I’m trying to get the loop start and end point metadata from an audio sample. I’m using soxi with the -V verbose flag. The data I need shows up in the terminal but isn’t captured, nor piped to the next command.
Showing the data with soxi:
$ soxi -V sample.aif
soxi INFO formats: detected file format type `aiff'
soxi INFO aiff: AIFF Loop markers:
soxi INFO aiff: Loop 0: start: 75576
soxi INFO aiff: end: 103868
soxi INFO aiff: count: 1
soxi INFO aiff: type:
soxi INFO aiff: forward
soxi INFO aiff: Unity MIDI Note: 52
soxi INFO aiff: Low MIDI Note: 50
soxi INFO aiff: High MIDI Note: 53
Input File : 'sample.aif'
Channels : 1
Sample Rate : 44100
Precision : 24-bit
Duration : 00:00:03.80 = 167665 samples = 285.145 CDDA sectors
File Size : 507k
Bit Rate : 1.07M
Sample Encoding: 24-bit Signed Integer PCM
But when I pipe that output into a text file the top section still appears in the terminal and only the bottom section is piped to the text file:
$ soxi -V sample.aif >> data.txt
soxi INFO formats: detected file format type `aiff'
soxi INFO aiff: AIFF Loop markers:
soxi INFO aiff: Loop 0: start: 75576
soxi INFO aiff: end: 103868
soxi INFO aiff: count: 1
soxi INFO aiff: type:
soxi INFO aiff: forward
soxi INFO aiff: Unity MIDI Note: 52
soxi INFO aiff: Low MIDI Note: 50
soxi INFO aiff: High MIDI Note: 53
$ cat data.txt
Input File : 'sample.aif'
Channels : 1
Sample Rate : 44100
Precision : 24-bit
Duration : 00:00:03.80 = 167665 samples = 285.145 CDDA sectors
File Size : 507k
Bit Rate : 1.07M
Sample Encoding: 24-bit Signed Integer PCM
How do I capture that top section of output, which contains the data I need?
>Solution :
The -V parameter of soxi outputs the verbose part to stderr (fd 2)
To include the verbose part as well, redirect stderr to stdout (fd 1)
$ soxi -V sample.aif 2>&1 | tee -a data.txt