* fix author field of OSX info dialog

[vlc] / modules / codec / theora.c

diff --git a/modules/codec/theora.c b/modules/codec/theora.c
index 32289431a30225f91842b0f6a5979b0e2b91b19a..0353b0467ea3022a3cacc0a83fea140f4984f0f5 100644 (file)
--- a/modules/codec/theora.c
+++ b/modules/codec/theora.c
@@ -53,6 +53,11 @@ struct decoder_sys_t
     theora_comment   tc;                            /* theora comment header */
     theora_state     td;                   /* theora bitstream user comments */
 
+    /*
+     * Decoding properties
+     */
+    vlc_bool_t b_decoded_first_keyframe;
+
     /*
      * Common properties
      */
@@ -139,6 +144,7 @@ static int OpenDecoder( vlc_object_t *p_this )
     p_dec->p_sys->b_packetizer = VLC_FALSE;
 
     p_sys->i_pts = 0;
+    p_sys->b_decoded_first_keyframe = VLC_FALSE;
 
     /* Set output properties */
     p_dec->fmt_out.i_cat = VIDEO_ES;
@@ -380,6 +386,14 @@ static void *ProcessPacket( decoder_t *p_dec, ogg_packet *p_oggpacket,
     block_t *p_block = *pp_block;
     void *p_buf;
 
+    if( ( p_block->i_flags & BLOCK_FLAG_DISCONTINUITY ) != 0 )
+    {
+        /* Don't send the the first packet after a discontinuity to
+         * theora_decode, otherwise we get purple/green display artifacts
+         * appearing in the video output */
+        return NULL;
+    }
+
     /* Date management */
     if( p_block->i_pts > 0 && p_block->i_pts != p_sys->i_pts )
     {
@@ -428,8 +442,20 @@ static picture_t *DecodePacket( decoder_t *p_dec, ogg_packet *p_oggpacket )
 
     theora_decode_packetin( &p_sys->td, p_oggpacket );
 
-    /* Decode */
-    theora_decode_YUVout( &p_sys->td, &yuv );
+    /* Check for keyframe */
+    if( !(p_oggpacket->packet[0] & 0x80) /* data packet */ &&
+        !(p_oggpacket->packet[0] & 0x40) /* intra frame */ )
+        p_sys->b_decoded_first_keyframe = VLC_TRUE;
+
+    /* If we haven't seen a single keyframe yet, don't let Theora decode
+     * anything, otherwise we'll get display artifacts.  (This is impossible
+     * in the general case, but can happen if e.g. we play a network stream
+     * using a timed URL, such that the server doesn't start the video with a
+     * keyframe). */
+    if( p_sys->b_decoded_first_keyframe )
+        theora_decode_YUVout( &p_sys->td, &yuv );
+    else
+        return NULL;
 
     /* Get a new picture */
     p_pic = p_dec->pf_vout_buffer_new( p_dec );