Fix memory leak in h264 decoder. allocated_edge_emu_buffer was being allocated

in both mpegvideo and h264 decoder. Fixed by allowing all (master and duplicate)
contexts to fully initialize in MPV_frame_start and copying these into
H264Contexts.

Mailing list discussion:
[FFmpeg-devel] Memory leak in h264
Tue, 22 Jan 2008 15:22:55

Originally committed as revision 11657 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -1951,7 +1951,6 @@ static void free_tables(H264Context *h){
         av_freep(&hx->top_borders[1]);
         av_freep(&hx->top_borders[0]);
         av_freep(&hx->s.obmc_scratchpad);
-        av_freep(&hx->s.allocated_edge_emu_buffer);
     }
 }
 
@@ -2096,10 +2095,6 @@ static int context_init(H264Context *h){
     CHECKED_ALLOCZ(h->top_borders[0], h->s.mb_width * (16+8+8) * sizeof(uint8_t))
     CHECKED_ALLOCZ(h->top_borders[1], h->s.mb_width * (16+8+8) * sizeof(uint8_t))
 
-    // edge emu needs blocksize + filter length - 1 (=17x17 for halfpel / 21x21 for h264)
-    CHECKED_ALLOCZ(s->allocated_edge_emu_buffer,
-                   (s->width+64)*2*21*2); //(width + edge + align)*interlaced*MBsize*tolerance
-    s->edge_emu_buffer= s->allocated_edge_emu_buffer + (s->width+64)*2*21;
     return 0;
 fail:
     return -1; // free_tables will clean up for us
@@ -3907,7 +3902,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
         for(i = 1; i < s->avctx->thread_count; i++) {
             H264Context *c;
             c = h->thread_context[i] = av_malloc(sizeof(H264Context));
-            memcpy(c, h, sizeof(MpegEncContext));
+            memcpy(c, h->s.thread_context[i], sizeof(MpegEncContext));
             memset(&c->s + 1, 0, sizeof(H264Context) - sizeof(MpegEncContext));
             c->sps = h->sps;
             c->pps = h->pps;

libavcodec/mpegvideo.c

@@ -587,9 +587,7 @@ int MPV_common_init(MpegEncContext *s)
     s->context_initialized = 1;
 
     s->thread_context[0]= s;
-    /* h264 does thread context setup itself, but it needs context[0]
-     * to be fully initialized for the error resilience code */
-    threads = s->codec_id == CODEC_ID_H264 ? 1 : s->avctx->thread_count;
+    threads = s->avctx->thread_count;
 
     for(i=1; i<threads; i++){
         s->thread_context[i]= av_malloc(sizeof(MpegEncContext));