class EngineBatch.BatchSeqCopyPart(seq_idx, seq_start_frame, seq_end_frame, batch_slice, batch_frame_offset)[source]
A batch used for training in CRNN can consist of several parts from sequences,
ordered in various ways. The dataset, depending on the configuration, can generate these. For the non-recurrent case, we usually concatenate them together into one slice. For the recurrent case, we have a single slice per sequence, or even multiple slices for a sequence in case of chunking.
This class represents one single such part and where it is going to
be stored in the batch.
class EngineBatch.Batch[source]

A batch can consists of several sequences (= segments). This is basically just a list of BatchSeqCopyPart.

Parameters:length (NumbersDict) – number of (time) frames
Returns:new shape which covers the old shape and one more data-batch, format (time,batch)
Return type:(NumbersDict,int)
add_sequence_as_slice(seq_idx, seq_start_frame, length)[source]

Adds one data-batch in an additional slice.

add_frames(seq_idx, seq_start_frame, length, frame_dim_corresponds=True)[source]

Adds frames to all data-batches. Will add one data-batch if we don’t have one yet.

  • seq_idx (int) –
  • seq_start_frame (NumbersDict|int) –
  • length (NumbersDict) – number of (time) frames
  • frame_dim_corresponds (bool) – if the batch frame offset should always be the same (max value) for all keys
init_with_one_full_sequence(seq_idx, dataset)[source]

Note that this is only an upper limit in case of data_shape[1] > 1 because data_shape[0] is the max frame len of all seqs. :return: related to the data-key with max length :rtype: int

class EngineBatch.BatchSetGenerator(dataset, generator, shuffle_batches=False, cache_whole_epoch=True)[source]

This will give you the next batches (list[Batch]) such that you can use them for assign_dev_data(). We get those batches from a generator, i.e. lazily on-the-fly. This is the whole point of BatchSetGenerator - that we must not know the whole list of batches in advance. As assign_dev_data() can fail for various reasons, we buffer the list of batches and you call self.advance() explicitly to go forward to next batches.


Call this after one epoch to reuse the previously cached batches.

Return type:list[Batch]

:returns it might return less. There is no way to know in advance. If self.has_more() is True, it will at least return one.

Return type:float

:returns 0-1, >0


This would also try to advance further in the dataset, thus it might block. If it returns False, no more data is available in the dataset.

Return type:bool
Return type:int