diff options
| -rw-r--r-- | libavcodec/indeo4.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/libavcodec/indeo4.c b/libavcodec/indeo4.c index 75714350a4..e5800741a1 100644 --- a/libavcodec/indeo4.c +++ b/libavcodec/indeo4.c @@ -459,7 +459,7 @@ static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band, } mb->mv_x = mb->mv_y = 0; /* no motion vector coded */ - if (band->inherit_mv) { + if (band->inherit_mv && ref_mb) { /* motion vector inheritance */ if (mv_scale) { mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale); @@ -471,7 +471,10 @@ static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band, } } else { if (band->inherit_mv) { - mb->type = ref_mb->type; /* copy mb_type from corresponding reference mb */ + /* copy mb_type from corresponding reference mb */ + if (!ref_mb) + return AVERROR_INVALIDDATA; + mb->type = ref_mb->type; } else if (ctx->frame_type == FRAMETYPE_INTRA || ctx->frame_type == FRAMETYPE_INTRA1) { mb->type = 0; /* mb_type is always INTRA for intra-frames */ @@ -495,14 +498,15 @@ static int decode_mb_info(IVI45DecContext *ctx, IVIBandDesc *band, mb->mv_x = mb->mv_y = 0; /* there is no motion vector in intra-macroblocks */ } else { if (band->inherit_mv) { - /* motion vector inheritance */ - if (mv_scale) { - mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale); - mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale); - } else { - mb->mv_x = ref_mb->mv_x; - mb->mv_y = ref_mb->mv_y; - } + if (ref_mb) + /* motion vector inheritance */ + if (mv_scale) { + mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale); + mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale); + } else { + mb->mv_x = ref_mb->mv_x; + mb->mv_y = ref_mb->mv_y; + } } else { /* decode motion vector deltas */ mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table, |