- lame_set_brate( pv->lame, job->abitrate );
- lame_set_in_samplerate( pv->lame, job->arate );
- lame_set_out_samplerate( pv->lame, job->arate );
+ // use ABR
+ lame_set_VBR( pv->lame, vbr_abr );
+ lame_set_VBR_mean_bitrate_kbps( pv->lame, audio->config.out.bitrate );
+ lame_set_in_samplerate( pv->lame, audio->config.out.samplerate );
+ lame_set_out_samplerate( pv->lame, audio->config.out.samplerate );
+
+ pv->out_discrete_channels = HB_AMIXDOWN_GET_DISCRETE_CHANNEL_COUNT(audio->config.out.mixdown);
+ // Lame's default encoding mode is JOINT_STEREO. This subtracts signal
+ // that is "common" to left and right (within some threshold) and encodes
+ // it separately. This improves quality at low bitrates, but hurts
+ // imaging (channel separation) at higher bitrates. So if the bitrate
+ // is suffeciently high, use regular STEREO mode.
+ if ( pv->out_discrete_channels == 1 )
+ {
+ lame_set_mode( pv->lame, MONO );
+ lame_set_num_channels( pv->lame, 1 );
+ }
+ else if ( audio->config.out.bitrate >= 128 )
+ {
+ lame_set_mode( pv->lame, STEREO );
+ }