[vorbis-dev] Am I missing something?

[Monty]

On Sun, Feb 04, 2001 at 05:52:05PM -0500, Martin C. Martin wrote:
> Hey all,
> 
> If my understanding is right, there's a serious big in vorbisfile.c, in
> the routine _fetch_headers(), which will only show up when comment
> packet spans multiple pages.  The code to read the first 3 Vorbis
> packets ogg_stream_pagein() once, then calls ogg_stream_packetout().  
> The problem is that ogg_stream_pagein() only adds a single page to the
> ogg stream state, whereas ogg_stream_packetout(), loops until it finds a
> non-255 lacing value.  So, if the comment packet is larger than one
> page, all lacing values will be 255, and ogg_stream_packetout will start
> reading uninitialized memory.

No, you've misunderstood how the buffering works.  Packetout says
"need more data" if the comment packet is > 1 page, the inner loop
breaks, a new page is read and then packetout is called again.  That
continues for as long as necessary to get a complete packet.

Monty

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