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         struct private_mp3dec_data *pmd = fn->private_data;
 105
 106         t->error = 0;
 107         if (iqs <= pmd->input_len_barrier)
 108                 return;
 109         if (btr_bytes_pending(fn->btrn) > MP3DEC_MAX_PENDING)
 110                 return; /* FIXME, should use reasonable bound on timeout */
 111         s->timeout.tv_sec = 0;
 112         s->timeout.tv_usec = 1;
 113 }
 114
 115 static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
 116 {
 117         int i, ret;
 118         struct private_mp3dec_data *pmd = fn->private_data;
 119         size_t copy = PARA_MIN(len, (size_t)4096);
 120
 121         if (fn->loaded + 16384 > fn->bufsize)
 122                 return 0;
 123         if (need_bad_data_delay(pmd, len))
 124                 return 0;
 125         mad_stream_buffer(&pmd->stream, (unsigned char *) inbuffer, copy);
 126         pmd->stream.error = 0;
 127 next_frame:
 128         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 129         if (ret < 0) {
 130                 if (pmd->stream.error != MAD_ERROR_BUFLEN &&
 131                         pmd->stream.error != MAD_ERROR_LOSTSYNC)
 132                         PARA_DEBUG_LOG("header decode: %s\n",
 133                                 mad_stream_errorstr(&pmd->stream));
 134                 goto out;
 135         }
 136         fn->fc->samplerate = pmd->frame.header.samplerate;
 137         fn->fc->channels = MAD_NCHANNELS(&pmd->frame.header);
 138         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 139         if (ret != 0) {
 140                 ret = handle_decode_error(pmd, len);
 141                 if (ret < 0)
 142                         return ret;
 143                 if (ret == 0)
 144                         goto out;
 145                 ret = copy - (pmd->stream.bufend - pmd->stream.next_frame);
 146                 PARA_NOTICE_LOG("skipping %d input bytes\n", ret);
 147                 return ret;
 148         }
 149         mad_synth_frame(&pmd->synth, &pmd->frame);
 150         pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
 151
 152         for (i = 0; i < pmd->synth.pcm.length; i++) {
 153                 int s = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 154                 write_int16_host_endian(fn->buf + fn->loaded, s);
 155                 fn->loaded += 2;
 156                 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
 157                         s = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 158                         write_int16_host_endian(fn->buf + fn->loaded, s);
 159                         fn->loaded += 2;
 160                 }
 161                 if (fn->loaded != fn->bufsize) /* output buffer not full */
 162                         continue;
 163                 PARA_ERROR_LOG("output buffer full: %zd\n", fn->loaded);
 164                         return -E_MP3DEC_OVERRUN;
 165         }
 166         if (fn->loaded + 16384 <= fn->bufsize)
 167                 goto next_frame;
 168 out:
 169         if (pmd->stream.next_frame) { /* we still have some data */
 170                 size_t off = pmd->stream.bufend - pmd->stream.next_frame;
 171                 if (fn->loaded + 16384 <= fn->bufsize && off > 2048)
 172                         goto next_frame;
 173                 return copy - off;
 174         }
 175         return copy;
 176 }
 177
 178 static size_t used_mad_buffer_bytes(struct mad_stream *s, size_t max)
 179 {
 180         size_t rv;
 181
 182         if (!s->next_frame)
 183                 return max;
 184         /* we still have some data */
 185         rv = s->next_frame - s->buffer;
 186         assert(rv <= max);
 187         return rv;
 188 }
 189
 190 static void mp3dec_close(struct filter_node *fn)
 191 {
 192         struct private_mp3dec_data *pmd = fn->private_data;
 193
 194         mad_synth_finish(&pmd->synth);
 195         mad_frame_finish(&pmd->frame);
 196         mad_stream_finish(&pmd->stream);
 197
 198         free(fn->buf);
 199         fn->buf = NULL;
 200         free(pmd);
 201         fn->private_data = NULL;
 202 }
 203
 204 static void mp3dec_post_select(__a_unused struct sched *s, struct task *t)
 205 {
 206         struct filter_node *fn = container_of(t, struct filter_node, task);
 207         int i, ret;
 208         struct private_mp3dec_data *pmd = fn->private_data;
 209         struct btr_node *btrn = fn->btrn;
 210         size_t loaded, used, len = btr_get_input_queue_size(btrn);
 211         char *inbuffer, *outbuffer;
 212
 213         pmd->stream.error = 0;
 214         t->error = 0;
 215         if (btr_bytes_pending(btrn) > MP3DEC_MAX_PENDING)
 216                 return;
 217         if (need_bad_data_delay(pmd, len))
 218                 return;
 219         if (len <= pmd->input_len_barrier && btr_no_parent(btrn)) {
 220                 ret = -E_MP3DEC_EOF;
 221                 goto err;
 222         }
 223 next_buffer:
 224         len = btr_next_buffer(btrn, &inbuffer);
 225         if (len == 0)
 226                 return;
 227         mad_stream_buffer(&pmd->stream, (unsigned char *)inbuffer, len);
 228 next_frame:
 229         ret = mad_header_decode(&pmd->frame.header, &pmd->stream);
 230         if (ret < 0) {
 231                 used = used_mad_buffer_bytes(&pmd->stream, len);
 232                 btr_consume(btrn, used);
 233                 if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 234                         pmd->input_len_barrier = len - used;
 235                         ret = btr_merge(btrn);
 236                         if (ret != 2)
 237                                 return;
 238                 } else if (pmd->stream.error != MAD_ERROR_LOSTSYNC)
 239                         PARA_DEBUG_LOG("header decode: %s\n",
 240                                 mad_stream_errorstr(&pmd->stream));
 241                 goto next_buffer;
 242         }
 243         pmd->input_len_barrier = 0;
 244         pmd->samplerate = pmd->frame.header.samplerate;
 245         pmd->channels = MAD_NCHANNELS(&pmd->frame.header);
 246         ret = mad_frame_decode(&pmd->frame, &pmd->stream);
 247         if (ret != 0) {
 248                 PARA_CRIT_LOG("frame decode: %d\n", ret);
 249                 used = used_mad_buffer_bytes(&pmd->stream, len);
 250                 ret = handle_decode_error(pmd, used);
 251                 btr_consume(btrn, used);
 252                 if (ret < 0)
 253                         goto err;
 254                 if (ret == 0)
 255                         goto next_buffer;
 256                 return;
 257         }
 258         mad_synth_frame(&pmd->synth, &pmd->frame);
 259         pmd->flags |= MP3DEC_FLAG_DECODE_STARTED;
 260
 261         outbuffer = para_malloc(pmd->synth.pcm.length * 4);
 262         loaded = 0;
 263         for (i = 0; i < pmd->synth.pcm.length; i++) {
 264                 int sample = MAD_TO_SHORT(pmd->synth.pcm.samples[0][i]);
 265                 write_int16_host_endian(outbuffer + loaded, sample);
 266                 loaded += 2;
 267                 if (MAD_NCHANNELS(&pmd->frame.header) == 2) { /* stereo */
 268                         sample = MAD_TO_SHORT(pmd->synth.pcm.samples[1][i]);
 269                         write_int16_host_endian(outbuffer + loaded, sample);
 270                         loaded += 2;
 271                 }
 272         }
 273         btr_add_output(outbuffer, loaded, btrn);
 274         goto next_frame;
 275 err:
 276         assert(ret < 0);
 277         mp3dec_close(fn);
 278         t->error = ret;
 279         btr_del_node(btrn);
 280 }
 281
 282 static void mp3dec_open(struct filter_node *fn)
 283 {
 284         struct private_mp3dec_data *pmd = para_calloc(sizeof(*pmd));
 285         struct mp3dec_filter_args_info *mp3_conf = fn->conf;
 286
 287         fn->private_data = pmd;
 288         mad_stream_init(&pmd->stream);
 289         mad_frame_init(&pmd->frame);
 290         mad_synth_init(&pmd->synth);
 291         fn->loaded = 0;
 292         fn->bufsize = mp3_conf->bufsize_arg * 1024;
 293         fn->buf = para_calloc(fn->bufsize);
 294         if (mp3_conf->ignore_crc_given)
 295                 mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 296 }
 297
 298 static int mp3dec_parse_config(int argc, char **argv, void **config)
 299 {
 300         int ret;
 301         struct mp3dec_filter_args_info *mp3_conf;
 302
 303         mp3_conf = para_calloc(sizeof(*mp3_conf));
 304         ret = -E_MP3DEC_SYNTAX;
 305         if (mp3dec_cmdline_parser(argc, argv, mp3_conf))
 306                 goto err;
 307         ret = -ERRNO_TO_PARA_ERROR(EINVAL);
 308         if (mp3_conf->bufsize_arg < 32)
 309                 goto err;
 310         if (mp3_conf->bufsize_arg >= INT_MAX / 1024)
 311                 goto err;
 312         *config = mp3_conf;
 313         return 1;
 314 err:
 315         free(mp3_conf);
 316         return ret;
 317 }
 318
 319 static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
 320 {
 321         struct filter_node *fn = btr_context(btrn);
 322         struct private_mp3dec_data *pmd = fn->private_data;
 323
 324         if (!strcmp(cmd, "samplerate")) {
 325                 if (pmd->samplerate == 0)
 326                         return -ERRNO_TO_PARA_ERROR(ENAVAIL);
 327                 *result = make_message("%u", pmd->samplerate);
 328                 return 1;
 329         }
 330         if (!strcmp(cmd, "channels")) {
 331                 if (pmd->channels == 0)
 332                         return -ERRNO_TO_PARA_ERROR(ENAVAIL);
 333                 *result = make_message("%u", pmd->channels);
 334                 return 1;
 335         }
 336         return -ERRNO_TO_PARA_ERROR(ENOTSUP);
 337 }
 338 /**
 339  * The init function of the mp3dec filter.
 340  *
 341  * \param f Pointer to the filter struct to initialize.
 342  *
 343  * \sa filter::init.
 344  */
 345 void mp3dec_filter_init(struct filter *f)
 346 {
 347         struct mp3dec_filter_args_info dummy;
 348
 349         mp3dec_cmdline_parser_init(&dummy);
 350         f->open = mp3dec_open;
 351         f->convert = mp3dec;
 352         f->close = mp3dec_close;
 353         f->parse_config = mp3dec_parse_config;
 354         f->pre_select = mp3dec_pre_select;
 355         f->post_select = mp3dec_post_select;
 356         f->execute = mp3dec_execute;
 357         f->help = (struct ggo_help) {
 358                 .short_help = mp3dec_filter_args_info_help,
 359                 .detailed_help = mp3dec_filter_args_info_detailed_help
 360         };
 361 }