mp3dec_filter.c

   1 /*
   2  * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file mp3dec_filter.c Paraslash's mp3 decoder. */
   8
   9 #include <mad.h>
  10 #include <regex.h>
  11 #include <stdbool.h>
  12
  13 #include "para.h"
  14 #include "mp3dec_filter.cmdline.h"
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "ggo.h"
  18 #include "buffer_tree.h"
  19 #include "filter.h"
  20 #include "error.h"
  21 #include "string.h"
  22
  23 /** Convert a sample value from libmad to a signed short. */
  24 #define MAD_TO_SHORT(f) (f) >= MAD_F_ONE? SHRT_MAX :\
  25         (f) <= -MAD_F_ONE? -SHRT_MAX : (signed short) ((f) >> (MAD_F_FRACBITS - 15))
  26
  27 /** State of the decoding process. */
  28 enum mp3dec_flags {
  29         /** Bad main_data_begin pointer encounterd. */
  30         MP3DEC_FLAG_BAD_DATA = 1,
  31         /** Some output has already been produced. */
  32         MP3DEC_FLAG_DECODE_STARTED = 2,
  33         MP3DEC_FLAG_NEED_MORE = 4,
  34 };
  35
  36 /** Data specific to the mp3dec filter. */
  37 struct private_mp3dec_data {
  38         /** Information on the current mp3 stream. */
  39         struct mad_stream stream;
  40         /** Information about the frame which is currently decoded. */
  41         struct mad_frame frame;
  42         /** Contains the PCM output. */
  43         struct mad_synth synth;
  44         /** See \ref mp3dec_flags. */
  45         unsigned flags;
  46         /** Defer decoding until this time. */
  47         struct timeval stream_start_barrier;
  48         /** Wait until this many input bytes are available. */
  49         size_t input_len_barrier;
  50         /** The number of channels of the current stream. */
  51         unsigned int channels;
  52         /** Current sample rate in Hz. */
  53         unsigned int samplerate;
  54 };
  55
  56 static int need_bad_data_delay(struct private_mp3dec_data *pmd,
  57                 size_t bytes_available)
  58 {
  59         if (!(pmd->flags & MP3DEC_FLAG_BAD_DATA))
  60                 return 0;
  61         if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
  62                 return 0;
  63         if (bytes_available >= pmd->input_len_barrier)
  64                 return 0;
  65         if (tv_diff(now, &pmd->stream_start_barrier, NULL) > 0)
  66                 return 0;
  67         return 1;
  68 }
  69
  70 /*
  71  * Returns negative on serious errors, zero if the error should be ignored and
  72  * positive on bad data pointer errors at stream start.
  73  */
  74 static int handle_decode_error(struct private_mp3dec_data *pmd, size_t len)
  75 {
  76         const struct timeval delay = {0, 60 * 1000};
  77         if (!MAD_RECOVERABLE(pmd->stream.error)
  78                         && pmd->stream.error != MAD_ERROR_BUFLEN) {
  79                 PARA_ERROR_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
  80                 return -E_MAD_FRAME_DECODE;
  81         }
  82         PARA_DEBUG_LOG("%s\n", mad_stream_errorstr(&pmd->stream));
  83         if (pmd->stream.error != MAD_ERROR_BADDATAPTR)
  84                 return 0;
  85         if (pmd->flags & MP3DEC_FLAG_DECODE_STARTED)
  86                 return 0;
  87         /*
  88          * Bad data pointer at stream start. Defer decoding until the amount of
  89          * data we are about to skip is available again, but wait at most 60ms.
  90          */
  91         pmd->flags |= MP3DEC_FLAG_BAD_DATA;
  92         pmd->input_len_barrier = len;
  93         tv_add(now, &delay, &pmd->stream_start_barrier);
  94         return 1;
  95 }
  96
  97 /** 640K ought to be enough for everybody ;) */
  98 #define MP3DEC_MAX_PENDING (640 * 1024)
  99
 100 static void mp3dec_pre_select(struct sched *s, struct task *t)
 101 {
 102         struct filter_node *fn = container_of(t, struct filter_node, task);
 103         size_t iqs = btr_get_input_queue_size(fn->btrn);
 104
 105         t->error = 0;
 106         if (iqs <= fn->min_iqs)
 107                 return;
 108         if (btr_bytes_pending(fn->btrn) > MP3DEC_MAX_PENDING)
 109                 return; /* FIXME, should use reasonable bound on timeout */
 110         s->timeout.tv_sec = 0;
 111         s->timeout.tv_usec = 1;
 112 }
 113
 114 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
 115 {
 116         int i, ret;
 117         struct private_mp3dec_data *pmd = fn->private_data;
 118         size_t copy = PARA_MIN(len, (size_t)4096);
 119
 120         if (fn->loaded + 16384 > fn->bufsize)
 121                 return 0;
 122         if (need_bad_data_delay(pmd, len))
 123                 return 0;
 124         mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
 125         pmd->stream.error = 0;
 126 next_frame:
 127         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 128         if (ret < 0) {
 129                 if (pmd->stream.error != MAD_ERROR_BUFLEN &&
 130                         pmd->stream.error != MAD_ERROR_LOSTSYNC)
 131                         PARA_DEBUG_LOG("header decode: %s\n",
 132                                 mad_stream_errorstr(&pmd->stream));
 133                 goto out;
 134         }
 135         fn->fc->samplerate = pmd->frame.header.samplerate;
 136         fn->fc->channels = MAD_NCHANNELS(&pmd->frame.header);
 137         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 138         if (ret != 0) {
 139                 ret = handle_decode_error(pmd, len);
 140                 if (ret < 0)
 141                         return ret;
 142                 if (ret == 0)
 143                         goto out;
 144                 ret = copy - (pmd->stream.bufend - pmd->stream.next_frame);
 145                 PARA_NOTICE_LOG("skipping %d input bytes\n", ret);
 146                 return ret;
 147         }
 148         mad_synth_frame(&pmd->synth, &pmd->frame);
 149         pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
 150
 151         for (i = 0; i < pmd->synth.pcm.length; i++) {
 152                 int s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 153                 write_int16_host_endian(fn->buf + fn->loaded, s);
 154                 fn->loaded += 2;
 155                 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
 156                         s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 157                         write_int16_host_endian(fn->buf + fn->loaded, s);
 158                         fn->loaded += 2;
 159                 }
 160                 if (fn->loaded != fn->bufsize) /* output buffer not full */
 161                         continue;
 162                 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
 163                         return -E_MP3DEC_OVERRUN;
 164         }
 165         if (fn->loaded + 16384 <= fn->bufsize)
 166                 goto next_frame;
 167 out:
 168         if (pmd->stream.next_frame) { /* we still have some data */
 169                 size_t off = pmd->stream.bufend - pmd->stream.next_frame;
 170                 if (fn->loaded + 16384 <= fn->bufsize && off > 2048)
 171                         goto next_frame;
 172                 return copy - off;
 173         }
 174         return copy;
 175 }
 176
 177 static size_t used_mad_buffer_bytes(struct mad_stream *s, size_t max)
 178 {
 179         size_t rv;
 180
 181         if (!s->next_frame)
 182                 return max;
 183         /* we still have some data */
 184         rv = s->next_frame - s->buffer;
 185         assert(rv <= max);
 186         return rv;
 187 }
 188
 189 static void mp3dec_close(struct filter_node *fn)
 190 {
 191         struct private_mp3dec_data *pmd = fn->private_data;
 192
 193         mad_synth_finish(&pmd->synth);
 194         mad_frame_finish(&pmd->frame);
 195         mad_stream_finish(&pmd->stream);
 196
 197         free(fn->buf);
 198         fn->buf = NULL;
 199         free(pmd);
 200         fn->private_data = NULL;
 201 }
 202
 203 static void mp3dec_post_select(__a_unused struct sched *s, struct task *t)
 204 {
 205         struct filter_node *fn = container_of(t, struct filter_node, task);
 206         int i, ret;
 207         struct private_mp3dec_data *pmd = fn->private_data;
 208         struct btr_node *btrn = fn->btrn;
 209         size_t loaded, used, len, iqs;
 210         char *inbuffer, *outbuffer;
 211
 212 next_buffer:
 213         pmd->stream.error = 0;
 214         t->error = 0;
 215         iqs = btr_get_input_queue_size(btrn);
 216         if (need_bad_data_delay(pmd, iqs))
 217                 return;
 218         ret = prepare_filter_node(btrn, fn->min_iqs);
 219         if (ret < 0)
 220                 goto err;
 221         if (ret == 0)
 222                 return;
 223         len = btr_next_buffer(btrn, &inbuffer);
 224         mad_stream_buffer(&pmd->stream, (unsigned char *)inbuffer, len);
 225 next_frame:
 226         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 227         if (ret < 0) {
 228                 used = used_mad_buffer_bytes(&pmd->stream, len);
 229                 btr_consume(btrn, used);
 230                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 231                         if (len == iqs && btr_no_parent(btrn)) {
 232                                 ret = -E_MP3DEC_EOF;
 233                                 goto err;
 234                         }
 235                         fn->min_iqs += 100;
 236                         goto next_buffer;
 237                 } else if (pmd->stream.error != MAD_ERROR_LOSTSYNC)
 238                         PARA_DEBUG_LOG("header decode: %s\n",
 239                                 mad_stream_errorstr(&pmd->stream));
 240                 goto next_buffer;
 241         }
 242         fn->min_iqs = 0;
 243         pmd->samplerate = pmd->frame.header.samplerate;
 244         pmd->channels = MAD_NCHANNELS(&pmd->frame.header);
 245         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 246         if (ret != 0) {
 247                 PARA_CRIT_LOG("frame decode: %d\n", ret);
 248                 used = used_mad_buffer_bytes(&pmd->stream, len);
 249                 ret = handle_decode_error(pmd, used);
 250                 btr_consume(btrn, used);
 251                 if (ret < 0)
 252                         goto err;
 253                 if (ret == 0)
 254                         goto next_buffer;
 255                 return;
 256         }
 257         mad_synth_frame(&pmd->synth, &pmd->frame);
 258         pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
 259
 260         outbuffer = para_malloc(pmd->synth.pcm.length * 4);
 261         loaded = 0;
 262         for (i = 0; i < pmd->synth.pcm.length; i++) {
 263                 int sample = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 264                 write_int16_host_endian(outbuffer + loaded, sample);
 265                 loaded += 2;
 266                 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
 267                         sample = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 268                         write_int16_host_endian(outbuffer + loaded, sample);
 269                         loaded += 2;
 270                 }
 271         }
 272         btr_add_output(outbuffer, loaded, btrn);
 273         goto next_frame;
 274 err:
 275         assert(ret < 0);
 276         mp3dec_close(fn);
 277         t->error = ret;
 278         btr_del_node(btrn);
 279 }
 280
 281 static void mp3dec_open(struct filter_node *fn)
 282 {
 283         struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
 284         struct mp3dec_filter_args_info *mp3_conf = fn->conf;
 285
 286         fn->private_data = pmd;
 287         mad_stream_init(&pmd->stream);
 288         mad_frame_init(&pmd->frame);
 289         mad_synth_init(&pmd->synth);
 290         fn->loaded = 0;
 291         fn->bufsize = mp3_conf->bufsize_arg * 1024;
 292         fn->buf = para_calloc(fn->bufsize);
 293         if (mp3_conf->ignore_crc_given)
 294                 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 295 }
 296
 297 static int mp3dec_parse_config(int argc, char **argv, void **config)
 298 {
 299         int ret;
 300         struct mp3dec_filter_args_info *mp3_conf;
 301
 302         mp3_conf = para_calloc(sizeof(*mp3_conf));
 303         ret = -E_MP3DEC_SYNTAX;
 304         if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
 305                 goto err;
 306         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
 307         if (mp3_conf->bufsize_arg < 32)
 308                 goto err;
 309         if (mp3_conf->bufsize_arg >= INT_MAX / 1024)
 310                 goto err;
 311         *config = mp3_conf;
 312         return 1;
 313 err:
 314         free(mp3_conf);
 315         return ret;
 316 }
 317
 318 static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
 319 {
 320         struct filter_node *fn = btr_context(btrn);
 321         struct private_mp3dec_data *pmd = fn->private_data;
 322
 323         if (!strcmp(cmd, "samplerate")) {
 324                 if (pmd->samplerate == 0)
 325                         return -ERRNO_TO_PARA_ERROR(ENAVAIL);
 326                 *result = make_message("%u", pmd->samplerate);
 327                 return 1;
 328         }
 329         if (!strcmp(cmd, "channels")) {
 330                 if (pmd->channels == 0)
 331                         return -ERRNO_TO_PARA_ERROR(ENAVAIL);
 332                 *result = make_message("%u", pmd->channels);
 333                 return 1;
 334         }
 335         return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 336 }
 337 /**
 338  * The init function of the mp3dec filter.
 339  *
 340  * \param f Pointer to the filter struct to initialize.
 341  *
 342  * \sa filter::init.
 343  */
 344 void mp3dec_filter_init(struct filter *f)
 345 {
 346         struct mp3dec_filter_args_info dummy;
 347
 348         mp3dec_cmdline_parser_init(&dummy);
 349         f->open = mp3dec_open;
 350         f->convert = mp3dec;
 351         f->close = mp3dec_close;
 352         f->parse_config = mp3dec_parse_config;
 353         f->pre_select = mp3dec_pre_select;
 354         f->post_select = mp3dec_post_select;
 355         f->execute = mp3dec_execute;
 356         f->help = (struct ggo_help) {
 357                 .short_help = mp3dec_filter_args_info_help,
 358                 .detailed_help = mp3dec_filter_args_info_detailed_help
 359         };
 360 }