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Diffstat (limited to 'src/pcm/Traits.hxx')
| -rw-r--r-- | src/pcm/Traits.hxx | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/pcm/Traits.hxx b/src/pcm/Traits.hxx new file mode 100644 index 000000000..97259ac73 --- /dev/null +++ b/src/pcm/Traits.hxx @@ -0,0 +1,153 @@ +/* + * Copyright (C) 2003-2014 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef MPD_PCM_TRAITS_HXX +#define MPD_PCM_TRAITS_HXX + +#include "check.h" +#include "AudioFormat.hxx" + +#include <stdint.h> +#include <stddef.h> + +/** + * This template describes the specified #SampleFormat. This is an + * empty prototype; the specializations contain the real definitions. + * See SampleTraits<uint8_t> for more documentation. + */ +template<SampleFormat F> +struct SampleTraits {}; + +template<> +struct SampleTraits<SampleFormat::S8> { + /** + * The type used for one sample value. + */ + typedef int8_t value_type; + + /** + * A writable pointer. + */ + typedef value_type *pointer_type; + + /** + * A read-only pointer. + */ + typedef const value_type *const_pointer_type; + + /** + * A "long" type that is large and accurate enough for adding + * two values without risking an (integer) overflow or + * (floating point) precision loss. + */ + typedef int sum_type; + + /** + * A "long" type that is large and accurate enough for + * arithmetic without risking an (integer) overflow or + * (floating point) precision loss. + */ + typedef int_least32_t long_type; + + /** + * The size of one sample in bytes. + */ + static constexpr size_t SAMPLE_SIZE = sizeof(value_type); + + /** + * The integer bit depth of one sample. This attribute may + * not exist if this is not an integer sample format. + */ + static constexpr unsigned BITS = sizeof(value_type) * 8; + + /** + * The minimum sample value. + */ + static constexpr value_type MIN = -(sum_type(1) << (BITS - 1)); + + /** + * The maximum sample value. + */ + static constexpr value_type MAX = (sum_type(1) << (BITS - 1)) - 1; +}; + +template<> +struct SampleTraits<SampleFormat::S16> { + typedef int16_t value_type; + typedef value_type *pointer_type; + typedef const value_type *const_pointer_type; + + typedef int_least32_t sum_type; + typedef int_least32_t long_type; + + static constexpr size_t SAMPLE_SIZE = sizeof(value_type); + static constexpr unsigned BITS = sizeof(value_type) * 8; + + static constexpr value_type MIN = -(sum_type(1) << (BITS - 1)); + static constexpr value_type MAX = (sum_type(1) << (BITS - 1)) - 1; +}; + +template<> +struct SampleTraits<SampleFormat::S32> { + typedef int32_t value_type; + typedef value_type *pointer_type; + typedef const value_type *const_pointer_type; + + typedef int_least64_t sum_type; + typedef int_least64_t long_type; + + static constexpr size_t SAMPLE_SIZE = sizeof(value_type); + static constexpr unsigned BITS = sizeof(value_type) * 8; + + static constexpr value_type MIN = -(sum_type(1) << (BITS - 1)); + static constexpr value_type MAX = (sum_type(1) << (BITS - 1)) - 1; +}; + +template<> +struct SampleTraits<SampleFormat::S24_P32> { + typedef int32_t value_type; + typedef value_type *pointer_type; + typedef const value_type *const_pointer_type; + + typedef int_least32_t sum_type; + typedef int_least64_t long_type; + + static constexpr size_t SAMPLE_SIZE = sizeof(value_type); + static constexpr unsigned BITS = 24; + + static constexpr value_type MIN = -(sum_type(1) << (BITS - 1)); + static constexpr value_type MAX = (sum_type(1) << (BITS - 1)) - 1; +}; + +template<> +struct SampleTraits<SampleFormat::FLOAT> { + typedef float value_type; + typedef value_type *pointer_type; + typedef const value_type *const_pointer_type; + + typedef float sum_type; + typedef float long_type; + + static constexpr size_t SAMPLE_SIZE = sizeof(value_type); + + static constexpr value_type MIN = -1; + static constexpr value_type MAX = 1; +}; + +#endif |