+static int ref_frames(Vp3DecodeContext *dst, Vp3DecodeContext *src)
+{
+ int ret;
+ if ((ret = ref_frame(dst, &dst->current_frame, &src->current_frame)) < 0 ||
+ (ret = ref_frame(dst, &dst->golden_frame, &src->golden_frame)) < 0 ||
+ (ret = ref_frame(dst, &dst->last_frame, &src->last_frame)) < 0)
+ return ret;
+ return 0;
+}
+
+static int vp3_update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
+{
+ Vp3DecodeContext *s = dst->priv_data, *s1 = src->priv_data;
+ int qps_changed = 0, i, err;
+
+#define copy_fields(to, from, start_field, end_field) \
+ memcpy(&to->start_field, &from->start_field, \
+ (char *) &to->end_field - (char *) &to->start_field)
+
+ if (!s1->current_frame.f->data[0] ||
+ s->width != s1->width || s->height != s1->height) {
+ if (s != s1)
+ ref_frames(s, s1);
+ return -1;
+ }
+
+ if (s != s1) {
+ // init tables if the first frame hasn't been decoded
+ if (!s->current_frame.f->data[0]) {
+ int y_fragment_count, c_fragment_count;
+ s->avctx = dst;
+ err = allocate_tables(dst);
+ if (err)
+ return err;
+ y_fragment_count = s->fragment_width[0] * s->fragment_height[0];
+ c_fragment_count = s->fragment_width[1] * s->fragment_height[1];
+ memcpy(s->motion_val[0], s1->motion_val[0],
+ y_fragment_count * sizeof(*s->motion_val[0]));
+ memcpy(s->motion_val[1], s1->motion_val[1],
+ c_fragment_count * sizeof(*s->motion_val[1]));
+ }
+
+ // copy previous frame data
+ if ((err = ref_frames(s, s1)) < 0)
+ return err;
+
+ s->keyframe = s1->keyframe;
+
+ // copy qscale data if necessary
+ for (i = 0; i < 3; i++) {
+ if (s->qps[i] != s1->qps[1]) {
+ qps_changed = 1;
+ memcpy(&s->qmat[i], &s1->qmat[i], sizeof(s->qmat[i]));
+ }
+ }
+
+ if (s->qps[0] != s1->qps[0])
+ memcpy(&s->bounding_values_array, &s1->bounding_values_array,
+ sizeof(s->bounding_values_array));
+
+ if (qps_changed)
+ copy_fields(s, s1, qps, superblock_count);
+#undef copy_fields
+ }
+
+ return update_frames(dst);