[FFmpeg-user] AMRDecSpecStruc is missing in 3gp file generated by ffmpeg

[prashantha S]

Hi,

Our product uses these fields while playing the 3gp files into the user
port.
It uses this filed to decide to go with trans-coding or Bypass based on
dawb atom


When we open the ffmpeg created amr-wb 3gp files using QTAtomizer, it shows
missing dawb atom in the sawb atom


[image: Inline image 1]


For example:
The format of the dawb atom is the same as the damr atom as defined in TS
26.244. The first 4 bytes after the dawb are the vendor in the output file,
the fifth byte is the decoder version=0, the 6th and 7th bytes are the mode
modeset= 0x0100 which is mode 8 as encoded, the 8th byte is the mode change
period=0 (no restriction ion mode changes) and the last byte is the frames
per sample =5.

Thank you
Prashantha S

On Wed, Jun 10, 2015 at 4:47 AM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> prashantha S <sayaprashantha <at> gmail.com> writes:
>
> > ffmpeg.exe -i 1.wav -ar 16000 -ab 19.85k -acodec libvo_amrwbenc test1.3gp
> >
> > But dawr/dawb atom is missing in the clips generated by ffmpeg
>
> Why do you think that damr atom is wrong?
> Which application fails for your output file?
>
> Carl Eugen
>
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