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 "para.h"
  14
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "ggo.h"
  18 #include "filter.h"
  19 #include "error.h"
  20 #include "string.h"
  21 #include "aac.h"
  22
  23 /** the output buffer size */
  24 #define AAC_OUTBUF_SIZE (32 * 1024)
  25
  26 /** give up decoding after that many errors */
  27 #define MAX_ERRORS 20
  28
  29 /**
  30  * data specific to the aacdec filter
  31  *
  32  * \sa filter, filter_node
  33  */
  34 struct private_aacdec_data {
  35         /** the return value of aac_open */
  36         NeAACDecHandle handle;
  37         /** info about the currently decoded frame */
  38         NeAACDecFrameInfo frame_info;
  39         /** whether this instance of the aac decoder is already initialized */
  40         int initialized;
  41         /**
  42          * return value of aac_find_esds(). Used to call the right aacdec
  43          * init function
  44          */
  45         unsigned long decoder_length;
  46         /** number of times the decoder returned an error */
  47         unsigned error_count;
  48         /** number of bytes already consumed from the imput stream */
  49         size_t consumed_total;
  50         /** return value of aac_find_entry_point */
  51         size_t entry;
  52 };
  53
  54 static ssize_t aacdec(char *input_buffer, size_t len, struct filter_node *fn)
  55 {
  56         struct private_aacdec_data *padd = fn->private_data;
  57         struct filter_chain *fc = fn->fc;
  58         int i, ret;
  59         unsigned char *p, *outbuffer;
  60         unsigned char *inbuf = (unsigned char*)input_buffer;
  61         size_t skip, consumed = 0;
  62
  63         if (fn->loaded > fn->bufsize * 3 / 5)
  64                 return 0;
  65         ret = *fc->input_error;
  66         if (ret < 0)
  67                 return ret;
  68         if (len < 2048)
  69                 return 0;
  70
  71         if (!padd->initialized) {
  72                 unsigned long rate = 0;
  73                 unsigned char channels = 0;
  74                 ret = aac_find_esds(inbuf, len, &skip, &padd->decoder_length);
  75                 if (ret < 0) {
  76                         PARA_INFO_LOG("%s\n", para_strerror(-ret));
  77                         ret = NeAACDecInit(padd->handle, inbuf,
  78                                 len, &rate, &channels);
  79                         PARA_INFO_LOG("decoder init: %d\n", ret);
  80                         if (ret < 0) {
  81                                 ret = -E_AACDEC_INIT;
  82                                 goto out;
  83                         }
  84                         consumed = ret;
  85                 } else {
  86                         PARA_INFO_LOG("decoder len: %lu\n",
  87                                 padd->decoder_length);
  88                         consumed += skip;
  89                         p = inbuf + consumed;
  90                         ret = -E_AACDEC_INIT;
  91                         if (NeAACDecInit2(padd->handle, p,
  92                                         padd->decoder_length, &rate,
  93                                         &channels) < 0)
  94                                 goto out;
  95                 }
  96                 fc->samplerate = rate;
  97                 fc->channels = channels;
  98                 PARA_INFO_LOG("rate: %u, channels: %d\n",
  99                         fc->samplerate, fc->channels);
 100                 padd->initialized = 1;
 101         }
 102         if (padd->decoder_length > 0) {
 103                 consumed = 0;
 104                 if (!padd->entry) {
 105                         ret = aac_find_entry_point(inbuf + consumed,
 106                                 len - consumed, &skip);
 107                         if (ret < 0) {
 108                                 ret = len;
 109                                 goto out;
 110                         }
 111                         consumed += skip;
 112                         padd->entry = ret;
 113                         PARA_INFO_LOG("entry: %zu\n", padd->entry);
 114                 }
 115                 ret = len;
 116                 if (padd->consumed_total + len < padd->entry)
 117                         goto out;
 118                 if (padd->consumed_total < padd->entry)
 119                         consumed = padd->entry - padd->consumed_total;
 120         }
 121         for (; consumed < len; consumed++)
 122                 if ((inbuf[consumed] & 0xfe) == 0x20)
 123                         break;
 124         if (consumed >= len)
 125                 goto success;
 126         p = inbuf + consumed;
 127         outbuffer = NeAACDecDecode(padd->handle, &padd->frame_info, p,
 128                 len - consumed);
 129         if (padd->frame_info.error) {
 130                 ret = -E_AAC_DECODE;
 131                 if (padd->error_count++ > MAX_ERRORS)
 132                         goto out;
 133                 PARA_ERROR_LOG("frame_error: %d, consumed: %zu + %zd + %lu\n",
 134                         padd->frame_info.error, padd->consumed_total,
 135                         consumed, padd->frame_info.bytesconsumed);
 136                 PARA_ERROR_LOG("%s\n", NeAACDecGetErrorMessage(
 137                         padd->frame_info.error));
 138                 consumed++; /* catch 21 */
 139                 goto success;
 140         }
 141         padd->error_count = 0;
 142         consumed += padd->frame_info.bytesconsumed;
 143         ret = consumed;
 144         if (!padd->frame_info.samples)
 145                 goto out;
 146         ret = -E_AAC_OVERRUN;
 147         if (padd->frame_info.samples * 2 + fn->loaded > fn->bufsize)
 148                 goto out;
 149         for (i = 0; i < padd->frame_info.samples; i++) {
 150                 short *s = (short *)outbuffer;
 151                 write_int16_host_endian(fn->buf + fn->loaded, s[i]);
 152                 fn->loaded += 2;
 153         }
 154 success:
 155         ret = consumed;
 156 out:
 157         if (ret > 0)
 158                 padd->consumed_total += ret;
 159         return ret;
 160 }
 161
 162 static void aacdec_open(struct filter_node *fn)
 163 {
 164         struct private_aacdec_data *padd = para_calloc(sizeof(*padd));
 165
 166         fn->private_data = padd;
 167         fn->bufsize = AAC_OUTBUF_SIZE;
 168         fn->buf = para_calloc(fn->bufsize);
 169         padd->handle = aac_open();
 170 }
 171
 172 static void aacdec_close(struct filter_node *fn)
 173 {
 174         struct private_aacdec_data *padd = fn->private_data;
 175
 176         NeAACDecClose(padd->handle);
 177         free(fn->buf);
 178         fn->buf = NULL;
 179         free(padd);
 180         fn->private_data = NULL;
 181 }
 182
 183 /**
 184  * the init function of the aacdec filter
 185  *
 186  * \param f pointer to the filter struct to initialize
 187  *
 188  * \sa filter::init
 189  */
 190 void aacdec_filter_init(struct filter *f)
 191 {
 192         f->open = aacdec_open;
 193         f->convert = aacdec;
 194         f->close = aacdec_close;
 195 }