If you are using Remote Call Recorder/Remote Audio Recorder and audio files captured are not showing call duration then most probably it’s corrupted.
The below article explains how to fix an audio file with zero duration but having content in it.
The corruption happens when the call recorder initiates the recording but terminates abruptly. The duration of the audio is written at the end as duration is not known beforehand. But if the recording is closed abruptly the duration is not written in the header and audio players will fail to play the file marking it as corrupted.
To fix this follow the below steps. The steps are taken from here. You can visit that site for a more detailed explanation:
1. Download and make sure the size of the audio file is more than 100 KB, else the audio is not played cause there is nothing in the file.
2. Download faad.exe from http://rarewares.org/aac-decoders.php
3. Download faac.exe from http://rarewares.org/aac-encoders.php
4. Download hex editor from http://download.cnet.com/HxD-Hex-…/3000-2352_4-10891068.html and install.
5. Open the corrupt audio file in hex editor and search and remove content till mdat (including mdat).
6. Decode by faad.exe using the below command in cmd (windows):
faad.exe “file name”
7. Encode by faac.exe using the below command:
faac.exe -b 160 -o "output file".m4a “input file from above step”
That’s it. The output file now should work in any player.