[Libav-user] Grab audio samples with ffmpeg and C, error with official example code

[Paul B Mahol]

On 8/30/20, Mohamed Nmn <mohamednmn28105 at gmail.com> wrote:
> Hello
> What are ffmbeg commands to remove noise from the sound

Please do not hijack this thread by replying with different and
unrelated mail subject.

For unrelated subject open new thread - send new mail to this mailing list.

> thanks
>
> ‫في الأحد، 30 أغسطس 2020 في 9:18 ص تمت كتابة ما يلي بواسطة ‪Paul B Mahol‬‏
> <‪onemda at gmail.com‬‏>:‬
>
>> On 8/29/20, nji9 at arcor.de <nji9 at arcor.de> wrote:
>> > For dev I'm using v. 4.3.1. and also the latest Git version of ffmpeg
>> > (Zeranoe's Windows 64 builds).
>> >
>> > I get "strange" problems when running the official example code for
>> decoding
>> > audio
>> >
>> > https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/decode_audio.c
>> >
>> > MP3DirectCut(Lib-bass).mp3
>> >
>> >
>> http://www.mediafire.com/file/ozmjjcpwyhhdnr7/MP3DirectCut(Lib-bass).mp3/file
>> >
>> > Generates pcm, but outputs:
>> >
>> > "Warning: the sample format the decoder produced is planar (s16p).
>> > This example will output the first channel only."
>> >
>> > But the output pcm has both channels!??
>> >
>> > When recoding the above mp3 to wav with ffmpeg (4.1.4, no error
>> > message)
>> >
>> > http://www.mediafire.com/file/gcq7ryg43pd57q5/ffmpeg4.1.4.wav/file
>> >
>> > and also when recoding the latter to mp3 again
>> >
>> >
>> http://www.mediafire.com/file/ij865dkrprn2lta/ffmpeg4.1.4_recode.mp3/file
>> >
>> > the example code breaks and produces these error messages ("mp2 @ ..."
>> also
>> > for the wav file):
>> >
>> > avcodec_send_packet ()
>> > from within:
>> > "[mp2 @ <someAddress>] Header missing"
>> > and returns error code -1094995529
>> > (= "Invalid data found when processing input")
>> >
>> > It produces that error message for literally all other formats I tried,
>> and
>> > also when written with another editor (Audition 3.0).
>> > But all the files play and show fine on all programs I have.
>> >
>> > I'm at a lost at this point. What is going on and wrong here?
>>
>> Just because decode_audio does not skip ID3 metadata from start of
>> later mp3 file.
>> That is reasonably as program is just demonstration and not full blown
>> solution.
>>
>> >
>> > _______________________________________________
>> > Libav-user mailing list
>> > Libav-user at ffmpeg.org
>> > https://ffmpeg.org/mailman/listinfo/libav-user
>> >
>> > To unsubscribe, visit link above, or email
>> > libav-user-request at ffmpeg.org with subject "unsubscribe".
>> _______________________________________________
>> Libav-user mailing list
>> Libav-user at ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/libav-user
>>
>> To unsubscribe, visit link above, or email
>> libav-user-request at ffmpeg.org with subject "unsubscribe".
>