CMCD (Common Media Client Data) is a relatively new specification for player beaconing some of it’s state to the server, usually CDN edge.
There is more details here
In short, it does help CND providers to improve video QoS and user experience
Is there any plans to add CMCD support to Roku device?
So it looks like there is support for a subset of the CMCD spec:
| Buffer Starvation | 0 |
|---|---|
| CMCD Content ID | 3778721911 |
| Measured Throughout | 21.3 Mib/s |
| Streaming Format | d |
| SessionID | PL01-445fba376044727f |
Stream Type |
v |
We actually use that data
Roku has more than this now. It’s all undocumented, but it’s doing a fair bit under the hood.
For a video segment, I got the following headers:
cmcd-session: st=l,sf=d,sid=“PL01-fe2d3b0e367e35cf”,cid=“3778721911”
cmcd-object: ot=v,br=1000,tb=1000,d=1920
cmcd-request: mtp=3400,bl=4600,nor=“scte35-video%3D1000000-1048341040128.dash”
If you want to add your own, you can get the roHttpAgent from the video node and use its addHeader method to add values to these headers. Sadly no way to get those headers that I can find.
