libmpdemux/demux_aac.c

   1 /*
   2  * This file is part of MPlayer.
   3  *
   4  * MPlayer 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  * MPlayer 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 along
  15  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22
  23 #include "config.h"
  24 #include "mp_msg.h"
  25
  26 #include "stream/stream.h"
  27 #include "demuxer.h"
  28 #include "parse_es.h"
  29 #include "stheader.h"
  30 #include "aac_hdr.h"
  31 #include "ms_hdr.h"
  32
  33 typedef struct {
  34         uint8_t *buf;
  35         uint64_t size;  /// amount of time of data packets pushed to demuxer->audio (in bytes)
  36         float time;     /// amount of time elapsed based upon samples_per_frame/sample_rate (in milliseconds)
  37         float last_pts; /// last pts seen
  38         int bitrate;    /// bitrate computed as size/time
  39 } aac_priv_t;
  40
  41 static int demux_aac_init(demuxer_t *demuxer)
  42 {
  43         aac_priv_t *priv;
  44
  45         priv = calloc(1, sizeof(aac_priv_t));
  46         if(!priv)
  47                 return 0;
  48
  49         priv->buf = malloc(8);
  50         if(!priv->buf)
  51         {
  52                 free(priv);
  53                 return 0;
  54         }
  55
  56         demuxer->priv = priv;
  57         return 1;
  58 }
  59
  60 static void demux_close_aac(demuxer_t *demuxer)
  61 {
  62         aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
  63
  64         if(!priv)
  65                 return;
  66
  67         if(priv->buf)
  68                 free(priv->buf);
  69
  70         free(demuxer->priv);
  71
  72         return;
  73 }
  74
  75 /// returns DEMUXER_TYPE_AAC if it finds 8 ADTS frames in 32768 bytes, 0 otherwise
  76 static int demux_aac_probe(demuxer_t *demuxer)
  77 {
  78         int cnt = 0, c, len, srate, num;
  79         off_t init, probed;
  80         aac_priv_t *priv;
  81
  82         if(! demux_aac_init(demuxer))
  83         {
  84                 mp_msg(MSGT_DEMUX, MSGL_ERR, "COULDN'T INIT aac_demux, exit\n");
  85                 return 0;
  86         }
  87
  88         priv = (aac_priv_t *) demuxer->priv;
  89
  90         init = probed = stream_tell(demuxer->stream);
  91         while(probed-init <= 32768 && cnt < 8)
  92         {
  93                 c = 0;
  94                 while(c != 0xFF)
  95                 {
  96                         c = stream_read_char(demuxer->stream);
  97                         if(c < 0)
  98                                 goto fail;
  99                 }
 100                 priv->buf[0] = 0xFF;
 101                 if(stream_read(demuxer->stream, &(priv->buf[1]), 7) < 7)
 102                         goto fail;
 103
 104                 len = aac_parse_frame(priv->buf, &srate, &num);
 105                 if(len > 0)
 106                 {
 107                         cnt++;
 108                         stream_skip(demuxer->stream, len - 8);
 109                 }
 110                 probed = stream_tell(demuxer->stream);
 111         }
 112
 113         stream_seek(demuxer->stream, init);
 114         if(cnt < 8)
 115                 goto fail;
 116
 117         mp_msg(MSGT_DEMUX, MSGL_V, "demux_aac_probe, INIT: %"PRIu64", PROBED: %"PRIu64", cnt: %d\n", init, probed, cnt);
 118         return DEMUXER_TYPE_AAC;
 119
 120 fail:
 121         mp_msg(MSGT_DEMUX, MSGL_V, "demux_aac_probe, failed to detect an AAC stream\n");
 122         return 0;
 123 }
 124
 125 static demuxer_t* demux_aac_open(demuxer_t *demuxer)
 126 {
 127         sh_audio_t *sh;
 128
 129         sh = new_sh_audio(demuxer, 0);
 130         sh->ds = demuxer->audio;
 131         sh->format = mmioFOURCC('M', 'P', '4', 'A');
 132         demuxer->audio->id = 0;
 133         demuxer->audio->sh = sh;
 134
 135         demuxer->filepos = stream_tell(demuxer->stream);
 136
 137         return demuxer;
 138 }
 139
 140 static int demux_aac_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds)
 141 {
 142         aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
 143         demux_packet_t *dp;
 144         int c1, c2, len, srate, num;
 145         float tm = 0;
 146
 147         if(demuxer->stream->eof || (demuxer->movi_end && stream_tell(demuxer->stream) >= demuxer->movi_end))
 148                 return 0;
 149
 150         while(! demuxer->stream->eof)
 151         {
 152                 c1 = c2 = 0;
 153                 while(c1 != 0xFF)
 154                 {
 155                         c1 = stream_read_char(demuxer->stream);
 156                         if(c1 < 0)
 157                                 return 0;
 158                 }
 159                 c2 = stream_read_char(demuxer->stream);
 160                 if(c2 < 0)
 161                         return 0;
 162                 if((c2 & 0xF6) != 0xF0)
 163                         continue;
 164
 165                 priv->buf[0] = (unsigned char) c1;
 166                 priv->buf[1] = (unsigned char) c2;
 167                 if(stream_read(demuxer->stream, &(priv->buf[2]), 6) < 6)
 168                         return 0;
 169
 170                 len = aac_parse_frame(priv->buf, &srate, &num);
 171                 if(len > 0)
 172                 {
 173                         dp = new_demux_packet(len);
 174                         if(! dp)
 175                         {
 176                                 mp_msg(MSGT_DEMUX, MSGL_ERR, "fill_buffer, NEW_ADD_PACKET(%d)FAILED\n", len);
 177                                 return 0;
 178                         }
 179
 180
 181                         memcpy(dp->buffer, priv->buf, 8);
 182                         stream_read(demuxer->stream, &(dp->buffer[8]), len-8);
 183                         if(srate)
 184                                 tm = (float) (num * 1024.0/srate);
 185                         priv->last_pts += tm;
 186                         dp->pts = priv->last_pts;
 187                         //fprintf(stderr, "\nPTS: %.3f\n", dp->pts);
 188                         ds_add_packet(demuxer->audio, dp);
 189                         priv->size += len;
 190                         priv->time += tm;
 191
 192                         priv->bitrate = (int) (priv->size / priv->time);
 193                         demuxer->filepos = stream_tell(demuxer->stream);
 194
 195                         return len;
 196                 }
 197                 else
 198                         stream_skip(demuxer->stream, -6);
 199         }
 200
 201         return 0;
 202 }
 203
 204
 205 //This is an almost verbatim copy of high_res_mp3_seek(), from demux_audio.c
 206 static void demux_aac_seek(demuxer_t *demuxer, float rel_seek_secs, float audio_delay, int flags)
 207 {
 208         aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
 209         demux_stream_t *d_audio=demuxer->audio;
 210         sh_audio_t *sh_audio=d_audio->sh;
 211         float time;
 212
 213         ds_free_packs(d_audio);
 214
 215         time = (flags & SEEK_ABSOLUTE) ? rel_seek_secs - priv->last_pts : rel_seek_secs;
 216         if(time < 0)
 217         {
 218                 stream_seek(demuxer->stream, demuxer->movi_start);
 219                 time = priv->last_pts + time;
 220                 priv->last_pts = 0;
 221         }
 222
 223         if(time > 0)
 224         {
 225                 int len, nf, srate, num;
 226
 227                 nf = time * sh_audio->samplerate/1024;
 228
 229                 while(nf > 0)
 230                 {
 231                         if(stream_read(demuxer->stream,priv->buf, 8) < 8)
 232                                 break;
 233                         len = aac_parse_frame(priv->buf, &srate, &num);
 234                         if(len <= 0)
 235                         {
 236                                 stream_skip(demuxer->stream, -7);
 237                                 continue;
 238                         }
 239                         stream_skip(demuxer->stream, len - 8);
 240                         priv->last_pts += (float) (num*1024.0/srate);
 241                         nf -= num;
 242                 }
 243         }
 244 }
 245
 246
 247 const demuxer_desc_t demuxer_desc_aac = {
 248   "AAC demuxer",
 249   "aac",
 250   "AAC",
 251   "Nico Sabbi",
 252   "Raw AAC files ",
 253   DEMUXER_TYPE_AAC,
 254   0, // unsafe autodetect
 255   demux_aac_probe,
 256   demux_aac_fill_buffer,
 257   demux_aac_open,
 258   demux_close_aac,
 259   demux_aac_seek,
 260   NULL
 261 };