2 files changed, 30 insertions, 13 deletions

diff --git a/src/liblzma/api/lzma/filter.h b/src/liblzma/api/lzma/filter.h
index c4bc69d3..01393dd4 100644
--- a/src/liblzma/api/lzma/filter.h
+++ b/src/liblzma/api/lzma/filter.h
@@ -198,6 +198,36 @@ extern LZMA_API(lzma_ret) lzma_raw_decoder(
 
 
 /**
+ * \brief       Update the filter chain in the encoder
+ *
+ * This function is for advanced users only. This function has two slightly
+ * different purposes:
+ *
+ *  - After LZMA_FULL_FLUSH when using Stream encoder: Set a new filter
+ *    chain, which will be used starting from the next Block.
+ *
+ *  - After LZMA_SYNC_FLUSH using Raw, Block, or Stream encoder: Change
+ *    the filter-specific options in the middle of encoding. The actual
+ *    filters in the chain (Filter IDs) cannot be changed. In the future,
+ *    it might become possible to change the filter options without
+ *    using LZMA_SYNC_FLUSH.
+ *
+ * While rarely useful, this function may be called also when no data has
+ * been compressed yet. In that case, this function will behave as if
+ * LZMA_FULL_FLUSH (Stream encoder) or LZMA_SYNC_FLUSH (Raw or Block
+ * encoder) had been used right before calling this function.
+ *
+ * \return      - LZMA_OK
+ *              - LZMA_MEM_ERROR
+ *              - LZMA_MEMLIMIT_ERROR
+ *              - LZMA_OPTIONS_ERROR
+ *              - LZMA_PROG_ERROR
+ */
+extern LZMA_API(lzma_ret) lzma_filters_update(
+		lzma_stream *strm, const lzma_filter *filters);
+
+
+/**
  * \brief       Single-call raw encoder
  *
  * \param       filters     Array of lzma_filter structures. The end of the
diff --git a/src/liblzma/api/lzma/lzma.h b/src/liblzma/api/lzma/lzma.h
index 28ebbb14..989425e3 100644
--- a/src/liblzma/api/lzma/lzma.h
+++ b/src/liblzma/api/lzma/lzma.h
@@ -298,19 +298,6 @@ typedef struct {
 #	define LZMA_PB_MAX      4
 #	define LZMA_PB_DEFAULT  2
 
-	/**
-	 * \brief       Indicate if the options structure is persistent
-	 *
-	 * If this is true, the application must keep this options structure
-	 * available after the LZMA2 encoder has been initialized. With
-	 * persistent structure it is possible to change some encoder options
-	 * in the middle of the encoding process without resetting the encoder.
-	 *
-	 * This option is used only by LZMA2. LZMA1 ignores this and it is
-	 * safe to not initialize this when encoding with LZMA1.
-	 */
-	lzma_bool persistent;
-
 	/** Compression mode */
 	lzma_mode mode;