/* * Copyright (C) 2003-2009 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_RESAMPLE_H #define MPD_PCM_RESAMPLE_H #include "pcm_buffer.h" #include "config.h" #include <stdint.h> #include <stddef.h> #include <stdbool.h> #ifdef HAVE_LIBSAMPLERATE #include <samplerate.h> #endif /** * This object is statically allocated (within another struct), and * holds buffer allocations and the state for the resampler. */ struct pcm_resample_state { #ifdef HAVE_LIBSAMPLERATE SRC_STATE *state; SRC_DATA data; struct pcm_buffer in, out; struct { unsigned src_rate; unsigned dest_rate; uint8_t channels; } prev; int error; #endif struct pcm_buffer buffer; }; /** * Initializes a pcm_resample_state object. */ void pcm_resample_init(struct pcm_resample_state *state); /** * Deinitializes a pcm_resample_state object and frees allocated * memory. */ void pcm_resample_deinit(struct pcm_resample_state *state); /** * Resamples 16 bit PCM data. * * @param state an initialized pcm_resample_state object * @param channels the number of channels * @param src_rate the source sample rate * @param src the source PCM buffer * @param src_size the size of #src in bytes * @param dest_rate the requested destination sample rate * @param dest_size_r returns the number of bytes of the destination buffer * @return the destination buffer */ const int16_t * pcm_resample_16(struct pcm_resample_state *state, uint8_t channels, unsigned src_rate, const int16_t *src_buffer, size_t src_size, unsigned dest_rate, size_t *dest_size_r, GError **error_r); /** * Resamples 32 bit PCM data. * * @param state an initialized pcm_resample_state object * @param channels the number of channels * @param src_rate the source sample rate * @param src the source PCM buffer * @param src_size the size of #src in bytes * @param dest_rate the requested destination sample rate * @param dest_size_r returns the number of bytes of the destination buffer * @return the destination buffer */ const int32_t * pcm_resample_32(struct pcm_resample_state *state, uint8_t channels, unsigned src_rate, const int32_t *src_buffer, size_t src_size, unsigned dest_rate, size_t *dest_size_r, GError **error_r); /** * Resamples 24 bit PCM data. * * @param state an initialized pcm_resample_state object * @param channels the number of channels * @param src_rate the source sample rate * @param src the source PCM buffer * @param src_size the size of #src in bytes * @param dest_rate the requested destination sample rate * @param dest_size_r returns the number of bytes of the destination buffer * @return the destination buffer */ static inline const int32_t * pcm_resample_24(struct pcm_resample_state *state, uint8_t channels, unsigned src_rate, const int32_t *src_buffer, size_t src_size, unsigned dest_rate, size_t *dest_size_r, GError **error_r) { /* reuse the 32 bit code - the resampler code doesn't care if the upper 8 bits are actually used */ return pcm_resample_32(state, channels, src_rate, src_buffer, src_size, dest_rate, dest_size_r, error_r); } #endif