[FFmpeg-devel] [PATCH] avcodec/libmp3lame: properly handle unaligned frame data

[Muhammad Faiz]

On Tue, May 2, 2017 at 12:45 AM, Paul B Mahol <onemda at gmail.com> wrote:
> On 5/1/17, Muhammad Faiz <mfcc64 at gmail.com> wrote:
>> On Mon, May 1, 2017 at 11:22 PM, Kyle Swanson <k at ylo.ph> wrote:
>>> Hi,
>>>
>>> On Mon, May 1, 2017 at 3:18 AM, Paul B Mahol <onemda at gmail.com> wrote:
>>>> On 4/30/17, Nicolas George <george at nsup.org> wrote:
>>>>> Le primidi 11 floreal, an CCXXV, Muhammad Faiz a ecrit :
>>>>>> Are you working on these? Because currently I'm not.
>>>>>
>>>>> There is nothing to work on yet: the message you answer to is raising a
>>>>> question about the global design of the internal API. That question
>>>>> needs an answer before any work can be done, and I can not decide alone.
>>>>>
>>>>
>>>> How nice, introducing bug that causes crash and then claiming there is
>>>> not such bug.
>>>>
>>>> Which filters you consider deemed worthy to not crash?
>>>> _______________________________________________
>>>> ffmpeg-devel mailing list
>>>> ffmpeg-devel at ffmpeg.org
>>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>>
>>> Maybe 383057f8e744efeaaa3648a59bc577b25b055835 should be reverted
>>> until API stuff is sorted. This should also be backported to 3.3
>>> because these issues are present in that release.
>>>
>>> Kyle
>>
>> Of course no. Reverting it will make more bug.
>>
>> Unless
>> https://lists.ffmpeg.org/pipermail/ffmpeg-devel/2017-January/206285.html
>> and
>> https://lists.ffmpeg.org/pipermail/ffmpeg-devel/2017-January/206284.html
>> are also applied.
>
> One of those are already reviewed, other looks like is not needed at all.
> Could you elaborate why it is needed?

The code before the patch write to unwritable frame.

test-case:
ffplay -i lavfi 'aevalsrc=sin(1000*t*t), aformat=sample_fmts=fltp,
asplit [a][b];
[a] firequalizer=fixed=on, showcqt=s=1280x360 [a1];
[b] firequalizer=fixed=on, showcqt=s=1280x360 [b1];
[a1][b1] vstack'

the data will be corrupted because fixed=on enables partial_buf_size stuff

Compare that without fixed=on.

Thank's