def get_masked():
x_masked = x
x_masked = _random_mask(
x_masked, batch_axis=data.batch_dim_axis, axis=data.time_dim_axis,
min_num=min_frame_masks,
max_num=tf.maximum(tf.shape(x)[data.time_dim_axis] // mask_each_n_frames, min_frame_masks),
max_dims=max_frames_per_mask)
x_masked = _random_mask(
x_masked, batch_axis=data.batch_dim_axis, axis=data.feature_dim_axis,
min_num=min_feature_masks, max_num=max_feature_masks,
max_dims=max_features_per_mask)
return x_masked
def get_masked():
x_masked = x
x_masked = random_mask(x_masked,
axis=1,
min_num=1,
max_num=tf.maximum(tf.shape(x)[1] // 100, 1),
max_dims=20)
x_masked = random_mask(x_masked,
axis=2,
min_num=1,
max_num=2,
max_dims=40 // 5)
return x_masked
def get_masked():
x_masked = x
x_masked = random_mask(
x_masked,
batch_axis=data.batch_dim_axis,
axis=data.time_dim_axis,
min_num=step1 + step2,
max_num=tf.maximum(tf.shape(x)[data.time_dim_axis] // 100, 2) *
(1 + step1 + step2 * 2),
max_dims=20 // time_factor)
x_masked = random_mask(x_masked,
batch_axis=data.batch_dim_axis,
axis=data.feature_dim_axis,
min_num=step1 + step2,
max_num=2 + step1 + step2 * 2,
max_dims=data.dim // 5)
return x_masked
def get_contrastive_loss_mask(source, **_kwargs):
def _random_mask(x, axis, min_num, max_num, max_dims):
from returnn.tf.compat import v1 as tf
n_batch = tf.shape(x)[0]
num = tf.random_uniform(shape=(n_batch, ),
minval=min_num,
maxval=max_num + 1,
dtype=tf.int32)
# https://github.com/tensorflow/tensorflow/issues/9260
# https://timvieira.github.io/blog/post/2014/08/01/gumbel-max-trick-and-weighted-reservoir-sampling/
z = -tf.log(
-tf.log(tf.random_uniform((n_batch, tf.shape(x)[axis]), 0, 1)))
_, indices = tf.nn.top_k(z, tf.reduce_max(num))
# indices should be sorted, and of shape (batch,num), entries (int32) in [0,dim)
# indices = tf.Print(indices, ["indices", indices, tf.shape(indices)])
res_mask = tf.zeros(shape=[n_batch, tf.shape(x)[axis]],
dtype=tf.bool) # all False
_, res_mask = tf.while_loop(
cond=lambda i, _: tf.less(i, tf.reduce_max(num)),
body=lambda i, res_mask:
(i + 1,
tf.where(
tf.less(i, num),
tf.math.logical_or(
res_mask,
_get_mask(
x, axis=axis, pos=indices[:, i], max_amount=max_dims)
), res_mask)),
loop_vars=(0, res_mask))
return res_mask # (batch,dim)
from returnn.tf.compat import v1 as tf
data = source(0, as_data=True, auto_convert=False)
assert (data.batch_dim_axis, data.time_dim_axis) == (0, 1)
x = data.placeholder
mask = _random_mask(x,
axis=1,
min_num=1,
max_num=tf.maximum(tf.shape(x)[1] // 100, 1),
max_dims=20)
return mask