modules/codec/fdkaac.c

   1 /*****************************************************************************
   2  * aac.c: FDK-AAC Encoder plugin for vlc.
   3  *****************************************************************************
   4  * Copyright (C) 2012 Sergio Ammirata
   5  *
   6  * Authors: Sergio Ammirata <sergio@ammirata.net>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24  * Preamble
  25  *****************************************************************************/
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <fdk-aac/aacenc_lib.h>
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_codec.h>
  35
  36 static int OpenEncoder( vlc_object_t * );
  37 static void CloseEncoder( vlc_object_t * );
  38
  39 #define ENC_CFG_PREFIX "sout-fdkaac-"
  40
  41 #define AOT_TEXT N_("Encoder Profile")
  42 #define AOT_LONGTEXT N_( "Encoder Algorithm to use" )
  43
  44 #define SIDEBAND_TEXT N_("Enable spectral band replication")
  45 #define SIDEBAND_LONGTEXT N_( "This is an optional feature only for the AAC-ELD profile" )
  46
  47 #define VBR_QUALITY_TEXT N_("VBR Quality")
  48 #define VBR_QUALITY_LONGTEXT N_( "Quality of the VBR Encoding (0=cbr, 1-5 constant quality vbr, 5 is best" )
  49
  50 #define AFTERBURNER_TEXT N_("Enable afterburner library")
  51 #define AFTERBURNER_LONGTEXT N_( "This library will produce higher quality audio at the expense of additional CPU usage (default is enabled)" )
  52
  53 #define BITRATE_TEXT N_("CBR Bitrate")
  54 #define BITRATE_LONGTEXT N_( "Bitrate of desired stream (in bps)" )
  55
  56 #define SIGNALING_TEXT N_("Signaling mode of the extension AOT")
  57 #define SIGNALING_LONGTEXT N_( "1 is explicit for SBR and implicit for PS (default), 2 is explicit hierarchical" )
  58
  59 #define  CH_ORDER_MPEG 0  /*!< MPEG channel ordering (e. g. 5.1: C, L, R, SL, SR, LFE)           */
  60 #define  CH_ORDER_WAV 1   /*!< WAV fileformat channel ordering (e. g. 5.1: L, R, C, LFE, SL, SR) */
  61 #define  CH_ORDER_WG4 2   /*!< WG4 fileformat channel ordering (e. g. 5.1: L, R, SL, SR, C, LFE) */
  62
  63 #define PROFILE_AAC_LC 2
  64 #define PROFILE_AAC_HE 5
  65 #define PROFILE_AAC_HE_v2 29
  66 #define PROFILE_AAC_LD 23
  67 #define PROFILE_AAC_ELD 39
  68
  69 #define SIGNALING_COMPATIBLE 1
  70 #define SIGNALING_HIERARCHICAL 2
  71
  72 static const int pi_aot_values[] = { PROFILE_AAC_LC, PROFILE_AAC_HE, PROFILE_AAC_HE_v2, PROFILE_AAC_LD, PROFILE_AAC_ELD };
  73 static const char *const ppsz_aot_descriptions[] =
  74 { N_("AAC-LC"), N_("HE-AAC"), N_("HE-AAC-v2"), N_("AAC-LD"), N_("AAC-ELD") };
  75
  76 vlc_module_begin ()
  77     set_shortname( N_("FDKAAC") )
  78     set_description( N_("FDK-AAC Audio encoder") )
  79     set_capability( "encoder", 50 )
  80     set_callbacks( OpenEncoder, CloseEncoder )
  81     add_shortcut( "fdkaac" )
  82     set_category( CAT_INPUT )
  83     set_subcategory( SUBCAT_INPUT_ACODEC )
  84     add_integer( ENC_CFG_PREFIX "profile", PROFILE_AAC_LC, AOT_TEXT,
  85              AOT_LONGTEXT, false )
  86     change_integer_list( pi_aot_values, ppsz_aot_descriptions );
  87     add_bool( ENC_CFG_PREFIX "sbr", false, SIDEBAND_TEXT,
  88               SIDEBAND_LONGTEXT, false )
  89     add_integer( ENC_CFG_PREFIX "vbr", 0, VBR_QUALITY_TEXT,
  90               VBR_QUALITY_LONGTEXT, false )
  91     change_integer_range (0, 5)
  92     add_bool( ENC_CFG_PREFIX "afterburner", true, AFTERBURNER_TEXT,
  93               AFTERBURNER_LONGTEXT, true )
  94     add_integer( ENC_CFG_PREFIX "signaling", SIGNALING_COMPATIBLE, SIGNALING_TEXT,
  95              SIGNALING_LONGTEXT, true )
  96     change_integer_range (0, 2)
  97 vlc_module_end ()
  98
  99 /*****************************************************************************
 100  * Local prototypes
 101  *****************************************************************************/
 102 static block_t *EncodeAudio( encoder_t *p_enc, block_t *p_buf );
 103
 104 static const char *const ppsz_enc_options[] = {
 105     "profile", "sbr", "vbr", "afterburner", "signaling", NULL
 106 };
 107
 108 /*****************************************************************************
 109  * encoder_sys_t : aac encoder descriptor
 110  *****************************************************************************/
 111 struct encoder_sys_t
 112 {
 113     double d_compression_ratio;
 114     mtime_t i_pts_last;
 115     int i_aot; /* This stores the aac profile chosen */
 116     int i_vbr; /* cbr or vbr-quality value chosen */
 117     int i_signaling; /* Library feature for backwards compatibility */
 118     int i_encoderdelay; /* Samples delay introduced by the profile */
 119     int i_frame_size;
 120     int i_maxoutputsize; /* Maximum buffer size for encoded output */
 121     HANDLE_AACENCODER handle;
 122     bool b_afterburner; /* Library feature for additional quality */
 123     bool b_eld_sbr; /* Spectral band replication option for ELD profile */
 124 };
 125
 126 static const char *aac_get_errorstring(AACENC_ERROR erraac)
 127 {
 128     switch (erraac) {
 129     case AACENC_OK:
 130         return "No error";
 131     case AACENC_INVALID_HANDLE:
 132         return "Invalid handle";
 133     case AACENC_MEMORY_ERROR:
 134         return "Memory allocation error";
 135     case AACENC_UNSUPPORTED_PARAMETER:
 136         return "Unsupported parameter";
 137     case AACENC_INVALID_CONFIG:
 138         return "Invalid config";
 139     case AACENC_INIT_ERROR:
 140         return "Initialization error";
 141     case AACENC_INIT_AAC_ERROR:
 142         return "AAC library initialization error";
 143     case AACENC_INIT_SBR_ERROR:
 144         return "SBR library initialization error";
 145     case AACENC_INIT_TP_ERROR:
 146         return "Transport library initialization error";
 147     case AACENC_INIT_META_ERROR:
 148         return "Metadata library initialization error";
 149     case AACENC_ENCODE_ERROR:
 150         return "Encoding error";
 151     case AACENC_ENCODE_EOF:
 152         return "End of file";
 153     default:
 154         return "Unknown error";
 155     }
 156 }
 157
 158 /*****************************************************************************
 159  * OpenDecoder: open the encoder.
 160  *****************************************************************************/
 161 static int OpenEncoder( vlc_object_t *p_this )
 162 {
 163     encoder_t *p_enc;
 164     encoder_sys_t *p_sys;
 165     CHANNEL_MODE mode;
 166     AACENC_ERROR erraac;
 167     bool b_profile_selected;
 168     int sce;
 169     int cpe;
 170     int i_profile;
 171     int i_bitrate;
 172
 173     p_enc = (encoder_t *)p_this;
 174     b_profile_selected = false;
 175     sce = 0;
 176     cpe = 0;
 177
 178     if( p_enc->fmt_out.i_codec != VLC_FOURCC( 'l', 'a', 'a', 'c' ) &&
 179         p_enc->fmt_out.i_codec != VLC_FOURCC( 'h', 'a', 'a', 'c' ) &&
 180         p_enc->fmt_out.i_codec != VLC_FOURCC( 's', 'a', 'a', 'c' ) &&
 181         p_enc->fmt_out.i_codec != VLC_CODEC_MP4A )
 182     {
 183         return VLC_EGENERIC;
 184     }
 185     else if ( p_enc->fmt_out.i_codec == VLC_FOURCC( 'l', 'a', 'a', 'c' ) )
 186     {
 187         b_profile_selected = true;
 188         i_profile = PROFILE_AAC_LC;
 189     }
 190     else if ( p_enc->fmt_out.i_codec == VLC_FOURCC( 'h', 'a', 'a', 'c' ) )
 191     {
 192         b_profile_selected = true;
 193         i_profile = PROFILE_AAC_HE;
 194     }
 195     else if ( p_enc->fmt_out.i_codec == VLC_FOURCC( 's', 'a', 'a', 'c' ) )
 196     {
 197         b_profile_selected = true;
 198         i_profile = PROFILE_AAC_HE_v2;
 199     }
 200
 201     switch (p_enc->fmt_in.audio.i_channels) {
 202     case 1: mode = MODE_1;       sce = 1; cpe = 0; break;
 203     case 2: mode = MODE_2;       sce = 0; cpe = 1; break;
 204     case 3: mode = MODE_1_2;     sce = 1; cpe = 1; break;
 205     case 4: mode = MODE_1_2_1;   sce = 2; cpe = 1; break;
 206     case 5: mode = MODE_1_2_2;   sce = 1; cpe = 2; break;
 207     case 6: mode = MODE_1_2_2_1; sce = 2; cpe = 2; break;
 208     case 8: mode = MODE_1_2_2_2_1; sce = 2; cpe = 3; break;
 209     default:
 210         msg_Err( p_enc, "we do not support > 8 input channels, this input has %i",
 211                         p_enc->fmt_in.audio.i_channels );
 212         return VLC_EGENERIC;
 213     }
 214
 215     msg_Info(p_enc, "Initializing AAC Encoder, %i channels", p_enc->fmt_in.audio.i_channels);
 216
 217     /* Allocate the memory needed to store the encoder's structure */
 218     p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t));
 219     if( unlikely( !p_sys ) )
 220         return VLC_ENOMEM;
 221     p_enc->p_sys = p_sys;
 222     p_enc->fmt_in.i_codec = VLC_CODEC_S16N;
 223     p_enc->fmt_out.i_cat = AUDIO_ES;
 224     p_enc->fmt_out.i_codec = VLC_CODEC_MP4A;
 225
 226     config_ChainParse( p_enc, ENC_CFG_PREFIX, ppsz_enc_options, p_enc->p_cfg );
 227
 228     if ( b_profile_selected == false )
 229         p_sys->i_aot = var_InheritInteger( p_enc, ENC_CFG_PREFIX "profile" );
 230     else
 231         p_sys->i_aot = i_profile;
 232     p_sys->b_eld_sbr = var_InheritBool( p_enc, ENC_CFG_PREFIX "sbr" );
 233     p_sys->i_vbr = var_InheritInteger( p_enc, ENC_CFG_PREFIX "vbr" );
 234     p_sys->b_afterburner = var_InheritBool( p_enc, ENC_CFG_PREFIX "afterburner" );
 235     p_sys->i_signaling = var_InheritInteger( p_enc, ENC_CFG_PREFIX "signaling" );
 236     p_sys->i_pts_last = 0;
 237
 238     if ((p_sys->i_aot == PROFILE_AAC_HE || p_sys->i_aot == PROFILE_AAC_HE_v2) && p_sys->i_vbr > 3)
 239     {
 240         msg_Warn(p_enc, "Maximum VBR quality for this profile is 3, setting vbr=3");
 241         p_sys->i_vbr = 3;
 242     }
 243     if ((erraac = aacEncOpen(&p_sys->handle, 0, p_enc->fmt_in.audio.i_channels)) != AACENC_OK) {
 244         msg_Err(p_enc, "Unable to open encoder: %s", aac_get_errorstring(erraac));
 245         free( p_sys );
 246         return VLC_EGENERIC;
 247     }
 248     if ( p_sys->i_aot == PROFILE_AAC_HE_v2 && p_enc->fmt_in.audio.i_channels != 2 )
 249     {
 250         msg_Err(p_enc, "The HE-AAC-v2 profile can only be used with stereo sources");
 251         goto error;
 252     }
 253     if ( p_sys->i_aot == PROFILE_AAC_ELD && p_enc->fmt_in.audio.i_channels != 2 )
 254     {
 255         msg_Err(p_enc, "The ELD-AAC profile can only be used with stereo sources");
 256         goto error;
 257     }
 258     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_AOT, p_sys->i_aot)) != AACENC_OK) {
 259         msg_Err(p_enc, "Unable to set the Profile %i: %s", p_sys->i_aot, aac_get_errorstring(erraac));
 260         goto error;
 261     }
 262     if (p_sys->i_aot == PROFILE_AAC_ELD && p_sys->b_eld_sbr) {
 263         if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_SBR_MODE, 1)) != AACENC_OK) {
 264             msg_Err(p_enc, "Unable to set SBR mode for ELD: %s", aac_get_errorstring(erraac));
 265         goto error;
 266         }
 267     }
 268     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_SAMPLERATE,
 269                     p_enc->fmt_out.audio.i_rate)) != AACENC_OK) {
 270         msg_Err(p_enc, "Unable to set the sample rate %i: %s",p_enc->fmt_out.audio.i_rate,
 271                         aac_get_errorstring(erraac));
 272         goto error;
 273     }
 274     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_CHANNELMODE, mode)) != AACENC_OK) {
 275         msg_Err(p_enc, "Unable to set the channel mode: %s", aac_get_errorstring(erraac));
 276         goto error;
 277     }
 278     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_CHANNELORDER, CH_ORDER_WG4)) != AACENC_OK) {
 279         msg_Err(p_enc, "Unable to set the sound channel order: %s", aac_get_errorstring(erraac));
 280         goto error;
 281     }
 282     if (p_sys->i_vbr != 0) {
 283         if ((erraac = aacEncoder_SetParam(p_sys->handle,
 284                          AACENC_BITRATEMODE, p_sys->i_vbr)) != AACENC_OK) {
 285             msg_Err(p_enc, "Unable to set the VBR bitrate mode: %s", aac_get_errorstring(erraac));
 286             goto error;
 287         }
 288     } else {
 289         if (p_enc->fmt_out.i_bitrate == 0) {
 290             if (p_sys->i_aot == PROFILE_AAC_HE_v2) {
 291                 sce = 1;
 292                 cpe = 0;
 293             }
 294             i_bitrate = (96*sce + 128*cpe) * p_enc->fmt_out.audio.i_rate / 44;
 295             if (p_sys->i_aot == PROFILE_AAC_HE ||
 296                 p_sys->i_aot == PROFILE_AAC_HE_v2 ||
 297                 p_sys->b_eld_sbr)
 298                 i_bitrate /= 2;
 299             p_enc->fmt_out.i_bitrate = i_bitrate;
 300             msg_Info(p_enc, "Setting optimal bitrate of %i", i_bitrate);
 301         }
 302         else
 303         {
 304             i_bitrate = p_enc->fmt_out.i_bitrate;
 305         }
 306         if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_BITRATE,
 307                                          i_bitrate)) != AACENC_OK) {
 308             msg_Err(p_enc, "Unable to set the bitrate %i: %s", i_bitrate,
 309                     aac_get_errorstring(erraac));
 310             goto error;
 311         }
 312     }
 313     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_TRANSMUX, 0)) != AACENC_OK) {
 314         msg_Err(p_enc, "Unable to set the ADTS transmux: %s", aac_get_errorstring(erraac));
 315         goto error;
 316     }
 317     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_SIGNALING_MODE,
 318                                  (int)p_sys->i_signaling)) != AACENC_OK) {
 319       /* use explicit backward compatible =1 */
 320       /* use explicit hierarchical signaling =2 */
 321         msg_Err(p_enc, "Unable to set signaling mode: %s", aac_get_errorstring(erraac));
 322         goto error;
 323     }
 324     if ((erraac = aacEncoder_SetParam(p_sys->handle, AACENC_AFTERBURNER,
 325                                (int)p_sys->b_afterburner)) != AACENC_OK) {
 326         msg_Err(p_enc, "Unable to set the afterburner mode: %s", aac_get_errorstring(erraac));
 327         goto error;
 328     }
 329     if ((erraac = aacEncEncode(p_sys->handle, NULL, NULL, NULL, NULL)) != AACENC_OK) {
 330         msg_Err(p_enc, "Unable to initialize the encoder: %s", aac_get_errorstring(erraac));
 331         goto error;
 332     }
 333     AACENC_InfoStruct info = { 0 };
 334     if ((erraac = aacEncInfo(p_sys->handle, &info)) != AACENC_OK) {
 335         msg_Err(p_enc, "Unable to get the encoder info: %s", aac_get_errorstring(erraac));
 336         goto error;
 337     }
 338
 339     /* The maximum packet size is 6144 bits aka 768 bytes per channel. */
 340     p_sys->i_maxoutputsize = 768*p_enc->fmt_in.audio.i_channels;
 341     p_enc->fmt_in.audio.i_bitspersample = 16;
 342     p_sys->i_frame_size = info.frameLength;
 343     p_sys->i_encoderdelay = info.encoderDelay;
 344
 345     p_enc->fmt_out.i_extra = info.confSize;
 346     if( p_enc->fmt_out.i_extra )
 347     {
 348         p_enc->fmt_out.p_extra = malloc( p_enc->fmt_out.i_extra );
 349         if ( p_enc->fmt_out.p_extra == NULL )
 350         {
 351             msg_Err(p_enc, "Unable to allocate fmt_out.p_extra");
 352             goto error;
 353         }
 354         memcpy( p_enc->fmt_out.p_extra, info.confBuf,
 355                 p_enc->fmt_out.i_extra );
 356     }
 357
 358     p_enc->pf_encode_audio = EncodeAudio;
 359
 360 #ifndef NDEBUG
 361     // TODO: Add more debug info to this config printout
 362     msg_Dbg(p_enc, "fmt_out.p_extra = %i", p_enc->fmt_out.i_extra);
 363 #endif
 364
 365     return VLC_SUCCESS;
 366
 367 error:
 368     aacEncClose(&p_sys->handle);
 369     free( p_sys );
 370     return VLC_EGENERIC;
 371 }
 372
 373 /****************************************************************************
 374  * EncodeAudio: the whole thing
 375  ****************************************************************************/
 376 static block_t *EncodeAudio( encoder_t *p_enc, block_t *p_aout_buf )
 377 {
 378     encoder_sys_t *p_sys;
 379     int16_t *p_buffer;
 380     int i_samples;
 381     int i_loop_count;
 382     int i_samples_left;
 383     mtime_t i_pts_out;
 384     block_t *p_chain;
 385     AACENC_ERROR erraac;
 386
 387     p_sys = p_enc->p_sys;
 388     p_chain = NULL;
 389
 390     if ( likely( p_aout_buf ) )
 391     {
 392         p_buffer = (int16_t *)p_aout_buf->p_buffer;
 393         i_samples = p_aout_buf->i_nb_samples;
 394         i_pts_out = p_aout_buf->i_pts - (mtime_t)((double)CLOCK_FREQ *
 395                (double)p_sys->i_encoderdelay /
 396                (double)p_enc->fmt_out.audio.i_rate);
 397         if (p_sys->i_pts_last == 0)
 398             p_sys->i_pts_last = i_pts_out - (mtime_t)((double)CLOCK_FREQ *
 399                (double)(p_sys->i_frame_size) /
 400                (double)p_enc->fmt_out.audio.i_rate);
 401     }
 402     else
 403     {
 404         i_samples = 0;
 405         i_pts_out = p_sys->i_pts_last;
 406     }
 407
 408     i_samples_left = i_samples;
 409     i_loop_count = 0;
 410
 411     while ( i_samples_left >= 0 )
 412     {
 413         AACENC_BufDesc in_buf = { 0 }, out_buf = { 0 };
 414         AACENC_InArgs in_args = { 0 };
 415         AACENC_OutArgs out_args = { 0 };
 416         int in_identifier = IN_AUDIO_DATA;
 417         int in_size, in_elem_size;
 418         int out_identifier = OUT_BITSTREAM_DATA;
 419         int out_size, out_elem_size;
 420         void *in_ptr, *out_ptr;
 421
 422         if ( unlikely(i_samples == 0) ) {
 423             // this forces the encoder to purge whatever is left in the internal buffer
 424             in_args.numInSamples = -1;
 425         } else {
 426             in_ptr = p_buffer + (i_samples - i_samples_left)*p_enc->fmt_in.audio.i_channels;
 427             in_size = 2*p_enc->fmt_in.audio.i_channels*i_samples_left;
 428             in_elem_size = 2;
 429             in_args.numInSamples = p_enc->fmt_in.audio.i_channels*i_samples_left;
 430             in_buf.numBufs = 1;
 431             in_buf.bufs = &in_ptr;
 432             in_buf.bufferIdentifiers = &in_identifier;
 433             in_buf.bufSizes = &in_size;
 434             in_buf.bufElSizes = &in_elem_size;
 435         }
 436         block_t *p_block;
 437         p_block = block_Alloc( p_sys->i_maxoutputsize );
 438         p_block->i_buffer = p_sys->i_maxoutputsize;
 439         out_ptr = p_block->p_buffer;
 440         out_size = p_block->i_buffer;
 441         out_elem_size = 1;
 442         out_buf.numBufs = 1;
 443         out_buf.bufs = &out_ptr;
 444         out_buf.bufferIdentifiers = &out_identifier;
 445         out_buf.bufSizes = &out_size;
 446         out_buf.bufElSizes = &out_elem_size;
 447
 448         if ((erraac = aacEncEncode(p_sys->handle, &in_buf, &out_buf, &in_args, &out_args)) != AACENC_OK) {
 449             if (erraac == AACENC_ENCODE_EOF) {
 450                 msg_Info( p_enc, "Encoding final bytes (EOF)");
 451             }
 452             else
 453             {
 454                 msg_Err( p_enc, "Encoding failed: %s", aac_get_errorstring(erraac));
 455                 block_Release(p_block);
 456                 break;
 457             }
 458         }
 459         if ( out_args.numOutBytes > 0 )
 460         {
 461             p_block->i_buffer = out_args.numOutBytes;
 462             if ( unlikely(i_samples == 0) )
 463             {
 464                 // I only have the numOutBytes so approximate based on compression factor
 465                 double d_samples_forward = p_sys->d_compression_ratio*(double)out_args.numOutBytes;
 466                 i_pts_out += (mtime_t)d_samples_forward;
 467                 p_block->i_length = (mtime_t)d_samples_forward;
 468                 // TODO: It would be more precise (a few microseconds) to use d_samples_forward =
 469                 // (mtime_t)CLOCK_FREQ * (mtime_t)p_sys->i_frame_size/(mtime_t)p_enc->fmt_out.audio.i_rate
 470                 // but I am not sure if the lib always outputs a full frame when
 471                 // emptying the internal buffer in the EOF scenario
 472             }
 473             else
 474             {
 475                 if ( i_loop_count == 0 )
 476                 {
 477                     // There can be an implicit delay in the first loop cycle because leftover bytes
 478                     // in the library buffer from the prior block
 479                     double d_samples_delay = (double)p_sys->i_frame_size - (double)out_args.numInSamples /
 480                                              (double)p_enc->fmt_in.audio.i_channels;
 481                     i_pts_out -= (mtime_t)((double)CLOCK_FREQ * d_samples_delay /
 482                                            (double)p_enc->fmt_out.audio.i_rate);
 483                     //p_block->i_length = (mtime_t)((double)CLOCK_FREQ * (double)p_sys->i_frame_size /
 484                     //    (double)p_enc->fmt_out.audio.i_rate);
 485                     p_block->i_length = i_pts_out - p_sys->i_pts_last;
 486                 }
 487                 else
 488                 {
 489                     double d_samples_forward = (double)out_args.numInSamples/(double)p_enc->fmt_in.audio.i_channels;
 490                     double d_length = ((double)CLOCK_FREQ * d_samples_forward /
 491                                             (double)p_enc->fmt_out.audio.i_rate);
 492                     i_pts_out += (mtime_t) d_length;
 493                     p_block->i_length = (mtime_t) d_length;
 494                 }
 495             }
 496             p_block->i_dts = p_block->i_pts = i_pts_out;
 497             block_ChainAppend( &p_chain, p_block );
 498             //msg_Dbg( p_enc, "p_block->i_dts %llu, p_block->i_length %llu, p_sys->i_pts_last %llu\n\
 499             //                  out_args.numOutBytes = %i, out_args.numInSamples = %i, i_samples %i, i_loop_count %i",
 500             //                  p_block->i_dts , p_block->i_length,p_sys->i_pts_last,
 501             //                  out_args.numOutBytes, out_args.numInSamples, i_samples, i_loop_count);
 502             if ( likely(i_samples > 0) )
 503             {
 504                 p_sys->d_compression_ratio = (double)p_block->i_length / (double)out_args.numOutBytes;
 505                 i_samples_left -= out_args.numInSamples/p_enc->fmt_in.audio.i_channels;
 506                 p_sys->i_pts_last = i_pts_out;
 507             }
 508         }
 509         else
 510         {
 511             block_Release(p_block);
 512             //msg_Dbg( p_enc, "aac_encode_audio: not enough data yet");
 513             break;
 514         }
 515         if ( unlikely(i_loop_count++ > 100) )
 516         {
 517             msg_Err( p_enc, "Loop count greater than 100!!!, something must be wrong with the encoder library");
 518             break;
 519         }
 520     }
 521
 522     return p_chain;
 523
 524 }
 525
 526 /*****************************************************************************
 527  * CloseDecoder: decoder destruction
 528  *****************************************************************************/
 529 static void CloseEncoder( vlc_object_t *p_this )
 530 {
 531     encoder_t *p_enc = (encoder_t *)p_this;
 532     encoder_sys_t *p_sys = p_enc->p_sys;
 533
 534     aacEncClose(&p_sys->handle);
 535
 536     free( p_sys );
 537 }