18 Aug
2016
18 Aug
'16
4:19 a.m.
I'm looking for a command line tool that can determine the length
(duration in seconds) of a sound file using more than just the file
header.
The situation is that some of the files have incorrect headers.
The data is intact, and they play correctly, but if you attempt to
determine the length based solely on the header, it will be incorrect.
I've tried soxi, mediainfo, and ffprobe (on xubuntu 16.04), and all
seem to rely exclusively on the header.
soxi is good enough that it warns if there's a discrepancy between
what the header says and what is present in the file, in a message to
stderr, but the value to stdout (from soxi -D) is the incorrect header
value.
I suppose i could write code to parse soxi's error message, but would
much prefer to have some option to pass to the program that says "use
file length instead of header info in the event of a conflict".
TIA for any suggestions!
dan
18 Aug
18 Aug
5:50 a.m.
Dan Hitt <dan.hitt(a)gmail.com> wrote:
Try: sox $FILE -n stats 2>&1 | awk '/^Length / {print $2}'
That will decode the entire file and run it through the
sox "stats" effect.
I just tried it on a 28MB FLAC file (3:49.80s) truncated to 5MB
with:
dd if=$ORIG of=truncated.flac bs=5M count=1
And was able to reproduce soxi showing the the length as
3:49.80 but "sox .. -n stats" showed only 44.304s
1:19 p.m.
On Thu, 18 Aug 2016 03:50:00 +0000, Eric Wong wrote:
And was able to reproduce soxi showing the the length
as
3:49.80 but "sox .. -n stats" showed only 44.304s
Hi,
I get three times the same duration for a wav
$ exiftool Audio_Oberheim_Matrix.wav|tail -1
Duration : 0:02:18
$ soxi Audio_Oberheim_Matrix.wav|grep D|cut -d= -f1
Duration : 00:02:18.19
$ sox Audio_Oberheim_Matrix.wav -n stats 2>&1|grep Len
Length s 138.194
and three times the same duration for a mp3.
$ exiftool *mix?.mp3|tail -1
Duration : 0:02:42 (approx)
$ soxi *mix?.mp3|grep D|cut -d= -f1|head -1
Duration : 00:02:42.25
$ sox *mix?.mp3 -n stats 2>&1|grep Len
Length s 162.246
I didn't check with a stopwatch, to ensure the duration is correct.
$ pacman -Q perl-image-exiftool sox
perl-image-exiftool 10.20-1
sox 14.4.2-1
Regards,
Ralf
19 Aug
19 Aug
5:58 a.m.
Thanks Paul, Eric, and Ralf,
Eric --- your command certainly works on my problematic sound file, thanks!
Paul --- thanks for pointing out sndfile-info. This also works, and
puts the results on stdout. (Presumably sox wants to write to stderr
to because it wants to reserve stdout for samples?)
Ralf --- thanks for pointing out exiftool. I had no idea it dealt
with sound files. Now, in my particular case, it didn't work because
my sound file is au/snd, and it doesn't know that format, so it
interpreted it as a (huge) jpeg. I think the reason that soxi can be
correct for some formats but not others is that the flow of control
goes through different paths depending on the file type, and some of
the handlers may be more capable than others (or at least have
different weak spots). Thus a problem showed up with Eric's flac and
my au/snd, but not your wav. (Pure conjecture here!)
Thanks again everybody for educating me!!
dan
On Thu, Aug 18, 2016 at 5:13 AM, Paul Davis <paul(a)linuxaudiosystems.com> wrote:
3152
days inactive
3153
days old
linux-audio-user@lists.linuxaudio.org
5 comments
4 participants
participants (4)
-
Dan Hitt -
Eric Wong -
Paul Davis -
Ralf Mardorf