diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/inputPlugins/mp3_plugin.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/src/inputPlugins/mp3_plugin.c b/src/inputPlugins/mp3_plugin.c index 90c3f6172..549e62af3 100644 --- a/src/inputPlugins/mp3_plugin.c +++ b/src/inputPlugins/mp3_plugin.c @@ -455,6 +455,18 @@ enum { XING_SCALE = 0x00000008L, }; +struct lame { + char encoder[10]; /* 9 byte encoder name/version ("LAME3.97b") */ +#if 0 + /* See related comment in parse_lame() */ + float peak; /* replaygain peak */ + float trackGain; /* replaygain track gain */ + float albumGain; /* replaygain album gain */ +#endif + int encoderDelay; /* # of added samples at start of mp3 */ + int encoderPadding; /* # of added samples at end of mp3 */ +}; + static int parse_xing(struct xing *xing, struct mad_bitptr *ptr, int *oldbitlen) { unsigned long bits; @@ -528,13 +540,67 @@ static int parse_xing(struct xing *xing, struct mad_bitptr *ptr, int *oldbitlen) return 0; } +static int parse_lame(struct lame *lame, struct mad_bitptr *ptr, int *bitlen) +{ + int i; + + /* Unlike the xing header, the lame tag has a fixed length. Fail if + * not all 36 bytes (288 bits) are there. */ + if (*bitlen < 288) return 0; + + for (i = 0; i < 9; i++) lame->encoder[i] = (char)mad_bit_read(ptr, 8); + lame->encoder[9] = '\0'; + + /* This is technically incorrect, since the encoder might not be lame. + * But there's no other way to determine if this is a lame tag, and we + * wouldn't want to go reading a tag that's not there. */ + if (strncmp(lame->encoder, "LAME", 4) != 0) return 0; + +#if 0 + /* Apparently lame versions <3.97b1 do not calculate replaygain. I'm + * using lame 3.97b2, and while it does calculate replaygain, it's + * setting the values to 0. Using --replaygain-(fast|accurate) doesn't + * make any difference. Leaving this code unused until we have a way + * of testing it. -- jat */ + + mad_bit_read(ptr, 16); + + mad_bit_read(ptr, 32); /* peak */ + + mad_bit_read(ptr, 6); /* header */ + bits = mad_bit_read(ptr, 1); /* sign bit */ + lame->trackGain = mad_bit_read(ptr, 9); /* gain*10 */ + lame->trackGain = (bits ? -lame->trackGain : lame->trackGain) / 10; + + mad_bit_read(ptr, 6); /* header */ + bits = mad_bit_read(ptr, 1); /* sign bit */ + lame->albumGain = mad_bit_read(ptr, 9); /* gain*10 */ + lame->albumGain = (bits ? -lame->albumGain : lame->albumGain) / 10; + + mad_bit_read(ptr, 16); +#else + mad_bit_read(ptr, 96); +#endif + + lame->encoderDelay = mad_bit_read(ptr, 12); + lame->encoderPadding = mad_bit_read(ptr, 12); + + mad_bit_read(ptr, 96); + + *bitlen -= 288; + + return 1; +} + static int decodeFirstFrame(mp3DecodeData * data, DecoderControl * dc, MpdTag ** tag, ReplayGainInfo ** replayGainInfo) { struct xing xing; + struct lame lame; struct mad_bitptr ptr; int bitlen; int found_xing; + int found_lame; int ret; int skip; @@ -557,6 +623,7 @@ static int decodeFirstFrame(mp3DecodeData * data, DecoderControl * dc, bitlen = data->stream.anc_bitlen; found_xing = parse_xing(&xing, &ptr, &bitlen); + found_lame = (found_xing ? parse_lame(&lame, &ptr, &bitlen) : 0); if (found_xing) { if (xing.flags & XING_FRAMES) { |