batch_idx_train,
-                )
-
-                tb_writer.add_scalar(
-                    "train/tot_avg_att_loss",
-                    tot_avg_att_loss,
-                    params.batch_idx_train,
-                )
-                tb_writer.add_scalar(
-                    "train/tot_avg_loss",
-                    tot_avg_loss,
-                    params.batch_idx_train,
-                )
-        if batch_idx > 0 and batch_idx % params.reset_interval == 0:
-            tot_loss = 0.0  # sum of losses over all batches
-            tot_ctc_loss = 0.0
-            tot_att_loss = 0.0
-
-            tot_frames = 0.0  # sum of frames over all batches
 
         if batch_idx > 0 and batch_idx % params.valid_interval == 0:
-            compute_validation_loss(
+            logging.info("Computing validation loss")
+            valid_info = compute_validation_loss(
                 params=params,
                 model=model,
                 graph_compiler=graph_compiler,
@@ -572,32 +609,14 @@ def train_one_epoch(
             )
             model.train()
             logging.info(
-                f"Epoch {params.cur_epoch}, "
+                f"Epoch {params.cur_epoch}, validation: {valid_info}"
-                f"valid ctc loss {params.valid_ctc_loss:.4f},"
-                f"valid att loss {params.valid_att_loss:.4f},"
-                f"valid loss {params.valid_loss:.4f},"
-                f" best valid loss: {params.best_valid_loss:.4f} "
-                f"best valid epoch: {params.best_valid_epoch}"
             )
             if tb_writer is not None:
-                tb_writer.add_scalar(
+                valid_info.write_summary(tb_writer, "train/valid_", params.batch_idx_train)
-                    "train/valid_ctc_loss",
-                    params.valid_ctc_loss,
-                    params.batch_idx_train,
-                )
-                tb_writer.add_scalar(
-                    "train/valid_att_loss",
-                    params.valid_att_loss,
-                    params.batch_idx_train,
-                )
-                tb_writer.add_scalar(
-                    "train/valid_loss",
-                    params.valid_loss,
-                    params.batch_idx_train,
-                )
 
-    params.train_loss = params.tot_loss / params.tot_frames
 
+    loss_value = tot_loss['loss'] / tot_loss['frames']
+    params.train_loss = loss_value
     if params.train_loss < params.best_train_loss:
         params.best_train_epoch = params.cur_epoch
         params.best_train_loss = params.train_loss
@@ -647,17 +666,21 @@ def run(rank, world_size, args):
     )
 
     logging.info("About to create model")
-    model = DiscreteBottleneckConformer(
+    model = BidirectionalConformer(
         num_features=params.feature_dim,
-        nhead=params.nhead,
-        d_model=params.attention_dim,
         num_classes=num_classes,
-        subsampling_factor=params.subsampling_factor,
+        d_model=params.attention_dim,
+        nhead=params.nhead,
+        num_trunk_encoder_layers=params.num_trunk_encoder_layers,
+        num_ctc_encoder_layers=params.num_ctc_encoder_layers,
         num_decoder_layers=params.num_decoder_layers,
-        vgg_frontend=False,
+        num_reverse_encoder_layers=params.num_reverse_encoder_layers,
-        is_espnet_structure=params.is_espnet_structure,
+        num_reverse_decoder_layers=params.num_reverse_decoder_layers,
-        mmi_loss=params.mmi_loss,
+        num_self_predictor_layers=params.num_self_predictor_layers,
-        use_feat_batchnorm=params.use_feat_batchnorm,
+        subsampling_factor=params.subsampling_factor,
+        is_bpe=params.is_bpe,
+        discretization_tot_classes=params.discretization_tot_clases,
+        discretization_num_groups=params.discretization_num_groups,
     )
 
     checkpoints = load_checkpoint_if_available(params=params, model=model)