Re: [FFmpeg-devel] [PATCH] avcodec/vp9: Fix undefined shifts in decode_frame_header()
Hi,
On Wed, Mar 11, 2015 at 9:11 PM, Michael Niedermayer michae...@gmx.at
wrote:
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu tfo...@google.com
Signed-off-by: Michael Niedermayer michae...@gmx.at
---
libavcodec/vp9.c |4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index 265dc7e..0405c05 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -689,10 +689,10 @@ static int decode_frame_header(AVCodecContext *ctx,
for (j = 1; j 4; j++) {
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[0]) sh), 6);
+ s-lf_delta.mode[0]) * (1
sh)), 6);
s-segmentation.feat[i].lflvl[j][1] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[1]) sh), 6);
+ s-lf_delta.mode[1]) * (1
sh)), 6);
Same question: why is this undefined?
Ronald
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Re: [FFmpeg-devel] [PATCH] avcodec/vp9: Fix undefined shifts in decode_frame_header()
On Thu, Mar 12, 2015 at 10:26:55AM -0400, Ronald S. Bultje wrote:
Hi,
On Thu, Mar 12, 2015 at 10:16 AM, Michael Niedermayer michae...@gmx.at
wrote:
On Thu, Mar 12, 2015 at 09:56:12AM -0400, Ronald S. Bultje wrote:
Hi,
On Thu, Mar 12, 2015 at 9:41 AM, Michael Niedermayer michae...@gmx.at
wrote:
On Thu, Mar 12, 2015 at 07:15:47AM -0400, Ronald S. Bultje wrote:
Hi,
On Wed, Mar 11, 2015 at 9:11 PM, Michael Niedermayer
michae...@gmx.at
wrote:
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu tfo...@google.com
Signed-off-by: Michael Niedermayer michae...@gmx.at
---
libavcodec/vp9.c |4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index 265dc7e..0405c05 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -689,10 +689,10 @@ static int decode_frame_header(AVCodecContext
*ctx,
for (j = 1; j 4; j++) {
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[0])
sh),
6);
+ s-lf_delta.mode[0]) *
(1
sh)), 6);
s-segmentation.feat[i].lflvl[j][1] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[1])
sh),
6);
+ s-lf_delta.mode[1]) *
(1
sh)), 6);
Same question: why is this undefined?
same awnser, left shifts of negative values are undefined in C
if that was by someone forgetting to define it or intentional or they
just didnt find a good definition in light of non twos-complement
i do not know
But the values aren't negative?
if i apply:
@@ -687,6 +687,10 @@ static int decode_frame_header(AVCodecContext *ctx,
s-segmentation.feat[i].lflvl[0][1] =
av_clip_uintp2(lflvl + (s-lf_delta.ref[0] sh), 6);
for (j = 1; j 4; j++) {
+av_assert0((s-lf_delta.ref[j] +
+ s-lf_delta.mode[0]) = 0);
+av_assert0((s-lf_delta.ref[j] +
+ s-lf_delta.mode[1]) = 0);
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
s-lf_delta.mode[0]) sh), 6);
and run fate it fails all over the place
so i think they are 0
Bleh, I was missing one bracket; the delta is indeed negative; lflvl itself
(and the sum) is not. So OK.
applied
thanks
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
The educated differ from the uneducated as much as the living from the
dead. -- Aristotle
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Re: [FFmpeg-devel] [PATCH] avcodec/vp9: Fix undefined shifts in decode_frame_header()
On Thu, Mar 12, 2015 at 09:56:12AM -0400, Ronald S. Bultje wrote:
Hi,
On Thu, Mar 12, 2015 at 9:41 AM, Michael Niedermayer michae...@gmx.at
wrote:
On Thu, Mar 12, 2015 at 07:15:47AM -0400, Ronald S. Bultje wrote:
Hi,
On Wed, Mar 11, 2015 at 9:11 PM, Michael Niedermayer michae...@gmx.at
wrote:
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu tfo...@google.com
Signed-off-by: Michael Niedermayer michae...@gmx.at
---
libavcodec/vp9.c |4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index 265dc7e..0405c05 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -689,10 +689,10 @@ static int decode_frame_header(AVCodecContext
*ctx,
for (j = 1; j 4; j++) {
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[0]) sh),
6);
+ s-lf_delta.mode[0]) * (1
sh)), 6);
s-segmentation.feat[i].lflvl[j][1] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[1]) sh),
6);
+ s-lf_delta.mode[1]) * (1
sh)), 6);
Same question: why is this undefined?
same awnser, left shifts of negative values are undefined in C
if that was by someone forgetting to define it or intentional or they
just didnt find a good definition in light of non twos-complement
i do not know
But the values aren't negative?
if i apply:
@@ -687,6 +687,10 @@ static int decode_frame_header(AVCodecContext *ctx,
s-segmentation.feat[i].lflvl[0][1] =
av_clip_uintp2(lflvl + (s-lf_delta.ref[0] sh), 6);
for (j = 1; j 4; j++) {
+av_assert0((s-lf_delta.ref[j] +
+ s-lf_delta.mode[0]) = 0);
+av_assert0((s-lf_delta.ref[j] +
+ s-lf_delta.mode[1]) = 0);
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
s-lf_delta.mode[0]) sh), 6);
and run fate it fails all over the place
so i think they are 0
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Those who are best at talking, realize last or never when they are wrong.
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Re: [FFmpeg-devel] [PATCH] avcodec/vp9: Fix undefined shifts in decode_frame_header()
Hi,
On Thu, Mar 12, 2015 at 9:41 AM, Michael Niedermayer michae...@gmx.at
wrote:
On Thu, Mar 12, 2015 at 07:15:47AM -0400, Ronald S. Bultje wrote:
Hi,
On Wed, Mar 11, 2015 at 9:11 PM, Michael Niedermayer michae...@gmx.at
wrote:
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu tfo...@google.com
Signed-off-by: Michael Niedermayer michae...@gmx.at
---
libavcodec/vp9.c |4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index 265dc7e..0405c05 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -689,10 +689,10 @@ static int decode_frame_header(AVCodecContext
*ctx,
for (j = 1; j 4; j++) {
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[0]) sh),
6);
+ s-lf_delta.mode[0]) * (1
sh)), 6);
s-segmentation.feat[i].lflvl[j][1] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[1]) sh),
6);
+ s-lf_delta.mode[1]) * (1
sh)), 6);
Same question: why is this undefined?
same awnser, left shifts of negative values are undefined in C
if that was by someone forgetting to define it or intentional or they
just didnt find a good definition in light of non twos-complement
i do not know
But the values aren't negative?
Ronald
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Re: [FFmpeg-devel] [PATCH] avcodec/vp9: Fix undefined shifts in decode_frame_header()
Hi,
On Thu, Mar 12, 2015 at 10:16 AM, Michael Niedermayer michae...@gmx.at
wrote:
On Thu, Mar 12, 2015 at 09:56:12AM -0400, Ronald S. Bultje wrote:
Hi,
On Thu, Mar 12, 2015 at 9:41 AM, Michael Niedermayer michae...@gmx.at
wrote:
On Thu, Mar 12, 2015 at 07:15:47AM -0400, Ronald S. Bultje wrote:
Hi,
On Wed, Mar 11, 2015 at 9:11 PM, Michael Niedermayer
michae...@gmx.at
wrote:
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu tfo...@google.com
Signed-off-by: Michael Niedermayer michae...@gmx.at
---
libavcodec/vp9.c |4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index 265dc7e..0405c05 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -689,10 +689,10 @@ static int decode_frame_header(AVCodecContext
*ctx,
for (j = 1; j 4; j++) {
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[0])
sh),
6);
+ s-lf_delta.mode[0]) *
(1
sh)), 6);
s-segmentation.feat[i].lflvl[j][1] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[1])
sh),
6);
+ s-lf_delta.mode[1]) *
(1
sh)), 6);
Same question: why is this undefined?
same awnser, left shifts of negative values are undefined in C
if that was by someone forgetting to define it or intentional or they
just didnt find a good definition in light of non twos-complement
i do not know
But the values aren't negative?
if i apply:
@@ -687,6 +687,10 @@ static int decode_frame_header(AVCodecContext *ctx,
s-segmentation.feat[i].lflvl[0][1] =
av_clip_uintp2(lflvl + (s-lf_delta.ref[0] sh), 6);
for (j = 1; j 4; j++) {
+av_assert0((s-lf_delta.ref[j] +
+ s-lf_delta.mode[0]) = 0);
+av_assert0((s-lf_delta.ref[j] +
+ s-lf_delta.mode[1]) = 0);
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
s-lf_delta.mode[0]) sh), 6);
and run fate it fails all over the place
so i think they are 0
Bleh, I was missing one bracket; the delta is indeed negative; lflvl itself
(and the sum) is not. So OK.
Ronald
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[FFmpeg-devel] [PATCH] avcodec/vp9: Fix undefined shifts in decode_frame_header()
Found-by: Clang -fsanitize=shift
Reported-by: Thierry Foucu tfo...@google.com
Signed-off-by: Michael Niedermayer michae...@gmx.at
---
libavcodec/vp9.c |4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/libavcodec/vp9.c b/libavcodec/vp9.c
index 265dc7e..0405c05 100644
--- a/libavcodec/vp9.c
+++ b/libavcodec/vp9.c
@@ -689,10 +689,10 @@ static int decode_frame_header(AVCodecContext *ctx,
for (j = 1; j 4; j++) {
s-segmentation.feat[i].lflvl[j][0] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[0]) sh), 6);
+ s-lf_delta.mode[0]) * (1 sh)), 6);
s-segmentation.feat[i].lflvl[j][1] =
av_clip_uintp2(lflvl + ((s-lf_delta.ref[j] +
- s-lf_delta.mode[1]) sh), 6);
+ s-lf_delta.mode[1]) * (1 sh)), 6);
}
}
--
1.7.9.5
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