TAV and TAD now shares same code for encoding and decoding

video_encoder/decoder_tad.h

@@ -0,0 +1,39 @@
+#ifndef TAD32_DECODER_H
+#define TAD32_DECODER_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+// TAD32 (Terrarum Advanced Audio - PCM32f version) Decoder
+// DWT-based perceptual audio codec for TSVM
+// Shared decoder library used by both decoder_tad (standalone) and decoder_tav (video decoder)
+
+// Constants (must match encoder)
+#define TAD32_SAMPLE_RATE 32000
+#define TAD32_CHANNELS 2  // Stereo
+#define TAD_DEFAULT_CHUNK_SIZE 31991  // Default chunk size for standalone TAD files
+
+/**
+ * Decode audio chunk with TAD32 codec
+ *
+ * @param input           Input TAD32 chunk data
+ * @param input_size      Size of input buffer
+ * @param pcmu8_stereo    Output PCMu8 stereo samples (interleaved L,R)
+ * @param bytes_consumed  [out] Number of bytes consumed from input
+ * @param samples_decoded [out] Number of samples decoded per channel
+ * @return                0 on success, -1 on error
+ *
+ * Input format:
+ *   uint16 sample_count (samples per channel)
+ *   uint8  max_index (maximum quantization index)
+ *   uint32 payload_size (bytes in payload)
+ *   *      payload (encoded M/S data, Zstd-compressed with EZBC)
+ *
+ * Output format:
+ *   PCMu8 stereo interleaved (8-bit unsigned PCM, L,R pairs)
+ *   Range: [0, 255] where 128 = silence
+ */
+int tad32_decode_chunk(const uint8_t *input, size_t input_size, uint8_t *pcmu8_stereo,
+                       size_t *bytes_consumed, size_t *samples_decoded);
+
+#endif // TAD32_DECODER_H