153 lines
3.0 KiB
Lua
153 lines
3.0 KiB
Lua
-- ****************************************************************************
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-- Network streaming example
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--
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-- stream = require("play_network")
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-- stream.init(pin)
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-- stream.play(pcm.RATE_8K, ip, port, "/jump_8k.u8", function () print("stream finished") end)
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--
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-- Playback can be stopped with stream.stop().
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-- And resources are free'd with stream.close().
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--
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local M, module = {}, ...
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_G[module] = M
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local _conn
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local _drv
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local _buf
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local _lower_thresh = 2
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local _upper_thresh = 5
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local _play_cb
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-- ****************************************************************************
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-- PCM
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local function stop_stream(cb)
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_drv:stop()
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if _conn then
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_conn:close()
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_conn = nil
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end
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_buf = nil
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if cb then cb()
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elseif _play_cb then _play_cb()
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end
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_play_cb = nil
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end
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local function cb_drained()
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print("drained "..node.heap())
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stop_stream()
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end
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local function cb_data()
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if #_buf > 0 then
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local data = table.remove(_buf, 1)
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if #_buf <= _lower_thresh then
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-- unthrottle server to get further data into the buffer
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_conn:unhold()
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end
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return data
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end
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end
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local _rate
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local function start_play()
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print("starting playback")
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-- start playback
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_drv:play(_rate)
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end
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-- ****************************************************************************
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-- Networking functions
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--
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local _skip_headers
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local _chunk
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local _buffering
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local function data_received(c, data)
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if _skip_headers then
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-- simple logic to filter the HTTP headers
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_chunk = _chunk..data
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local i, j = string.find(_chunk, '\r\n\r\n')
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if i then
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_skip_headers = false
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data = string.sub(_chunk, j+1, -1)
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_chunk = nil
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end
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end
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if not _skip_headers then
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_buf[#_buf+1] = data
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if #_buf > _upper_thresh then
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-- throttle server to avoid buffer overrun
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c:hold()
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if _buffering then
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-- buffer got filled, start playback
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start_play()
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_buffering = false
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end
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end
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end
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end
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local function cb_disconnected()
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if _buffering then
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-- trigger playback when disconnected but we're still buffering
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start_play()
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_buffering = false
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end
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end
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local _path
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local function cb_connected(c)
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c:send("GET ".._path.." HTTP/1.0\r\nHost: iot.nix.nix\r\n".."Connection: close\r\nAccept: /\r\n\r\n")
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_path = nil
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end
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function M.play(rate, ip, port, path, cb)
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_skip_headers = true
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_chunk = ""
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_buffering = true
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_buf = {}
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_rate = rate
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_path = path
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_play_cb = cb
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_conn = net.createConnection(net.TCP, 0)
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_conn:on("receive", data_received)
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_conn:on("disconnection", cb_disconnected)
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_conn:connect(port, ip, cb_connected)
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end
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function M.stop(cb)
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stop_stream(cb)
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end
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function M.init(pin)
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_drv = pcm.new(pcm.SD, pin)
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-- get called back when all samples were read from stream
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_drv:on("drained", cb_drained)
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_drv:on("data", cb_data)
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--_drv:on("stopped", cb_stopped)
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end
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function M.vu(cb, freq)
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_drv:on("vu", cb, freq)
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end
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function M.close()
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stop_stream()
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_drv:close()
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_drv = nil
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end
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return M
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