doxygen info of av1_cost_coeffs_txb_estimate()
Change-Id: Ia405dc07d9d1882852c7de40305a39e635731c4a
diff --git a/av1/encoder/encodetxb.h b/av1/encoder/encodetxb.h
index ca98536..a300d90 100644
--- a/av1/encoder/encodetxb.h
+++ b/av1/encoder/encodetxb.h
@@ -100,10 +100,43 @@
const TXB_CTX *const txb_ctx,
const int reduced_tx_set_used,
const int adjust_eob);
+/*!\endcond */
+
+/*!\brief Estimate the entropy cost of transform coefficients using Laplacian
+ * distribution.
+ *
+ * \ingroup coefficient_coding
+ *
+ * This function assumes each transform coefficient is of its own Laplacian
+ * distribution and the coefficient is the only observation of the Laplacian
+ * distribution.
+ *
+ * Based on that, each coefficient's coding cost can be estimated by computing
+ * the entropy of the corresponding Laplacian distribution.
+ *
+ * This function then return the sum of the estimated entropy cost for all
+ * coefficients in the transform block.
+ *
+ * Note that the entropy cost of end of block (eob) and transform type (tx_type)
+ * are not included.
+ *
+ * Compared to \ref av1_cost_coeffs_txb, this function is much faster but less
+ * accurate.
+ *
+ * \param[in] x Pointer to structure holding the data for the
+ current encoding macroblock
+ * \param[in] plane The index of the current plane
+ * \param[in] block The index of the current transform block in the
+ * macroblock. It's defined by number of 4x4 units that have been coded before
+ * the currernt transform block
+ * \param[in] tx_size The transform size
+ * \param[in] tx_type The transform type
+ * \return int Estimated entropy cost of coefficients in the
+ * transform block.
+ */
int av1_cost_coeffs_txb_estimate(const MACROBLOCK *x, const int plane,
const int block, const TX_SIZE tx_size,
const TX_TYPE tx_type);
-/*!\endcond */
/*!\brief Write quantized coefficients in a transform block into bitstream using
* entropy coding.
