<?php
$json = '{"meta": [
    "rectime",
    "strid",
    "ambt",
    "stri",
    "b1",
    "b2",
    "b3",
    "b4"
],
"data": [
    [
        1377597739,
        1,
        0,
        77,
        816,
        13791,
        13794,
        13945
    ],
    [
        1377597739,
        2,
        0,
        0,
        816,
        13744,
        13725,
        13898
    ]
]}';

$array = json_decode($json, true);

print_r($array);

Array
(
    [meta] => Array
        (
            [0] => rectime
            [1] => strid
            [2] => ambt
            [3] => stri
            [4] => b1
            [5] => b2
            [6] => b3
            [7] => b4
        )

    [data] => Array
        (
            [0] => Array
                (
                    [0] => 1377597739
                    [1] => 1
                    [2] => 0
                    [3] => 77
                    [4] => 816
                    [5] => 13791
                    [6] => 13794
                    [7] => 13945
                )

            [1] => Array
                (
                    [0] => 1377597739
                    [1] => 2
                    [2] => 0
                    [3] => 0
                    [4] => 816
                    [5] => 13744
                    [6] => 13725
                    [7] => 13898
                )

        )

)