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
  15 #include "para.h"
  16 #include "list.h"
  17 #include "sched.h"
  18 #include "ggo.h"
  19 #include "buffer_tree.h"
  20 #include "filter.h"
  21 #include "error.h"
  22 #include "string.h"
  23 #include "aac.h"
  24
  25 /** Give up decoding after that many errors. */
  26 #define MAX_ERRORS 20
  27
  28 /**
  29  * data specific to the aacdec filter
  30  *
  31  * \sa filter, filter_node
  32  */
  33 struct private_aacdec_data {
  34         /** the return value of aac_open */
  35         NeAACDecHandle handle;
  36         /** info about the currently decoded frame */
  37         NeAACDecFrameInfo frame_info;
  38         /** whether this instance of the aac decoder is already initialized */
  39         int initialized;
  40         /**
  41          * return value of aac_find_esds(). Used to call the right aacdec
  42          * init function
  43          */
  44         unsigned long decoder_length;
  45         /** number of times the decoder returned an error */
  46         unsigned error_count;
  47         /** number of bytes already consumed from the imput stream */
  48         size_t consumed_total;
  49         /** return value of aac_find_entry_point */
  50         size_t entry;
  51         /** The number of channels of the current stream. */
  52         unsigned int channels;
  53         /** Current sample rate in Hz. */
  54         unsigned int sample_rate;
  55 };
  56
  57 static int aacdec_execute(struct btr_node *btrn, const char *cmd, char **result)
  58 {
  59         struct filter_node *fn = btr_context(btrn);
  60         struct private_aacdec_data *padd = fn->private_data;
  61
  62         return decoder_execute(cmd, padd->sample_rate, padd->channels, result);
  63 }
  64
  65 static void aacdec_open(struct filter_node *fn)
  66 {
  67         struct private_aacdec_data *padd = para_calloc(sizeof(*padd));
  68
  69         fn->private_data = padd;
  70         fn->min_iqs = 2048;
  71         padd->handle = aac_open();
  72 }
  73
  74 static void aacdec_close(struct filter_node *fn)
  75 {
  76         struct private_aacdec_data *padd = fn->private_data;
  77
  78         NeAACDecClose(padd->handle);
  79         free(padd);
  80         fn->private_data = NULL;
  81 }
  82
  83 static int aacdec_post_select(__a_unused struct sched *s, void *context)
  84 {
  85         struct filter_node *fn = context;
  86         struct btr_node *btrn = fn->btrn;
  87         struct private_aacdec_data *padd = fn->private_data;
  88         int i, ret;
  89         char *p, *inbuf, *outbuffer;
  90         char *btr_buf;
  91         size_t len, skip, consumed, loaded;
  92
  93 next_buffer:
  94         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
  95         if (ret < 0)
  96                 goto err;
  97         if (ret == 0)
  98                 return 0;
  99         btr_merge(btrn, fn->min_iqs);
 100         len = btr_next_buffer(btrn, &inbuf);
 101         len = PARA_MIN(len, (size_t)8192);
 102         consumed = 0;
 103         if (!padd->initialized) {
 104                 unsigned long rate = 0;
 105                 unsigned char channels = 0;
 106                 ret = aac_find_esds(inbuf, len, &skip, &padd->decoder_length);
 107                 if (ret < 0) {
 108                         PARA_INFO_LOG("%s\n", para_strerror(-ret));
 109                         ret = NeAACDecInit(padd->handle, (unsigned char *)inbuf,
 110                                 len, &rate, &channels);
 111                         PARA_INFO_LOG("decoder init: %d\n", ret);
 112                         if (ret < 0) {
 113                                 ret = -E_AACDEC_INIT;
 114                                 goto out;
 115                         }
 116                         consumed = ret;
 117                 } else {
 118                         PARA_INFO_LOG("decoder len: %lu\n",
 119                                 padd->decoder_length);
 120                         consumed += skip;
 121                         p = inbuf + consumed;
 122                         ret = -E_AACDEC_INIT;
 123                         if (NeAACDecInit2(padd->handle, (unsigned char *)p,
 124                                         padd->decoder_length, &rate,
 125                                         &channels) != 0)
 126                                 goto out;
 127                 }
 128                 padd->sample_rate = rate;
 129                 padd->channels = channels;
 130                 PARA_INFO_LOG("rate: %u, channels: %u\n",
 131                         padd->sample_rate, padd->channels);
 132                 padd->initialized = 1;
 133         }
 134         if (padd->decoder_length > 0) {
 135                 consumed = 0;
 136                 if (!padd->entry) {
 137                         ret = aac_find_entry_point(inbuf + consumed,
 138                                 len - consumed, &skip);
 139                         if (ret < 0) {
 140                                 ret = len;
 141                                 goto out;
 142                         }
 143                         consumed += skip;
 144                         padd->entry = ret;
 145                         PARA_INFO_LOG("entry: %zu\n", padd->entry);
 146                 }
 147                 ret = len;
 148                 if (padd->consumed_total + len < padd->entry)
 149                         goto out;
 150                 if (padd->consumed_total < padd->entry)
 151                         consumed = padd->entry - padd->consumed_total;
 152         }
 153         for (; consumed < len; consumed++)
 154                 if ((inbuf[consumed] & 0xfe) == 0x20)
 155                         break;
 156         if (consumed >= len)
 157                 goto success;
 158         p = inbuf + consumed;
 159         //PARA_CRIT_LOG("consumed: %zu (%zu + %zu), have: %zu\n", padd->consumed_total + consumed,
 160         //      padd->consumed_total, consumed, len - consumed);
 161         outbuffer = NeAACDecDecode(padd->handle, &padd->frame_info,
 162                 (unsigned char *)p, len - consumed);
 163         if (padd->frame_info.error) {
 164                 int err = padd->frame_info.error;
 165                 ret = -E_AAC_DECODE;
 166                 if (padd->error_count++ > MAX_ERRORS)
 167                         goto err;
 168                 /* Suppress non-fatal bitstream error message at BOF/EOF */
 169                 if (len < fn->min_iqs || padd->consumed_total == 0) {
 170                         consumed = len;
 171                         goto success;
 172                 }
 173                 PARA_ERROR_LOG("%s\n", NeAACDecGetErrorMessage(err));
 174                 PARA_ERROR_LOG("consumed: %zu + %zu + %lu\n",
 175                         padd->consumed_total, consumed,
 176                         padd->frame_info.bytesconsumed);
 177                 if (consumed < len)
 178                         consumed++; /* catch 21 */
 179                 goto success;
 180         }
 181         padd->error_count = 0;
 182         //PARA_CRIT_LOG("decoder ate %lu\n", padd->frame_info.bytesconsumed);
 183         consumed += padd->frame_info.bytesconsumed;
 184         ret = consumed;
 185         if (!padd->frame_info.samples)
 186                 goto out;
 187         btr_buf = para_malloc(2 * padd->frame_info.samples);
 188         loaded = 0;
 189         for (i = 0; i < padd->frame_info.samples; i++) {
 190                 short sh = ((short *)outbuffer)[i];
 191                 write_int16_host_endian(btr_buf + loaded, sh);
 192                 loaded += 2;
 193         }
 194         btr_add_output(btr_buf, loaded, btrn);
 195 success:
 196         ret = consumed;
 197 out:
 198         if (ret >= 0) {
 199                 padd->consumed_total += ret;
 200                 btr_consume(btrn, ret);
 201                 goto next_buffer;
 202         }
 203 err:
 204         assert(ret < 0);
 205         btr_remove_node(&fn->btrn);
 206         return ret;
 207 }
 208
 209 /**
 210  * The init function of the aacdec filter.
 211  *
 212  * \param f Pointer to the filter struct to initialize.
 213  *
 214  * \sa filter::init
 215  */
 216 void aacdec_filter_init(struct filter *f)
 217 {
 218         f->open = aacdec_open;
 219         f->close = aacdec_close;
 220         f->pre_select = generic_filter_pre_select;
 221         f->post_select = aacdec_post_select;
 222         f->execute = aacdec_execute;
 223 }