Re: [libav-devel] [PATCH] mov: Rework stsc index validation

2017-02-03 Thread Diego Biurrun 
On Fri, Feb 03, 2017 at 01:51:50PM +0100, Diego Biurrun wrote:
> On Fri, Feb 03, 2017 at 01:05:27PM +0100, Vittorio Giovara wrote:
> > In order to avoid potential integer overflow change the comparison
> > andmake sure to use the same unsigned type for both elements.
> 
> In order to avoid a potential integer overflow change the comparison
> and make sure to use the same unsigned type for both elements.
> 
> > --- a/libavformat/mov.c
> > +++ b/libavformat/mov.c
> > @@ -1983,13 +1983,13 @@ static int mov_read_stsc(MOVContext *c, AVIOContext 
> > *pb, MOVAtom atom)
> >  
> > -static inline int mov_stsc_index_valid(int index, int count)
> > +static inline int mov_stsc_index_valid(unsigned int index, unsigned int 
> > count)
> >  {
> > -return index + 1 < count;
> > +return index < count - 1;
> 
> If count is 0, this changes behavior; is that intentional?

Yes, so probably OK.

Diego
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Re: [libav-devel] [PATCH] mov: Rework stsc index validation

2017-02-03 Thread Diego Biurrun 
On Fri, Feb 03, 2017 at 01:05:27PM +0100, Vittorio Giovara wrote:
> In order to avoid potential integer overflow change the comparison
> andmake sure to use the same unsigned type for both elements.

In order to avoid a potential integer overflow change the comparison
and make sure to use the same unsigned type for both elements.

> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -1983,13 +1983,13 @@ static int mov_read_stsc(MOVContext *c, AVIOContext 
> *pb, MOVAtom atom)
>  
> -static inline int mov_stsc_index_valid(int index, int count)
> +static inline int mov_stsc_index_valid(unsigned int index, unsigned int 
> count)
>  {
> -return index + 1 < count;
> +return index < count - 1;

If count is 0, this changes behavior; is that intentional?

> -static inline int mov_get_stsc_samples(MOVStreamContext *sc, int index)
> +static inline int mov_get_stsc_samples(MOVStreamContext *sc, unsigned int 
> index)

I'd use plain "unsigned" everywhere, but whatever.

Diego
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[libav-devel] [PATCH] mov: Rework stsc index validation

2017-02-03 Thread Vittorio Giovara 
In order to avoid potential integer overflow change the comparison
andmake sure to use the same unsigned type for both elements.
---
Thanks to Clement for pointing this issue out.
Vittorio

 libavformat/isom.h | 2 +-
 libavformat/mov.c  | 8 
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index 85b8761..8cc5ab7 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -111,7 +111,7 @@ typedef struct MOVStreamContext {
 MOVStts *ctts_data;
 unsigned int stsc_count;
 MOVStsc *stsc_data;
-int stsc_index;
+unsigned int stsc_index;
 int stsc_sample;
 unsigned int stps_count;
 unsigned *stps_data;  ///< partial sync sample for mpeg-2 open gop
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 9afd020..e42e04f 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1983,13 +1983,13 @@ static int mov_read_stsc(MOVContext *c, AVIOContext 
*pb, MOVAtom atom)
 return 0;
 }
 
-static inline int mov_stsc_index_valid(int index, int count)
+static inline int mov_stsc_index_valid(unsigned int index, unsigned int count)
 {
-return index + 1 < count;
+return index < count - 1;
 }
 
 /* Compute the samples value for the stsc entry at the given index. */
-static inline int mov_get_stsc_samples(MOVStreamContext *sc, int index)
+static inline int mov_get_stsc_samples(MOVStreamContext *sc, unsigned int 
index)
 {
 int chunk_count;
 
@@ -3982,7 +3982,7 @@ static int mov_seek_stream(AVFormatContext *s, AVStream 
*st, int64_t timestamp,
 {
 MOVStreamContext *sc = st->priv_data;
 int sample, time_sample;
-int i;
+unsigned int i;
 
 sample = av_index_search_timestamp(st, timestamp, flags);
 av_log(s, AV_LOG_TRACE, "stream %d, timestamp %"PRId64", sample %d\n", 
st->index, timestamp, sample);
-- 
2.10.0

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