[vlc-devel] [RFC] dcp: Audio channels reordering

[Nicolas Bertrand]

Just the part about channel ordering. based on patch v11.



---
 modules/access/dcp/dcp.cpp |   51 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 48 insertions(+), 3 deletions(-)

diff --git a/modules/access/dcp/dcp.cpp b/modules/access/dcp/dcp.cpp
index bb7dee9..ba72a82 100644
--- a/modules/access/dcp/dcp.cpp
+++ b/modules/access/dcp/dcp.cpp
@@ -43,6 +43,7 @@
 #include <vlc_plugin.h>
 #include <vlc_xml.h>
 #include <vlc_url.h>
+#include <vlc_aout.h>
 
 /* ASDCP headers */
 #include <AS_DCP.h>
@@ -133,6 +134,10 @@ class demux_sys_t
     /* total number of frames */
     uint32_t frames_total;
 
+    uint8_t i_chans_to_reorder;            /* do we need channel reordering */
+    uint8_t pi_chan_table[AOUT_CHAN_MAX];
+    uint8_t i_channels;
+
     mtime_t i_pts;
 
     demux_sys_t():
@@ -168,6 +173,30 @@ class demux_sys_t
     }
 };
 
+/*TODO: basic correlation between SMPTE S428-3/S429-2
+ * Real sound is more complex with case of left/right surround, ...
+ * and hearing impaired/Narration channels */
+static const uint32_t pi_channels_aout[][9] = {
+    /* case CFG 1; 5.1 */
+    { AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT,      AOUT_CHAN_CENTER,
+      AOUT_CHAN_LFE,  AOUT_CHAN_REARLEFT,   AOUT_CHAN_REARRIGHT,
+     0 ,              0,                    0 },
+    /* case CFG2 : 6.1 */
+    { AOUT_CHAN_LEFT,       AOUT_CHAN_RIGHT,    AOUT_CHAN_CENTER,
+      AOUT_CHAN_LFE,        AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT,
+      AOUT_CHAN_REARCENTER, 0,                  0  },
+    /* case CFG2 : 7.1 */
+    { AOUT_CHAN_LEFT,        AOUT_CHAN_RIGHT,      AOUT_CHAN_CENTER,
+      AOUT_CHAN_LFE,         AOUT_CHAN_REARLEFT,   AOUT_CHAN_REARRIGHT,
+      AOUT_CHAN_MIDDLELEFT,  AOUT_CHAN_MIDDLELEFT, 0 },
+};
+
+static const unsigned i_channel_mask[] = {
+    AOUT_CHANS_5_1,
+    AOUT_CHANS_6_1_MIDDLE,
+    AOUT_CHANS_7_1
+} ;
+
 /*****************************************************************************
  * Local prototypes
  *****************************************************************************/
@@ -364,10 +393,22 @@ static int Open( vlc_object_t *obj )
 
         audio_format.audio.i_bitspersample = p_AudioDesc->QuantizationBits;
         audio_format.audio.i_blockalign    = p_AudioDesc->BlockAlign;
-        audio_format.audio.i_channels      = p_AudioDesc->ChannelCount;
-
+        audio_format.audio.i_channels      =
+        p_sys->i_channels                  = p_AudioDesc->ChannelCount;
         p_sys->i_audio_buffer = PCM::CalcFrameBufferSize(*p_AudioDesc);
 
+        /* Manage channel orders */
+        /* TODO Case CF_CFG_1, CF_CFG_2, CF_CFG_3 only supported */
+        if ( ( p_AudioDesc->ChannelFormat == PCM::CF_CFG_4 ) ||
+           ( p_AudioDesc->ChannelFormat == PCM::CF_CFG_5 ) ) {
+             msg_Err( p_demux, "Sound config not supported. Set to 7.1 order");
+             p_AudioDesc->ChannelFormat = PCM::CF_CFG_3;
+        };
+        p_sys->i_chans_to_reorder =  aout_CheckChannelReorder(
+                pi_channels_aout[p_AudioDesc->ChannelFormat], NULL,
+                i_channel_mask[p_AudioDesc->ChannelFormat],
+                p_sys->pi_chan_table );
+
         if( ( p_sys->p_audio_es = es_out_Add( p_demux->out, &audio_format ) ) == NULL ) {
             msg_Err( p_demux, "Failed to add audio es" );
             retval = VLC_EGENERIC;
@@ -384,7 +425,6 @@ static int Open( vlc_object_t *obj )
         goto error;
     }
 
-
     p_sys->p_out = p_demux->out;
     p_demux->pf_demux = Demux;
     p_demux->pf_control = Control;
@@ -489,6 +529,11 @@ static int Demux( demux_t *p_demux )
         goto error_asdcp;
     }
 
+    if( p_sys->i_chans_to_reorder )
+        aout_ChannelReorder( p_audio_frame->p_buffer, p_audio_frame->i_buffer,
+                p_sys->i_channels,
+                p_sys->pi_chan_table, VLC_CODEC_S24L );
+
     p_audio_frame->i_buffer = AudioFrameBuff.Size();
     p_audio_frame->i_length = CLOCK_FREQ * p_sys->frame_rate_denom / p_sys->frame_rate_num;
     p_audio_frame->i_pts = CLOCK_FREQ * p_sys->frame_no * p_sys->frame_rate_denom / p_sys->frame_rate_num;
-- 
1.7.9.5