Partially supported audio file format

Started by polaris6262, July 13, 2016, 07:35:22 PM

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polaris6262

Hi Phil,

I've recently downloaded an audio file in a format I'd never encountered before; its extension is 'opus'. ExifTool recognizes it is as an audio file of type 'ogg' but does not provide any additional information on the audio part itself.

ExifTool Version Number         : 10.22
File Name                       : Vangelis - Blade Runner 2002 Esper Edition.opus
Directory                       : .
File Size                       : 105 MB
File Modification Date/Time     : 2015:07:12 10:31:23-04:00
File Access Date/Time           : 2016:07:13 02:08:23-04:00
File Inode Change Date/Time     : 2016:07:13 02:07:23-04:00
File Permissions                : rw-r--r--
File Type                       : OGG
File Type Extension             : ogg
MIME Type                       : audio/x-ogg


I have another tool on one of my Linux distributions that provides a bit more information on this 'opus' audio file:

General
Complete name                            : Vangelis - Blade Runner 2002 Esper Edition.opus
Format                                   : Ogg
File size                                : 105 MiB
Duration                                 : 1 h 51 min
Overall bit rate                         : 132 kb/s
Writing application                      : Lavf57.25.100

Audio
ID                                       : 444259542 (0x1A7ADCD6)
Format                                   : Opus
Duration                                 : 1 h 51 min
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Compression mode                         : Lossy
Writing library                          : Lavf57.25.100
Language                                 : English


A bit of research indicates that 'opus' is a fairly new (4 years old) open low-latency lossy audio coding format providing much better sound quality than either MP3 or AAC. It's intended to replace 'Vorbis' audio, which explains its relationship with the Ogg container format.

Phil Harvey

Thanks for this report.  Send me a sample if you can, and I'll take a look (philharvey66 at gmail.com).

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).

polaris6262

Thanks Phil. I've emailed you a sample OggOpus audio file. Its audio characteristics do not quite match my own OggOpus file (mine's a whopping 105MB) but hopefully it should be representative enough of the format to allow for proper decoding.

The tool I've used before on my own file has the following to say on the sample file:

General
Complete name                            : example.opus
Format                                   : Ogg
File size                                : 1.44 MiB
Duration                                 : 37 s 576 ms
Overall bit rate                         : 322 kb/s
Album                                    : Example Files
Track name                               : OPUS Example File
Performer                                : Online-Convert.com
Writing application                      : opusenc from opus-tools v0.1.9
ENCODER_OPTIONS                          : --hard-cbr --comp 8 --bitrate 320

Audio
ID                                       : 14772 (0x39B4)
Format                                   : Opus
Duration                                 : 37 s 576 ms
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 44.1 kHz
Compression mode                         : Lossy
Writing library                          : libopus 1.1.x-git


I also found a technical link on OggOpus: https://wiki.xiph.org/OggOpus

The information is straight from the format's creators. Hope this helps!

Phil Harvey

I've just released ExifTool 10.23 with support for Opus metadata.

- Phil
...where DIR is the name of a directory/folder containing the images.  On Mac/Linux/PowerShell, use single quotes (') instead of double quotes (") around arguments containing a dollar sign ($).