libhb: work around the lack of 6.1 support for DTS sources

libhb doesn't support 6.1 sources and assumes they're 7.0 instead. This breaks downmixing.

Libav can decode the DTS-ES 6.1 core of DTS-HD 6.1 audio tracks; tell it to not process the additional channel so that such tracks can be re-encoded correctly.

See https://reviews.handbrake.fr/r/200/ for more information.



git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@4209 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 23 insertions, 0 deletions

diff --git a/libhb/decavcodec.c b/libhb/decavcodec.c
index f67850d86..4d62c0274 100644
--- a/libhb/decavcodec.c
+++ b/libhb/decavcodec.c
@@ -203,6 +203,24 @@ static int decavcodecaInit( hb_work_object_t * w, hb_job_t * job )
         return 1;
     }
 
+    // DTS: work around lack of 6.1 support in libhb
+    if( hb_ff_dts_request_5point1( pv->context ) )
+    {
+        hb_deep_log( 2, "decavcodecaInit: found DTS-ES 6.1, requesting 5.1 core" );
+    }
+    else if( ( !pv->context->channels || !pv->context->channel_layout ) &&
+             ( w->audio->config.in.codec == HB_ACODEC_DCA_HD ) &&
+             ( w->audio->config.in.channel_layout == ( HB_INPUT_CH_LAYOUT_3F2R|HB_INPUT_CH_LAYOUT_HAS_LFE ) ) )
+    {
+        /* XXX: when we are demuxing the stream ourselves, it seems we have no
+         * channel count/layout info in the context until we decode audio for
+         * the first time. If the scan info says the source is DTS-HD 5.1,
+         * make sure XCh processing is disabled in Libav before decoding. */
+        pv->context->request_channels = pv->context->channels = 6;
+        pv->context->channel_layout = AV_CH_LAYOUT_5POINT1;
+        hb_deep_log( 2, "decavcodecaInit: scan detected DTS 5.1, disabling XCh processing" );
+    }
+
     if ( w->audio != NULL )
     {
         if ( hb_need_downmix( w->audio->config.in.channel_layout, 
@@ -439,6 +457,11 @@ static int decavcodecaBSInfo( hb_work_object_t *w, const hb_buffer_t *buf,
                                              &out_size, &avp );
                 if ( len > 0 && context->sample_rate > 0 )
                 {
+                    // DTS: work around lack of 6.1 support in libhb
+                    if( hb_ff_dts_request_5point1( context ) )
+                    {
+                        hb_deep_log( 2, "decavcodecaBSInfo: found DTS-ES 6.1, requesting 5.1 core" );
+                    }
                     int isamp = av_get_bytes_per_sample( context->sample_fmt );
                     info->bitrate = context->bit_rate;
                     info->rate = context->sample_rate;