X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fcbs.h;h=9ca1fbd60902c6ab746c6c0352a79b8a4e722f6a;hb=5501bb28ddfa6441dcbf8ea0a964a13aa33f66fe;hp=53ac360bb1dda214b6e3e0d958993e1589e04503;hpb=22219a3ac46ac18f797c94e4619a34728556786c;p=ffmpeg

diff --git a/libavcodec/cbs.h b/libavcodec/cbs.h
index 53ac360bb1d..9ca1fbd6090 100644
--- a/libavcodec/cbs.h
+++ b/libavcodec/cbs.h
@@ -145,10 +145,19 @@ typedef struct CodedBitstreamFragment {
      * and has not been decomposed.
      */
     int              nb_units;
+
+    /**
+     * Number of allocated units.
+     *
+     * Must always be >= nb_units; designed for internal use by cbs.
+     */
+     int             nb_units_allocated;
+
     /**
-     * Pointer to an array of units of length nb_units.
+     * Pointer to an array of units of length nb_units_allocated.
+     * Only the first nb_units are valid.
      *
-     * Must be NULL if nb_units is zero.
+     * Must be NULL if nb_units_allocated is zero.
      */
     CodedBitstreamUnit *units;
 } CodedBitstreamFragment;
@@ -201,6 +210,13 @@ typedef struct CodedBitstreamContext {
      * From AV_LOG_*; defaults to AV_LOG_TRACE.
      */
     int trace_level;
+
+    /**
+     * Write buffer. Used as intermediate buffer when writing units.
+     * For internal use of cbs only.
+     */
+    uint8_t *write_buffer;
+    size_t   write_buffer_size;
 } CodedBitstreamContext;
 
 
@@ -231,6 +247,9 @@ void ff_cbs_close(CodedBitstreamContext **ctx);
  * This also updates the internal state, so will need to be called for
  * codecs with extradata to read parameter sets necessary for further
  * parsing even if the fragment itself is not desired.
+ *
+ * The fragment must have been zeroed or reset via ff_cbs_fragment_reset
+ * before use.
  */
 int ff_cbs_read_extradata(CodedBitstreamContext *ctx,
                           CodedBitstreamFragment *frag,
@@ -243,6 +262,9 @@ int ff_cbs_read_extradata(CodedBitstreamContext *ctx,
  * This also updates the internal state of the coded bitstream context
  * with any persistent data from the fragment which may be required to
  * read following fragments (e.g. parameter sets).
+ *
+ * The fragment must have been zeroed or reset via ff_cbs_fragment_reset
+ * before use.
  */
 int ff_cbs_read_packet(CodedBitstreamContext *ctx,
                        CodedBitstreamFragment *frag,
@@ -255,6 +277,9 @@ int ff_cbs_read_packet(CodedBitstreamContext *ctx,
  * This also updates the internal state of the coded bitstream context
  * with any persistent data from the fragment which may be required to
  * read following fragments (e.g. parameter sets).
+ *
+ * The fragment must have been zeroed or reset via ff_cbs_fragment_reset
+ * before use.
  */
 int ff_cbs_read(CodedBitstreamContext *ctx,
                 CodedBitstreamFragment *frag,
@@ -279,7 +304,8 @@ int ff_cbs_write_fragment_data(CodedBitstreamContext *ctx,
 /**
  * Write the bitstream of a fragment to the extradata in codec parameters.
  *
- * This replaces any existing extradata in the structure.
+ * Modifies context and fragment as ff_cbs_write_fragment_data does and
+ * replaces any existing extradata in the structure.
  */
 int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
                            AVCodecParameters *par,
@@ -287,6 +313,13 @@ int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
 
 /**
  * Write the bitstream of a fragment to a packet.
+ *
+ * Modifies context and fragment as ff_cbs_write_fragment_data does.
+ *
+ * On success, the packet's buf is unreferenced and its buf, data and
+ * size fields are set to the corresponding values from the newly updated
+ * fragment; other fields are not touched.  On failure, the packet is not
+ * touched at all.
  */
 int ff_cbs_write_packet(CodedBitstreamContext *ctx,
                         AVPacket *pkt,
@@ -294,11 +327,18 @@ int ff_cbs_write_packet(CodedBitstreamContext *ctx,
 
 
 /**
- * Free all allocated memory in a fragment.
+ * Free the units contained in a fragment as well as the fragment's
+ * own data buffer, but not the units array itself.
  */
-void ff_cbs_fragment_uninit(CodedBitstreamContext *ctx,
+void ff_cbs_fragment_reset(CodedBitstreamContext *ctx,
                             CodedBitstreamFragment *frag);
 
+/**
+ * Free the units array of a fragment in addition to what
+ * ff_cbs_fragment_reset does.
+ */
+void ff_cbs_fragment_free(CodedBitstreamContext *ctx,
+                          CodedBitstreamFragment *frag);
 
 /**
  * Allocate a new internal content buffer of the given size in the unit.
@@ -308,7 +348,7 @@ void ff_cbs_fragment_uninit(CodedBitstreamContext *ctx,
 int ff_cbs_alloc_unit_content(CodedBitstreamContext *ctx,
                               CodedBitstreamUnit *unit,
                               size_t size,
-                              void (*free)(void *unit, uint8_t *content));
+                              void (*free)(void *opaque, uint8_t *content));
 
 /**
  * Allocate a new internal data buffer of the given size in the unit.
@@ -336,7 +376,8 @@ int ff_cbs_insert_unit_content(CodedBitstreamContext *ctx,
  * Insert a new unit into a fragment with the given data bitstream.
  *
  * If data_buf is not supplied then data must have been allocated with
- * av_malloc() and will become owned by the unit after this call.
+ * av_malloc() and will on success become owned by the unit after this
+ * call or freed on error.
  */
 int ff_cbs_insert_unit_data(CodedBitstreamContext *ctx,
                             CodedBitstreamFragment *frag,
@@ -347,10 +388,12 @@ int ff_cbs_insert_unit_data(CodedBitstreamContext *ctx,
 
 /**
  * Delete a unit from a fragment and free all memory it uses.
+ *
+ * Requires position to be >= 0 and < frag->nb_units.
  */
-int ff_cbs_delete_unit(CodedBitstreamContext *ctx,
-                       CodedBitstreamFragment *frag,
-                       int position);
+void ff_cbs_delete_unit(CodedBitstreamContext *ctx,
+                        CodedBitstreamFragment *frag,
+                        int position);
 
 
 #endif /* AVCODEC_CBS_H */