allow mono mixdown with lame encoder

enable mono mode in lame encoder when mixdown is mono.

use lame_encode_buffer_float instead of lame_encode_buffer_interleave. this 
eliminates the clipping issue in lame without reducing the level of the input.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@3294 b64f7644-9d1e-0410-96f1-a4d463321fa5

4 files changed, 32 insertions, 44 deletions

diff --git a/libhb/deca52.c b/libhb/deca52.c
index 3cb2f3355..785bf6aef 100644
--- a/libhb/deca52.c
+++ b/libhb/deca52.c
@@ -101,8 +101,6 @@ static int deca52Init( hb_work_object_t * w, hb_job_t * job )
     work.c has already done some of this deduction for us in do_job() */
 
     pv->flags_out = HB_AMIXDOWN_GET_A52_FORMAT(audio->config.out.mixdown);
-    if ( audio->config.out.codec == HB_ACODEC_LAME )
-        pv->flags_out |= A52_ADJUST_LEVEL;
 
     /* pass the number of channels used into the private work data */
     /* will only be actually used if we're not doing AC3 passthru */
diff --git a/libhb/decavcodec.c b/libhb/decavcodec.c
index 0a9f63fec..31c0b751a 100644
--- a/libhb/decavcodec.c
+++ b/libhb/decavcodec.c
@@ -210,8 +210,6 @@ static int decavcodecInit( hb_work_object_t * w, hb_job_t * job )
         pv->downmix = hb_downmix_init(w->audio->config.in.channel_layout, 
                                       w->audio->config.out.mixdown);
         hb_downmix_set_chan_map( pv->downmix, &hb_smpte_chan_map, &hb_qt_chan_map );
-        if ( w->audio->config.out.codec == HB_ACODEC_LAME )
-            hb_downmix_adjust_level( pv->downmix );
     }
 
     return 0;
@@ -1101,8 +1099,6 @@ static int decavcodecviInit( hb_work_object_t * w, hb_job_t * job )
         pv->downmix = hb_downmix_init(w->audio->config.in.channel_layout, 
                                       w->audio->config.out.mixdown);
         hb_downmix_set_chan_map( pv->downmix, &hb_smpte_chan_map, &hb_qt_chan_map );
-        if ( w->audio->config.out.codec == HB_ACODEC_LAME )
-            hb_downmix_adjust_level( pv->downmix );
     }
 
     return 0;
diff --git a/libhb/enclame.c b/libhb/enclame.c
index a3f4a3882..9692eef29 100644
--- a/libhb/enclame.c
+++ b/libhb/enclame.c
@@ -29,6 +29,7 @@ struct hb_work_private_s
     lame_global_flags * lame;
 
     int             done;
+    int             out_discrete_channels;
     unsigned long   input_samples;
     unsigned long   output_bytes;
     uint8_t       * buf;
@@ -41,6 +42,7 @@ int enclameInit( hb_work_object_t * w, hb_job_t * job )
 {
     hb_work_private_t * pv = calloc( 1, sizeof( hb_work_private_t ) );
     hb_audio_t * audio = w->audio;
+
     w->private_data = pv;
 
     pv->job   = job;
@@ -53,16 +55,25 @@ int enclameInit( hb_work_object_t * w, hb_job_t * job )
     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 );
-    lame_init_params( pv->lame );
+
+    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 ( audio->config.out.bitrate >= 128 )
+    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 );
+    }
+    lame_init_params( pv->lame );
 
-    pv->input_samples = 1152 * 2;
+    pv->input_samples = 1152 * pv->out_discrete_channels;
     pv->output_bytes = LAME_MAXMP3BUFFER;
     pv->buf  = malloc( pv->input_samples * sizeof( float ) );
 
@@ -98,9 +109,9 @@ static hb_buffer_t * Encode( hb_work_object_t * w )
     hb_work_private_t * pv = w->private_data;
     hb_audio_t * audio = w->audio;
     hb_buffer_t * buf;
-    int16_t samples_s16[1152 * 2];
+    float samples[2][1152];
     uint64_t pts, pos;
-	int      i;
+    int      i, j;
 
     if( hb_list_bytes( pv->list ) < pv->input_samples * sizeof( float ) )
     {
@@ -110,16 +121,22 @@ static hb_buffer_t * Encode( hb_work_object_t * w )
     hb_list_getbytes( pv->list, pv->buf, pv->input_samples * sizeof( float ),
                       &pts, &pos);
 
-    for( i = 0; i < 1152 * 2; i++ )
+    memset(samples, 0, 2*1152*sizeof(float));
+    for( i = 0; i < 1152; i++ )
     {
-        samples_s16[i] = ((float*) pv->buf)[i];
+        for( j = 0; j < pv->out_discrete_channels; j++ )
+        {
+            samples[j][i] = ((float *) pv->buf)[(pv->out_discrete_channels * i + j)];
+        }
     }
 
     buf        = hb_buffer_init( pv->output_bytes );
-    buf->start = pts + 90000 * pos / 2 / sizeof( float ) / audio->config.out.samplerate;
+    buf->start = pts + 90000 * pos / pv->out_discrete_channels / sizeof( float ) / audio->config.out.samplerate;
     buf->stop  = buf->start + 90000 * 1152 / audio->config.out.samplerate;
-    buf->size  = lame_encode_buffer_interleaved( pv->lame, samples_s16,
+    buf->size  = lame_encode_buffer_float( 
+            pv->lame, samples[0], samples[1],
             1152, buf->data, LAME_MAXMP3BUFFER );
+
     buf->frametype   = HB_FRAME_AUDIO;
 
     if( !buf->size )
diff --git a/libhb/work.c b/libhb/work.c
index 838e50702..6c783032a 100644
--- a/libhb/work.c
+++ b/libhb/work.c
@@ -568,16 +568,13 @@ static void do_job( hb_job_t * job, int cpu_count )
             // So if the encoder is lame we need the output to be stereo (or multichannel
             // matrixed into stereo like dpl). If the decoder is not AC3 or DCA the
             // encoder has to handle the input format since we can't do a mixdown.
-#define STEREO_ONLY(a) ( a->config.out.codec & HB_ACODEC_LAME )
-
             switch (audio->config.in.channel_layout & HB_INPUT_CH_LAYOUT_DISCRETE_NO_LFE_MASK)
             {
                 // stereo input or something not handled below
                 default:
                 case HB_INPUT_CH_LAYOUT_STEREO:
                     // mono gets mixed up to stereo & more than stereo gets mixed down
-                    if ( STEREO_ONLY( audio ) ||
-                         audio->config.out.mixdown > HB_AMIXDOWN_STEREO)
+                    if ( audio->config.out.mixdown > HB_AMIXDOWN_STEREO )
                     {
                         audio->config.out.mixdown = HB_AMIXDOWN_STEREO;
                     }
@@ -585,23 +582,15 @@ static void do_job( hb_job_t * job, int cpu_count )
 
                 // mono input
                 case HB_INPUT_CH_LAYOUT_MONO:
-                    if ( STEREO_ONLY( audio ) )
-                    {
-                        audio->config.out.mixdown = HB_AMIXDOWN_STEREO;
-                    }
-                    else
-                    {
-                        // everything else passes through
-                        audio->config.out.mixdown = HB_AMIXDOWN_MONO;
-                    }
+                    // everything else passes through
+                    audio->config.out.mixdown = HB_AMIXDOWN_MONO;
                     break;
 
                 // dolby (DPL1 aka Dolby Surround = 4.0 matrix-encoded) input
                 // the A52 flags don't allow for a way to distinguish between DPL1 and
                 // DPL2 on a DVD so we always assume a DPL1 source for A52_DOLBY.
                 case HB_INPUT_CH_LAYOUT_DOLBY:
-                    if ( STEREO_ONLY( audio ) ||
-                         audio->config.out.mixdown > HB_AMIXDOWN_DOLBY )
+                    if ( audio->config.out.mixdown > HB_AMIXDOWN_DOLBY )
                     {
                         audio->config.out.mixdown = HB_AMIXDOWN_DOLBY;
                     }
@@ -610,8 +599,7 @@ static void do_job( hb_job_t * job, int cpu_count )
                 // 4 channel discrete
                 case HB_INPUT_CH_LAYOUT_2F2R:
                 case HB_INPUT_CH_LAYOUT_3F1R:
-                    if ( STEREO_ONLY( audio ) ||
-                         audio->config.out.mixdown > HB_AMIXDOWN_DOLBY )
+                    if ( audio->config.out.mixdown > HB_AMIXDOWN_DOLBY )
                     {
                         audio->config.out.mixdown = HB_AMIXDOWN_DOLBY;
                     }
@@ -619,18 +607,7 @@ static void do_job( hb_job_t * job, int cpu_count )
 
                 // 5 or 6 channel discrete
                 case HB_INPUT_CH_LAYOUT_3F2R:
-                    if ( STEREO_ONLY( audio ) )
-                    {
-                        if ( audio->config.out.mixdown < HB_AMIXDOWN_STEREO )
-                        {
-                            audio->config.out.mixdown = HB_AMIXDOWN_STEREO;
-                        }
-                        else if ( audio->config.out.mixdown > HB_AMIXDOWN_DOLBYPLII )
-                        {
-                            audio->config.out.mixdown = HB_AMIXDOWN_DOLBYPLII;
-                        }
-                    }
-                    else if ( ! ( audio->config.in.channel_layout &
+                    if ( ! ( audio->config.in.channel_layout &
                                     HB_INPUT_CH_LAYOUT_HAS_LFE ) )
                     {
                         // we don't do 5 channel discrete so mixdown to DPLII