decoder: add decoder_QueueVideo

This function allow asynchronous decoders to queue a picture to the video
output. Decoders that use this function should return NULL in pf_decode_video
callback.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

include/vlc_codec.h

@@ -121,6 +121,9 @@ struct decoder_t
      * XXX use decoder_GetDisplayRate */
     int             (*pf_get_display_rate)( decoder_t * );
 
+    /* XXX use decoder_QueueVideo */
+    int             (*pf_queue_video)( decoder_t *, picture_t * );
+
     /* Private structure for the owner of the decoder */
     decoder_owner_sys_t *p_owner;
 
@@ -238,6 +241,26 @@ static inline picture_t *decoder_NewPicture( decoder_t *dec )
     return decoder_GetPicture( dec );
 }
 
+/**
+ * This function queues a picture to the video output.
+ *
+ * \note
+ * The caller doesn't own the picture anymore after this call (even in case of
+ * error).
+ * FIXME: input_DecoderFrameNext won't work if a module use this function.
+ *
+ * \return 0 if the picture is queued, -1 on error
+ */
+static inline int decoder_QueueVideo( decoder_t *dec, picture_t *p_pic )
+{
+    if( !dec->pf_queue_video )
+    {
+        picture_Release( p_pic );
+        return -1;
+    }
+    return dec->pf_queue_video( dec, p_pic );
+}
+
 /**
  * This function notifies the audio output pipeline of a new audio output
  * format (fmt_out.audio). If there is currently no audio output or if the

src/input/decoder.c

@@ -894,50 +894,45 @@ static void DecoderPlayVideo( decoder_t *p_dec, picture_t *p_picture,
     *pi_lost_sum += i_tmp_lost;
 }
 
-static void DecoderDecodeVideo( decoder_t *p_dec, block_t *p_block )
+static int DecoderPreparePlayVideo( decoder_t *p_dec, picture_t *p_pic )
 {
     decoder_owner_sys_t *p_owner = p_dec->p_owner;
-    picture_t      *p_pic;
-    int i_lost = 0;
-    int i_decoded = 0;
-    int i_displayed = 0;
+    vout_thread_t  *p_vout = p_owner->p_vout;
 
-    while( (p_pic = p_dec->pf_decode_video( p_dec, &p_block )) )
+    vlc_mutex_lock( &p_owner->lock );
+    if( p_owner->i_preroll_end > VLC_TS_INVALID && p_pic->date < p_owner->i_preroll_end )
     {
-        vout_thread_t  *p_vout = p_owner->p_vout;
-
-        i_decoded++;
-
-        vlc_mutex_lock( &p_owner->lock );
-        if( p_owner->i_preroll_end > VLC_TS_INVALID && p_pic->date < p_owner->i_preroll_end )
-        {
-            vlc_mutex_unlock( &p_owner->lock );
-            picture_Release( p_pic );
-            continue;
-        }
+        vlc_mutex_unlock( &p_owner->lock );
+        picture_Release( p_pic );
+        return -1;
+    }
 
-        if( p_owner->i_preroll_end > VLC_TS_INVALID )
-        {
-            msg_Dbg( p_dec, "End of video preroll" );
-            p_owner->i_preroll_end = VLC_TS_INVALID;
-            vlc_mutex_unlock( &p_owner->lock );
-            /* */
-            if( p_vout )
-                vout_Flush( p_vout, VLC_TS_INVALID+1 );
-        }
-        else
-            vlc_mutex_unlock( &p_owner->lock );
+    if( p_owner->i_preroll_end > VLC_TS_INVALID )
+    {
+        msg_Dbg( p_dec, "End of video preroll" );
+        p_owner->i_preroll_end = VLC_TS_INVALID;
+        vlc_mutex_unlock( &p_owner->lock );
+        /* */
+        if( p_vout )
+            vout_Flush( p_vout, VLC_TS_INVALID+1 );
+    }
+    else
+        vlc_mutex_unlock( &p_owner->lock );
 
-        if( p_dec->pf_get_cc &&
-            ( !p_owner->p_packetizer || !p_owner->p_packetizer->pf_get_cc ) )
-            DecoderGetCc( p_dec, p_dec );
+    if( p_dec->pf_get_cc &&
+        ( !p_owner->p_packetizer || !p_owner->p_packetizer->pf_get_cc ) )
+        DecoderGetCc( p_dec, p_dec );
 
-        DecoderPlayVideo( p_dec, p_pic, &i_displayed, &i_lost );
-    }
+    return 0;
+}
 
-    /* Update ugly stat */
+static void DecoderUpdateStatVideo( decoder_t *p_dec, int i_decoded,
+                                    int i_lost, int i_displayed )
+{
+    decoder_owner_sys_t *p_owner = p_dec->p_owner;
     input_thread_t *p_input = p_owner->p_input;
 
+    /* Update ugly stat */
     if( p_input != NULL && (i_decoded > 0 || i_lost > 0 || i_displayed > 0) )
     {
         vlc_mutex_lock( &p_input->p->counters.counters_lock );
@@ -949,6 +944,40 @@ static void DecoderDecodeVideo( decoder_t *p_dec, block_t *p_block )
     }
 }
 
+static int DecoderQueueVideo( decoder_t *p_dec, picture_t *p_pic )
+{
+    assert( p_pic );
+    int i_lost = 0;
+    int i_displayed = 0;
+    int i_ret;
+
+    if( ( i_ret = DecoderPreparePlayVideo( p_dec, p_pic ) ) == 0 )
+        DecoderPlayVideo( p_dec, p_pic, &i_displayed, &i_lost );
+
+    DecoderUpdateStatVideo( p_dec, 1, i_lost, i_displayed );
+    return i_ret;
+}
+
+static void DecoderDecodeVideo( decoder_t *p_dec, block_t *p_block )
+{
+    picture_t      *p_pic;
+    int i_lost = 0;
+    int i_decoded = 0;
+    int i_displayed = 0;
+
+    while( (p_pic = p_dec->pf_decode_video( p_dec, &p_block )) )
+    {
+        i_decoded++;
+
+        if( DecoderPreparePlayVideo( p_dec, p_pic ) != 0 )
+            continue;
+
+        DecoderPlayVideo( p_dec, p_pic, &i_displayed, &i_lost );
+    }
+
+    DecoderUpdateStatVideo( p_dec, i_decoded, i_lost, i_displayed );
+}
+
 /* This function process a video block
  */
 static void DecoderProcessVideo( decoder_t *p_dec, block_t *p_block )
@@ -1533,6 +1562,7 @@ static decoder_t * CreateDecoder( vlc_object_t *p_parent,
     p_dec->pf_get_attachments  = DecoderGetInputAttachments;
     p_dec->pf_get_display_date = DecoderGetDisplayDate;
     p_dec->pf_get_display_rate = DecoderGetDisplayRate;
+    p_dec->pf_queue_video = DecoderQueueVideo;
 
     /* Load a packetizer module if the input is not already packetized */
     if( p_sout == NULL && !fmt->b_packetized )