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 #include "help_mp.h"
  26
  27 #include "stream/stream.h"
  28 #include "demuxer.h"
  29 #include "parse_es.h"
  30 #include "stheader.h"
  31 #include "aac_hdr.h"
  32 #include "ms_hdr.h"
  33
  34 typedef struct {
  35         uint8_t *buf;
  36         uint64_t size;  /// amount of time of data packets pushed to demuxer->audio (in bytes)
  37         float time;     /// amount of time elapsed based upon samples_per_frame/sample_rate (in milliseconds)
  38         float last_pts; /// last pts seen
  39         int bitrate;    /// bitrate computed as size/time
  40 } aac_priv_t;
  41
  42 static int demux_aac_init(demuxer_t *demuxer)
  43 {
  44         aac_priv_t *priv;
  45
  46         priv = calloc(1, sizeof(aac_priv_t));
  47         if(!priv)
  48                 return 0;
  49
  50         priv->buf = malloc(8);
  51         if(!priv->buf)
  52         {
  53                 free(priv);
  54                 return 0;
  55         }
  56
  57         demuxer->priv = priv;
  58         return 1;
  59 }
  60
  61 static void demux_close_aac(demuxer_t *demuxer)
  62 {
  63         aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
  64
  65         if(!priv)
  66                 return;
  67
  68         if(priv->buf)
  69                 free(priv->buf);
  70
  71         free(demuxer->priv);
  72
  73         return;
  74 }
  75
  76 /// returns DEMUXER_TYPE_AAC if it finds 8 ADTS frames in 32768 bytes, 0 otherwise
  77 static int demux_aac_probe(demuxer_t *demuxer)
  78 {
  79         int cnt = 0, c, len, srate, num;
  80         off_t init, probed;
  81         aac_priv_t *priv;
  82
  83         if(! demux_aac_init(demuxer))
  84         {
  85                 mp_msg(MSGT_DEMUX, MSGL_ERR, "COULDN'T INIT aac_demux, exit\n");
  86                 return 0;
  87         }
  88
  89         priv = (aac_priv_t *) demuxer->priv;
  90
  91         init = probed = stream_tell(demuxer->stream);
  92         while(probed-init <= 32768 && cnt < 8)
  93         {
  94                 c = 0;
  95                 while(c != 0xFF)
  96                 {
  97                         c = stream_read_char(demuxer->stream);
  98                         if(c < 0)
  99                                 goto fail;
 100                 }
 101                 priv->buf[0] = 0xFF;
 102                 if(stream_read(demuxer->stream, &(priv->buf[1]), 7) < 7)
 103                         goto fail;
 104
 105                 len = aac_parse_frame(priv->buf, &srate, &num);
 106                 if(len > 0)
 107                 {
 108                         cnt++;
 109                         stream_skip(demuxer->stream, len - 8);
 110                 }
 111                 probed = stream_tell(demuxer->stream);
 112         }
 113
 114         stream_seek(demuxer->stream, init);
 115         if(cnt < 8)
 116                 goto fail;
 117
 118         mp_msg(MSGT_DEMUX, MSGL_V, "demux_aac_probe, INIT: %"PRIu64", PROBED: %"PRIu64", cnt: %d\n", init, probed, cnt);
 119         return DEMUXER_TYPE_AAC;
 120
 121 fail:
 122         mp_msg(MSGT_DEMUX, MSGL_V, "demux_aac_probe, failed to detect an AAC stream\n");
 123         return 0;
 124 }
 125
 126 static demuxer_t* demux_aac_open(demuxer_t *demuxer)
 127 {
 128         sh_audio_t *sh;
 129
 130         sh = new_sh_audio(demuxer, 0);
 131         sh->ds = demuxer->audio;
 132         sh->format = mmioFOURCC('M', 'P', '4', 'A');
 133         demuxer->audio->id = 0;
 134         demuxer->audio->sh = sh;
 135
 136         demuxer->filepos = stream_tell(demuxer->stream);
 137
 138         return demuxer;
 139 }
 140
 141 static int demux_aac_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds)
 142 {
 143         aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
 144         demux_packet_t *dp;
 145         int c1, c2, len, srate, num;
 146         float tm = 0;
 147
 148         if(demuxer->stream->eof || (demuxer->movi_end && stream_tell(demuxer->stream) >= demuxer->movi_end))
 149                 return 0;
 150
 151         while(! demuxer->stream->eof)
 152         {
 153                 c1 = c2 = 0;
 154                 while(c1 != 0xFF)
 155                 {
 156                         c1 = stream_read_char(demuxer->stream);
 157                         if(c1 < 0)
 158                                 return 0;
 159                 }
 160                 c2 = stream_read_char(demuxer->stream);
 161                 if(c2 < 0)
 162                         return 0;
 163                 if((c2 & 0xF6) != 0xF0)
 164                         continue;
 165
 166                 priv->buf[0] = (unsigned char) c1;
 167                 priv->buf[1] = (unsigned char) c2;
 168                 if(stream_read(demuxer->stream, &(priv->buf[2]), 6) < 6)
 169                         return 0;
 170
 171                 len = aac_parse_frame(priv->buf, &srate, &num);
 172                 if(len > 0)
 173                 {
 174                         dp = new_demux_packet(len);
 175                         if(! dp)
 176                         {
 177                                 mp_msg(MSGT_DEMUX, MSGL_ERR, "fill_buffer, NEW_ADD_PACKET(%d)FAILED\n", len);
 178                                 return 0;
 179                         }
 180
 181
 182                         memcpy(dp->buffer, priv->buf, 8);
 183                         stream_read(demuxer->stream, &(dp->buffer[8]), len-8);
 184                         if(srate)
 185                                 tm = (float) (num * 1024.0/srate);
 186                         priv->last_pts += tm;
 187                         dp->pts = priv->last_pts;
 188                         //fprintf(stderr, "\nPTS: %.3f\n", dp->pts);
 189                         ds_add_packet(demuxer->audio, dp);
 190                         priv->size += len;
 191                         priv->time += tm;
 192
 193                         priv->bitrate = (int) (priv->size / priv->time);
 194                         demuxer->filepos = stream_tell(demuxer->stream);
 195
 196                         return len;
 197                 }
 198                 else
 199                         stream_skip(demuxer->stream, -6);
 200         }
 201
 202         return 0;
 203 }
 204
 205
 206 //This is an almost verbatim copy of high_res_mp3_seek(), from demux_audio.c
 207 static void demux_aac_seek(demuxer_t *demuxer, float rel_seek_secs, float audio_delay, int flags)
 208 {
 209         aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
 210         demux_stream_t *d_audio=demuxer->audio;
 211         sh_audio_t *sh_audio=d_audio->sh;
 212         float time;
 213
 214         ds_free_packs(d_audio);
 215
 216         time = (flags & SEEK_ABSOLUTE) ? rel_seek_secs - priv->last_pts : rel_seek_secs;
 217         if(time < 0)
 218         {
 219                 stream_seek(demuxer->stream, demuxer->movi_start);
 220                 time = priv->last_pts + time;
 221                 priv->last_pts = 0;
 222         }
 223
 224         if(time > 0)
 225         {
 226                 int len, nf, srate, num;
 227
 228                 nf = time * sh_audio->samplerate/1024;
 229
 230                 while(nf > 0)
 231                 {
 232                         if(stream_read(demuxer->stream,priv->buf, 8) < 8)
 233                                 break;
 234                         len = aac_parse_frame(priv->buf, &srate, &num);
 235                         if(len <= 0)
 236                         {
 237                                 stream_skip(demuxer->stream, -7);
 238                                 continue;
 239                         }
 240                         stream_skip(demuxer->stream, len - 8);
 241                         priv->last_pts += (float) (num*1024.0/srate);
 242                         nf -= num;
 243                 }
 244         }
 245 }
 246
 247
 248 const demuxer_desc_t demuxer_desc_aac = {
 249   "AAC demuxer",
 250   "aac",
 251   "AAC",
 252   "Nico Sabbi",
 253   "Raw AAC files ",
 254   DEMUXER_TYPE_AAC,
 255   0, // unsafe autodetect
 256   demux_aac_probe,
 257   demux_aac_fill_buffer,
 258   demux_aac_open,
 259   demux_close_aac,
 260   demux_aac_seek,
 261   NULL
 262 };