[FFmpeg-devel] [PATCH]lavf/cafdec: Do not fail hard for files ending with junk

[Carl Eugen Hoyos]

2019-01-22 12:21 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
> On 1/22/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>> 2019-01-22 12:04 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>> On 1/22/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>> 2019-01-22 11:56 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>>>> On 1/22/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>>>> 2019-01-22 11:38 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>>>>>> On 1/22/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>>>>>> 2019-01-22 11:28 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>>>>>>>> On 1/22/19, Paul B Mahol <onemda at gmail.com> wrote:
>>>>>>>>>> On 1/22/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>>>>>>>>> 2019-01-15 13:17 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>>>>>>>>>>> On 1/15/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>>>>>>>>>>> 2019-01-15 12:53 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>>>>>>>>>>>>> On 1/15/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>>>>>>>>>>>>> 2019-01-15 10:23 GMT+01:00, Paul B Mahol <onemda at gmail.com>:
>>>>>>>>>>>>>>>> On 1/15/19, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> A user provided a real-life caf file ending with junk after
>>>>>>>>>>>>>>>>> the
>>>>>>>>>>>>>>>>> data
>>>>>>>>>>>>>>>>> chunk, QuickTime reads such files.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Please comment, Carl Eugen
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> NACK, there is data after junk bytes, which would get simply
>>>>>>>>>>>>>>>> discarded with your patch.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Please elaborate: I don't think any data gets discarded
>>>>>>>>>>>>>>> because
>>>>>>>>>>>>>>> of this patch.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I told you already, hex edit size of data chunk to very big
>>>>>>>>>>>>>> number
>>>>>>>>>>>>>> and
>>>>>>>>>>>>>> play file again.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Of course.
>>>>>>>>>>>>>
>>>>>>>>>>>>> But how does this change the output compared to my patch?
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> It does change, full length of audio is:
>>>>>>>>>>>>
>>>>>>>>>>>> MD5=5128bc2cd0e7b0560f15dd4c0546d1a0rate=   0.0kbits/s speed=
>>>>>>>>>>>> 777x
>>>>>>>>>>>> size=       0kB time=00:09:18.16 bitrate=   0.0kbits/s speed=
>>>>>>>>>>>> 769x
>>>>>>>>>>>
>>>>>>>>>>> Sorry for the delay:
>>>>>>>>>>> QuickTime Player only plays the file for ~6:20.
>>>>>>>>>>> Playing the file longer would be an issue since atoms after the
>>>>>>>>>>> data atom are allowed.
>>>>>>>>>>> And most important: This is unrelated, my patch is about playing
>>>>>>>>>>> a file that is supposed to be played but currently doesn't work.
>>>>>>>>>>> If there is something else to be improved, it should be a
>>>>>>>>>>> separate
>>>>>>>>>>> patch.
>>>>>>>>>>>
>>>>>>>>>>> Please comment, Carl Eugen
>>>>>>>>>>
>>>>>>>>>> You can not claim it fixes playback.
>>>>>>>>
>>>>>>>> It does here: The file does not play without my patch, it plays
>>>>>>>> (for the right duration) with my patch.
>>>>>>>
>>>>>>> Duration is not right at all.
>>>>>>
>>>>>> Does QuickTime play the file longer for you than FFmpeg
>>>>>> with my patch?
>>>>>> Or do I misunderstand you?
>>>>>
>>>>> Correct duration is one I showed it here.
>>>>
>>>> No, the correct duration for the given file is ~6:20 as
>>>> already explained.
>>>
>>> Nope, you are removing actual valid audio samples this way.
>>
>> But the caf structure claims that the discussed data are
>> not valid audio samples but other caf atoms, since valid
>> files exist that have atoms there, it is correct to skip the
>> atoms if they cannot be detected, that is just how caf
>> works.
>
> I'm not talking about CAF structure.

But the CAF structure is the relevant talking point for caf files, no?

>> Is my explanation sufficient for you now?
>
> You still claim 2 things in your patch which are lie.

So you claim I am a liar? Does that mean we can
finally drop the CoC?

Please elaborate, Carl Eugen