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Audio

music​

music(N, [FADE_LEN], [CHANNEL_MASK])

Play music starting from pattern N (0..63)

  • N = 0-63, Play from music template N
  • N = -1, stop

FADE_LEN: transition time (ms) (default: 0).

Example: Play from template 0, transition time 1 second.

music(0, 1000)

CHANNEL_MASK: Define the channels reserved for music (bit mode).

Example, only play on channels 0-2:

music(0, nil, 7) -- 1 | 2 | 4

If the command to play the sound effect specifies a channel to use, the sound effect ignores the reserved option, and if no channel is specified, the reserved channel will not be used.

sfx​

sfx(N, [CHANNEL], [OFFSET], [LENGTH])

Play the sound effect N on the specified channel (CHANNEL), OFFSET is the data offset point of the sound effect, and LENGTH is the data length.

CHANNEL special value:

  • CHANNEL -1: (default) automatically select an unused channel.
  • CHANNEL -2: Pause all sound effects.

N special value:

  • N -1: Stop the sound effect of the specified channel.
  • N -2: Stop the sound effect loop of the specified channel.
sfx(3)    -- play sound effect 3
sfx(3,2)  -- play sound effect 3, use channel 2
sfx(3,-2) -- notify all channels of the sound effect 3
sfx(-1,2) -- stop sound effects on channel 2
sfx(-2,2) -- stop sound effects looping on channel 2
sfx(-1)   -- stop all sound effects
sfx(-2)   -- exit all sound loops

wave​

wave(data, [from, to, audiotype])

Play pcm audio data directly, the audio needs to meet the device specification 22050hz, 16bit little format.

data has a special meaning when it is a special value:

  • wave('I') -- initialization (apply for internal resources)
  • wave('R') -- reset data buffer
  • wave('D') -- release resources
  • wave('L') -- returns remaining buffer size
  • wave() -- returns remaining buffer size

audiotype indicates the audio type, the default is PCM.

  • 1 : adpcm
  • 2 : G711a
coloX-4
version 1
__lua__

local wavefile={
#blob :ea:22050: canon.pcm
}

local curpos=0
wave('I')
function _update()
    if wave()>22050 then
        curpos=curpos+1
        local c=wavefile[curpos]
        if c then
            wave(c,nil,nil,1)
        else
            curpos=0
        end
    end
end
function _draw()
    cls(dark_green)
end

micpoll [version>=7]​

micpoll([flag,maxlen, audiotype])

get mic data. 22050hz, 16bit little. need open mic on sys setting.

flag :

  • 1 -- clear buffer
  • 2 -- get valid data length(16bit)
  • 3 -- get data, maxlen to limit the max return data length(16bit)
  • 4 -- get fft info, return: avg,maxidx,maxval,[ffts]. for ffts, maxlen means how many seq points will be return. 0 means no need ffts data ,1 means return fft[0] data,n(n>1) means return table include n seq data

audiotype indicates the audio type, the default is PCM.

  • 1 : adpcm
  • 2 : G711a
coloX-4
version 1
__lua__

wave('I')
micpoll(1)
function _update()
    local d=micpoll(nil,nil,1)
    if d then
        wave(d,nil,nil,1)
    end
end
function _draw()
    cls(dark_green)
end