ogg.k.ogg.k at googlemail.com wrote:>> We're also doing scheduled metadata change to indicate the current show >> to listeners. So for a 4pm show a url is hit which causes icecast to >> change the metadata indicating the 4pm show. That also works fine. >> > > And this causes segmentation because the metadata is stored in the > second header of the Vorbis stream, so changing metadata will cause > a new stream to be started, with the updated metadata. While such > streams are valid, they are not, as you found, well supported. There > is also no way to insert a Vorbis comments header packet within a > Vorbis stream without starting a new logical stream (well, there is, but > it would not be a valid stream, and would be ignored the decoder). > > >> oggdec -o - metadata_segmentation.ogg | oggenc -o contiguous_metadata.ogg - >> > > This will lose all metadata, which you don't want. If you add again the > metadata, it will apply to that single stream again. > > That said, Internet radio streams are usually handled fairly well by > various players, which detect new streams and update metadata > accordingly. These are typically live and not seekable though. > >Thanks for the reply. What I'm after is basically the conversion of a live stream to a seekable stream. The metadata is known and a wipe and reset is possible, but is it possible to wipe metadata segements across the whole file without re-encoding? Andy
ogg.k.ogg.k at googlemail.com
2009-Jun-15 19:15 UTC
[ogg-dev] Removing metadata segmentation
> What I'm after is basically the conversion of a live stream to a > seekable stream. The metadata is known and a wipe and reset is > possible, but is it possible to wipe metadata segements across the whole > file without re-encoding?Ah right, if you're OK with the metadata being wiped, then it should be possible to collapse the audio in a single stream without having to decode and reencode (I assume all the logical streams in the original have the same parameters - channels, sample rate, etc). There's no tool to do this, however, and there might be little pops at the boundaries, as Vorbis has a couple packets' preroll, but I think it's theoretically possible. Now, I don't have a practical solution :)
ogg.k.ogg.k at googlemail.com wrote:>> What I'm after is basically the conversion of a live stream to a >> seekable stream. The metadata is known and a wipe and reset is >> possible, but is it possible to wipe metadata segements across the whole >> file without re-encoding? >> > > Ah right, if you're OK with the metadata being wiped, then it should be > possible to collapse the audio in a single stream without having to decode > and reencode (I assume all the logical streams in the original have the > same parameters - channels, sample rate, etc). There's no tool to do > this, however, and there might be little pops at the boundaries, as > Vorbis has a couple packets' preroll, but I think it's theoretically possible. > Now, I don't have a practical solution :) > >Great, thanks. /me moves towards implementing something.