[Flac-dev] reading vorbis comments with FLAC++?

[Joshua Kwan]

On Wed, Nov 12, 2003 at 11:46:23AM -0800, Josh Coalson wrote:
> that's correct; vorbis comments are not c strings and the API
> does not expose them as such (you could argue that it should I
> guess).  they are a length plus a buffer in UTF-8.

A buffer in UTF-8? I thought it was just junk memory - and valgrind
seems to prove this:

==13477== Invalid read of size 1
==13477==    at 0x40023F18: strlen (mac_replace_strmem.c:164)
==13477==    by 0x80501F9: get_flac(Song*, char const*) (char_traits.h:143)
==13477==    by 0x8050F9F: get_artist_title(Song*, std::string, char*) (basic_string.h:717)
==13477==    by 0x804E28C: traverse_dir(char*) (sstream:502)
==13477==    Address 0x415CDE5A is 0 bytes after a block of size 22 alloc'd
==13477==    at 0x4002CA4D: malloc (vg_replace_malloc.c:153)
==13477==    by 0x402AAF1D: FLAC::Metadata::VorbisComment::Entry::parse_field() (in /usr/lib/libFLAC++.so.2.1.2)
==13477==    by 0x8050F9F: get_artist_title(Song*, std::string, char*) (basic_string.h:717)
==13477==    by 0x804E28C: traverse_dir(char*) (sstream:502)

However, the C++ API exposes the field names and values as C strings:

                                const char *get_field() const;
                                const char *get_field_name() const;
                                const char *get_field_value() const;

but there's still junk on the char* i get back from get_field_value().
Should the type be changed to prevent the ambiguity/assumption?

> char str[entry->length+1];
> memcpy(str, entry->entry);
> str[entry->length] = '\0';

That's about the size of what I've been doing.

-- 
Joshua Kwan
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