Add frame op and CPU/GPU kernels.

[KPatr1ck]

• PR types
  New features

• PR changes
  OPs

• Describe

  • Add frame op.
  • Add frame op kernel which is available on cpu and gpu.
  • Input dims >= 1 and axis can be 0/-1.(Will be checked in python api. )

[KPatr1ck]

1. Simple test cases in dynamic graph

import paddle
from paddle import _C_ops

paddle.set_device('cpu')
paddle.seed(0)

op = getattr(_C_ops, 'frame')

cases = [
    # Case 1: 1D:(seq_length,), axis:0
    [paddle.arange(1, 16), 0], 

    # Case 2: 1D:(seq_length,), axis:-1
    [paddle.arange(1, 16), -1],

    # Case 3: 2D:(seq_length, batch_size), axis:0
    [paddle.arange(1, 16).unsqueeze(-1), 0],

    # Case 4: 2D:(batch_size, seq_length), axis:-1
    [paddle.arange(1, 16).unsqueeze(0), -1],

    # Case 5: 4D:(seq_length, d2, d3, d4), axis:0
    [paddle.arange(120).reshape((10, 3, 2, 2)), 0],

    # Case 6: 4D:(d1, d2, d3, seq_length), axis:-1
    [paddle.arange(120).reshape((3, 2, 2, 10)), -1],
]

frame_length = 4
hop_length = 2

for idx, case in enumerate(cases):
    inp, axis = case
    attrs = ('frame_length', frame_length, 'hop_length', hop_length, 'axis', axis)

    print(f'============= Case {idx+1} ==============')
    print(f'input type: {inp.dtype}, input shape: {inp.shape}, axis: {axis}')
    print(f'input data: {inp}')
    print('***********************************')
    out = op(inp, *attrs)
    print('***********************************')
    print(f'output type: {out.dtype}, output shape: {out.shape}')
    print(f'output data: {out}')
    print('===================================')

2. Results

[iclementine]

LGTM