lavf: deprecate AVFMT_FLAG_SHORTEST

It was added in cb114ed4640 with the comment
"This will allow fixing several bugs with the -shortest option".

Since
* there is no explanation of what these bugs are
* libavformat is not the place to work around ffmpeg CLI bugs
* there is no indication that this feature is actually in use
deprecate it without replacement.

doc/APIchanges

@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09
 
 API changes, most recent first:
 
+2023-09-xx - xxxxxxxxxx - lavf 60 - avformat.h
+  Deprecate AVFMT_FLAG_SHORTEST without replacement.
+
 2023-09-07 - xxxxxxxxxx - lavu 58.24.100 - imgutils.h
   Add av_image_copy2(), a wrapper around the av_image_copy()
   to overcome limitations of automatic conversions.

libavformat/avformat.h

@@ -1242,7 +1242,9 @@ typedef struct AVFormatContext {
 #define AVFMT_FLAG_BITEXACT         0x0400
 #define AVFMT_FLAG_SORT_DTS    0x10000 ///< try to interleave outputted packets by dts (using this flag can slow demuxing down)
 #define AVFMT_FLAG_FAST_SEEK   0x80000 ///< Enable fast, but inaccurate seeks for some formats
+#if FF_API_LAVF_SHORTEST
 #define AVFMT_FLAG_SHORTEST   0x100000 ///< Stop muxing when the shortest stream stops.
+#endif
 #define AVFMT_FLAG_AUTO_BSF   0x200000 ///< Add bitstream filters as requested by the muxer
 
     /**

libavformat/internal.h

@@ -151,10 +151,12 @@ typedef struct FFFormatContext {
 
     int avoid_negative_ts_use_pts;
 
+#if FF_API_LAVF_SHORTEST
     /**
      * Timestamp of the end of the shortest stream.
      */
     int64_t shortest_end;
+#endif
 
     /**
      * Whether or not avformat_init_output has already been called

libavformat/mux.c

@@ -992,6 +992,7 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *pkt,
         }
     }
 
+#if FF_API_LAVF_SHORTEST
     if (si->packet_buffer.head &&
         eof &&
         (s->flags & AVFMT_FLAG_SHORTEST) &&
@@ -1027,6 +1028,7 @@ int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *pkt,
             flush = 0;
         }
     }
+#endif
 
     if (stream_count && flush) {
         PacketListEntry *pktl = si->packet_buffer.head;

libavformat/options.c

@@ -190,7 +190,9 @@ FF_ENABLE_DEPRECATION_WARNINGS
         return NULL;
     }
 
+#if FF_API_LAVF_SHORTEST
     si->shortest_end = AV_NOPTS_VALUE;
+#endif
 
     return s;
 }

libavformat/options_table.h

@@ -51,7 +51,9 @@ static const AVOption avformat_options[] = {
 {"fastseek", "fast but inaccurate seeks", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FAST_SEEK }, INT_MIN, INT_MAX, D, "fflags"},
 {"nobuffer", "reduce the latency introduced by optional buffering", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_NOBUFFER }, 0, INT_MAX, D, "fflags"},
 {"bitexact", "do not write random/volatile data", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_BITEXACT }, 0, 0, E, "fflags" },
-{"shortest", "stop muxing with the shortest stream", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E, "fflags" },
+#if FF_API_LAVF_SHORTEST
+{"shortest", "stop muxing with the shortest stream", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E | AV_OPT_FLAG_DEPRECATED, "fflags" },
+#endif
 {"autobsf", "add needed bsfs automatically", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_AUTO_BSF }, 0, 0, E, "fflags" },
 {"seek2any", "allow seeking to non-keyframes on demuxer level when supported", OFFSET(seek2any), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, D},
 {"analyzeduration", "specify how many microseconds are analyzed to probe the input", OFFSET(max_analyze_duration), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D},

libavformat/version_major.h

@@ -46,6 +46,7 @@
 #define FF_API_AVIODIRCONTEXT           (LIBAVFORMAT_VERSION_MAJOR < 61)
 #define FF_API_AVFORMAT_IO_CLOSE        (LIBAVFORMAT_VERSION_MAJOR < 61)
 #define FF_API_AVIO_WRITE_NONCONST      (LIBAVFORMAT_VERSION_MAJOR < 61)
+#define FF_API_LAVF_SHORTEST            (LIBAVFORMAT_VERSION_MAJOR < 61)
 
 
 #define FF_API_R_FRAME_RATE            1