WAV File missing Audio and Recordings

Question

We use FreePBX to record a conference line. This Line appears not to have disconnected and it created a continuous WAV file for 209 hours.

[matt@ait-debian ~/SLP ]$ mediainfo 7000-7000-always-20170823-162901-
1503469728.35757-1503469748.wav                                                                                                               

General
Complete name                            : 7000-7000-always-20170823-162901-
1503469728.35757-1503469748.wav
Format                                   : Wave
File size                                : 11.2 GiB
Duration                                 : 209 h
Overall bit rate mode                    : Constant
Overall bit rate                         : 128 kb/s

Audio
Format                                   : PCM
Format settings, Endianness              : Little
Format settings, Sign                    : Signed
Codec ID                                 : 1
Duration                                 : 209 h
Bit rate mode                            : Constant
Bit rate                                 : 128 kb/s
Channel(s)                               : 1 channel
Sampling rate                            : 8 000 Hz
Bit depth                                : 16 bits
Stream size                              : 11.2 GiB (100%)

But when I check with sox (Sound Exchange) it shows only 60hours worth of audio. VLC shows the same when listening to the file.

[matt@ait-debian ~/SLP ]$ soxi 7000-7000-always-20170823-162901-1503469728.35757-1503469748.wav                                                                                                                    

Input File     : '7000-7000-always-20170823-162901-1503469728.35757-
1503469748.wav'
Channels       : 1
Sample Rate    : 8000
Precision      : 16-bit
Duration       : 60:22:32.63 = 1738821024 samples ~ 1.63014e+07 CDDA sectors
File Size      : 12.1G
Bit Rate       : 444k
Sample Encoding: 16-bit Signed Integer PCM

The issue is that some timer after the 60 hours, at the about 72 hour mark another conference call was made that I need the recording for.

Now I would have thought that the conference continued to record so it should have recorded this audio.

Issue is. VLC, SOX don't see it. But mediainfo says there is 209h worth. So which is correct. I would think that VLC, SOX should show 109h duration.

Can anyone help or advise what happened?

Answer 1

I also posted this to reddit - https://www.reddit.com/r/linuxquestions/comments/6xbz8u/wav_file_missing_audio/

And was able to get an answer:

Using Audacity

• Import the WAV file as RAW Data
• Set Encoding to Signed 16-bit PCM Set
• Set the Start Offset to 44 bytes
• Set the Sample Rate 8000 Hz