Add sample speed informatin to OnUserSpeak() hook about lua-mumble

[bkacjios]

You could always calculate the delay between each packet by doing something like this.

client:hook("OnUserStartSpeaking", function(client, user)
	user.last_spoke = mumble.gettime()
end)

client:hook("OnUserSpeak", function(client, event)
	local t = mumble.gettime()

	local user = event.user

	-- Round to nearest tenth
	local delay = math.floor((t - user.last_spoke) * 100 + 0.5) / 100
	-- delay = time between each packet

	user.speech_delay = delay
	user.last_spoke = t
end)

client:hook("OnUserStopSpeaking", function(client, user)
	print("User spoke with a delay of", user.speech_delay)
end)

[bkacjios]

Hey, so I also just pushed a commit to fix a bug where OnUserStartSpeaking and OnUserStopSpeaking could potentially not be called if the user only sent 1 frame of audio data. This can happen if a user presses their push to talk button really fast.

Also, for calculating the delay, it may be better to use the highest delay value during the transmission.

client:hook("OnUserStartSpeaking", function(client, user)
	user.last_spoke = mumble.gettime()
	user.speech_delay = 0
end)

client:hook("OnUserSpeak", function(client, event)
	local t = mumble.gettime()

	local user = event.user

	-- Round to nearest tenth
	local delay = math.floor((t - user.last_spoke) * 100 + 0.5) / 100
	-- delay = time between each packet

	if delay > user.speech_delay then
		-- Only update the delay value when it's higher than the last value
		user.speech_delay
	end

	user.last_spoke = t
end)

client:hook("OnUserStopSpeaking", function(client, user)
	print("User spoke with a delay of", user.speech_delay)
end)

I found that sometimes the delay can be sometimes be low on the last transmitted frame, which is perfectly fine, but could cause your value to be lower than it should.

[bkacjios]

There's not a real easy way to do this. The client just accepts the voice packets as they come, so it doesn't actually know the rate in which they are received.

[hbeni]

Very recently, in the plugins WIP branch, an addition was made that exposes this information:
mumble-voip/mumble@41244d7

So, somewhere it must be hidden... Sorry that i have not much more information :(

[bkacjios]

Sample rate is not the same as the time between each packet. Sample rate is the quality of the audio.

Actually I'm dumb. I haven't been messing with this mumble stuff for a bit. Even still, there's no way for me to tell what the sample rate is just from the voice packets it receives alone. There has to be more to that commit you linked, because the information has to come from somewhere.

[bkacjios]

From what I can tell, they end up passing SAMPLE_RATE define to those calls, which is defined as 48000, so I don't think that value even helps you here either.

https://github.com/mumble-voip/mumble/blob/41244d7df41651876033e227d8ef625bf38ca839/src/mumble/AudioOutput.cpp#L530
https://github.com/mumble-voip/mumble/blob/3d7f8cc4e5f502652f6660822eb791cec79a61f7/src/mumble/Audio.h#L18

[hbeni]

so I don't think that value even helps you here either.

I hoped there would be some magic formula to calculate the spacing... and unfortunately, i have no clue about PCM and audio sampling :(

[hbeni]

I will try that soon, thank you very much!

[hbeni]

Cool, thanks!!!

[hbeni]

Just for the archives, it works.

I however record all seen delays into an array and then take the average from that to smooth out possible excess values. The result gets rounded to the nearest tenth like coded above. That seems to work very reliably.

https://github.com/hbeni/fgcom-mumble/blob/d779699b3a81ec712ea2d23e7507fbcc6e858c2e/server/fgcom-radio-recorder.bot.lua#L312

        -- record timings between voice packets to determine the sampling speed
        local time  = mumble.getTime()
        local delay = time - (remote.last_spoke or time)
        remote.last_spoke = time
        if delay > 0 then
            if not remote.record_delay then
                remote.record_delay = {delay}
            else
                remote.record_delay[#(remote.record_delay)+1] = delay
            end
        end

https://github.com/hbeni/fgcom-mumble/blob/d779699b3a81ec712ea2d23e7507fbcc6e858c2e/server/fgcom-radio-recorder.bot.lua#L388

                -- calculate the packet speed
                local calculated_packet_speed = 0.02   -- mumbles default setting
                if #(remote.record_delay) > 0 then
                    calculated_packet_speed       = math.average(remote.record_delay)
                    calculated_packet_speed       = math.floor(calculated_packet_speed * 100 + 0.5) / 100   -- round to nearest tenth
                end
                fgcom.dbg("calculated packet per audio: "..calculated_packet_speed)