[FFmpeg-devel] [PATCH] libavfilter/af_atempo: Fix uninitialized memory access

[Pavel Koshevoy]

On 4/18/13 2:42 PM, Paul B Mahol wrote:
> On 4/18/13, Michael Niedermayer <michaelni at gmx.at> wrote:
>> On Wed, Apr 17, 2013 at 10:33:34PM -0600, pkoshevoy at gmail.com wrote:
>>> From: Pavel Koshevoy <pkoshevoy at gmail.com>
>>>
>>> valgrind reported uninitialized memory access which was caused by
>>> incorrect number of samples being passed to push_samples(..)
>>>
>>> Signed-off-by: Pavel Koshevoy <pkoshevoy at gmail.com>
>>> ---
>>>   libavfilter/af_atempo.c |    6 ++++--
>>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/libavfilter/af_atempo.c b/libavfilter/af_atempo.c
>>> index 3e2bc06..f5c5da8 100644
>>> --- a/libavfilter/af_atempo.c
>>> +++ b/libavfilter/af_atempo.c
>>> @@ -1061,7 +1061,7 @@ static int filter_frame(AVFilterLink *inlink,
>>> AVFrame *src_buffer)
>>>       ATempoContext *atempo = ctx->priv;
>>>       AVFilterLink *outlink = ctx->outputs[0];
>>>
>>> -    int ret = 0;
>>> +    int ret = AVERROR(EAGAIN);
>>>       int n_in = src_buffer->nb_samples;
>>>       int n_out = (int)(0.5 + ((double)n_in) / atempo->tempo);
>>>
>> this looks odd, what is the intent of this change ?
> Its unrelated to original problem, so should be disscussed separately.
>

I observed that this change caused intermittent non-fatal error messages:
     Error while decoding stream #0:0: Resource temporarily unavailable

The command line I used was /Developer/x86_64/bin/ffmpeg -f lavfi -i 
'aevalsrc=s=8000:c=mono:exprs=sin(0.5*2*PI*t)*sin(440*2*PI*t):d=24000' 
-af atempo=23976/25000 -y 
/nfs/scratch/DataSets/Video/au/06h-40m-23976to25000.au

So, I am OK with dropping this change.  Do I need to submit another patch?

I am working on a fix for ticket #2484, and I don't think it makes sense 
to submit a patch for 2484 if this patch hasn't been applied yet.

Thank you,
     Pavel.