It seems there still isn't a tool (at least not a Xiph one) for modifying Opus comments from the command line. I've had a go at adding support in liboggz (which is fairly trivial, since it just means adding recognition for the Opus stream). That certainly works for comment editing, but I'm not sure if it's is good enough to commit back, because timing gets reported back slightly out, due to the Opus pre-seek, I think. Fixing that probably requires adding an Opus-specific metric to liboggz, since the current default linear one doesn't deal with first granule position being set. Thought I'd check before getting into that whether anyone has looked at this already? (I also suspect the way liboggz handles pre-roll may need to be extended, since it seems to be working in packet count, like Vorbis, rather than sample count as Opus does.) Another thought, could vorbiscomment do with having Opus comment support added? -- imalone http://ibmalone.blogspot.co.uk
Timothy B. Terriberry
2016-Dec-31 14:03 UTC
[ogg-dev] [opus] comment writing in opus / liboggz
Ian Malone wrote:> out, due to the Opus pre-seek, I think. Fixing that probably requires > adding an Opus-specific metric to liboggz, since the current default > linear one doesn't deal with first granule position being set. Thought > I'd check before getting into that whether anyone has looked at this > already?I thought Mark Harris implemented this in <https://git.xiph.org/?p=liboggz.git;a=commitdiff;h=0a523700afbb>. I'm not sure there's been a release since then, though. Are you looking at the latest git, or is there something wrong with that implementation?> Another thought, could vorbiscomment do with having Opus comment support added?Or make an opuscomment for opus-tools. I'm not sure which is the better approach, though the latter certainly seems like it would be less surprising for users.
On 31 December 2016 at 14:03, Timothy B. Terriberry <tterribe at xiph.org> wrote:> Ian Malone wrote: >> >> out, due to the Opus pre-seek, I think. Fixing that probably requires >> adding an Opus-specific metric to liboggz, since the current default >> linear one doesn't deal with first granule position being set. Thought >> I'd check before getting into that whether anyone has looked at this >> already? > > > I thought Mark Harris implemented this in > <https://git.xiph.org/?p=liboggz.git;a=commitdiff;h=0a523700afbb>. I'm not > sure there's been a release since then, though. Are you looking at the > latest git, or is there something wrong with that implementation? >Thanks, that does look like the right set of changes, with metrics handled too. The distro packaged version I've got didn't have it, and I'd found kfish's github rather than the Xiph git.>> Another thought, could vorbiscomment do with having Opus comment support >> added? > > > Or make an opuscomment for opus-tools. I'm not sure which is the better > approach, though the latter certainly seems like it would be less surprising > for users.It'd certainly make sense for it to be included with other Opus tools, vorbiscomment is a bit of an oddity within vorbis-tools since (hazily recalled) it supports other stream types than just Vorbis (and a general comment editor is useful, though it sounds like liboggz has that covered again). -- imalone http://ibmalone.blogspot.co.uk