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