rate/rate_samplerate.c

   1 /*
   2  * Rate converter plugin using libsamplerate
   3  *
   4  * Copyright (c) 2006 by Takashi Iwai <tiwai@suse.de>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  */
  16
  17 #include <stdio.h>
  18 #include <samplerate.h>
  19 #include <alsa/asoundlib.h>
  20 #include <alsa/pcm_rate.h>
  21
  22 struct rate_src {
  23         unsigned int version;
  24         double ratio;
  25         int converter;
  26         unsigned int channels;
  27         int in_int;
  28         int out_int;
  29         float *src_buf;
  30         float *dst_buf;
  31         SRC_STATE *state;
  32         SRC_DATA data;
  33 };
  34
  35 static snd_pcm_uframes_t input_frames(void *obj, snd_pcm_uframes_t frames)
  36 {
  37         struct rate_src *rate = obj;
  38         if (frames == 0)
  39                 return 0;
  40         return (snd_pcm_uframes_t)(frames / rate->ratio);
  41 }
  42
  43 static snd_pcm_uframes_t output_frames(void *obj, snd_pcm_uframes_t frames)
  44 {
  45         struct rate_src *rate = obj;
  46         if (frames == 0)
  47                 return 0;
  48         return (snd_pcm_uframes_t)(frames * rate->ratio);
  49 }
  50
  51 static void pcm_src_free(void *obj)
  52 {
  53         struct rate_src *rate = obj;
  54
  55         free(rate->src_buf);
  56         free(rate->dst_buf);
  57         rate->src_buf = rate->dst_buf = NULL;
  58
  59         if (rate->state) {
  60                 src_delete(rate->state);
  61                 rate->state = NULL;
  62         }
  63 }
  64
  65 static int pcm_src_init(void *obj, snd_pcm_rate_info_t *info)
  66 {
  67         struct rate_src *rate = obj;
  68         int err;
  69
  70         if (! rate->state || rate->channels != info->channels) {
  71                 if (rate->state)
  72                         src_delete(rate->state);
  73                 rate->channels = info->channels;
  74                 rate->state = src_new(rate->converter, rate->channels, &err);
  75                 if (! rate->state)
  76                         return -EINVAL;
  77         }
  78
  79         rate->ratio = (double)info->out.rate / (double)info->in.rate;
  80
  81         free(rate->src_buf);
  82         rate->src_buf = malloc(sizeof(float) * rate->channels * info->in.period_size);
  83         free(rate->dst_buf);
  84         rate->dst_buf = malloc(sizeof(float) * rate->channels * info->out.period_size);
  85         if (! rate->src_buf || ! rate->dst_buf) {
  86                 pcm_src_free(rate);
  87                 return -ENOMEM;
  88         }
  89
  90         rate->data.data_in = rate->src_buf;
  91         rate->data.data_out = rate->dst_buf;
  92         rate->data.src_ratio = rate->ratio;
  93         rate->data.end_of_input = 0;
  94
  95 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010003
  96         if (rate->version >= 0x010003) {
  97                 rate->in_int = info->in.format == SND_PCM_FORMAT_S32;
  98                 rate->out_int = info->out.format == SND_PCM_FORMAT_S32;
  99         }
 100 #endif
 101
 102         return 0;
 103 }
 104
 105 static int pcm_src_adjust_pitch(void *obj, snd_pcm_rate_info_t *info)
 106 {
 107         struct rate_src *rate = obj;
 108
 109         rate->ratio = ((double)info->out.period_size / (double)info->in.period_size);
 110         rate->data.src_ratio = rate->ratio;
 111         return 0;
 112 }
 113
 114 static void pcm_src_reset(void *obj)
 115 {
 116         struct rate_src *rate = obj;
 117
 118         src_reset(rate->state);
 119 }
 120
 121 static void do_convert(struct rate_src *rate,
 122                        void *dst, unsigned int dst_frames,
 123                        const void *src, unsigned int src_frames)
 124 {
 125         unsigned int ofs;
 126
 127         rate->data.input_frames = src_frames;
 128         rate->data.output_frames = dst_frames;
 129         rate->data.end_of_input = 0;
 130
 131         if (rate->in_int)
 132                 src_int_to_float_array(src, rate->src_buf, src_frames * rate->channels);
 133         else
 134                 src_short_to_float_array(src, rate->src_buf, src_frames * rate->channels);
 135         src_process(rate->state, &rate->data);
 136         if (rate->data.output_frames_gen < dst_frames)
 137                 ofs = dst_frames - rate->data.output_frames_gen;
 138         else
 139                 ofs = 0;
 140         if (rate->out_int)
 141                 src_float_to_int_array(rate->dst_buf, dst + ofs * rate->channels * 4,
 142                                        rate->data.output_frames_gen * rate->channels);
 143         else
 144                 src_float_to_short_array(rate->dst_buf, dst + ofs * rate->channels * 2,
 145                                          rate->data.output_frames_gen * rate->channels);
 146 }
 147
 148 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010003
 149 static void pcm_src_convert(void *obj,
 150                             const snd_pcm_channel_area_t *dst_areas,
 151                             snd_pcm_uframes_t dst_offset,
 152                             unsigned int dst_frames,
 153                             const snd_pcm_channel_area_t *src_areas,
 154                             snd_pcm_uframes_t src_offset,
 155                             unsigned int src_frames)
 156 {
 157         struct rate_src *rate = obj;
 158         const void *src = snd_pcm_channel_area_addr(src_areas, src_offset);
 159         void *dst = snd_pcm_channel_area_addr(dst_areas, dst_offset);
 160
 161         do_convert(rate, dst, dst_frames, src, src_frames);
 162 }
 163 #endif
 164
 165 static void pcm_src_convert_s16(void *obj, int16_t *dst, unsigned int dst_frames,
 166                                 const int16_t *src, unsigned int src_frames)
 167 {
 168         struct rate_src *rate = obj;
 169
 170         do_convert(rate, dst, dst_frames, src, src_frames);
 171 }
 172
 173 static void pcm_src_close(void *obj)
 174 {
 175         free(obj);
 176 }
 177
 178 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010002
 179 static int get_supported_rates(void *obj ATTRIBUTE_UNUSED, unsigned int *rate_min,
 180                                unsigned int *rate_max)
 181 {
 182         *rate_min = *rate_max = 0; /* both unlimited */
 183         return 0;
 184 }
 185
 186 static void dump(void *obj ATTRIBUTE_UNUSED, snd_output_t *out)
 187 {
 188         snd_output_printf(out, "Converter: libsamplerate\n");
 189 }
 190 #endif
 191
 192 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010003
 193 static int get_supported_formats(void *obj, uint64_t *in_formats,
 194                                  uint64_t *out_formats,
 195                                  unsigned int *flags)
 196 {
 197         *in_formats = *out_formats =
 198                 (1ULL << SND_PCM_FORMAT_S16) |
 199                 (1ULL << SND_PCM_FORMAT_S32);
 200         *flags = SND_PCM_RATE_FLAG_INTERLEAVED;
 201         return 0;
 202 }
 203 #endif
 204
 205 static snd_pcm_rate_ops_t pcm_src_ops = {
 206         .close = pcm_src_close,
 207         .init = pcm_src_init,
 208         .free = pcm_src_free,
 209         .reset = pcm_src_reset,
 210         .adjust_pitch = pcm_src_adjust_pitch,
 211 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010003
 212         .convert = pcm_src_convert,
 213 #endif
 214         .convert_s16 = pcm_src_convert_s16,
 215         .input_frames = input_frames,
 216         .output_frames = output_frames,
 217 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010002
 218         .version = SND_PCM_RATE_PLUGIN_VERSION,
 219         .get_supported_rates = get_supported_rates,
 220         .dump = dump,
 221 #endif
 222 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010003
 223         .get_supported_formats = get_supported_formats,
 224 #endif
 225 };
 226
 227 static int pcm_src_open(unsigned int version, void **objp,
 228                         snd_pcm_rate_ops_t *ops, int type)
 229 {
 230         struct rate_src *rate;
 231
 232         rate = calloc(1, sizeof(*rate));
 233         if (! rate)
 234                 return -ENOMEM;
 235
 236         rate->version = version;
 237         rate->converter = type;
 238
 239         *objp = rate;
 240 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010002
 241         if (version == 0x010001) {
 242                 memcpy(ops, &pcm_src_ops, sizeof(snd_pcm_rate_old_ops_t));
 243                 return 0;
 244         }
 245 #endif
 246 #if SND_PCM_RATE_PLUGIN_VERSION >= 0x010003
 247         if (version == 0x010002) {
 248                 memcpy(ops, &pcm_src_ops, sizeof(snd_pcm_rate_v2_ops_t));
 249                 return 0;
 250         }
 251 #endif
 252         *ops = pcm_src_ops;
 253         return 0;
 254 }
 255
 256 int SND_PCM_RATE_PLUGIN_ENTRY(samplerate) (unsigned int version, void **objp,
 257                                            snd_pcm_rate_ops_t *ops)
 258 {
 259         return pcm_src_open(version, objp, ops, SRC_SINC_FASTEST);
 260 }
 261
 262 int SND_PCM_RATE_PLUGIN_ENTRY(samplerate_best) (unsigned int version, void **objp,
 263                                                 snd_pcm_rate_ops_t *ops)
 264 {
 265         return pcm_src_open(version, objp, ops, SRC_SINC_BEST_QUALITY);
 266 }
 267
 268 int SND_PCM_RATE_PLUGIN_ENTRY(samplerate_medium) (unsigned int version, void **objp,
 269                                                   snd_pcm_rate_ops_t *ops)
 270 {
 271         return pcm_src_open(version, objp, ops, SRC_SINC_MEDIUM_QUALITY);
 272 }
 273
 274 int SND_PCM_RATE_PLUGIN_ENTRY(samplerate_order) (unsigned int version, void **objp,
 275                                                  snd_pcm_rate_ops_t *ops)
 276 {
 277         return pcm_src_open(version, objp, ops, SRC_ZERO_ORDER_HOLD);
 278 }
 279
 280 int SND_PCM_RATE_PLUGIN_ENTRY(samplerate_linear) (unsigned int version, void **objp,
 281                                                   snd_pcm_rate_ops_t *ops)
 282 {
 283         return pcm_src_open(version, objp, ops, SRC_LINEAR);
 284 }