def CNN_3d(x, out_channels_0, out_channels_1, add_relu=True):
    '''Add a 3d convlution layer with relu and max pooling layer.

    Args:
        x: a tensor with shape [batch, in_depth, in_height, in_width, in_channels]
        out_channels: a number
        filter_size: a number
        pooling_size: a number

    Returns:
        a flattened tensor with shape [batch, num_features]

    Raises:
    '''
    in_channels = x.shape[-1]
    weights_0 = tf.get_variable(
        name='filter_0',
        shape=[3, 3, 3, in_channels, out_channels_0],
        dtype=tf.float32,
        initializer=tf.random_uniform_initializer(-0.01, 0.01))
    bias_0 = tf.get_variable(
        name='bias_0',
        shape=[out_channels_0],
        dtype=tf.float32,
        initializer=tf.zeros_initializer())

    conv_0 = tf.nn.conv3d(x, weights_0, strides=[1, 1, 1, 1, 1], padding="SAME")
    print('conv_0 shape: %s' %conv_0.shape)
    conv_0 = conv_0 + bias_0

    if add_relu:
        conv_0 = tf.nn.elu(conv_0)

    pooling_0 = tf.nn.max_pool3d(
        conv_0, 
        ksize=[1, 3, 3, 3, 1],
        strides=[1, 3, 3, 3, 1], 
        padding="SAME")
    print('pooling_0 shape: %s' %pooling_0.shape)

    #layer_1
    weights_1 = tf.get_variable(
        name='filter_1',
        shape=[3, 3, 3, out_channels_0, out_channels_1],
        dtype=tf.float32,
        initializer=tf.random_uniform_initializer(-0.01, 0.01))
    bias_1 = tf.get_variable(
        name='bias_1',
        shape=[out_channels_1],
        dtype=tf.float32,
        initializer=tf.zeros_initializer())

    conv_1 = tf.nn.conv3d(pooling_0, weights_1, strides=[1, 1, 1, 1, 1], padding="SAME")
    print('conv_1 shape: %s' %conv_1.shape)
    conv_1 = conv_1 + bias_1

    if add_relu:
        conv_1 = tf.nn.elu(conv_1)

    pooling_1 = tf.nn.max_pool3d(
        conv_1, 
        ksize=[1, 3, 3, 3, 1],
        strides=[1, 3, 3, 3, 1], 
        padding="SAME")
    print('pooling_1 shape: %s' %pooling_1.shape)

    return tf.contrib.layers.flatten(pooling_1)

调用比如CNN_3d(x, 32, 16)
其中输入x是一个类似[batch_size,9,50,50,12]
则输出是[batch_size,576]