M2: Ambiguities in the standard

[mcamardon]

We have some keys (dl, bl or mtp) that are reported with a value equal to zero. We discoverd this in videojs and dash players.

AC:

1. Investigate if the value is zero or is something wrong with the player
2. Ask to CMCD's team if this has sense.

[mcamardon]

After some investigation, I created an issue in the cmcd repository asking for clarification on this. The issue is cta-wave/common-media-client-data#100.

[mcamardon]

We got a response to the issue we created on the cmcd repository. I'll leave a brief summary for each key:

• bl: It is possible to sent it with 0. However it is incorrect to use a value of 0 if the buffer length is unknown.
• mtp: It should not be possible to send it as 0. A value of 0 does not make sense since it should report what what the player measured and any measurement is going to have some non-zero value associated with it.
• dl: A deadline of 0 would mean that you need the object instantly (versus an infinite waiting time). It is legal to send a value of 0, however this is impossible for the server to fulfil and it would likely ignore that key as a result.
• rtp: It can be sent with a value of 0. This would be self-destructive for the player and it would be silly to send it, but it is legal. The server would likely consider it nonsensical and ignore it.