diff options
Diffstat (limited to 'src/pcm_resample_libsamplerate.c')
| -rw-r--r-- | src/pcm_resample_libsamplerate.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/pcm_resample_libsamplerate.c b/src/pcm_resample_libsamplerate.c new file mode 100644 index 000000000..5321c0e0b --- /dev/null +++ b/src/pcm_resample_libsamplerate.c @@ -0,0 +1,140 @@ +/* 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 "conf.h" +#include "log.h" +#include "utils.h" + +#include <stdlib.h> +#include <string.h> + +static int pcm_resample_get_converter(void) +{ + const char *conf = getConfigParamValue(CONF_SAMPLERATE_CONVERTER); + long convalgo; + char *test; + const char *test2; + size_t len; + + if (!conf) { + convalgo = SRC_SINC_FASTEST; + goto out; + } + + convalgo = strtol(conf, &test, 10); + if (*test == '\0' && src_get_name(convalgo)) + goto out; + + len = strlen(conf); + for (convalgo = 0 ; ; convalgo++) { + test2 = src_get_name(convalgo); + if (!test2) { + convalgo = SRC_SINC_FASTEST; + break; + } + if (strncasecmp(test2, conf, len) == 0) + goto out; + } + + ERROR("unknown samplerate converter \"%s\"\n", conf); +out: + DEBUG("selecting samplerate converter \"%s\"\n", + src_get_name(convalgo)); + + return convalgo; +} + +size_t +pcm_resample_16(uint8_t channels, + unsigned src_rate, + const int16_t *src_buffer, size_t src_size, + unsigned dest_rate, + int16_t *dest_buffer, size_t dest_size, + struct pcm_resample_state *state) +{ + static int convalgo = -1; + SRC_DATA *data = &state->data; + size_t data_in_size; + size_t data_out_size; + int error; + + if (convalgo < 0) + convalgo = pcm_resample_get_converter(); + + /* (re)set the state/ratio if the in or out format changed */ + if (channels != state->prev.channels || + src_rate != state->prev.src_rate || + dest_rate != state->prev.dest_rate) { + state->error = false; + state->prev.channels = channels; + state->prev.src_rate = src_rate; + state->prev.dest_rate = dest_rate; + + if (state->state) + state->state = src_delete(state->state); + + state->state = src_new(convalgo, channels, &error); + if (!state->state) { + ERROR("cannot create new libsamplerate state: %s\n", + src_strerror(error)); + state->error = true; + return 0; + } + + data->src_ratio = (double)dest_rate / (double)src_rate; + DEBUG("setting samplerate conversion ratio to %.2lf\n", + data->src_ratio); + src_set_ratio(state->state, data->src_ratio); + } + + /* there was an error previously, and nothing has changed */ + if (state->error) + return 0; + + data->input_frames = src_size / 2 / channels; + data_in_size = data->input_frames * sizeof(float) * channels; + if (data_in_size > state->data_in_size) { + state->data_in_size = data_in_size; + data->data_in = xrealloc(data->data_in, data_in_size); + } + + data->output_frames = dest_size / 2 / channels; + data_out_size = data->output_frames * sizeof(float) * channels; + if (data_out_size > state->data_out_size) { + state->data_out_size = data_out_size; + data->data_out = xrealloc(data->data_out, data_out_size); + } + + src_short_to_float_array(src_buffer, data->data_in, + data->input_frames * channels); + + error = src_process(state->state, data); + if (error) { + ERROR("error processing samples with libsamplerate: %s\n", + src_strerror(error)); + state->error = true; + return 0; + } + + src_float_to_short_array(data->data_out, dest_buffer, + data->output_frames_gen * channels); + + return data->output_frames_gen * 2 * channels; +} |