Added support for avcodec audio channel layout.

modules/codec/avcodec/audio.c

@@ -45,25 +45,6 @@
 
 #include "avcodec.h"
 
-static const unsigned int pi_channels_maps[9] =
-{
-    0,
-    AOUT_CHAN_CENTER,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER |
-        AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER |
-        AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER |
-        AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT |
-        AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT,
-    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER |
-        AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT |
-        AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE,
-};
-
 /*****************************************************************************
  * decoder_sys_t : decoder descriptor
  *****************************************************************************/
@@ -89,9 +70,15 @@ struct decoder_sys_t
 
     /* */
     int     i_reject_count;
+
+    /* */
+    bool    b_extract;
+    int     pi_extraction[AOUT_CHAN_MAX];
+    int     i_previous_channels;
+    int64_t i_previous_layout;
 };
 
-static void SetupOutputCodec( decoder_t *p_dec );
+static void SetupOutputFormat( decoder_t *p_dec );
 
 /*****************************************************************************
  * InitAudioDec: initialize audio decoder
@@ -118,17 +105,6 @@ int InitAudioDec( decoder_t *p_dec, AVCodecContext *p_context,
     /* ***** Fill p_context with init values ***** */
     p_sys->p_context->sample_rate = p_dec->fmt_in.audio.i_rate;
     p_sys->p_context->channels = p_dec->fmt_in.audio.i_channels;
-    if( !p_dec->fmt_in.audio.i_physical_channels )
-    {
-        msg_Warn( p_dec, "Physical channel configuration not set : guessing" );
-        p_dec->fmt_in.audio.i_original_channels =
-            p_dec->fmt_in.audio.i_physical_channels =
-                pi_channels_maps[p_sys->p_context->channels];
-    }
-
-    p_dec->fmt_out.audio.i_physical_channels =
-        p_dec->fmt_out.audio.i_original_channels =
-        p_dec->fmt_in.audio.i_physical_channels;
 
     p_sys->p_context->block_align = p_dec->fmt_in.audio.i_blockalign;
     p_sys->p_context->bit_rate = p_dec->fmt_in.i_bitrate;
@@ -222,18 +198,20 @@ int InitAudioDec( decoder_t *p_dec, AVCodecContext *p_context,
         p_sys->i_output_max = AVCODEC_MAX_AUDIO_FRAME_SIZE;
     msg_Dbg( p_dec, "Using %d bytes output buffer", p_sys->i_output_max );
     p_sys->p_output = malloc( p_sys->i_output_max );
+
     p_sys->p_samples = NULL;
     p_sys->i_samples = 0;
     p_sys->i_reject_count = 0;
+    p_sys->b_extract = false;
+    p_sys->i_previous_channels = 0;
+    p_sys->i_previous_layout = 0;
 
     aout_DateSet( &p_sys->end_date, 0 );
     if( p_dec->fmt_in.audio.i_rate )
         aout_DateInit( &p_sys->end_date, p_dec->fmt_in.audio.i_rate );
 
-    /* Set output properties */
-    p_dec->fmt_out.i_cat = AUDIO_ES;
-
-    SetupOutputCodec( p_dec );
+    /* */
+    es_format_Init( &p_dec->fmt_out, AUDIO_ES, 0 );
 
     return VLC_SUCCESS;
 }
@@ -256,7 +234,12 @@ static aout_buffer_t *SplitBuffer( decoder_t *p_dec )
     p_buffer->start_date = aout_DateGet( &p_sys->end_date );
     p_buffer->end_date = aout_DateIncrement( &p_sys->end_date, i_samples );
 
-    memcpy( p_buffer->p_buffer, p_sys->p_samples, p_buffer->i_nb_bytes );
+    if( p_sys->b_extract )
+        aout_ChannelExtract( p_buffer->p_buffer, p_dec->fmt_out.audio.i_channels,
+                             p_sys->p_samples, p_sys->p_context->channels, i_samples,
+                             p_sys->pi_extraction, p_dec->fmt_out.audio.i_bitspersample );
+    else
+        memcpy( p_buffer->p_buffer, p_sys->p_samples, p_buffer->i_nb_bytes );
 
     p_sys->p_samples += p_buffer->i_nb_bytes;
     p_sys->i_samples -= i_samples;
@@ -310,6 +293,7 @@ aout_buffer_t * DecodeAudio ( decoder_t *p_dec, block_t **pp_block )
         block_Release( p_block );
         return NULL;
     }
+
     i_output = __MAX( p_block->i_buffer, p_sys->i_output_max );
     if( i_output < p_sys->i_output_max )
     {
@@ -366,12 +350,7 @@ aout_buffer_t * DecodeAudio ( decoder_t *p_dec, block_t **pp_block )
     }
 
     /* **** Set audio output parameters **** */
-    SetupOutputCodec( p_dec );
-    p_dec->fmt_out.audio.i_rate     = p_sys->p_context->sample_rate;
-    p_dec->fmt_out.audio.i_channels = p_sys->p_context->channels;
-    p_dec->fmt_out.audio.i_original_channels =
-        p_dec->fmt_out.audio.i_physical_channels =
-            pi_channels_maps[p_sys->p_context->channels];
+    SetupOutputFormat( p_dec );
 
     if( p_block->i_pts != 0 &&
         p_block->i_pts != aout_DateGet( &p_sys->end_date ) )
@@ -409,7 +388,31 @@ void EndAudioDec( decoder_t *p_dec )
 /*****************************************************************************
  *
  *****************************************************************************/
-static void SetupOutputCodec( decoder_t *p_dec )
+static const uint64_t pi_channels_map[][2] =
+{
+    { CH_FRONT_LEFT,        AOUT_CHAN_LEFT },
+    { CH_FRONT_RIGHT,       AOUT_CHAN_RIGHT },
+    { CH_FRONT_CENTER,      AOUT_CHAN_CENTER },
+    { CH_LOW_FREQUENCY,     AOUT_CHAN_LFE },
+    { CH_BACK_LEFT,         AOUT_CHAN_REARLEFT },
+    { CH_BACK_RIGHT,        AOUT_CHAN_REARRIGHT },
+    { CH_FRONT_LEFT_OF_CENTER, 0 },
+    { CH_FRONT_RIGHT_OF_CENTER, 0 },
+    { CH_BACK_CENTER,       AOUT_CHAN_REARCENTER },
+    { CH_SIDE_LEFT,         AOUT_CHAN_MIDDLELEFT },
+    { CH_SIDE_RIGHT,        AOUT_CHAN_MIDDLERIGHT },
+    { CH_TOP_CENTER,        0 },
+    { CH_TOP_FRONT_LEFT,    0 },
+    { CH_TOP_FRONT_CENTER,  0 },
+    { CH_TOP_FRONT_RIGHT,   0 },
+    { CH_TOP_BACK_LEFT,     0 },
+    { CH_TOP_BACK_CENTER,   0 },
+    { CH_TOP_BACK_RIGHT,    0 },
+    { CH_STEREO_LEFT,       0 },
+    { CH_STEREO_RIGHT,      0 },
+};
+
+static void SetupOutputFormat( decoder_t *p_dec )
 {
     decoder_sys_t *p_sys = p_dec->p_sys;
 
@@ -443,4 +446,54 @@ static void SetupOutputCodec( decoder_t *p_dec )
     p_dec->fmt_out.i_codec = AOUT_FMT_S16_NE;
     p_dec->fmt_out.audio.i_bitspersample = 16;
 #endif
+    p_dec->fmt_out.audio.i_rate     = p_sys->p_context->sample_rate;
+    p_dec->fmt_out.audio.i_channels = p_sys->p_context->channels;
+
+    /* */
+    if( p_sys->i_previous_channels == p_sys->p_context->channels &&
+        p_sys->i_previous_layout == p_sys->p_context->channel_layout )
+        return;
+    p_sys->i_previous_channels = p_sys->p_context->channels;
+    p_sys->i_previous_layout = p_sys->p_context->channel_layout;
+
+    /* Specified order
+     * FIXME should we use fmt_in.audio.i_physical_channels or not ?
+     */
+    const unsigned i_order_max = 8 * sizeof(p_sys->p_context->channel_layout);
+    uint32_t pi_order_src[i_order_max];
+    int i_channels_src = 0;
+
+    if( p_sys->p_context->channel_layout )
+    {
+        for( unsigned i = 0; i < sizeof(pi_channels_map)/sizeof(*pi_channels_map); i++ )
+        {
+            if( p_sys->p_context->channel_layout & pi_channels_map[i][0] )
+                pi_order_src[i_channels_src++] = pi_channels_map[i][1];
+        }
+    }
+    else
+    {
+        /* Create default order  */
+        msg_Warn( p_dec, "Physical channel configuration not set : guessing" );
+        for( unsigned int i = 0; i < __MIN( i_order_max, (unsigned)p_sys->p_context->channels ); i++ )
+        {
+            if( i < sizeof(pi_channels_map)/sizeof(*pi_channels_map) )
+                pi_order_src[i_channels_src++] = pi_channels_map[i][1];
+        }
+    }
+    if( i_channels_src != p_sys->p_context->channels )
+        msg_Err( p_dec, "Channel layout not understood" );
+
+    uint32_t i_layout_dst;
+    int      i_channels_dst;
+    p_sys->b_extract = aout_CheckChannelExtraction( p_sys->pi_extraction,
+                                                    &i_layout_dst, &i_channels_dst,
+                                                    NULL, pi_order_src, i_channels_src );
+    if( i_channels_dst != i_channels_src )
+        msg_Warn( p_dec, "%d channels are dropped", i_channels_src - i_channels_dst );
+
+    p_dec->fmt_out.audio.i_physical_channels =
+    p_dec->fmt_out.audio.i_original_channels = i_layout_dst;
+    p_dec->fmt_out.audio.i_channels = i_channels_dst;
 }
+