+ local wav = {
+ --[[
+ Writes audio file in WAVE format with PCM integer samples.
+
+ Function 'create_context' requires a filename and returns a table with the
+ following methods:
+ - init(channels_number, sample_rate, bits_per_sample)
+ - write_samples_interlaced(samples)
+ - finish()
+
+ (WAVE format: https://ccrma.stanford.edu/courses/422/projects/WaveFormat/)
+ ]]
+ --[[
+ Copyright © 2014, Christoph "Youka" Spanknebel
+ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ ]]
+ create_context = function(filename)
+ -- Check function parameters
+ if type(filename) ~= "string" then
+ error("invalid function parameter, expected string filename", 2)
+ end
+ local absolute_path = love.filesystem.getSaveDirectory()..'/'..filename
+ -- ensure directory exists
+ love.filesystem.write(absolute_path, '')
+ -- Audio file handle
+ local file = io.open(absolute_path, "wb")
+ if not file then
+ error(string.format("couldn't open file %q", filename), 2)
+ end
+ -- Byte-string(unsigned integer,little endian)<-Lua-number converter
+ local function ntob(n, len)
+ local n, bytes = math.max(math.floor(n), 0), {}
+ for i=1, len do
+ bytes[i] = n % 256
+ n = math.floor(n / 256)
+ end
+ return string.char(unpack(bytes))
+ end
+ -- Check for integer
+ local function isint(n)
+ return type(n) == "number" and n == math.floor(n)
+ end
+ -- Audio meta informations
+ local channels_number_private, bytes_per_sample
+ -- Return audio handler
+ return {
+ init = function(channels_number, sample_rate, bits_per_sample)
+ -- Check function parameters
+ if not isint(channels_number) or channels_number < 1 or
+ not isint(sample_rate) or sample_rate < 2 or
+ not (bits_per_sample == 8 or bits_per_sample == 16 or bits_per_sample == 24 or bits_per_sample == 32) then
+ error("valid channels number, sample rate and bits per sample expected", 2)
+ end
+ -- Write file type
+ file:write("RIFF????WAVE") -- file size to insert later
+ -- Write format chunk
+ file:write("fmt ",
+ ntob(16, 4),
+ ntob(1, 2),
+ ntob(channels_number, 2),
+ ntob(sample_rate, 4),
+ ntob(sample_rate * channels_number * (bits_per_sample / 8), 4),
+ ntob(channels_number * (bits_per_sample / 8), 2),
+ ntob(bits_per_sample, 2))
+ -- Write data chunk (so far)
+ file:write("data????") -- data size to insert later
+ -- Set format memory
+ channels_number_private, bytes_per_sample = channels_number, bits_per_sample / 8
+ end,
+ write_samples_interlaced = function(samples)
+ -- Check function parameters
+ if type(samples) ~= "table" then
+ error("samples table expected", 2)
+ end
+ local samples_n = #samples
+ if samples_n == 0 or samples_n % channels_number_private ~= 0 then
+ error("valid number of samples expected (multiple of channels)", 2)
+ -- Already finished?
+ elseif not file then
+ error("already finished", 2)
+ -- Already initialized?
+ elseif file:seek() == 0 then
+ error("initialize before writing samples", 2)
+ end
+ -- All samples are numbers?
+ for i=1, samples_n do
+ if type(samples[i]) ~= "number" then
+ error("samples have to be numbers", 2)
+ end
+ end
+ -- Write samples to file
+ local sample
+ if bytes_per_sample == 1 then
+ for i=1, samples_n do
+ sample = samples[i]
+ file:write(ntob(sample < 0 and sample + 256 or sample, 1))
+ end
+ elseif bytes_per_sample == 2 then
+ for i=1, samples_n do
+ sample = samples[i]
+ file:write(ntob(sample < 0 and sample + 65536 or sample, 2))
+ end
+ elseif bytes_per_sample == 3 then
+ for i=1, samples_n do
+ sample = samples[i]
+ file:write(ntob(sample < 0 and sample + 16777216 or sample, 3))
+ end
+ else -- if bytes_per_sample == 4 then
+ for i=1, samples_n do
+ sample = samples[i]
+ file:write(ntob(sample < 0 and sample + 4294967296 or sample, 4))
+ end
+ end
+ end,
+ finish = function()
+ -- Already finished?
+ if not file then
+ error("already finished", 2)
+ -- Already initialized?
+ elseif file:seek() == 0 then
+ error("initialize before finishing", 2)
+ end
+ -- Get file size
+ local file_size = file:seek()
+ -- Save file size
+ file:seek("set", 4)
+ file:write(ntob(file_size - 8, 4))
+ -- Save data size
+ file:seek("set", 40)
+ file:write(ntob(file_size - 44, 4))
+ -- Finalize file for secure reading
+ file:close()
+ file = nil
+ end
+ }
+ end,
+ }
+
+ function save_wav(filename, sounddata)
+ -- credit to Intas and zorg on the LÖVE forum <3
+ -- https://love2d.org/forums/viewtopic.php?t=86173
+ local samples = {}
+ for i = 0, sounddata:getSampleCount() - 1 do
+ local sample = sounddata:getSample(i)
+ local n
+ local to16bit = sample * 32767
+ if (to16bit > 0) then
+ n = math.floor(math.min(to16bit, 32767))
+ else
+ n = math.floor(math.max(to16bit, -32768))
+ end
+ table.insert(samples, n)
+ end
+ local w = wav.create_context(filename, "w")
+ w.init(sounddata:getChannelCount(), sounddata:getSampleRate(), sounddata:getBitDepth())
+ w.write_samples_interlaced(samples)
+ w.finish()
+ end