Mercurial > SDL_sound_CoreAudio
diff decoders/flac.c @ 182:3849438b735e
Checks magic number again, unless the file extension is recognized.
author | Ryan C. Gordon <icculus@icculus.org> |
---|---|
date | Mon, 17 Dec 2001 00:26:10 +0000 |
parents | d8904267d23c |
children | 47cc2de2ae36 |
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--- a/decoders/flac.c Mon Dec 17 00:25:46 2001 +0000 +++ b/decoders/flac.c Mon Dec 17 00:26:10 2001 +0000 @@ -235,6 +235,8 @@ } /* FLAC_quit */ +#define FLAC_MAGIC 0x43614C66 /* "fLaC" in ASCII. */ + static int FLAC_open(Sound_Sample *sample, const char *ext) { Sound_SampleInternal *internal = (Sound_SampleInternal *) sample->opaque; @@ -242,6 +244,34 @@ FLAC__StreamDecoder *decoder; flac_t *f; int i; + int has_extension = 0; + + /* + * If the extension is "flac", we'll believe that this is really meant + * to be a FLAC stream, and will try to grok it from existing metadata. + * metadata searching can be a very expensive operation, however, so + * unless the user swears that it is a FLAC stream through the extension, + * we decide what to do based on the existance of a 32-bit magic number. + */ + for (i = 0; extensions_flac[i] != NULL; i++) + { + if (__Sound_strcasecmp(ext, extensions_flac[i]) == 0) + { + has_extension = 1; + break; + } /* if */ + } /* for */ + + if (!has_extension) + { + int rc; + Uint32 flac_magic = SDL_ReadLE32(rw); + BAIL_IF_MACRO(flac_magic != FLAC_MAGIC, "FLAC: Not a FLAC stream.", 0); + + /* move back over magic number for metadata scan... */ + rc = SDL_RWseek(internal->rw, -sizeof (flac_magic), SEEK_CUR); + BAIL_IF_MACRO(rc < 0, ERR_IO_ERROR, 0); + } /* if */ f = (flac_t *) malloc(sizeof (flac_t)); BAIL_IF_MACRO(f == NULL, ERR_OUT_OF_MEMORY, 0); @@ -264,34 +294,16 @@ f->sample = sample; f->decoder = decoder; f->sample->actual.format = 0; - f->is_flac = 0; - -#if 0 - /* !!! FIXME: - * - * It should be possible to play a FLAC stream starting at any frame, - * but we can only do that if we know for sure that it is a FLAC - * stream. Otherwise we have to check for metadata, and then we need - * the entire stream, from the beginning. - * - * But getting this to work right seems to be an enormous pain in the - * butt for what is, at the moment, a very small gain. Maybe later. - */ - for (i = 0; extensions_flac[i] != NULL; i++) - if (__Sound_strcasecmp(ext, extensions_flac[i]) == 0) - { - f->is_flac = 1; - break; - } /* if */ -#endif + f->is_flac = 0 /* !!! FIXME: should be "has_extension", not "0". */; internal->decoder_private = f; FLAC__stream_decoder_init(decoder); - /* If we are not sure this is a FLAC stream, check for the STREAMINFO + /* + * If we are not sure this is a FLAC stream, check for the STREAMINFO * metadata block. If not, we'd have to peek at the first audio frame - * and get the sound format from there but, as stated above, that is - * not yet implemented. + * and get the sound format from there, but that is not yet + * implemented. */ if (!f->is_flac) {