aacdec.c

   1 /*
   2  * Copyright (C) 2006-2007 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  * based in parts on libfaad, Copyright (C) 2003-2005 M. Bakker,
  20  * Ahead Software AG
  21  */
  22
  23 /** \file aacdec.c paraslash's aac (m4a) decoder */
  24
  25 #include "para.h"
  26
  27 #include "list.h"
  28 #include "sched.h"
  29 #include "filter.h"
  30 #include "error.h"
  31 #include "string.h"
  32 #include "aac.h"
  33
  34 /** the output buffer size */
  35 #define AAC_OUTBUF_SIZE (32 * 1024)
  36
  37 /** give up decoding after that many errors */
  38 #define MAX_ERRORS 20
  39
  40 /**
  41  * data specific to the aacdec filter
  42  *
  43  * \sa filter, filter_node
  44  */
  45 struct private_aacdec_data {
  46         /** the return value of aac_open */
  47         NeAACDecHandle handle;
  48         /** info about the currently decoded frame */
  49         NeAACDecFrameInfo frame_info;
  50         /** whether this instance of the aac decoder is already initialized */
  51         int initialized;
  52         /**
  53          * return value of aac_find_esds(). Used to call the right aacdec
  54          * init function
  55          */
  56         int decoder_length;
  57         /** number of times the decoder returned an error */
  58         unsigned error_count;
  59         /** number of bytes already consumed from the imput stream */
  60         size_t consumed_total;
  61         /** return value of aac_find_entry_point */
  62         size_t entry;
  63 };
  64
  65 static ssize_t aacdec(char *input_buffer, size_t len, struct filter_node *fn)
  66 {
  67         struct private_aacdec_data *padd = fn->private_data;
  68         struct filter_chain *fc = fn->fc;
  69         int i, ret;
  70         unsigned char *p, *outbuffer;
  71         unsigned char *inbuf = (unsigned char*)input_buffer;
  72         size_t skip, consumed = 0;
  73
  74         if (fn->loaded > fn->bufsize * 3 / 5)
  75                 return 0;
  76         if (len < 2048 && !*fc->input_eof)
  77                 return 0;
  78
  79         if (!padd->initialized) {
  80                 unsigned long rate = 0;
  81                 unsigned char channels = 0;
  82                 padd->decoder_length = aac_find_esds(inbuf, len, &skip);
  83                 PARA_INFO_LOG("decoder len: %d\n", padd->decoder_length);
  84                 if (padd->decoder_length < 0) {
  85                         ret = NeAACDecInit(padd->handle, inbuf,
  86                                 len, &rate, &channels);
  87                         PARA_INFO_LOG("decoder init: %d\n", ret);
  88                         if (ret < 0) {
  89                                 ret = -E_AACDEC_INIT;
  90                                 goto out;
  91                         }
  92                         consumed = ret;
  93                 } else {
  94                         consumed += skip;
  95                         p = inbuf + consumed;
  96                         ret = -E_AACDEC_INIT;
  97                         if (NeAACDecInit2(padd->handle, p,
  98                                         padd->decoder_length, &rate,
  99                                         &channels) < 0)
 100                                 goto out;
 101                 }
 102                 fc->samplerate = rate;
 103                 fc->channels = channels;
 104                 PARA_INFO_LOG("rate: %u, channels: %d\n",
 105                         fc->samplerate, fc->channels);
 106                 padd->initialized = 1;
 107         }
 108         if (padd->decoder_length > 0) {
 109                 consumed = 0;
 110                 if (!padd->entry) {
 111                         ret = aac_find_entry_point(inbuf + consumed,
 112                                 len - consumed, &skip);
 113                         if (ret < 0) {
 114                                 ret = len;
 115                                 goto out;
 116                         }
 117                         consumed += skip;
 118                         padd->entry = ret;
 119                         PARA_INFO_LOG("entry: %zu\n", padd->entry);
 120                 }
 121                 ret = len;
 122                 if (padd->consumed_total + len < padd->entry)
 123                         goto out;
 124                 if (padd->consumed_total < padd->entry)
 125                         consumed = padd->entry - padd->consumed_total;
 126         }
 127         for (; consumed < len; consumed++)
 128                 if ((inbuf[consumed] & 0xfe) == 0x20)
 129                         break;
 130         if (consumed >= len)
 131                 goto success;
 132         p = inbuf + consumed;
 133         outbuffer = NeAACDecDecode(padd->handle, &padd->frame_info, p,
 134                 len - consumed);
 135         if (padd->frame_info.error) {
 136                 ret = -E_AAC_DECODE;
 137                 if (padd->error_count++ > MAX_ERRORS)
 138                         goto out;
 139                 PARA_ERROR_LOG("frame_error: %d, consumed: %zu + %zd + %lu\n",
 140                         padd->frame_info.error, padd->consumed_total,
 141                         consumed, padd->frame_info.bytesconsumed);
 142                 PARA_ERROR_LOG("%s\n", NeAACDecGetErrorMessage(
 143                         padd->frame_info.error));
 144                 consumed++; /* catch 21 */
 145                 goto success;
 146         }
 147         padd->error_count = 0;
 148         consumed += padd->frame_info.bytesconsumed;
 149         ret = consumed;
 150         if (!padd->frame_info.samples)
 151                 goto out;
 152         ret = -E_AAC_OVERRUN;
 153         if (padd->frame_info.samples * 2 + fn->loaded > fn->bufsize)
 154                 goto out;
 155         for (i = 0; i < padd->frame_info.samples; i++) {
 156                 short *s = (short *)outbuffer;
 157                 fn->buf[fn->loaded++] = s[i] & 0xff;
 158                 fn->buf[fn->loaded++] = (s[i] >> 8) & 0xff;
 159         }
 160 success:
 161         ret = consumed;
 162 out:
 163         if (ret > 0)
 164                 padd->consumed_total += ret;
 165         return ret;
 166 }
 167
 168 static void aacdec_open(struct filter_node *fn)
 169 {
 170         fn->private_data = para_calloc(sizeof(struct private_aacdec_data));
 171         struct private_aacdec_data *padd = fn->private_data;
 172
 173         fn->bufsize = AAC_OUTBUF_SIZE;
 174         fn->buf = para_calloc(fn->bufsize);
 175         padd->handle = aac_open();
 176 }
 177
 178 static void aacdec_close(struct filter_node *fn)
 179 {
 180         struct private_aacdec_data *padd = fn->private_data;
 181
 182         NeAACDecClose(padd->handle);
 183         free(fn->buf);
 184         fn->buf = NULL;
 185         free(padd);
 186         fn->private_data = NULL;
 187 }
 188
 189 /**
 190  * the init function of the aacdec filter
 191  *
 192  * \param f pointer to the filter struct to initialize
 193  *
 194  * \sa filter::init
 195  */
 196 void aacdec_init(struct filter *f)
 197 {
 198         f->open = aacdec_open;
 199         f->convert = aacdec;
 200         f->close = aacdec_close;
 201 }