play.c

   1 /*
   2  * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /*
  20  * Based in parts on aplay.c from the alsa-utils-1.0.8 package,
  21  * Copyright (c) by Jaroslav Kysela <perex@suse.cz>, which is
  22  * based on the vplay program by Michael Beck.
  23  */
  24
  25 #define WAV_HEADER_LEN 44
  26 #include <sys/time.h> /* gettimeofday */
  27 #include "para.h"
  28 #include "play.cmdline.h"
  29 #include <alsa/asoundlib.h>
  30
  31 enum {  E_BROKEN_CONF,          /* Broken configuration for this PCM */
  32         E_ACCESS_TYPE,          /* Access type not available */
  33         E_SAMPLE_FORMAT,        /* Sample format not available */
  34         E_CHANNEL_COUNT,        /* Channels count not available */
  35         E_HW_PARAMS,            /* Unable to install hw params */
  36         E_SW_PARAMS,            /* Unable to install sw params */
  37         E_BAD_PERIOD,           /* Can't use period equal to buffer size */
  38         E_GET_XFER,             /* Unable to obtain xfer align */
  39         E_SET_XFER,             /* snd_pcm_sw_params_set_xfer_align failed */
  40         E_MEM,                  /* not enough memory */
  41         E_READ,                 /* read error */
  42         E_WRITE,                /* write error */
  43         E_PIPE,                 /* write to pipe with other side closed */
  44         E_PCM_OPEN,             /* unable to open pcm */
  45         E_SND_PCM_INFO,         /* pcm info error */
  46         E_GET_BUFFER_TIME,      /* snd_pcm_hw_params_get_buffer_time_max failed */
  47         E_SET_BUFFER_TIME,      /* snd_pcm_hw_params_set_buffer_time_near failed */
  48         E_SET_RATE,             /* snd_pcm_hw_params_set_rate_near failed */
  49         E_START_THRESHOLD,      /* snd_pcm_sw_params_set_start_threshold failed */
  50         E_STOP_THRESHOLD,       /* snd_pcm_sw_params_set_stop_threshold failed */
  51         E_LOG,                  /* snd_output_stdio_attach failed */
  52         E_SYNTAX                /* could not parse start_time option */
  53 };
  54
  55 #define FORMAT SND_PCM_FORMAT_S16_LE
  56
  57 #define EXIT(EXP) \
  58 do { if (EXP) \
  59         fprintf (stderr, "error: " #EXP "\n"); exit(EXP);} \
  60 while (0)
  61
  62 static snd_pcm_t *handle;
  63 static unsigned char *audiobuf;
  64 static snd_pcm_uframes_t chunk_size;
  65 static size_t bytes_per_frame;
  66 static struct timeval *start_time;
  67 static struct gengetopt_args_info conf;
  68
  69 /*
  70  * read_wav_header - read WAV_HEADER_LEN bytes from stdin to audio buffer
  71  *
  72  * Exit on errors and on eof before WAV_HEADER_LEN could be read.
  73  */
  74 static void read_wav_header(void)
  75 {
  76         ssize_t ret, count = 0;
  77
  78         while (count < WAV_HEADER_LEN) {
  79                 ret = read(STDIN_FILENO, audiobuf + count, WAV_HEADER_LEN - count);
  80                 if (ret <= 0)
  81                         EXIT(E_READ);
  82                 count += ret;
  83         }
  84 }
  85
  86 /*
  87  * set_alsa_params - Prepare the PCM handle for writing
  88  *
  89  * Install PCM software and hardware configuration. Exit on errors.
  90  */
  91 static void set_alsa_params(void)
  92 {
  93         snd_pcm_hw_params_t *hwparams;
  94         snd_pcm_sw_params_t *swparams;
  95         snd_pcm_uframes_t buffer_size, xfer_align, start_threshold,
  96                 stop_threshold;
  97         unsigned buffer_time = 0;
  98         int err;
  99
 100         snd_pcm_hw_params_alloca(&hwparams);
 101         snd_pcm_sw_params_alloca(&swparams);
 102         if (snd_pcm_hw_params_any(handle, hwparams) < 0)
 103                 EXIT(E_BROKEN_CONF);
 104         if (snd_pcm_hw_params_set_access(handle, hwparams,
 105                         SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
 106                 EXIT(E_ACCESS_TYPE);
 107         if (snd_pcm_hw_params_set_format(handle, hwparams, FORMAT) < 0)
 108                 EXIT(E_SAMPLE_FORMAT);
 109         if (snd_pcm_hw_params_set_channels(handle, hwparams, conf.channels_arg) < 0)
 110                 EXIT(E_CHANNEL_COUNT);
 111         if (snd_pcm_hw_params_set_rate_near(handle, hwparams,
 112                         (unsigned int*) &conf.sample_rate_arg, 0) < 0)
 113                 EXIT(E_SET_RATE);
 114         err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time, 0);
 115         if (err < 0 || !buffer_time)
 116                 EXIT(E_GET_BUFFER_TIME);
 117         fprintf(stderr, "buffer time: %d\n", buffer_time);
 118         if (snd_pcm_hw_params_set_buffer_time_near(handle, hwparams,
 119                         &buffer_time, 0) < 0)
 120                 EXIT(E_SET_BUFFER_TIME);
 121         if (snd_pcm_hw_params(handle, hwparams) < 0)
 122                 EXIT(E_HW_PARAMS);
 123         snd_pcm_hw_params_get_period_size(hwparams, &chunk_size, 0);
 124         snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
 125         fprintf(stderr, "buffer size: %lu, period_size: %lu\n", buffer_size, chunk_size);
 126         if (chunk_size == buffer_size)
 127                 EXIT(E_BAD_PERIOD);
 128         snd_pcm_sw_params_current(handle, swparams);
 129         err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
 130         if (err < 0 || !xfer_align)
 131                 EXIT(E_GET_XFER);
 132 //      snd_pcm_sw_params_set_sleep_min(handle, swparams, 0);
 133         snd_pcm_sw_params_set_avail_min(handle, swparams, chunk_size);
 134         /* round to closest transfer boundary */
 135         start_threshold = (buffer_size / xfer_align) * xfer_align;
 136         if (start_threshold < 1)
 137                 start_threshold = 1;
 138         if (snd_pcm_sw_params_set_start_threshold(handle, swparams,
 139                         start_threshold) < 0)
 140                 EXIT(E_START_THRESHOLD);
 141         stop_threshold = buffer_size;
 142         if (snd_pcm_sw_params_set_stop_threshold(handle, swparams,
 143                         stop_threshold) < 0)
 144                 EXIT(E_STOP_THRESHOLD);
 145         if (snd_pcm_sw_params_set_xfer_align(handle, swparams, xfer_align) < 0)
 146                 EXIT(E_SET_XFER);
 147         if (snd_pcm_sw_params(handle, swparams) < 0)
 148                 EXIT(E_SW_PARAMS);
 149         bytes_per_frame = snd_pcm_format_physical_width(FORMAT) * conf.channels_arg / 8;
 150 }
 151
 152 /*
 153  * pcm_write - push out pcm frames
 154  * \param data pointer do data to be written
 155  * \param count number of frames
 156  *
 157  * \return Number of bytes written. Exit on errors.
 158  */
 159 static snd_pcm_sframes_t pcm_write(u_char *data, size_t count)
 160 {
 161         snd_pcm_sframes_t r, result = 0;
 162         while (count > 0) {
 163                 /* write interleaved frames */
 164                 r = snd_pcm_writei(handle, data, count);
 165                 if (r < 0)
 166                         fprintf(stderr, "write error: %s\n", snd_strerror(r));
 167                 if (r == -EAGAIN || (r >= 0 && r < count))
 168                         snd_pcm_wait(handle, 1);
 169                 else if (r == -EPIPE)
 170                         snd_pcm_prepare(handle);
 171                 else if (r < 0)
 172                         EXIT(E_WRITE);
 173                 if (r > 0) {
 174                         result += r;
 175                         count -= r;
 176                         data += r * bytes_per_frame;
 177                 }
 178         }
 179         return result;
 180 }
 181
 182 /*
 183  * start_time_in_future - check if current time is later than start_time
 184  * \param diff pointer to write remaining time to
 185  *
 186  * If start_time was not given, or current time is later than given
 187  * start_time, return 0. Otherwise, return 1 and write the time
 188  * difference between current time and start_time to diff. diff may be
 189  * NULL.
 190  *
 191  */
 192 static int start_time_in_future(struct timeval *diff)
 193 {
 194         struct timeval now;
 195
 196         if (!conf.start_time_given)
 197                 return 0;
 198         gettimeofday(&now, NULL);
 199         return tv_diff(start_time, &now, diff) > 0? 1 : 0;
 200 }
 201
 202 /*
 203  * do_initial_delay - sleep until time given at command line
 204  *
 205  * This is called if the initial buffer is filled. It returns
 206  * immediately if no start_time was given at the command line
 207  * or if the given start time is in the past.
 208  *
 209  */
 210 static void do_initial_delay(struct timeval *delay)
 211 {
 212 //      fprintf(stderr, "sleeping %lums\n", tv2ms(delay));
 213         do
 214                 select(1, NULL, NULL, NULL, delay);
 215         while (start_time_in_future(delay));
 216 }
 217
 218 /*
 219  * play_pcm - play raw pcm data
 220  * \param loaded number of bytes already loaded
 221  *
 222  * If start_time was given, prebuffer data until buffer is full or
 223  * start_time is reached. In any case, do not start playing before
 224  * start_time.
 225  */
 226 static void play_pcm(size_t loaded)
 227 {
 228         size_t chunk_bytes, bufsize, written = 0, prebuf_size;
 229         ssize_t ret;
 230         unsigned char *p;
 231         struct timeval delay;
 232
 233         set_alsa_params();
 234         chunk_bytes = chunk_size * bytes_per_frame;
 235         bufsize = (conf.bufsize_arg * 1024 / chunk_bytes) * chunk_bytes;
 236         audiobuf = realloc(audiobuf, bufsize);
 237         if (!audiobuf)
 238                 EXIT(E_MEM);
 239         prebuf_size = conf.prebuffer_arg * bufsize / 100;
 240 again:
 241         if (!written) {
 242                 if (loaded < prebuf_size)
 243                         goto read;
 244                 if (start_time && start_time_in_future(&delay)) {
 245                         do_initial_delay(&delay);
 246                         start_time = NULL;
 247                 }
 248         }
 249         p = audiobuf;
 250         while (loaded >= chunk_bytes) {
 251 //                      fprintf(stderr, "write (loaded = %d)\n", loaded);
 252                 ret = pcm_write(p, chunk_size) * bytes_per_frame;
 253                 p += ret;
 254                 written += ret;
 255                 loaded -= ret;
 256         }
 257         if (loaded && p != audiobuf) {
 258 //                      fprintf(stderr, "memcpy: %d@%d\n", loaded, p - audiobuf);
 259                 memcpy(audiobuf, p, loaded);
 260         }
 261 read:
 262         ret = read(STDIN_FILENO, audiobuf + loaded, bufsize - loaded);
 263         if (ret < 0)
 264                 EXIT(E_READ);
 265         if (ret) {
 266                 loaded += ret;
 267                 goto again;
 268         }
 269         snd_pcm_drain(handle);
 270 }
 271
 272 /*
 273  * check_wave - test if audio buffer contains a valid wave header
 274  *
 275  * If not, return 0, otherwise, store number of channels and sample rate
 276  * in struct conf and return WAV_HEADER_LEN.
 277  */
 278 static size_t check_wave(void)
 279 {
 280         unsigned char *a = audiobuf;
 281         if (a[0] != 'R' || a[1] != 'I' || a[2] != 'F' || a[3] != 'F')
 282                 return WAV_HEADER_LEN;
 283         conf.channels_arg = (unsigned) a[22];
 284         conf.sample_rate_arg = a[24] + (a[25] << 8) + (a[26] << 16) + (a[27] << 24);
 285 //      fprintf(stderr, "channels: %d, rate: %d\n", conf.channels_arg,
 286 //              conf.sample_rate_arg);
 287         return 0;
 288 }
 289
 290 int main(int argc, char *argv[])
 291 {
 292         snd_pcm_info_t *info;
 293         snd_output_t *log;
 294         struct timeval tv;
 295         int err;
 296
 297         cmdline_parser(argc, argv, &conf);
 298         if (conf.start_time_given) {
 299                 if (sscanf(conf.start_time_arg, "%lu:%lu",
 300                                 &tv.tv_sec, &tv.tv_usec) != 2)
 301                         EXIT(E_SYNTAX);
 302                 start_time = &tv;
 303         }
 304 //      fprintf(stderr, "argc=%d, argv[1]=%s\n",argc,  argv[1]);
 305         snd_pcm_info_alloca(&info);
 306         if (snd_output_stdio_attach(&log, stderr, 0) < 0)
 307                 EXIT(E_LOG);
 308         err = snd_pcm_open(&handle, conf.device_arg,
 309                 SND_PCM_STREAM_PLAYBACK, 0);
 310         if (err < 0)
 311                 EXIT(E_PCM_OPEN);
 312         if ((err = snd_pcm_info(handle, info)) < 0)
 313                 EXIT(E_SND_PCM_INFO);
 314         audiobuf = malloc(WAV_HEADER_LEN);
 315         read_wav_header();
 316         play_pcm(check_wave());
 317         snd_pcm_close(handle);
 318         free(audiobuf);
 319 //      snd_output_close(log);
 320         snd_config_update_free_global();
 321         return EXIT_SUCCESS;
 322 }