transcode: implement SetPCR

Refs #27050

modules/stream_out/transcode/transcode.c

@@ -230,6 +230,7 @@ static const char *const ppsz_sout_options[] = {
 static void *Add( sout_stream_t *, const es_format_t * );
 static void  Del( sout_stream_t *, void * );
 static int   Send( sout_stream_t *, void *, block_t * );
+static void  SetPCR(sout_stream_t *, vlc_tick_t );
 
 static void SetAudioEncoderConfig( sout_stream_t *p_stream, transcode_encoder_config_t *p_cfg )
 {
@@ -368,7 +369,7 @@ static int Control( sout_stream_t *p_stream, int i_query, va_list args )
 }
 
 static const struct sout_stream_operations ops = {
-    Add, Del, Send, Control, NULL, NULL,
+    Add, Del, Send, Control, NULL, SetPCR,
 };
 
 /*****************************************************************************
@@ -385,6 +386,13 @@ static int Open( vlc_object_t *p_this )
     config_ChainParse( p_stream, SOUT_CFG_PREFIX, ppsz_sout_options,
                    p_stream->p_cfg );
 
+    p_sys->pcr_sync = vlc_pcr_sync_New();
+    if( unlikely( p_sys->pcr_sync == NULL ) )
+    {
+        free( p_sys );
+        return VLC_ENOMEM;
+    }
+
     /* Audio transcoding parameters */
     transcode_encoder_config_init( &p_sys->aenc_cfg );
     SetAudioEncoderConfig( p_stream, &p_sys->aenc_cfg );
@@ -477,6 +485,8 @@ static void Close( vlc_object_t * p_this )
 
     transcode_encoder_config_clean( &p_sys->senc_cfg );
 
+    vlc_pcr_sync_Delete( p_sys->pcr_sync );
+
     free( p_sys );
 }
 
@@ -648,6 +658,18 @@ static void *Add( sout_stream_t *p_stream, const es_format_t *p_fmt )
     if(!success)
         goto error;
 
+    if( id->b_transcode )
+    {
+        // TODO properly estimate the delay
+        id->pcr_helper = transcode_track_pcr_helper_New( p_sys->pcr_sync, VLC_TICK_FROM_SEC( 2 ) );
+        if( unlikely( id->pcr_helper == NULL ) )
+            goto error;
+    }
+    else
+    {
+        id->pcr_helper = NULL;
+    }
+
     return id;
 
 error:
@@ -694,6 +716,7 @@ static void Del( sout_stream_t *p_stream, void *_id )
         default:
             break;
         }
+        transcode_track_pcr_helper_Delete( id->pcr_helper );
     }
     else decoder_Destroy( id->p_decoder );
 
@@ -718,6 +741,19 @@ static int Send( sout_stream_t *p_stream, void *_id, block_t *p_buffer )
             goto error;
     }
 
+    sout_stream_sys_t *sys = p_stream->p_sys;
+    if( p_buffer != NULL )
+    {
+        assert( p_buffer->p_next == NULL );
+        vlc_tick_t dropped_frame_ts;
+        transcode_track_pcr_helper_SignalEnteringFrame( id->pcr_helper, p_buffer,
+                                                       &dropped_frame_ts );
+        if (dropped_frame_ts != VLC_TICK_INVALID)
+        {
+            sout_StreamSetPCR( p_stream->p_next, dropped_frame_ts );
+        }
+    }
+
     int i_ret;
     switch( id->p_decoder->fmt_in.i_cat )
     {
@@ -737,9 +773,30 @@ static int Send( sout_stream_t *p_stream, void *_id, block_t *p_buffer )
         goto error;
     }
 
-    if( p_out &&
-        sout_StreamIdSend( p_stream->p_next, id->downstream_id, p_out ) )
-        i_ret = VLC_EGENERIC;
+    if( p_out )
+    {
+        for( block_t *it = p_out; it != NULL; )
+        {
+            block_t *next = it->p_next;
+            it->p_next = NULL;
+
+            const vlc_tick_t pcr =
+                transcode_track_pcr_helper_SignalLeavingFrame( id->pcr_helper, it );
+
+            if( sout_StreamIdSend( p_stream->p_next, id->downstream_id, it ) != VLC_SUCCESS )
+            {
+                p_buffer = next;
+                goto error;
+            }
+
+            if( pcr != VLC_TICK_INVALID )
+            {
+                sout_StreamSetPCR( p_stream->p_next, pcr );
+            }
+
+            it = next;
+        }
+    }
 
     if (i_ret != VLC_SUCCESS)
         id->b_error = true;
@@ -750,3 +807,13 @@ error:
         block_Release( p_buffer );
     return VLC_EGENERIC;
 }
+
+static void SetPCR( sout_stream_t *stream, vlc_tick_t pcr )
+{
+    sout_stream_sys_t *sys = stream->p_sys;
+    const int status = vlc_pcr_sync_SignalPCR( sys->pcr_sync, pcr );
+    if ( status == VLC_PCR_SYNC_FORWARD_PCR )
+    {
+        sout_StreamSetPCR( stream->p_next, pcr );
+    }
+}

modules/stream_out/transcode/transcode.h

@@ -2,6 +2,7 @@
 #include <vlc_filter.h>
 #include <vlc_codec.h>
 #include "encoder/encoder.h"
+#include "pcr_helper.h"
 
 /*100ms is around the limit where people are noticing lipsync issues*/
 #define MASTER_SYNC_MAX_DRIFT VLC_TICK_FROM_MS(100)
@@ -64,6 +65,7 @@ typedef struct
     /* Spu's video */
     sout_stream_id_sys_t *id_video;
 
+    vlc_pcr_sync_t *pcr_sync;
 } sout_stream_sys_t;
 
 struct aout_filters;
@@ -147,6 +149,8 @@ struct sout_stream_id_sys_t
     /* Sync */
     date_t          next_input_pts; /**< Incoming calculated PTS */
     vlc_tick_t      i_drift; /** how much buffer is ahead of calculated PTS */
+
+    transcode_track_pcr_helper_t *pcr_helper;
 };
 
 struct decoder_owner