mpeg/h264: update thread context even if it is not initialized.

Fixes decoding of Ticket952

Tested-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 8 insertions, 5 deletions

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index a4892ac902..a3343da6e4 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -1224,7 +1224,7 @@ static int decode_update_thread_context(AVCodecContext *dst, const AVCodecContex
     int inited = s->context_initialized, err;
     int i;
 
-    if(dst == src || !s1->context_initialized) return 0;
+    if(dst == src) return 0;
 
     err = ff_mpeg_update_thread_context(dst, src);
     if(err) return err;
@@ -1240,12 +1240,19 @@ static int decode_update_thread_context(AVCodecContext *dst, const AVCodecContex
         memcpy(&h->s + 1, &h1->s + 1, sizeof(H264Context) - sizeof(MpegEncContext)); //copy all fields after MpegEnc
         memset(h->sps_buffers, 0, sizeof(h->sps_buffers));
         memset(h->pps_buffers, 0, sizeof(h->pps_buffers));
+
+        if (s1->context_initialized) {
         if (ff_h264_alloc_tables(h) < 0) {
             av_log(dst, AV_LOG_ERROR, "Could not allocate memory for h264\n");
             return AVERROR(ENOMEM);
         }
         context_init(h);
 
+        // frame_start may not be called for the next thread (if it's decoding a bottom field)
+        // so this has to be allocated here
+        h->s.obmc_scratchpad = av_malloc(16*6*s->linesize);
+        }
+
         for(i=0; i<2; i++){
             h->rbsp_buffer[i] = NULL;
             h->rbsp_buffer_size[i] = 0;
@@ -1253,10 +1260,6 @@ static int decode_update_thread_context(AVCodecContext *dst, const AVCodecContex
 
         h->thread_context[0] = h;
 
-        // frame_start may not be called for the next thread (if it's decoding a bottom field)
-        // so this has to be allocated here
-        h->s.obmc_scratchpad = av_malloc(16*6*s->linesize);
-
         s->dsp.clear_blocks(h->mb);
         s->dsp.clear_blocks(h->mb+(24*16<<h->pixel_shift));
     }