diff options
| author | mid-kid <esteve.varela@gmail.com> | 2021-11-04 21:07:26 +0000 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-11-04 14:07:26 -0700 |
| commit | 681ca68ac96e8d39f49eb2c9f42e5c1e1041f5e0 (patch) | |
| tree | 52a507350ab3fb83d1207b7ccf8266693c2f5a24 /tools/aif2pcm/main.c | |
| parent | f1394cbb03aa9fb1c928c6de1648ef459d2bf66b (diff) | |
Disassemble some more tables and the first graphic (#71)
* Sync tools/ directory with pokeemerald
We really ought to have a central repository for this mess
* Make incremental builds faster
Scientists hate him!
He made NODEP disappear with this ONE SIMPLE TRICK!!!
Want to know more? -> __click here__ <-
* Disassemble some more tables and the first graphic
Diffstat (limited to 'tools/aif2pcm/main.c')
| -rw-r--r-- | tools/aif2pcm/main.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/tools/aif2pcm/main.c b/tools/aif2pcm/main.c index cd5ac4a..3dad6fc 100644 --- a/tools/aif2pcm/main.c +++ b/tools/aif2pcm/main.c @@ -351,6 +351,12 @@ const int gDeltaEncodingTable[] = { -64, -49, -36, -25, -16, -9, -4, -1, }; +#define POSITIVE_DELTAS_START 0 +#define POSITIVE_DELTAS_END 8 + +#define NEGATIVE_DELTAS_START 8 +#define NEGATIVE_DELTAS_END 16 + struct Bytes *delta_decompress(struct Bytes *delta, unsigned int expected_length) { struct Bytes *pcm = malloc(sizeof(struct Bytes)); @@ -418,15 +424,32 @@ struct Bytes *delta_decompress(struct Bytes *delta, unsigned int expected_length return pcm; } +#define U8_TO_S8(value) ((value) < 128 ? (value) : (value) - 256) +#define ABS(value) ((value) >= 0 ? (value) : -(value)) + int get_delta_index(uint8_t sample, uint8_t prev_sample) { int best_error = INT_MAX; int best_index = -1; + int delta_table_start_index; + int delta_table_end_index; + int sample_signed = U8_TO_S8(sample); + int prev_sample_signed = U8_TO_S8(prev_sample); + + // if we're going up (or equal), only choose positive deltas + if (prev_sample_signed <= sample_signed) { + delta_table_start_index = POSITIVE_DELTAS_START; + delta_table_end_index = POSITIVE_DELTAS_END; + } else { + delta_table_start_index = NEGATIVE_DELTAS_START; + delta_table_end_index = NEGATIVE_DELTAS_END; + } - for (int i = 0; i < 16; i++) + for (int i = delta_table_start_index; i < delta_table_end_index; i++) { uint8_t new_sample = prev_sample + gDeltaEncodingTable[i]; - int error = sample > new_sample ? sample - new_sample : new_sample - sample; + int new_sample_signed = U8_TO_S8(new_sample); + int error = ABS(new_sample_signed - sample_signed); if (error < best_error) { |