[FFmpeg-devel] libavcodec/als: remove check for predictor order of a block

[Umair Khan]

On Sat, Oct 14, 2017 at 7:29 PM, Umair Khan <omerjerk at gmail.com> wrote:
> Hi,
>
> On Sat, Sep 23, 2017 at 8:45 PM, Michael Niedermayer
> <michael at niedermayer.cc> wrote:
>>
>> On Fri, Sep 22, 2017 at 01:54:27PM +0530, Umair Khan wrote:
>> > On Thu, Sep 21, 2017 at 6:30 PM, Paul B Mahol <onemda at gmail.com> wrote:
>> > > On 9/21/17, Umair Khan <omerjerk at gmail.com> wrote:
>> > >> Hi Ronald,
>> > >>
>> > >> On Mon, Sep 11, 2017 at 10:27 PM, Ronald S. Bultje <rsbultje at gmail.com>
>> > >> wrote:
>> > >>> Hi Umair,
>> > >>>
>> > >>> On Mon, Sep 11, 2017 at 4:06 AM, Umair Khan <omerjerk at gmail.com> wrote:
>> > >>>
>> > >>>> On Sun, Sep 10, 2017 at 10:30 PM, Paul B Mahol <onemda at gmail.com> wrote:
>> > >>>> > On 9/10/17, Umair Khan <omerjerk at gmail.com> wrote:
>> > >>>> >> On Sun, Sep 10, 2017 at 9:52 PM, Thilo Borgmann
>> > >>>> >> <thilo.borgmann at mail.de
>> > >>>> >
>> > >>>> >> wrote:
>> > >>>> >>>
>> > >>>> >>> Hi,
>> > >>>> >>>
>> > >>>> >>> > This patch fixes this bug - https://trac.ffmpeg.org/ticket/5297
>> > >>>> >>>
>> > >>>> >>> this is yet another iteration of
>> > >>>> >>>
>> > >>>> >>> http://ffmpeg.org/pipermail/ffmpeg-devel/2017-June/213005.html
>> > >>>> >>
>> > >>>> >> I see. I was keepnig reference codec as the source of truth.
>> > >>>> >>
>> > >>>> >> How do I reproduce this segfault? -
>> > >>>> >> http://ffmpeg.org/pipermail/ffmpeg-devel/2016-November/202530.html
>> > >>>> >> Is it one of the fate tests failing?
>> > >>>> >
>> > >>>> > No.
>> > >>>>
>> > >>>> In that case there's not much which can be done with this bug.
>> > >>>> That being said, I'm pretty sure we will anyways end up removing this
>> > >>>> check.
>> > >>>
>> > >>>
>> > >>> I think your question is "how do I get access to this sample", right? You
>> > >>> could ask Michael.
>> > >>
>> > >> Paul also tried to fix this bug, hence I'm assuming that he already
>> > >> asked Michael about the sample file. Anyways, it'd not be difficult to
>> > >> fix this bug if we can reproduce it.
>> > >
>> > > Thilo do not want to apply Michael fix because he do not understand his patch.
>> >
>> > Which fix are you talking about?
>> >
>> > I see that Michael added this check in the first place -
>> > http://git.videolan.org/?p=ffmpeg.git;a=commit;h=18f94df8af
>> > If someone can provide me with the file which is causing the segfault,
>> > maybe I can look into it.
>>
>> file sent privatly to umair
>
> I tested the file which Michael sent. The thing is that I'm getting
> error in decoding that file in both the cases, with or without the
> patch. I will begin debugging this issue, however I think the file
> which Michael sent has got nothing to do with the patch in this
> thread.

I tried decoding the file with the reference codec, and it also gives
an error with it. I think the issue is with the file itself.

➜  mp4alsRM23 ./bin/mac/mp4alsRM23 -x als_05_2ch48k16b.mp4
ERROR: Unable to convert MP4 to ALS: A2MERR_INIT_MP4READER

IMO, we are good to go with the current patch.

-Umair