When I run following code:
$json2=json_decode($output, true);
echo "<pre>";
echo json_encode($json2, JSON_PRETTY_PRINT);
echo "</pre>";
I get output as following:
[
    {
        "stream": "live\/cm1",
        "size": 1120438999,
        "duration": 16233,
        "periods": 7,
        "path": "\/var\/cache\/nimble\/dvr\/live\/cm1",
        "space_available": 212516282368,
        "vcodec": "avc1.4d001f",
        "resolution": "1280x720",
        "bandwidth": 552176,
        "timeline": [
            {
                "start": 1477757618,
                "duration": 535
            },
            {
                "start": 1477758226,
                "duration": 703
            },
            {
                "start": 1477760431,
                "duration": 14295
            },
            {
                "start": 1477829472,
                "duration": 559
            },
            {
                "start": 1477879433,
                "duration": 40
            },
            {
                "start": 1477881429,
                "duration": 79
            },
            {
                "start": 1477881925,
                "duration": 22
            }
        ]
    },
    {
        "stream": "live\/cm10",
        "size": 1790211828,
        "duration": 33976,
        "periods": 23,
        "path": "\/var\/cache\/nimble\/dvr\/live\/cm10",
        "space_available": 212516282368,
        "vcodec": "avc1.4d001f",
        "resolution": "1280x720",
        "bandwidth": 421520,
        "timeline": [
            {
                "start": 1477757606,
                "duration": 193
            },
            {
                "start": 1477757817,
                "duration": 336
            },
            {
                "start": 1477758226,
                "duration": 703
            },
            {
                "start": 1477759027,
                "duration": 1378
            },
            {
                "start": 1477760460,
                "duration": 14273
            },
            {
                "start": 1477829464,
                "duration": 1235
            },
            {
                "start": 1477878029,
                "duration": 469
            },
            {
                "start": 1477882600,
                "duration": 1260
            },
            {
                "start": 1477883914,
                "duration": 208
            },
            {
                "start": 1477911214,
                "duration": 1528
            },
            {
                "start": 1477913185,
                "duration": 185
            },
            {
                "start": 1477913546,
                "duration": 759
            },
            {
                "start": 1477915819,
                "duration": 68
            },
            {
                "start": 1478782219,
                "duration": 69
            },
            {
                "start": 1478782375,
                "duration": 76
            },
            {
                "start": 1478812920,
                "duration": 659
            },
            {
                "start": 1478911726,
                "duration": 2334
            },
            {
                "start": 1478914138,
                "duration": 5
            },
            {
                "start": 1478914233,
                "duration": 2872
            },
            {
                "start": 1478917165,
                "duration": 1133
            },
            {
                "start": 1478976623,
                "duration": 224
            },
            {
                "start": 1478981537,
                "duration": 3658
            },
            {
                "start": 1479065575,
                "duration": 351
            }
        ]
    },
    {
        "stream": "live\/cm2",
        "size": 1320002727,
        "duration": 20809,
        "periods": 13,
...........
}]
The question I have is how do I access various elements here including how many total sets are there and in each set access a particular object.
Thanks for your help in advance.