aacdec_filter.c

   1 /*
   2  * Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6 /*
   7  * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
   8  * Ahead Software AG
   9  */
  10
  11 /** \file aacdec_filter.c paraslash's aac (m4a) decoder. */
  12
  13 #include <regex.h>
  14 #include <neaacdec.h>
  15
  16 #include "para.h"
  17 #include "portable_io.h"
  18 #include "list.h"
  19 #include "sched.h"
  20 #include "ggo.h"
  21 #include "buffer_tree.h"
  22 #include "filter.h"
  23 #include "error.h"
  24 #include "string.h"
  25
  26 /** Give up decoding after that many errors. */
  27 #define MAX_ERRORS 20
  28
  29 /**
  30  * data specific to the aacdec filter
  31  *
  32  * \sa filter, filter_node
  33  */
  34 struct private_aacdec_data {
  35         /** the return value of aac_open */
  36         NeAACDecHandle handle;
  37         /** info about the currently decoded frame */
  38         NeAACDecFrameInfo frame_info;
  39         /** whether this instance of the aac decoder is already initialized */
  40         int initialized;
  41         /**
  42          * return value of aac_find_esds(). Used to call the right aacdec
  43          * init function
  44          */
  45         unsigned long decoder_length;
  46         /** number of times the decoder returned an error */
  47         unsigned error_count;
  48         /** number of bytes already consumed from the imput stream */
  49         size_t consumed_total;
  50         /** return value of aac_find_entry_point */
  51         size_t entry;
  52         /** The number of channels of the current stream. */
  53         unsigned int channels;
  54         /** Current sample rate in Hz. */
  55         unsigned int sample_rate;
  56 };
  57
  58 /*
  59  * Get a new libfaad decoder handle.
  60  *
  61  * \return The handle returned by NeAACDecOpen().
  62  */
  63 static NeAACDecHandle aac_open(void)
  64 {
  65         NeAACDecHandle h = NeAACDecOpen();
  66         NeAACDecConfigurationPtr c = NeAACDecGetCurrentConfiguration(h);
  67
  68         c->defObjectType = LC;
  69         c->outputFormat = FAAD_FMT_16BIT;
  70         c->downMatrix = 0;
  71         NeAACDecSetConfiguration(h, c);
  72         return h;
  73 }
  74
  75 static unsigned long aac_read_decoder_length(char *buf, int *description_len)
  76 {
  77         uint8_t b;
  78         uint8_t numBytes = 0;
  79         unsigned long length = 0;
  80
  81         do {
  82                 b = buf[numBytes];
  83                 numBytes++;
  84                 length = (length << 7) | (b & 0x7F);
  85         } while
  86                 ((b & 0x80) && numBytes < 4);
  87         *description_len = numBytes;
  88         return length;
  89 }
  90
  91 /*
  92  * Search for the position and the length of the decoder configuration.
  93  *
  94  * \param buf Buffer to seach.
  95  * \param buflen Length of \a buf.
  96  * \param skip Upon succesful return, this contains the offset in \a buf where
  97  * the decoder config starts.
  98  * \param decoder_length Result pointer that is filled in with the length of
  99  * the decoder configuration on success.
 100  *
 101  * \return Standard.
 102  */
 103 static int aac_find_esds(char *buf, size_t buflen, size_t *skip,
 104                 unsigned long *decoder_length)
 105 {
 106         size_t i;
 107
 108         for (i = 0; i + 4 < buflen; i++) {
 109                 char *p = buf + i;
 110                 int description_len;
 111
 112                 if (p[0] != 'e' || p[1] != 's' || p[2] != 'd' || p[3] != 's')
 113                         continue;
 114                 i += 8;
 115                 p = buf + i;
 116                 PARA_INFO_LOG("found esds@%zu, next: %x\n", i, *p);
 117                 if (*p == 3)
 118                         i += 8;
 119                 else
 120                         i += 6;
 121                 p = buf + i;
 122                 PARA_INFO_LOG("next: %x\n", *p);
 123                 if (*p != 4)
 124                         continue;
 125                 i += 18;
 126                 p = buf + i;
 127                 PARA_INFO_LOG("next: %x\n", *p);
 128                 if (*p != 5)
 129                         continue;
 130                 i++;
 131                 p = buf + i;
 132                 *decoder_length = aac_read_decoder_length(p, &description_len);
 133                 PARA_INFO_LOG("decoder length: %lu\n", *decoder_length);
 134                 i += description_len;
 135                 *skip = i;
 136                 return 1;
 137         }
 138         return -E_ESDS;
 139 }
 140
 141 /*
 142  * Search for the first entry in the stco table.
 143  *
 144  * \param buf Buffer to seach.
 145  * \param buflen Length of \a buf.
 146  * \param skip Upon succesful return, this contains the number
 147  * of bytes to skip from the input buffer.
 148  *
 149  * \return The position of the first entry in the table on success,
 150  * -E_STCO on errors.
 151  */
 152 static ssize_t aac_find_entry_point(char *buf, size_t buflen, size_t *skip)
 153 {
 154         ssize_t ret;
 155         size_t i;
 156
 157         for (i = 0; i + 20 < buflen; i++) {
 158                 char *p = buf + i;
 159
 160                 if (p[0] != 's' || p[1] != 't' || p[2] != 'c' || p[3] != 'o')
 161                         continue;
 162                 PARA_INFO_LOG("found stco@%zu\n", i);
 163                 i += 12;
 164                 ret = read_u32_be(buf + i); /* first offset */
 165                 i += 4;
 166                 PARA_INFO_LOG("entry point: %zd\n", ret);
 167                 *skip = i;
 168                 return ret;
 169         }
 170         PARA_WARNING_LOG("stco not found, buflen: %zu\n", buflen);
 171         return -E_STCO;
 172 }
 173
 174 static int aacdec_execute(struct btr_node *btrn, const char *cmd, char **result)
 175 {
 176         struct filter_node *fn = btr_context(btrn);
 177         struct private_aacdec_data *padd = fn->private_data;
 178
 179         return decoder_execute(cmd, padd->sample_rate, padd->channels, result);
 180 }
 181
 182 static void aacdec_open(struct filter_node *fn)
 183 {
 184         struct private_aacdec_data *padd = para_calloc(sizeof(*padd));
 185
 186         fn->private_data = padd;
 187         fn->min_iqs = 2048;
 188         padd->handle = aac_open();
 189 }
 190
 191 static void aacdec_close(struct filter_node *fn)
 192 {
 193         struct private_aacdec_data *padd = fn->private_data;
 194
 195         NeAACDecClose(padd->handle);
 196         free(padd);
 197         fn->private_data = NULL;
 198 }
 199
 200 static int aacdec_post_select(__a_unused struct sched *s, void *context)
 201 {
 202         struct filter_node *fn = context;
 203         struct btr_node *btrn = fn->btrn;
 204         struct private_aacdec_data *padd = fn->private_data;
 205         int i, ret;
 206         char *p, *inbuf, *outbuffer;
 207         char *btr_buf;
 208         size_t len, skip, consumed, loaded;
 209
 210 next_buffer:
 211         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
 212         if (ret < 0)
 213                 goto err;
 214         if (ret == 0)
 215                 return 0;
 216         btr_merge(btrn, fn->min_iqs);
 217         len = btr_next_buffer(btrn, &inbuf);
 218         len = PARA_MIN(len, (size_t)8192);
 219         consumed = 0;
 220         if (!padd->initialized) {
 221                 unsigned long rate = 0;
 222                 unsigned char channels = 0;
 223                 ret = aac_find_esds(inbuf, len, &skip, &padd->decoder_length);
 224                 if (ret < 0) {
 225                         PARA_INFO_LOG("%s\n", para_strerror(-ret));
 226                         ret = NeAACDecInit(padd->handle, (unsigned char *)inbuf,
 227                                 len, &rate, &channels);
 228                         PARA_INFO_LOG("decoder init: %d\n", ret);
 229                         if (ret < 0) {
 230                                 ret = -E_AACDEC_INIT;
 231                                 goto out;
 232                         }
 233                         consumed = ret;
 234                 } else {
 235                         PARA_INFO_LOG("decoder len: %lu\n",
 236                                 padd->decoder_length);
 237                         consumed += skip;
 238                         p = inbuf + consumed;
 239                         ret = -E_AACDEC_INIT;
 240                         if (NeAACDecInit2(padd->handle, (unsigned char *)p,
 241                                         padd->decoder_length, &rate,
 242                                         &channels) != 0)
 243                                 goto out;
 244                 }
 245                 padd->sample_rate = rate;
 246                 padd->channels = channels;
 247                 PARA_INFO_LOG("rate: %u, channels: %u\n",
 248                         padd->sample_rate, padd->channels);
 249                 padd->initialized = 1;
 250         }
 251         if (padd->decoder_length > 0) {
 252                 consumed = 0;
 253                 if (!padd->entry) {
 254                         ret = aac_find_entry_point(inbuf + consumed,
 255                                 len - consumed, &skip);
 256                         if (ret < 0) {
 257                                 ret = len;
 258                                 goto out;
 259                         }
 260                         consumed += skip;
 261                         padd->entry = ret;
 262                         PARA_INFO_LOG("entry: %zu\n", padd->entry);
 263                 }
 264                 ret = len;
 265                 if (padd->consumed_total + len < padd->entry)
 266                         goto out;
 267                 if (padd->consumed_total < padd->entry)
 268                         consumed = padd->entry - padd->consumed_total;
 269         }
 270         if (consumed >= len)
 271                 goto success;
 272         p = inbuf + consumed;
 273         //PARA_CRIT_LOG("consumed: %zu (%zu + %zu), have: %zu\n", padd->consumed_total + consumed,
 274         //      padd->consumed_total, consumed, len - consumed);
 275         outbuffer = NeAACDecDecode(padd->handle, &padd->frame_info,
 276                 (unsigned char *)p, len - consumed);
 277         if (padd->frame_info.error) {
 278                 int err = padd->frame_info.error;
 279                 ret = -E_AAC_DECODE;
 280                 if (padd->error_count++ > MAX_ERRORS)
 281                         goto err;
 282                 /* Suppress non-fatal bitstream error message at BOF/EOF */
 283                 if (len < fn->min_iqs || padd->consumed_total == 0) {
 284                         consumed = len;
 285                         goto success;
 286                 }
 287                 PARA_ERROR_LOG("%s\n", NeAACDecGetErrorMessage(err));
 288                 PARA_ERROR_LOG("consumed: %zu + %zu + %lu\n",
 289                         padd->consumed_total, consumed,
 290                         padd->frame_info.bytesconsumed);
 291                 if (consumed < len)
 292                         consumed++; /* catch 21 */
 293                 goto success;
 294         }
 295         padd->error_count = 0;
 296         //PARA_CRIT_LOG("decoder ate %lu\n", padd->frame_info.bytesconsumed);
 297         consumed += padd->frame_info.bytesconsumed;
 298         ret = consumed;
 299         if (!padd->frame_info.samples)
 300                 goto out;
 301         btr_buf = para_malloc(2 * padd->frame_info.samples);
 302         loaded = 0;
 303         for (i = 0; i < padd->frame_info.samples; i++) {
 304                 short sh = ((short *)outbuffer)[i];
 305                 write_int16_host_endian(btr_buf + loaded, sh);
 306                 loaded += 2;
 307         }
 308         btr_add_output(btr_buf, loaded, btrn);
 309 success:
 310         ret = consumed;
 311 out:
 312         if (ret >= 0) {
 313                 padd->consumed_total += ret;
 314                 btr_consume(btrn, ret);
 315                 goto next_buffer;
 316         }
 317 err:
 318         assert(ret < 0);
 319         btr_remove_node(&fn->btrn);
 320         return ret;
 321 }
 322
 323 /**
 324  * The init function of the aacdec filter.
 325  *
 326  * \param f Pointer to the filter struct to initialize.
 327  *
 328  * \sa filter::init
 329  */
 330 void aacdec_filter_init(struct filter *f)
 331 {
 332         f->open = aacdec_open;
 333         f->close = aacdec_close;
 334         f->pre_select = generic_filter_pre_select;
 335         f->post_select = aacdec_post_select;
 336         f->execute = aacdec_execute;
 337 }