Author Topic: Opus track invisible in MKV  (Read 374 times)

Blues

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Opus track invisible in MKV
« on: October 17, 2018, 11:20:16 AM »
Code: [Select]
matroska_reader: The CodecID for track 1 is 'A_OPUS', but the private codec data does not contain valid headers.
This is what I get from mkvtoolnix when I try to open a file encoded by Avidemux.

eumagga0x2a

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Re: Opus track invisible in MKV
« Reply #1 on: October 17, 2018, 11:53:45 AM »
WFM with Avidemux from the current git master and mkvtoolnix 25.0.0. Please specify steps to reproduce.

Blues

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Re: Opus track invisible in MKV
« Reply #2 on: October 17, 2018, 03:43:47 PM »
Loaded file to Avidemux (git a few days ago), video to copy, audio to Opus bitrate 96, container MKV. Resulting file plays in MPV, but when loaded to mkvtoolnix-23.0 GUI [to add subtitles] there is no audio track. Getting the mentioned error instead. You think the mkvtoolnix is too old?

eumagga0x2a

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Re: Opus track invisible in MKV
« Reply #3 on: October 17, 2018, 04:07:58 PM »
Well, I tested with bitrate set to 128 kbit/s, but I doubt this would matter.

Quote
You think the mkvtoolnix is too old?

It may depend on the opus version on your system as well. I use v1.3.

Actually, mkvtoolnix has such a high pace of development that trying a build from the git head looks reasonable.
« Last Edit: October 17, 2018, 04:16:27 PM by eumagga0x2a »

Blues

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Re: Opus track invisible in MKV
« Reply #4 on: October 18, 2018, 03:39:07 AM »
OK, thanks. At least I know now where to look.

Blues

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Re: Opus track invisible in MKV
« Reply #5 on: December 17, 2018, 11:47:16 PM »
OK, something is wrong. I have a file here, from youtube, mkv, opus audio. When I use Avidemux to extract audio I get a file which does not identify as opus. When I use mkvextract it gives me opus file.
File itself is here: http://www.asclinux.com/tmp/hmsn.mkv

eumagga0x2a

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Re: Opus track invisible in MKV
« Reply #6 on: December 20, 2018, 02:42:12 PM »
Avidemux saves only raw audio data, no Ogg container structures and no codec extradata, unfortunately, which renders the feature in case of Opus audio useless.

Blues

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Re: Opus track invisible in MKV
« Reply #7 on: December 21, 2018, 11:28:13 PM »
Right, so this is also the reason for problem in the first post.

eumagga0x2a

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Re: Opus track invisible in MKV
« Reply #8 on: December 21, 2018, 11:44:34 PM »
I don't think so. Avidemux correctly handles Opus extradata when muxing, just not when dumping a raw stream.