lavf: Add an MPEG-DASH ISOFF segmenting muxer

This is mostly to serve as a reference example on how to segment
the output from the mp4 muxer, capable of writing the segment
list in four different ways:
- SegmentTemplate with SegmentTimeline
- SegmentTemplate with implicit segments
- SegmentList with individual files
- SegmentList with one single file per track, and byte ranges

The muxer is able to serve live content (with optional windowing)
or create a static segmented MPD.

In advanced cases, users will probably want to do the segmenting
in their own application code.
Signed-off-by: Martin Storsjö <martin@martin.st>

Changelog

@@ -6,7 +6,7 @@ version <next>:
 - HEVC/H.265 RTP payload format (draft v6) packetizer and depacketizer
 - avplay now exits by default at the end of playback
 - XCB-based screen-grabber
-- creating DASH compatible fragmented MP4
+- creating DASH compatible fragmented MP4, MPEG-DASH segmenting muxer
 
 
 version 11:

configure

@@ -2039,6 +2039,7 @@ avi_muxer_select="riffenc"
 avisynth_demuxer_deps="avisynth"
 avisynth_demuxer_select="riffdec"
 caf_demuxer_select="riffdec"
+dash_muxer_select="mp4_muxer"
 dirac_demuxer_select="dirac_parser"
 dv_demuxer_select="dvprofile"
 dv_muxer_select="dvprofile"

libavformat/Makefile

@@ -91,6 +91,7 @@ OBJS-$(CONFIG_CAVSVIDEO_MUXER)           += rawenc.o
 OBJS-$(CONFIG_CDG_DEMUXER)               += cdg.o
 OBJS-$(CONFIG_CDXL_DEMUXER)              += cdxl.o
 OBJS-$(CONFIG_CRC_MUXER)                 += crcenc.o
+OBJS-$(CONFIG_DASH_MUXER)                += dashenc.o isom.o
 OBJS-$(CONFIG_DAUD_DEMUXER)              += dauddec.o
 OBJS-$(CONFIG_DAUD_MUXER)                += daudenc.o
 OBJS-$(CONFIG_DFA_DEMUXER)               += dfa.o

libavformat/allformats.c

@@ -88,6 +88,7 @@ void av_register_all(void)
     REGISTER_DEMUXER (CDG,              cdg);
     REGISTER_DEMUXER (CDXL,             cdxl);
     REGISTER_MUXER   (CRC,              crc);
+    REGISTER_MUXER   (DASH,             dash);
     REGISTER_MUXDEMUX(DAUD,             daud);
     REGISTER_DEMUXER (DFA,              dfa);
     REGISTER_MUXDEMUX(DIRAC,            dirac);

libavformat/version.h

@@ -30,8 +30,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 56
-#define LIBAVFORMAT_VERSION_MINOR  6
-#define LIBAVFORMAT_VERSION_MICRO  5
+#define LIBAVFORMAT_VERSION_MINOR  7
+#define LIBAVFORMAT_VERSION_MICRO  0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \