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

[Carl Eugen Hoyos]

2019-01-22 13:47 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 12:21 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
>
> You claim that:
> 1. There is junk data after end of data chunk as set in that file.
> 2. No useful data is being discarded.
>
> Both are not true.

New patch sent.

Carl Eugen