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         unsigned long 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                 ret = aac_find_esds(inbuf, len, &skip, &padd->decoder_length);
  83                 if (ret < 0) {
  84                         PARA_INFO_LOG("%s\n", PARA_STRERROR(-ret));
  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                         PARA_INFO_LOG("decoder len: %lu\n",
  95                                 padd->decoder_length);
  96                         consumed += skip;
  97                         p = inbuf + consumed;
  98                         ret = -E_AACDEC_INIT;
  99                         if (NeAACDecInit2(padd->handle, p,
 100                                         padd->decoder_length, &rate,
 101                                         &channels) < 0)
 102                                 goto out;
 103                 }
 104                 fc->samplerate = rate;
 105                 fc->channels = channels;
 106                 PARA_INFO_LOG("rate: %u, channels: %d\n",
 107                         fc->samplerate, fc->channels);
 108                 padd->initialized = 1;
 109         }
 110         if (padd->decoder_length > 0) {
 111                 consumed = 0;
 112                 if (!padd->entry) {
 113                         ret = aac_find_entry_point(inbuf + consumed,
 114                                 len - consumed, &skip);
 115                         if (ret < 0) {
 116                                 ret = len;
 117                                 goto out;
 118                         }
 119                         consumed += skip;
 120                         padd->entry = ret;
 121                         PARA_INFO_LOG("entry: %zu\n", padd->entry);
 122                 }
 123                 ret = len;
 124                 if (padd->consumed_total + len < padd->entry)
 125                         goto out;
 126                 if (padd->consumed_total < padd->entry)
 127                         consumed = padd->entry - padd->consumed_total;
 128         }
 129         for (; consumed < len; consumed++)
 130                 if ((inbuf[consumed] & 0xfe) == 0x20)
 131                         break;
 132         if (consumed >= len)
 133                 goto success;
 134         p = inbuf + consumed;
 135         outbuffer = NeAACDecDecode(padd->handle, &padd->frame_info, p,
 136                 len - consumed);
 137         if (padd->frame_info.error) {
 138                 ret = -E_AAC_DECODE;
 139                 if (padd->error_count++ > MAX_ERRORS)
 140                         goto out;
 141                 PARA_ERROR_LOG("frame_error: %d, consumed: %zu + %zd + %lu\n",
 142                         padd->frame_info.error, padd->consumed_total,
 143                         consumed, padd->frame_info.bytesconsumed);
 144                 PARA_ERROR_LOG("%s\n", NeAACDecGetErrorMessage(
 145                         padd->frame_info.error));
 146                 consumed++; /* catch 21 */
 147                 goto success;
 148         }
 149         padd->error_count = 0;
 150         consumed += padd->frame_info.bytesconsumed;
 151         ret = consumed;
 152         if (!padd->frame_info.samples)
 153                 goto out;
 154         ret = -E_AAC_OVERRUN;
 155         if (padd->frame_info.samples * 2 + fn->loaded > fn->bufsize)
 156                 goto out;
 157         for (i = 0; i < padd->frame_info.samples; i++) {
 158                 short *s = (short *)outbuffer;
 159                 write_int16_host_endian(fn->buf + fn->loaded, s[i]);
 160                 fn->loaded += 2;
 161         }
 162 success:
 163         ret = consumed;
 164 out:
 165         if (ret > 0)
 166                 padd->consumed_total += ret;
 167         return ret;
 168 }
 169
 170 static void aacdec_open(struct filter_node *fn)
 171 {
 172         fn->private_data = para_calloc(sizeof(struct private_aacdec_data));
 173         struct private_aacdec_data *padd = fn->private_data;
 174
 175         fn->bufsize = AAC_OUTBUF_SIZE;
 176         fn->buf = para_calloc(fn->bufsize);
 177         padd->handle = aac_open();
 178 }
 179
 180 static void aacdec_close(struct filter_node *fn)
 181 {
 182         struct private_aacdec_data *padd = fn->private_data;
 183
 184         NeAACDecClose(padd->handle);
 185         free(fn->buf);
 186         fn->buf = NULL;
 187         free(padd);
 188         fn->private_data = NULL;
 189 }
 190
 191 /**
 192  * the init function of the aacdec filter
 193  *
 194  * \param f pointer to the filter struct to initialize
 195  *
 196  * \sa filter::init
 197  */
 198 void aacdec_init(struct filter *f)
 199 {
 200         f->open = aacdec_open;
 201         f->convert = aacdec;
 202         f->close = aacdec_close;
 203 }