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