diff options
| -rw-r--r-- | src/tag_rva2.c | 57 |
1 files changed, 39 insertions, 18 deletions
diff --git a/src/tag_rva2.c b/src/tag_rva2.c index bcc78500a..95f1b5464 100644 --- a/src/tag_rva2.c +++ b/src/tag_rva2.c @@ -21,6 +21,7 @@ #include "tag_rva2.h" #include "replay_gain_info.h" +#include <stdint.h> #include <glib.h> #include <id3tag.h> @@ -36,6 +37,40 @@ enum rva2_channel { CHANNEL_SUBWOOFER = 0x08 }; +struct rva2_data { + uint8_t type; + uint8_t volume_adjustment[2]; + uint8_t peak_bits; +}; + +static inline id3_length_t +rva2_peak_bytes(const struct rva2_data *data) +{ + return (data->peak_bits + 7) / 8; +} + +static inline int +rva2_fixed_volume_adjustment(const struct rva2_data *data) +{ + signed int voladj_fixed; + voladj_fixed = (data->volume_adjustment[0] << 8) | + data->volume_adjustment[1]; + voladj_fixed |= -(voladj_fixed & 0x8000); + return voladj_fixed; +} + +static inline float +rva2_float_volume_adjustment(const struct rva2_data *data) +{ + /* + * "The volume adjustment is encoded as a fixed point decibel + * value, 16 bit signed integer representing (adjustment*512), + * giving +/- 64 dB with a precision of 0.001953125 dB." + */ + + return (float)rva2_fixed_volume_adjustment(data) / (float)512; +} + bool tag_rva2_parse(struct id3_tag *tag, struct replay_gain_info *replay_gain_info) { @@ -70,27 +105,13 @@ tag_rva2_parse(struct id3_tag *tag, struct replay_gain_info *replay_gain_info) */ while (length >= 4) { - unsigned int peak_bytes; - - peak_bytes = (data[3] + 7) / 8; + const struct rva2_data *d = (const struct rva2_data *)data; + unsigned int peak_bytes = rva2_peak_bytes(d); if (4 + peak_bytes > length) break; - if (data[0] == CHANNEL_MASTER_VOLUME) { - signed int voladj_fixed; - double voladj_float; - - /* - * "The volume adjustment is encoded as a fixed - * point decibel value, 16 bit signed integer - * representing (adjustment*512), giving +/- 64 - * dB with a precision of 0.001953125 dB." - */ - - voladj_fixed = (data[1] << 8) | (data[2] << 0); - voladj_fixed |= -(voladj_fixed & 0x8000); - - voladj_float = (double) voladj_fixed / 512; + if (d->type == CHANNEL_MASTER_VOLUME) { + double voladj_float = rva2_float_volume_adjustment(d); replay_gain_info->tuples[REPLAY_GAIN_TRACK].gain = voladj_float; replay_gain_info->tuples[REPLAY_GAIN_ALBUM].gain = voladj_float; |