added Stream.save() and SndfileStream based on FFI wrapper around libsndfile

1 files changed, 197 insertions, 0 deletions

diff --git a/sndfile.lua b/sndfile.lua
new file mode 100644
index 0000000..263893d
--- /dev/null
+++ b/sndfile.lua
@@ -0,0 +1,197 @@
+-- module table
+local sndfile = {}
+
+local ffi = require "ffi"
+
+ffi.cdef[[
+typedef struct SNDFILE_tag SNDFILE;
+
+typedef int64_t sf_count_t;
+
+typedef enum SF_FORMAT {	/* Major formats. */
+	SF_FORMAT_WAV			= 0x010000,		/* Microsoft WAV format (little endian default). */
+	SF_FORMAT_AIFF			= 0x020000,		/* Apple/SGI AIFF format (big endian). */
+	SF_FORMAT_AU			= 0x030000,		/* Sun/NeXT AU format (big endian). */
+	SF_FORMAT_RAW			= 0x040000,		/* RAW PCM data. */
+	SF_FORMAT_PAF			= 0x050000,		/* Ensoniq PARIS file format. */
+	SF_FORMAT_SVX			= 0x060000,		/* Amiga IFF / SVX8 / SV16 format. */
+	SF_FORMAT_NIST			= 0x070000,		/* Sphere NIST format. */
+	SF_FORMAT_VOC			= 0x080000,		/* VOC files. */
+	SF_FORMAT_IRCAM			= 0x0A0000,		/* Berkeley/IRCAM/CARL */
+	SF_FORMAT_W64			= 0x0B0000,		/* Sonic Foundry's 64 bit RIFF/WAV */
+	SF_FORMAT_MAT4			= 0x0C0000,		/* Matlab (tm) V4.2 / GNU Octave 2.0 */
+	SF_FORMAT_MAT5			= 0x0D0000,		/* Matlab (tm) V5.0 / GNU Octave 2.1 */
+	SF_FORMAT_PVF			= 0x0E0000,		/* Portable Voice Format */
+	SF_FORMAT_XI			= 0x0F0000,		/* Fasttracker 2 Extended Instrument */
+	SF_FORMAT_HTK			= 0x100000,		/* HMM Tool Kit format */
+	SF_FORMAT_SDS			= 0x110000,		/* Midi Sample Dump Standard */
+	SF_FORMAT_AVR			= 0x120000,		/* Audio Visual Research */
+	SF_FORMAT_WAVEX			= 0x130000,		/* MS WAVE with WAVEFORMATEX */
+	SF_FORMAT_SD2			= 0x160000,		/* Sound Designer 2 */
+	SF_FORMAT_FLAC			= 0x170000,		/* FLAC lossless file format */
+	SF_FORMAT_CAF			= 0x180000,		/* Core Audio File format */
+	SF_FORMAT_WVE			= 0x190000,		/* Psion WVE format */
+	SF_FORMAT_OGG			= 0x200000,		/* Xiph OGG container */
+	SF_FORMAT_MPC2K			= 0x210000,		/* Akai MPC 2000 sampler */
+	SF_FORMAT_RF64			= 0x220000,		/* RF64 WAV file */
+
+	/* Subtypes from here on. */
+
+	SF_FORMAT_PCM_S8		= 0x0001,		/* Signed 8 bit data */
+	SF_FORMAT_PCM_16		= 0x0002,		/* Signed 16 bit data */
+	SF_FORMAT_PCM_24		= 0x0003,		/* Signed 24 bit data */
+	SF_FORMAT_PCM_32		= 0x0004,		/* Signed 32 bit data */
+
+	SF_FORMAT_PCM_U8		= 0x0005,		/* Unsigned 8 bit data (WAV and RAW only) */
+
+	SF_FORMAT_FLOAT			= 0x0006,		/* 32 bit float data */
+	SF_FORMAT_DOUBLE		= 0x0007,		/* 64 bit float data */
+
+	SF_FORMAT_ULAW			= 0x0010,		/* U-Law encoded. */
+	SF_FORMAT_ALAW			= 0x0011,		/* A-Law encoded. */
+	SF_FORMAT_IMA_ADPCM		= 0x0012,		/* IMA ADPCM. */
+	SF_FORMAT_MS_ADPCM		= 0x0013,		/* Microsoft ADPCM. */
+
+	SF_FORMAT_GSM610		= 0x0020,		/* GSM 6.10 encoding. */
+	SF_FORMAT_VOX_ADPCM		= 0x0021,		/* OKI / Dialogix ADPCM */
+
+	SF_FORMAT_G721_32		= 0x0030,		/* 32kbs G721 ADPCM encoding. */
+	SF_FORMAT_G723_24		= 0x0031,		/* 24kbs G723 ADPCM encoding. */
+	SF_FORMAT_G723_40		= 0x0032,		/* 40kbs G723 ADPCM encoding. */
+
+	SF_FORMAT_DWVW_12		= 0x0040, 		/* 12 bit Delta Width Variable Word encoding. */
+	SF_FORMAT_DWVW_16		= 0x0041, 		/* 16 bit Delta Width Variable Word encoding. */
+	SF_FORMAT_DWVW_24		= 0x0042, 		/* 24 bit Delta Width Variable Word encoding. */
+	SF_FORMAT_DWVW_N		= 0x0043, 		/* N bit Delta Width Variable Word encoding. */
+
+	SF_FORMAT_DPCM_8		= 0x0050,		/* 8 bit differential PCM (XI only) */
+	SF_FORMAT_DPCM_16		= 0x0051,		/* 16 bit differential PCM (XI only) */
+
+	SF_FORMAT_VORBIS		= 0x0060,		/* Xiph Vorbis encoding. */
+
+	/* Endian-ness options. */
+
+	SF_ENDIAN_FILE			= 0x00000000,	/* Default file endian-ness. */
+	SF_ENDIAN_LITTLE		= 0x10000000,	/* Force little endian-ness. */
+	SF_ENDIAN_BIG			= 0x20000000,	/* Force big endian-ness. */
+	SF_ENDIAN_CPU			= 0x30000000,	/* Force CPU endian-ness. */
+
+	SF_FORMAT_SUBMASK		= 0x0000FFFF,
+	SF_FORMAT_TYPEMASK		= 0x0FFF0000,
+	SF_FORMAT_ENDMASK		= 0x30000000
+} SF_FORMAT;
+
+typedef struct SF_INFO {
+	sf_count_t      frames;                /* Used to be called samples.  Changed to avoid confusion. */
+	int             samplerate;
+	int             channels;
+	int             format;
+	int             sections;
+	int             seekable;
+} SF_INFO;
+
+typedef struct {
+	int             format;
+	const char      *name;
+	const char      *extension;
+} SF_FORMAT_INFO;
+
+/* The enum was not named in the sndfile.h */
+typedef enum SF_MODE {
+        /* Modes for opening files. */
+        SFM_READ        = 0x10,
+        SFM_WRITE       = 0x20,
+        SFM_RDWR        = 0x30
+} SF_MODE;
+
+SNDFILE* sf_open(const char *path, int mode, SF_INFO *sfinfo);
+const char* sf_strerror(SNDFILE *sndfile);
+
+int sf_command(SNDFILE *sndfile, int command, void *data, int datasize);
+
+sf_count_t sf_read_double(SNDFILE *sndfile, double *ptr, sf_count_t items) ;
+sf_count_t sf_write_double(SNDFILE *sndfile, const double *ptr, sf_count_t items);
+
+int sf_close(SNDFILE *sndfile);
+]]
+
+local lib = ffi.load("sndfile")
+
+local double_type = ffi.typeof("double[?]")
+
+-- This can be reused in sndfile:read() and sndfile:write()
+-- to avoid allocations.
+local double_buffer = double_type(1)
+
+-- NOTE: Constants are also in ffi.C
+sndfile.SF_FORMAT = ffi.typeof("SF_FORMAT")
+
+-- FIXME: Maybe fall back to sf_command(SFC_GET_SIMPLE_FORMAT)
+-- for unknown extensions. The simple formats are not always
+-- ideal. 
+function sndfile.guess_format(filename)
+	local ext2format = {
+		raw = ffi.C.SF_FORMAT_RAW + ffi.C.SF_FORMAT_DOUBLE,
+		wav = ffi.C.SF_FORMAT_WAV + ffi.C.SF_FORMAT_FLOAT,
+		xi = ffi.C.SF_FORMAT_XI + ffi.C.SF_FORMAT_DPCM_16,
+		flac = ffi.C.SF_FORMAT_FLAC + ffi.C.SF_FORMAT_PCM_24,
+		ogg = ffi.C.SF_FORMAT_OGG + ffi.C.SF_FORMAT_DOUBLE
+	}
+
+	local ext = filename:match("%.(.+)$")
+
+	-- assume raw format for missing extensions
+	local format = ext2format[ext and ext:lower() or "raw"]
+	if not format then error("Unknown extension \""..ext.."\"") end
+
+	return format
+end
+
+function sndfile:new(path, mode, samplerate, channels, format)
+	local obj = {}
+
+	local info = ffi.new("SF_INFO[1]")
+
+	if mode ~= "SFM_READ" then
+		info[0].samplerate = samplerate or 44100
+		info[0].channels = channels or 1
+		info[0].format = format or sndfile.guess_format(path)
+	end
+
+	obj.handle = lib.sf_open(path, ffi.new("SF_MODE", mode), info)
+	if obj.handle == nil then
+		error(ffi.string(lib.sf_strerror(nil)))
+	end
+
+	obj.info = info[0]
+
+	-- NOTE: FFI also allows metatables and finalizers
+	-- to be set on the C-type itself.
+	setmetatable(obj, {
+		__index = self,
+		__gc = sndfile.close
+	})
+
+	return obj
+end
+
+-- TODO: Maybe support reading multiple samples at once.
+function sndfile:read()
+	return lib.sf_read_double(self.handle, double_buffer, 1) == 1 and
+	       tonumber(double_buffer[0]) or nil
+end
+
+-- TODO: Maybe support writing multiple samples at once
+function sndfile:write(sample)
+	double_buffer[0] = sample
+	return lib.sf_write_double(self.handle, double_buffer, 1)
+end
+
+function sndfile:close()
+	if self.handle then
+		lib.sf_close(self.handle)
+		self.handle = nil
+	end
+end
+
+return sndfile