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Diffstat (limited to 'mpg123.32/include/fmt123.h')
| -rw-r--r-- | mpg123.32/include/fmt123.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/mpg123.32/include/fmt123.h b/mpg123.32/include/fmt123.h new file mode 100644 index 00000000..dcabf5e0 --- /dev/null +++ b/mpg123.32/include/fmt123.h @@ -0,0 +1,159 @@ +/* + libmpg123: MPEG Audio Decoder library + + separate header just for audio format definitions not tied to + library code + + copyright 1995-2020 by the mpg123 project + free software under the terms of the LGPL 2.1 + see COPYING and AUTHORS files in distribution or http://mpg123.org +*/ + +#ifndef MPG123_ENC_H +#define MPG123_ENC_H + +/** \file fmt123.h Audio format definitions. */ + +/** \defgroup mpg123_enc mpg123 PCM sample encodings + * These are definitions for audio formats used by libmpg123 and + * libout123. + * + * @{ + */ + +/** An enum over all sample types possibly known to mpg123. + * The values are designed as bit flags to allow bitmasking for encoding + * families. + * This is also why the enum is not used as type for actual encoding variables, + * plain integers (at least 16 bit, 15 bit being used) cover the possible + * combinations of these flags. + * + * Note that (your build of) libmpg123 does not necessarily support all these. + * Usually, you can expect the 8bit encodings and signed 16 bit. + * Also 32bit float will be usual beginning with mpg123-1.7.0 . + * What you should bear in mind is that (SSE, etc) optimized routines may be + * absent for some formats. We do have SSE for 16, 32 bit and float, though. + * 24 bit integer is done via postprocessing of 32 bit output -- just cutting + * the last byte, no rounding, even. If you want better, do it yourself. + * + * All formats are in native byte order. If you need different endinaness, you + * can simply postprocess the output buffers (libmpg123 wouldn't do anything + * else). The macro MPG123_SAMPLESIZE() can be helpful there. + */ +enum mpg123_enc_enum +{ +/* 0000 0000 0000 1111 Some 8 bit integer encoding. */ + MPG123_ENC_8 = 0x00f +/* 0000 0000 0100 0000 Some 16 bit integer encoding. */ +, MPG123_ENC_16 = 0x040 +/* 0100 0000 0000 0000 Some 24 bit integer encoding. */ +, MPG123_ENC_24 = 0x4000 +/* 0000 0001 0000 0000 Some 32 bit integer encoding. */ +, MPG123_ENC_32 = 0x100 +/* 0000 0000 1000 0000 Some signed integer encoding. */ +, MPG123_ENC_SIGNED = 0x080 +/* 0000 1110 0000 0000 Some float encoding. */ +, MPG123_ENC_FLOAT = 0xe00 +/* 0000 0000 1101 0000 signed 16 bit */ +, MPG123_ENC_SIGNED_16 = (MPG123_ENC_16|MPG123_ENC_SIGNED|0x10) +/* 0000 0000 0110 0000 unsigned 16 bit */ +, MPG123_ENC_UNSIGNED_16 = (MPG123_ENC_16|0x20) +/* 0000 0000 0000 0001 unsigned 8 bit */ +, MPG123_ENC_UNSIGNED_8 = 0x01 +/* 0000 0000 1000 0010 signed 8 bit */ +, MPG123_ENC_SIGNED_8 = (MPG123_ENC_SIGNED|0x02) +/* 0000 0000 0000 0100 ulaw 8 bit */ +, MPG123_ENC_ULAW_8 = 0x04 +/* 0000 0000 0000 1000 alaw 8 bit */ +, MPG123_ENC_ALAW_8 = 0x08 +/* 0001 0001 1000 0000 signed 32 bit */ +, MPG123_ENC_SIGNED_32 = MPG123_ENC_32|MPG123_ENC_SIGNED|0x1000 +/* 0010 0001 0000 0000 unsigned 32 bit */ +, MPG123_ENC_UNSIGNED_32 = MPG123_ENC_32|0x2000 +/* 0101 0000 1000 0000 signed 24 bit */ +, MPG123_ENC_SIGNED_24 = MPG123_ENC_24|MPG123_ENC_SIGNED|0x1000 +/* 0110 0000 0000 0000 unsigned 24 bit */ +, MPG123_ENC_UNSIGNED_24 = MPG123_ENC_24|0x2000 +/* 0000 0010 0000 0000 32bit float */ +, MPG123_ENC_FLOAT_32 = 0x200 +/* 0000 0100 0000 0000 64bit float */ +, MPG123_ENC_FLOAT_64 = 0x400 +/* Any possibly known encoding from the list above. */ +, MPG123_ENC_ANY = ( MPG123_ENC_SIGNED_16 | MPG123_ENC_UNSIGNED_16 + | MPG123_ENC_UNSIGNED_8 | MPG123_ENC_SIGNED_8 + | MPG123_ENC_ULAW_8 | MPG123_ENC_ALAW_8 + | MPG123_ENC_SIGNED_32 | MPG123_ENC_UNSIGNED_32 + | MPG123_ENC_SIGNED_24 | MPG123_ENC_UNSIGNED_24 + | MPG123_ENC_FLOAT_32 | MPG123_ENC_FLOAT_64 ) +}; + +/** Get size of one PCM sample with given encoding. + * This is included both in libmpg123 and libout123. Both offer + * an API function to provide the macro results from library + * compile-time, not that of you application. This most likely + * does not matter as I do not expect any fresh PCM sample + * encoding to appear. But who knows? Perhaps the encoding type + * will be abused for funny things in future, not even plain PCM. + * And, by the way: Thomas really likes the ?: operator. + * \param enc the encoding (mpg123_enc_enum value) + * \return size of one sample in bytes + */ +#define MPG123_SAMPLESIZE(enc) ( \ + (enc) < 1 \ + ? 0 \ + : ( (enc) & MPG123_ENC_8 \ + ? 1 \ + : ( (enc) & MPG123_ENC_16 \ + ? 2 \ + : ( (enc) & MPG123_ENC_24 \ + ? 3 \ + : ( ( (enc) & MPG123_ENC_32 \ + || (enc) == MPG123_ENC_FLOAT_32 ) \ + ? 4 \ + : ( (enc) == MPG123_ENC_FLOAT_64 \ + ? 8 \ + : 0 \ +) ) ) ) ) ) + +/** Representation of zero in differing encodings. + * This exists to define proper silence in various encodings without + * having to link to libsyn123 to do actual conversions at runtime. + * You have to handle big/little endian order yourself, though. + * This takes the shortcut that any signed encoding has a zero with + * all-zero bits. Unsigned linear encodings just have the highest bit set + * (2^(n-1) for n bits), while the nonlinear 8-bit ones are special. + * \param enc the encoding (mpg123_enc_enum value) + * \param siz bytes per sample (return value of MPG123_SAMPLESIZE(enc)) + * \param off byte (octet) offset counted from LSB + * \return unsigned byte value for the designated octet + */ +#define MPG123_ZEROSAMPLE(enc, siz, off) ( \ + (enc) == MPG123_ENC_ULAW_8 \ + ? (off == 0 ? 0xff : 0x00) \ + : ( (enc) == MPG123_ENC_ALAW_8 \ + ? (off == 0 ? 0xd5 : 0x00) \ + : ( (((enc) & (MPG123_ENC_SIGNED|MPG123_ENC_FLOAT)) || (siz) != ((off)+1)) \ + ? 0x00 \ + : 0x80 \ + ) ) ) + +/** Structure defining an audio format. + * Providing the members as individual function arguments to define a certain + * output format is easy enough. This struct makes is more comfortable to deal + * with a list of formats. + * Negative values for the members might be used to communicate use of default + * values. + */ +struct mpg123_fmt +{ + long rate; /**< sampling rate in Hz */ + int channels; /**< channel count */ + /** encoding code, can be single value or bitwise or of members of + * mpg123_enc_enum */ + int encoding; +}; + +/* @} */ + +#endif + |