1 files changed, 44 insertions, 24 deletions

diff --git a/libavcodec/vp8.c b/libavcodec/vp8.c
index 833819890d..d68a91ea54 100644
--- a/libavcodec/vp8.c
+++ b/libavcodec/vp8.c
@@ -5,20 +5,20 @@
  * Copyright (C) 2010 Ronald S. Bultje
  * Copyright (C) 2010 Jason Garrett-Glaser
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -639,9 +639,10 @@ void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, uint8_
 {
     VP56RangeCoder *c = &s->c;
 
-    if (s->segmentation.update_map)
-        *segment = vp8_rac_get_tree(c, vp8_segmentid_tree, s->prob->segmentid);
-    else
+    if (s->segmentation.update_map) {
+        int bit  = vp56_rac_get_prob(c, s->prob->segmentid[0]);
+        *segment = vp56_rac_get_prob(c, s->prob->segmentid[1+bit]) + 2*bit;
+    } else
         *segment = ref ? *ref : *segment;
     s->segment = *segment;
 
@@ -1560,6 +1561,18 @@ static void release_queued_segmaps(VP8Context *s, int is_close)
     s->maps_are_invalid = 0;
 }
 
+/**
+ * Sets things up for skipping the current frame.
+ * In particular, removes it from the reference buffers.
+ */
+static void skipframe_clear(VP8Context *s)
+{
+    s->invisible = 1;
+    s->next_framep[VP56_FRAME_CURRENT] = NULL;
+    if (s->update_last)
+        s->next_framep[VP56_FRAME_PREVIOUS] = NULL;
+}
+
 static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                             AVPacket *avpkt)
 {
@@ -1581,10 +1594,6 @@ static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     skip_thresh = !referenced ? AVDISCARD_NONREF :
                     !s->keyframe ? AVDISCARD_NONKEY : AVDISCARD_ALL;
 
-    if (avctx->skip_frame >= skip_thresh) {
-        s->invisible = 1;
-        goto skip_decode;
-    }
     s->deblock_filter = s->filter.level && avctx->skip_loop_filter < skip_thresh;
 
     // release no longer referenced frames
@@ -1609,16 +1618,6 @@ static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
         av_log(avctx, AV_LOG_FATAL, "Ran out of free frames!\n");
         abort();
     }
-    if (curframe->data[0])
-        vp8_release_frame(s, curframe, 1, 0);
-
-    curframe->key_frame = s->keyframe;
-    curframe->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
-    curframe->reference = referenced ? 3 : 0;
-    if ((ret = vp8_alloc_frame(s, curframe))) {
-        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed!\n");
-        return ret;
-    }
 
     // check if golden and altref are swapped
     if (s->update_altref != VP56_FRAME_NONE) {
@@ -1638,7 +1637,11 @@ static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     }
     s->next_framep[VP56_FRAME_CURRENT]      = curframe;
 
-    ff_thread_finish_setup(avctx);
+    if (avctx->skip_frame >= skip_thresh) {
+        skipframe_clear(s);
+        ret = avpkt->size;
+        goto skip_decode;
+    }
 
     // Given that arithmetic probabilities are updated every frame, it's quite likely
     // that the values we have on a random interframe are complete junk if we didn't
@@ -1647,9 +1650,25 @@ static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
                          !s->framep[VP56_FRAME_GOLDEN] ||
                          !s->framep[VP56_FRAME_GOLDEN2])) {
         av_log(avctx, AV_LOG_WARNING, "Discarding interframe without a prior keyframe!\n");
-        return AVERROR_INVALIDDATA;
+        skipframe_clear(s);
+        ret = AVERROR_INVALIDDATA;
+        goto skip_decode;
+    }
+
+    if (curframe->data[0])
+        vp8_release_frame(s, curframe, 1, 0);
+
+    curframe->key_frame = s->keyframe;
+    curframe->pict_type = s->keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
+    curframe->reference = referenced ? 3 : 0;
+    if ((ret = vp8_alloc_frame(s, curframe))) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed!\n");
+        skipframe_clear(s);
+        goto skip_decode;
     }
 
+    ff_thread_finish_setup(avctx);
+
     s->linesize   = curframe->linesize[0];
     s->uvlinesize = curframe->linesize[1];
 
@@ -1759,6 +1778,7 @@ static int vp8_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     }
 
     ff_thread_report_progress(curframe, INT_MAX, 0);
+    ret = avpkt->size;
 skip_decode:
     // if future frames don't use the updated probabilities,
     // reset them to the values we saved
@@ -1772,7 +1792,7 @@ skip_decode:
         *data_size = sizeof(AVFrame);
     }
 
-    return avpkt->size;
+    return ret;
 }
 
 static av_cold int vp8_decode_init(AVCodecContext *avctx)