[FFmpeg-user] Strange output of ffprobe

[Анатолий Коростелев]

 > 48000 Hz seems the correct one, so no FFmpeg bug but MediaInfo bug 
(as a first shot, issue is that there is an ES descriptor without 
AudioSpecificConfig element in the track header and MediaInfo does not 
manage correctly this case; note that this may be the reason some 
players does not play sound).

Under the absence of the AudioSpecificConfig element in the track header 
do you mean to the absence of the "Format profile" field of the medianfo 
output? I've looked at the difference between mediainfo output of this 
bad mp4 file and a good mp4 file and I've found that the good one 
contains "Format profile":

diff -u mediainfo_output_of_bad_file mediainfo_output_of_good_file:

...

  Audio
  ID                                       : 2
-Format                                   : ER Parametric
+Format                                   : AAC
  Format/Info                              : Advanced Audio Codec
+Format profile                           : LC
  Codec ID                                 : 40
  Duration                                 : 22 min 49 s
  Bit rate mode                            : Constant
  Bit rate                                 : 128 kb/s
  Channel(s)                               : 2 channels
-Sampling rate                            : 7 350 Hz
-Frame rate                               : 7.178 FPS (1024 spf)
+Channel positions                        : Front: L R
+Sampling rate                            : 48.0 kHz
+Frame rate                               : 46.875 FPS (1024 spf)
  Compression mode                         : Lossy
  Stream size                              : 21.0 MiB (38%)
  Default                                  : Yes
  Alternate group                          : 1

...

28.10.16 0:11, Jerome Martinez пишет:
> Le 27/10/2016 à 18:06, Анатолий Коростелев a écrit :
>> Hello!
>>
>> Recently I recieved a mp4 for playing. When I tried to play this file 
>> I didn't hear any sound in some players (in ffplay sound worked). 
>> When I looked at the metadata of this file (via ffprobe), I saw the 
>> following:
>>
>> [...]
>>
>> Then I used mediainfo utility to see the metadata of the file:
>>
>> [...]
>>
>>
>> As you can see the "Sampling rate" in mediainfo is 7 350 Hz (it's 
>> illegal value) 
>
> It is not an illegal value, AAC specs authorize it.
>
>> while "Sampling rate" in ffprobe is 48000 Hz. I think that the 
>> problem with the sound of this file has been caused by encoder 
>> errors/misconfiguration. But it's very strange that ffrobe always 
>> shows me 48000 Hz Sampling rate. Is this a bug or something else?
>
> 48000 Hz seems the correct one, so no FFmpeg bug but MediaInfo bug (as 
> a first shot, issue is that there is an ES descriptor without 
> AudioSpecificConfig element in the track header and MediaInfo does not 
> manage correctly this case; note that this may be the reason some 
> players does not play sound).
>
> Jérôme, developer of MediaInfo.
>
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-- 
С уважением,
Коростелев Анатолий