libhb/enclame.c

   1 /* enclame.c
   2
   3    Copyright (c) 2003-2015 HandBrake Team
   4    This file is part of the HandBrake source code
   5    Homepage: <http://handbrake.fr/>.
   6    It may be used under the terms of the GNU General Public License v2.
   7    For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
   8  */
   9 #include "hb.h"
  10
  11 #include "lame/lame.h"
  12
  13 int  enclameInit( hb_work_object_t *, hb_job_t * );
  14 int  enclameWork( hb_work_object_t *, hb_buffer_t **, hb_buffer_t ** );
  15 void enclameClose( hb_work_object_t * );
  16
  17 hb_work_object_t hb_enclame =
  18 {
  19     WORK_ENCLAME,
  20     "MP3 encoder (libmp3lame)",
  21     enclameInit,
  22     enclameWork,
  23     enclameClose
  24 };
  25
  26 struct hb_work_private_s
  27 {
  28     hb_job_t   * job;
  29
  30     /* LAME handle */
  31     lame_global_flags * lame;
  32
  33     int             out_discrete_channels;
  34     unsigned long   input_samples;
  35     unsigned long   output_bytes;
  36     uint8_t       * buf;
  37
  38     hb_list_t     * list;
  39     int64_t         pts;
  40 };
  41
  42 int enclameInit( hb_work_object_t * w, hb_job_t * job )
  43 {
  44     hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
  45     hb_audio_t * audio = w->audio;
  46
  47     w->private_data = pv;
  48
  49     pv->job   = job;
  50
  51     hb_log( "enclame: opening libmp3lame" );
  52
  53     pv->lame = lame_init();
  54     // use ABR
  55     lame_set_scale( pv->lame, 32768.0 );
  56     if( audio->config.out.compression_level >= 0 )
  57     {
  58         lame_set_quality( pv->lame, audio->config.out.compression_level );
  59     }
  60     if( audio->config.out.bitrate > 0 )
  61     {
  62         lame_set_VBR( pv->lame, vbr_abr );
  63         lame_set_VBR_mean_bitrate_kbps( pv->lame, audio->config.out.bitrate );
  64     }
  65     else if( audio->config.out.quality >= 0 )
  66     {
  67         lame_set_brate( pv->lame, 0 );
  68         lame_set_VBR( pv->lame, vbr_default );
  69         lame_set_VBR_quality( pv->lame, audio->config.out.quality );
  70     }
  71     lame_set_in_samplerate( pv->lame, audio->config.out.samplerate );
  72     lame_set_out_samplerate( pv->lame, audio->config.out.samplerate );
  73
  74     pv->out_discrete_channels = hb_mixdown_get_discrete_channel_count( audio->config.out.mixdown );
  75     // Lame's default encoding mode is JOINT_STEREO.  This subtracts signal
  76     // that is "common" to left and right (within some threshold) and encodes
  77     // it separately.  This improves quality at low bitrates, but hurts
  78     // imaging (channel separation) at higher bitrates.  So if the bitrate
  79     // is suffeciently high, use regular STEREO mode.
  80     if ( pv->out_discrete_channels == 1 )
  81     {
  82         lame_set_mode( pv->lame, MONO );
  83         lame_set_num_channels( pv->lame, 1 );
  84     }
  85     else if ( audio->config.out.bitrate >= 128 )
  86     {
  87         lame_set_mode( pv->lame, STEREO );
  88     }
  89     lame_init_params( pv->lame );
  90
  91     pv->input_samples = 1152 * pv->out_discrete_channels;
  92     pv->output_bytes = LAME_MAXMP3BUFFER;
  93     pv->buf  = malloc( pv->input_samples * sizeof( float ) );
  94     audio->config.out.samples_per_frame = 1152;
  95
  96     pv->list = hb_list_init();
  97     pv->pts  = AV_NOPTS_VALUE;
  98
  99     return 0;
 100 }
 101
 102 /***********************************************************************
 103  * Close
 104  ***********************************************************************
 105  *
 106  **********************************************************************/
 107 void enclameClose( hb_work_object_t * w )
 108 {
 109     hb_work_private_t * pv = w->private_data;
 110
 111     lame_close( pv->lame );
 112     hb_list_empty( &pv->list );
 113     free( pv->buf );
 114     free( pv );
 115     w->private_data = NULL;
 116 }
 117
 118 /***********************************************************************
 119  * Encode
 120  ***********************************************************************
 121  *
 122  **********************************************************************/
 123 static hb_buffer_t * Encode( hb_work_object_t * w )
 124 {
 125     hb_work_private_t * pv = w->private_data;
 126     hb_audio_t * audio = w->audio;
 127     hb_buffer_t * buf;
 128     float samples[2][1152];
 129     uint64_t pts, pos;
 130     int      i, j;
 131
 132     if( hb_list_bytes( pv->list ) < pv->input_samples * sizeof( float ) )
 133     {
 134         return NULL;
 135     }
 136
 137     hb_list_getbytes( pv->list, pv->buf, pv->input_samples * sizeof( float ),
 138                       &pts, &pos);
 139
 140     for( i = 0; i < 1152; i++ )
 141     {
 142         for( j = 0; j < pv->out_discrete_channels; j++ )
 143         {
 144             samples[j][i] = ((float *) pv->buf)[(pv->out_discrete_channels * i + j)];
 145         }
 146     }
 147
 148     buf             = hb_buffer_init( pv->output_bytes );
 149     buf->s.start    = pts + 90000 * pos / pv->out_discrete_channels / sizeof( float ) / audio->config.out.samplerate;
 150     buf->s.duration = (double)90000 * 1152 / audio->config.out.samplerate;
 151     buf->s.stop     = buf->s.start + buf->s.duration;
 152     pv->pts = buf->s.stop;
 153     buf->size  = lame_encode_buffer_float(
 154             pv->lame, samples[0], samples[1],
 155             1152, buf->data, LAME_MAXMP3BUFFER );
 156
 157     buf->s.type = AUDIO_BUF;
 158     buf->s.frametype = HB_FRAME_AUDIO;
 159
 160     if( !buf->size )
 161     {
 162         /* Encoding was successful but we got no data. Try to encode
 163            more */
 164         hb_buffer_close( &buf );
 165         return Encode( w );
 166     }
 167     else if( buf->size < 0 )
 168     {
 169         hb_log( "enclame: lame_encode_buffer failed" );
 170         hb_buffer_close( &buf );
 171         return NULL;
 172     }
 173     return buf;
 174 }
 175
 176 /***********************************************************************
 177  * Work
 178  ***********************************************************************
 179  *
 180  **********************************************************************/
 181 int enclameWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
 182                  hb_buffer_t ** buf_out )
 183 {
 184     hb_work_private_t * pv = w->private_data;
 185     hb_audio_t * audio = w->audio;
 186     hb_buffer_t * in = *buf_in;
 187     hb_buffer_t * buf;
 188
 189     if (in->s.flags & HB_BUF_FLAG_EOF)
 190     {
 191         /* EOF on input - send it downstream & say we're done */
 192
 193         buf = hb_buffer_init( pv->output_bytes );
 194         buf->size = lame_encode_flush( pv->lame, buf->data, LAME_MAXMP3BUFFER );
 195         buf->s.start = pv->pts;
 196         buf->s.stop  = buf->s.start + 90000 * 1152 / audio->config.out.samplerate;
 197
 198         buf->s.type = AUDIO_BUF;
 199         buf->s.frametype = HB_FRAME_AUDIO;
 200
 201         if( buf->size <= 0 )
 202         {
 203             hb_buffer_close( &buf );
 204         }
 205
 206         // Add the flushed data
 207         *buf_out = buf;
 208
 209         // Add the eof
 210         if ( buf )
 211         {
 212             buf->next = in;
 213         }
 214         else
 215         {
 216             *buf_out = in;
 217         }
 218
 219         *buf_in = NULL;
 220         return HB_WORK_DONE;
 221     }
 222
 223     hb_list_add( pv->list, *buf_in );
 224     *buf_in = NULL;
 225
 226     *buf_out = buf = Encode( w );
 227
 228     while( buf )
 229     {
 230         buf->next = Encode( w );
 231         buf       = buf->next;
 232     }
 233
 234     return HB_WORK_OK;
 235 }
 236