43 lines
1.3 KiB
Lua
43 lines
1.3 KiB
Lua
local pcm = {}
|
|
|
|
-- Reads a file containing signed 8-bit PCM audio data, and converts it into a list of buffers to play.
|
|
function pcm.readFile(filename)
|
|
if not fs.exists(filename) then error("Audio file " .. filename .. " doesn't exist.") end
|
|
if fs.isDir(filename) then error("Cannot read audio from directory: " .. filename) end
|
|
local frames = {}
|
|
local currentFrame = {}
|
|
local currentFrameSampleCount = 0
|
|
local file = fs.open(filename, "rb")
|
|
while true do
|
|
local n = file.read()
|
|
if n == nil then break end
|
|
if n > 127 then n = n - 256 end
|
|
table.insert(currentFrame, n)
|
|
currentFrameSampleCount = currentFrameSampleCount + 1
|
|
if currentFrameSampleCount == (128 * 1024) then
|
|
table.insert(frames, currentFrame)
|
|
currentFrame = {}
|
|
currentFrameSampleCount = 0
|
|
end
|
|
end
|
|
file.close()
|
|
if currentFrameSampleCount > 0 then
|
|
table.insert(frames, currentFrame)
|
|
end
|
|
return frames
|
|
end
|
|
|
|
function pcm.playFrames(speaker, frames)
|
|
for i = 1, #frames do
|
|
while not speaker.playAudio(frames[i]) do
|
|
os.pullEvent("speaker_audio_empty")
|
|
end
|
|
end
|
|
end
|
|
|
|
function pcm.playFile(speaker, filename)
|
|
local frames = pcm.readFile(filename)
|
|
pcm.playFrames(frames)
|
|
end
|
|
|
|
return pcm |