avformat/movenc: mov/mp4 should support negative timestamps through edit lists

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/movenc.c

@@ -3954,7 +3954,7 @@ AVOutputFormat ff_mov_muxer = {
     .write_header      = mov_write_header,
     .write_packet      = mov_write_packet,
     .write_trailer     = mov_write_trailer,
-    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH,
+    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH | AVFMT_TS_NEGATIVE,
     .codec_tag         = (const AVCodecTag* const []){
         ff_codec_movvideo_tags, ff_codec_movaudio_tags, 0
     },
@@ -3973,7 +3973,7 @@ AVOutputFormat ff_tgp_muxer = {
     .write_header      = mov_write_header,
     .write_packet      = mov_write_packet,
     .write_trailer     = mov_write_trailer,
-    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH,
+    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH | AVFMT_TS_NEGATIVE,
     .codec_tag         = (const AVCodecTag* const []){ codec_3gp_tags, 0 },
     .priv_class        = &tgp_muxer_class,
 };
@@ -3992,7 +3992,7 @@ AVOutputFormat ff_mp4_muxer = {
     .write_header      = mov_write_header,
     .write_packet      = mov_write_packet,
     .write_trailer     = mov_write_trailer,
-    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH,
+    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH | AVFMT_TS_NEGATIVE,
     .codec_tag         = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
     .priv_class        = &mp4_muxer_class,
 };
@@ -4027,7 +4027,7 @@ AVOutputFormat ff_tg2_muxer = {
     .write_header      = mov_write_header,
     .write_packet      = mov_write_packet,
     .write_trailer     = mov_write_trailer,
-    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH,
+    .flags             = AVFMT_GLOBALHEADER | AVFMT_ALLOW_FLUSH | AVFMT_TS_NEGATIVE,
     .codec_tag         = (const AVCodecTag* const []){ codec_3gp_tags, 0 },
     .priv_class        = &tg2_muxer_class,
 };