/* the Music Player Daemon (MPD) * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com) * Copyright (C) 2008 Max Kellermann <max@duempel.org> * This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "pcm_resample.h" #include <assert.h> #include <glib.h> void pcm_resample_deinit(struct pcm_resample_state *state) { pcm_buffer_deinit(&state->buffer); } /* resampling code blatantly ripped from ESD */ 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) { unsigned src_pos, dest_pos = 0; unsigned src_frames = src_size / channels / sizeof(*src_buffer); unsigned dest_frames = (src_frames * dest_rate + src_rate - 1) / src_rate; unsigned dest_samples = dest_frames * channels; size_t dest_size = dest_samples * sizeof(*src_buffer); int16_t *dest_buffer = pcm_buffer_get(&state->buffer, dest_size); assert((src_size % (sizeof(*src_buffer) * channels)) == 0); switch (channels) { case 1: while (dest_pos < dest_samples) { src_pos = dest_pos * src_rate / dest_rate; dest_buffer[dest_pos++] = src_buffer[src_pos]; } break; case 2: while (dest_pos < dest_samples) { src_pos = dest_pos * src_rate / dest_rate; src_pos &= ~1; dest_buffer[dest_pos++] = src_buffer[src_pos]; dest_buffer[dest_pos++] = src_buffer[src_pos + 1]; } break; } *dest_size_r = dest_size; return dest_buffer; } const int32_t * pcm_resample_24(struct pcm_resample_state *state, uint8_t channels, unsigned src_rate, const int32_t *src_buffer, G_GNUC_UNUSED size_t src_size, unsigned dest_rate, size_t *dest_size_r) { unsigned src_pos, dest_pos = 0; unsigned src_frames = src_size / channels / sizeof(*src_buffer); unsigned dest_frames = (src_frames * dest_rate + src_rate - 1) / src_rate; unsigned dest_samples = dest_frames * channels; size_t dest_size = dest_samples * sizeof(*src_buffer); int32_t *dest_buffer = pcm_buffer_get(&state->buffer, dest_size); assert((src_size % (sizeof(*src_buffer) * channels)) == 0); switch (channels) { case 1: while (dest_pos < dest_samples) { src_pos = dest_pos * src_rate / dest_rate; dest_buffer[dest_pos++] = src_buffer[src_pos]; } break; case 2: while (dest_pos < dest_samples) { src_pos = dest_pos * src_rate / dest_rate; src_pos &= ~1; dest_buffer[dest_pos++] = src_buffer[src_pos]; dest_buffer[dest_pos++] = src_buffer[src_pos + 1]; } break; } *dest_size_r = dest_size; return dest_buffer; }