Update atrac9.cpp

backgamon · Jan 19, 2024 · f133dad · f133dad
1 parent 7f68c61
commit f133dad
Showing 1 changed file with 28 additions and 0 deletions.
diff --git a/vita3k/ngs/src/modules/atrac9.cpp b/vita3k/ngs/src/modules/atrac9.cpp
@@ -28,6 +28,34 @@ namespace ngs {
 SwrContext *Atrac9Module::swr_mono_to_stereo = nullptr;
 SwrContext *Atrac9Module::swr_stereo = nullptr;
 
+void atrac9_get_buffer_parameter(const uint32_t start_sample, const uint32_t num_samples, const uint32_t info, SceNgsAT9SkipBufferInfo &parameter) {
+    const uint8_t sample_rate_index = ((info & (0b1111 << 12)) >> 12);
+    const uint8_t block_rate_index = ((info & (0b111 << 9)) >> 9);
+    const uint16_t frame_bytes = ((((info & 0xFF0000) >> 16) << 3) | ((info & (0b111 << 29)) >> 29)) + 1;
+    const uint8_t superframe_index = (info & (0b11 << 27)) >> 27;
+
+    // Calculate bytes per superframe.
+    const uint32_t frame_per_superframe = 1 << superframe_index;
+    const uint32_t bytes_per_superframe = frame_bytes * frame_per_superframe;
+
+    // Calculate total superframe
+    static const int8_t sample_rate_index_to_frame_sample_power[] = {
+        6, 6, 7, 7, 7, 8, 8, 8, 6, 6, 7, 7, 7, 8, 8, 8
+    };
+
+    const uint32_t samples_per_frame = 1 << sample_rate_index_to_frame_sample_power[sample_rate_index];
+    const uint32_t samples_per_superframe = samples_per_frame * frame_per_superframe;
+
+    const uint32_t start_superframe = (start_sample / samples_per_superframe);
+    const uint32_t num_superframe = (start_sample + num_samples + samples_per_superframe - 1) / samples_per_superframe - start_superframe;
+
+    parameter.num_bytes = num_superframe * bytes_per_superframe;
+    parameter.is_super_packet = (frame_per_superframe == 1) ? 0 : 1;
+    parameter.start_byte_offset = start_superframe * bytes_per_superframe;
+    parameter.start_skip = (start_sample - (start_superframe * samples_per_superframe));
+    parameter.end_skip = (start_superframe + num_superframe) * samples_per_superframe - (start_sample + num_samples);
+}
+
 void Atrac9Module::on_state_change(const MemState &mem, ModuleData &data, const VoiceState previous) {
     SceNgsAT9States *state = data.get_state<SceNgsAT9States>();
     if (data.parent->state == VOICE_STATE_ACTIVE && previous == VOICE_STATE_AVAILABLE) {