aacdec_filter.c

   1 /*
   2  * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
   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 <stdbool.h>
  15
  16 #include "para.h"
  17 #include "list.h"
  18 #include "sched.h"
  19 #include "ggo.h"
  20 #include "buffer_tree.h"
  21 #include "filter.h"
  22 #include "error.h"
  23 #include "string.h"
  24 #include "aac.h"
  25
  26 /** the output buffer size */
  27 #define AAC_OUTBUF_SIZE (32 * 1024)
  28
  29 /** give up decoding after that many errors */
  30 #define MAX_ERRORS 20
  31
  32 /**
  33  * data specific to the aacdec filter
  34  *
  35  * \sa filter, filter_node
  36  */
  37 struct private_aacdec_data {
  38         /** the return value of aac_open */
  39         NeAACDecHandle handle;
  40         /** info about the currently decoded frame */
  41         NeAACDecFrameInfo frame_info;
  42         /** whether this instance of the aac decoder is already initialized */
  43         int initialized;
  44         /**
  45          * return value of aac_find_esds(). Used to call the right aacdec
  46          * init function
  47          */
  48         unsigned long decoder_length;
  49         /** number of times the decoder returned an error */
  50         unsigned error_count;
  51         /** number of bytes already consumed from the imput stream */
  52         size_t consumed_total;
  53         /** return value of aac_find_entry_point */
  54         size_t entry;
  55 };
  56
  57 static ssize_t aacdec(char *input_buffer, size_t len, struct filter_node *fn)
  58 {
  59         struct private_aacdec_data *padd = fn->private_data;
  60         struct filter_chain *fc = fn->fc;
  61         int i, ret;
  62         unsigned char *p, *outbuffer;
  63         unsigned char *inbuf = (unsigned char*)input_buffer;
  64         size_t skip, consumed = 0;
  65
  66         if (fn->loaded > fn->bufsize * 3 / 5)
  67                 return 0;
  68         ret = *fc->input_error;
  69         if (ret < 0)
  70                 return ret;
  71         if (len < 2048)
  72                 return 0;
  73
  74         if (!padd->initialized) {
  75                 unsigned long rate = 0;
  76                 unsigned char channels = 0;
  77                 ret = aac_find_esds(inbuf, len, &skip, &padd->decoder_length);
  78                 if (ret < 0) {
  79                         PARA_INFO_LOG("%s\n", para_strerror(-ret));
  80                         ret = NeAACDecInit(padd->handle, inbuf,
  81                                 len, &rate, &channels);
  82                         PARA_INFO_LOG("decoder init: %d\n", ret);
  83                         if (ret < 0) {
  84                                 ret = -E_AACDEC_INIT;
  85                                 goto out;
  86                         }
  87                         consumed = ret;
  88                 } else {
  89                         PARA_INFO_LOG("decoder len: %lu\n",
  90                                 padd->decoder_length);
  91                         consumed += skip;
  92                         p = inbuf + consumed;
  93                         ret = -E_AACDEC_INIT;
  94                         if (NeAACDecInit2(padd->handle, p,
  95                                         padd->decoder_length, &rate,
  96                                         &channels) < 0)
  97                                 goto out;
  98                 }
  99                 fc->samplerate = rate;
 100                 fc->channels = channels;
 101                 PARA_INFO_LOG("rate: %u, channels: %d\n",
 102                         fc->samplerate, fc->channels);
 103                 padd->initialized = 1;
 104         }
 105         if (padd->decoder_length > 0) {
 106                 consumed = 0;
 107                 if (!padd->entry) {
 108                         ret = aac_find_entry_point(inbuf + consumed,
 109                                 len - consumed, &skip);
 110                         if (ret < 0) {
 111                                 ret = len;
 112                                 goto out;
 113                         }
 114                         consumed += skip;
 115                         padd->entry = ret;
 116                         PARA_INFO_LOG("entry: %zu\n", padd->entry);
 117                 }
 118                 ret = len;
 119                 if (padd->consumed_total + len < padd->entry)
 120                         goto out;
 121                 if (padd->consumed_total < padd->entry)
 122                         consumed = padd->entry - padd->consumed_total;
 123         }
 124         for (; consumed < len; consumed++)
 125                 if ((inbuf[consumed] & 0xfe) == 0x20)
 126                         break;
 127         if (consumed >= len)
 128                 goto success;
 129         p = inbuf + consumed;
 130         outbuffer = NeAACDecDecode(padd->handle, &padd->frame_info, p,
 131                 len - consumed);
 132         if (padd->frame_info.error) {
 133                 ret = -E_AAC_DECODE;
 134                 if (padd->error_count++ > MAX_ERRORS)
 135                         goto out;
 136                 PARA_ERROR_LOG("frame_error: %d, consumed: %zu + %zd + %lu\n",
 137                         padd->frame_info.error, padd->consumed_total,
 138                         consumed, padd->frame_info.bytesconsumed);
 139                 PARA_ERROR_LOG("%s\n", NeAACDecGetErrorMessage(
 140                         padd->frame_info.error));
 141                 consumed++; /* catch 21 */
 142                 goto success;
 143         }
 144         padd->error_count = 0;
 145         consumed += padd->frame_info.bytesconsumed;
 146         ret = consumed;
 147         if (!padd->frame_info.samples)
 148                 goto out;
 149         ret = -E_AAC_OVERRUN;
 150         if (padd->frame_info.samples * 2 + fn->loaded > fn->bufsize)
 151                 goto out;
 152         for (i = 0; i < padd->frame_info.samples; i++) {
 153                 short *s = (short *)outbuffer;
 154                 write_int16_host_endian(fn->buf + fn->loaded, s[i]);
 155                 fn->loaded += 2;
 156         }
 157 success:
 158         ret = consumed;
 159 out:
 160         if (ret > 0)
 161                 padd->consumed_total += ret;
 162         return ret;
 163 }
 164
 165 static void aacdec_open(struct filter_node *fn)
 166 {
 167         struct private_aacdec_data *padd = para_calloc(sizeof(*padd));
 168
 169         fn->private_data = padd;
 170         fn->bufsize = AAC_OUTBUF_SIZE;
 171         fn->buf = para_calloc(fn->bufsize);
 172         padd->handle = aac_open();
 173 }
 174
 175 static void aacdec_close(struct filter_node *fn)
 176 {
 177         struct private_aacdec_data *padd = fn->private_data;
 178
 179         NeAACDecClose(padd->handle);
 180         free(fn->buf);
 181         fn->buf = NULL;
 182         free(padd);
 183         fn->private_data = NULL;
 184 }
 185
 186 /**
 187  * the init function of the aacdec filter
 188  *
 189  * \param f pointer to the filter struct to initialize
 190  *
 191  * \sa filter::init
 192  */
 193 void aacdec_filter_init(struct filter *f)
 194 {
 195         f->open = aacdec_open;
 196         f->convert = aacdec;
 197         f->close = aacdec_close;
 198 }