When either video dimension is only one macroblock, subtractions
based on v_edge_pos and the macroblock size may be negative. In
that situation, an unsigned comparison isn't sufficent to test for
MV overruns, because a limit of (unsigned)-1 will let any other
value pass.
---
libavcodec/mpegvideo.c | 12 ++++++------
libavcodec/mpegvideo_common.h | 28 ++++++++++++++--------------
2 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index f2651c8..cd0588f 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -1771,8 +1771,8 @@ static inline int hpel_motion_lowres(MpegEncContext *s,
src += src_y * stride + src_x;
- if( (unsigned)src_x > h_edge_pos - (!!sx) - w
- || (unsigned)src_y >(v_edge_pos >> field_based) - (!!sy) - h){
+ if( (unsigned)src_x > FFMAX( h_edge_pos - (!!sx) - w, 0)
+ || (unsigned)src_y > FFMAX((v_edge_pos >> field_based) - (!!sy) - h,
0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, src, s->linesize, w+1,
(h+1)<<field_based,
src_x, src_y<<field_based, h_edge_pos, v_edge_pos);
src= s->edge_emu_buffer;
@@ -1844,8 +1844,8 @@ static av_always_inline void
mpeg_motion_lowres(MpegEncContext *s,
ptr_cb = ref_picture[1] + uvsrc_y * uvlinesize + uvsrc_x;
ptr_cr = ref_picture[2] + uvsrc_y * uvlinesize + uvsrc_x;
- if( (unsigned)src_x > h_edge_pos - (!!sx) - 2*block_s
- || (unsigned)src_y >(v_edge_pos >> field_based) - (!!sy) - h){
+ if( (unsigned)src_x > FFMAX( h_edge_pos - (!!sx) -
2*block_s, 0)
+ || (unsigned)src_y > FFMAX((v_edge_pos >> field_based) - (!!sy) - h
, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr_y, s->linesize,
17, 17+field_based,
src_x, src_y<<field_based, h_edge_pos,
v_edge_pos);
ptr_y = s->edge_emu_buffer;
@@ -1917,8 +1917,8 @@ static inline void
chroma_4mv_motion_lowres(MpegEncContext *s,
offset = src_y * s->uvlinesize + src_x;
ptr = ref_picture[1] + offset;
if(s->flags&CODEC_FLAG_EMU_EDGE){
- if( (unsigned)src_x > h_edge_pos - (!!sx) - block_s
- || (unsigned)src_y > v_edge_pos - (!!sy) - block_s){
+ if( (unsigned)src_x > FFMAX(h_edge_pos - (!!sx) - block_s, 0)
+ || (unsigned)src_y > FFMAX(v_edge_pos - (!!sy) - block_s, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr, s->uvlinesize, 9,
9, src_x, src_y, h_edge_pos, v_edge_pos);
ptr= s->edge_emu_buffer;
emu=1;
diff --git a/libavcodec/mpegvideo_common.h b/libavcodec/mpegvideo_common.h
index b5b0d23..6c817a2 100644
--- a/libavcodec/mpegvideo_common.h
+++ b/libavcodec/mpegvideo_common.h
@@ -81,8 +81,8 @@ static inline void gmc1_motion(MpegEncContext *s,
ptr = ref_picture[0] + (src_y * linesize) + src_x;
if(s->flags&CODEC_FLAG_EMU_EDGE){
- if( (unsigned)src_x >= s->h_edge_pos - 17
- || (unsigned)src_y >= s->v_edge_pos - 17){
+ if( (unsigned)src_x >= FFMAX(s->h_edge_pos - 17, 0)
+ || (unsigned)src_y >= FFMAX(s->v_edge_pos - 17, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr, linesize, 17, 17,
src_x, src_y, s->h_edge_pos, s->v_edge_pos);
ptr= s->edge_emu_buffer;
}
@@ -120,8 +120,8 @@ static inline void gmc1_motion(MpegEncContext *s,
offset = (src_y * uvlinesize) + src_x;
ptr = ref_picture[1] + offset;
if(s->flags&CODEC_FLAG_EMU_EDGE){
- if( (unsigned)src_x >= (s->h_edge_pos>>1) - 9
- || (unsigned)src_y >= (s->v_edge_pos>>1) - 9){
+ if( (unsigned)src_x >= FFMAX((s->h_edge_pos>>1) - 9, 0)
+ || (unsigned)src_y >= FFMAX((s->v_edge_pos>>1) - 9, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr, uvlinesize, 9, 9,
src_x, src_y, s->h_edge_pos>>1, s->v_edge_pos>>1);
ptr= s->edge_emu_buffer;
emu=1;
@@ -221,8 +221,8 @@ static inline int hpel_motion(MpegEncContext *s,
src += src_y * stride + src_x;
if(s->unrestricted_mv && (s->flags&CODEC_FLAG_EMU_EDGE)){
- if( (unsigned)src_x > h_edge_pos - (motion_x&1) - w
- || (unsigned)src_y > v_edge_pos - (motion_y&1) - h){
+ if( (unsigned)src_x > FFMAX(h_edge_pos - (motion_x&1) - w, 0)
+ || (unsigned)src_y > FFMAX(v_edge_pos - (motion_y&1) - h, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, src, s->linesize, w+1,
(h+1)<<field_based,
src_x, src_y<<field_based, h_edge_pos,
s->v_edge_pos);
src= s->edge_emu_buffer;
@@ -307,8 +307,8 @@ if(s->quarter_sample)
ptr_cb = ref_picture[1] + uvsrc_y * uvlinesize + uvsrc_x;
ptr_cr = ref_picture[2] + uvsrc_y * uvlinesize + uvsrc_x;
- if( (unsigned)src_x > s->h_edge_pos - (motion_x&1) - 16
- || (unsigned)src_y > v_edge_pos - (motion_y&1) - h){
+ if( (unsigned)src_x > FFMAX(s->h_edge_pos - (motion_x&1) - 16, 0)
+ || (unsigned)src_y > FFMAX( v_edge_pos - (motion_y&1) - h , 0)){
if(is_mpeg12 || s->codec_id == CODEC_ID_MPEG2VIDEO ||
s->codec_id == CODEC_ID_MPEG1VIDEO){
av_log(s->avctx,AV_LOG_DEBUG,
@@ -510,8 +510,8 @@ static inline void qpel_motion(MpegEncContext *s,
ptr_cb = ref_picture[1] + uvsrc_y * uvlinesize + uvsrc_x;
ptr_cr = ref_picture[2] + uvsrc_y * uvlinesize + uvsrc_x;
- if( (unsigned)src_x > s->h_edge_pos - (motion_x&3) - 16
- || (unsigned)src_y > v_edge_pos - (motion_y&3) - h ){
+ if( (unsigned)src_x > FFMAX(s->h_edge_pos - (motion_x&3) - 16, 0)
+ || (unsigned)src_y > FFMAX( v_edge_pos - (motion_y&3) - h , 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr_y, s->linesize,
17, 17+field_based, src_x, src_y<<field_based,
s->h_edge_pos, s->v_edge_pos);
@@ -588,8 +588,8 @@ static inline void chroma_4mv_motion(MpegEncContext *s,
offset = src_y * s->uvlinesize + src_x;
ptr = ref_picture[1] + offset;
if(s->flags&CODEC_FLAG_EMU_EDGE){
- if( (unsigned)src_x > (s->h_edge_pos>>1) - (dxy &1) - 8
- || (unsigned)src_y > (s->v_edge_pos>>1) - (dxy>>1) - 8){
+ if( (unsigned)src_x > FFMAX((s->h_edge_pos>>1) - (dxy &1) - 8, 0)
+ || (unsigned)src_y > FFMAX((s->v_edge_pos>>1) - (dxy>>1) - 8, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr, s->uvlinesize,
9, 9, src_x, src_y,
s->h_edge_pos>>1, s->v_edge_pos>>1);
@@ -760,8 +760,8 @@ static av_always_inline void
MPV_motion_internal(MpegEncContext *s,
ptr = ref_picture[0] + (src_y * s->linesize) + (src_x);
if(s->flags&CODEC_FLAG_EMU_EDGE){
- if( (unsigned)src_x > s->h_edge_pos - (motion_x&3) - 8
- || (unsigned)src_y > s->v_edge_pos - (motion_y&3) - 8 ){
+ if( (unsigned)src_x > FFMAX(s->h_edge_pos - (motion_x&3)
- 8, 0)
+ || (unsigned)src_y > FFMAX(s->v_edge_pos - (motion_y&3)
- 8, 0)){
s->dsp.emulated_edge_mc(s->edge_emu_buffer, ptr,
s->linesize, 9, 9,
src_x, src_y,
--
1.7.5.4
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
