Port to the new send/receive API by: James Almer <jamrial@gmail.com>.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

This filter accepts all the dnn networks which do image processing.
Currently, frame with formats rgb24 and bgr24 are supported. Other
formats such as gray and YUV will be supported next. The dnn network
can accept data in float32 or uint8 format. And the dnn network can
change frame size.

The following is a python script to halve the value of the first
channel of the pixel. It demos how to setup and execute dnn model
with python+tensorflow. It also generates .pb file which will be
used by ffmpeg.

import tensorflow as tf
import numpy as np
import imageio
in_img = imageio.imread('in.bmp')
in_img = in_img.astype(np.float32)/255.0
in_data = in_img[np.newaxis, :]
filter_data = np.array([0.5, 0, 0, 0, 1., 0, 0, 0, 1.]).reshape(1,1,3,3).astype(np.float32)
filter = tf.Variable(filter_data)
x = tf.placeholder(tf.float32, shape=[1, None, None, 3], name='dnn_in')
y = tf.nn.conv2d(x, filter, strides=[1, 1, 1, 1], padding='VALID', name='dnn_out')
sess=tf.Session()
sess.run(tf.global_variables_initializer())
output = sess.run(y, feed_dict={x: in_data})
graph_def = tf.graph_util.convert_variables_to_constants(sess, sess.graph_def, ['dnn_out'])
tf.train.write_graph(graph_def, '.', 'halve_first_channel.pb', as_text=False)
output = output * 255.0
output = output.astype(np.uint8)
imageio.imsave("out.bmp", np.squeeze(output))

To do the same thing with ffmpeg:
- generate halve_first_channel.pb with the above script
- generate halve_first_channel.model with tools/python/convert.py
- try with following commands
  ./ffmpeg -i input.jpg -vf dnn_processing=model=halve_first_channel.model:input=dnn_in:output=dnn_out:fmt=rgb24:dnn_backend=native -y out.native.png
  ./ffmpeg -i input.jpg -vf dnn_processing=model=halve_first_channel.pb:input=dnn_in:output=dnn_out:fmt=rgb24:dnn_backend=tensorflow -y out.tf.png

Signed-off-by: Guo, Yejun <yejun.guo@intel.com>
Signed-off-by: Pedro Arthur <bygrandao@gmail.com>

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

This introduces two new AVOption options for the FTP protocol,
one named ftp-user to supply the username to be used for auth,
one named ftp-password to supply the password to be used for auth.

These are useful for when an API user does not wish to deal with
URL manipulation and percent encoding.

Setting them while also having credentials in the URL will use the
credentials from the URL. The rationale for this is that credentials
embedded in the URL are probably more specific to what the user is
trying to do than anything set by some API user.

Signed-off-by: Nicolas Frattaroli <ffmpeg@fratti.ch>
Signed-off-by: Marton Balint <cus@passwd.hu>

Allows user to set maximum number of buffered packets when
probing a codec. It was a hard-coded parameter before this commit.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Reported-by: Yabo Wei <weiyabo@kuaishou.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Reviewed-by: Moritz Barsnick <barsnick@gmx.net>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Reviewed-by: Moritz Barsnick <barsnick@gmx.net>
Signed-off-by: Limin Wang <lance.lmwang@gmail.com>

Fixes #7066

Adjusted formatting and prose for option force_divisible_by in scale filter

Signed-off-by: James Almer <jamrial@gmail.com>

Silence detection can only be set with algorithm version 3.

Reviewed-by: Gyan Doshi <ffmpeg@gyani.pro>

Fixes #8032.

Update documentation for flags/flags2

Signed-off-by: Jun Zhao <barryjzhao@tencent.com>