Trying to get the output using HttpRequest's 'onprogress'.

http_stream_test.php

#!/usr/bin/php
<?php

$request = new \HttpRequest(
    'http://10.1.1.150:8888/watch',
    HTTP_METH_GET,
    array(
        'onprogress' => function ($input) {
            echo print_r($input, true);
        },
        'timeout' => 60
    )
);

$response = $request->send();
return print_r($response->getBody(), true);

?>

output.txt

$ ./http_stream_test.php 
Array
(
    [dltotal] => 0
    [dlnow] => 0
    [ultotal] => 0
    [ulnow] => 0
)
Array
(
    [dltotal] => 0
    [dlnow] => 16
    [ultotal] => 0
    [ulnow] => 0
)
Array
(
    [dltotal] => 0
    [dlnow] => 21
    [ultotal] => 0
    [ulnow] => 0
)

...

Array
(
    [dltotal] => 0
    [dlnow] => 76
    [ultotal] => 0
    [ulnow] => 0
)
Array
(
    [dltotal] => 0
    [dlnow] => 725
    [ultotal] => 0
    [ulnow] => 0
)

...