lavf: reorder AVInput/OutputFormat fields.

Put all private fields at the end and mark them as such so they can be
easily changed/removed.

This breaks ABI.

libavformat/avformat.h

@@ -309,34 +309,16 @@ typedef struct AVOutputFormat {
     const char *long_name;
     const char *mime_type;
     const char *extensions; /**< comma-separated filename extensions */
-    /**
-     * size of private data so that it can be allocated in the wrapper
-     */
-    int priv_data_size;
     /* output support */
     enum CodecID audio_codec;    /**< default audio codec */
     enum CodecID video_codec;    /**< default video codec */
-    int (*write_header)(struct AVFormatContext *);
-    /**
-     * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
-     * pkt can be NULL in order to flush data buffered in the muxer.
-     * When flushing, return 0 if there still is more data to flush,
-     * or 1 if everything was flushed and there is no more buffered
-     * data.
-     */
-    int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
-    int (*write_trailer)(struct AVFormatContext *);
+    enum CodecID subtitle_codec; /**< default subtitle codec */
     /**
      * can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE,
      * AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS,
      * AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH
      */
     int flags;
-    /**
-     * Currently only used to set pixel format if not YUV420P.
-     */
-    int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
-                             AVPacket *in, int flush);
 
     /**
      * List of supported codec_id-codec_tag pairs, ordered by "better
@@ -344,10 +326,37 @@ typedef struct AVOutputFormat {
      */
     const struct AVCodecTag * const *codec_tag;
 
-    enum CodecID subtitle_codec; /**< default subtitle codec */
 
     const AVClass *priv_class; ///< AVClass for the private context
 
+    /*****************************************************************
+     * No fields below this line are part of the public API. They
+     * may not be used outside of libavformat and can be changed and
+     * removed at will.
+     * New public fields should be added right above.
+     *****************************************************************
+     */
+    struct AVOutputFormat *next;
+    /**
+     * size of private data so that it can be allocated in the wrapper
+     */
+    int priv_data_size;
+
+    int (*write_header)(struct AVFormatContext *);
+    /**
+     * Write a packet. If AVFMT_ALLOW_FLUSH is set in flags,
+     * pkt can be NULL in order to flush data buffered in the muxer.
+     * When flushing, return 0 if there still is more data to flush,
+     * or 1 if everything was flushed and there is no more buffered
+     * data.
+     */
+    int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
+    int (*write_trailer)(struct AVFormatContext *);
+    /**
+     * Currently only used to set pixel format if not YUV420P.
+     */
+    int (*interleave_packet)(struct AVFormatContext *, AVPacket *out,
+                             AVPacket *in, int flush);
     /**
      * Test if the given codec can be stored in this container.
      *
@@ -355,9 +364,6 @@ typedef struct AVOutputFormat {
      *         A negative number if unknown.
      */
     int (*query_codec)(enum CodecID id, int std_compliance);
-
-    /* private fields */
-    struct AVOutputFormat *next;
 } AVOutputFormat;
 /**
  * @}
@@ -381,6 +387,38 @@ typedef struct AVInputFormat {
      */
     const char *long_name;
 
+    /**
+     * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
+     * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
+     * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
+     */
+    int flags;
+
+    /**
+     * If extensions are defined, then no probe is done. You should
+     * usually not use extension format guessing because it is not
+     * reliable enough
+     */
+    const char *extensions;
+
+    const struct AVCodecTag * const *codec_tag;
+
+    const AVClass *priv_class; ///< AVClass for the private context
+
+    /*****************************************************************
+     * No fields below this line are part of the public API. They
+     * may not be used outside of libavformat and can be changed and
+     * removed at will.
+     * New public fields should be added right above.
+     *****************************************************************
+     */
+    struct AVInputFormat *next;
+
+    /**
+     * General purpose read-only value that the format can use.
+     */
+    int value;
+
     /**
      * Size of private data so that it can be allocated in the wrapper.
      */
@@ -436,25 +474,6 @@ typedef struct AVInputFormat {
     int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
                               int64_t *pos, int64_t pos_limit);
 
-    /**
-     * Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS,
-     * AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH,
-     * AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
-     */
-    int flags;
-
-    /**
-     * If extensions are defined, then no probe is done. You should
-     * usually not use extension format guessing because it is not
-     * reliable enough
-     */
-    const char *extensions;
-
-    /**
-     * General purpose read-only value that the format can use.
-     */
-    int value;
-
     /**
      * Start/resume playing - only meaningful if using a network-based format
      * (RTSP).
@@ -467,8 +486,6 @@ typedef struct AVInputFormat {
      */
     int (*read_pause)(struct AVFormatContext *);
 
-    const struct AVCodecTag * const *codec_tag;
-
     /**
      * Seek to timestamp ts.
      * Seeking will be done so that the point from which all active streams
@@ -476,11 +493,6 @@ typedef struct AVInputFormat {
      * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
      */
     int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
-
-    const AVClass *priv_class; ///< AVClass for the private context
-
-    /* private fields */
-    struct AVInputFormat *next;
 } AVInputFormat;
 /**
  * @}