I'm taking a look at moving.c and the mov_write_sidx_tags calls; I'm assuming this is the area of the code that is responsible for this.
However, I'd have to have a way to detect the input streams are audio only; no video tracks. What would be the best way to do that? > On Nov 12, 2018, at 12:11 PM, Ronak <ronak2...@yahoo.com> wrote: > > Hey All, > > I noticed that ffmpeg always seems to generate a SIDX box when it's not > really required for Audio Only content. > > Example command: > > ffmpeg -i atmosTest.mp4 -codec copy -hls_time 0.993 -hls_segment_type fmp4 > -hls_flags single_file -hls_playlist_type vod atmosTestffmpeg.m3u8 > ffmpeg version N-92272-g0e9c01f Copyright (c) 2000-2018 the FFmpeg developers > built with Apple LLVM version 10.0.0 (clang-1000.11.45.2) > configuration: --prefix=/Users/ronakp/ffmpeg_build > --pkg-config-flags=--static > --extra-cflags=-I/Users/ronakp/ffmpeg_build/include > --extra-ldflags=-L/Users/ronakp/ffmpeg_build/lib --extra-libs=-lpthread > --extra-libs=-lm --bindir=/Users/ronakp/bin --enable-libfdk_aac > --enable-libmp3lame --enable-libopus --enable-nonfree > libavutil 56. 20.100 / 56. 20.100 > libavcodec 58. 34.100 / 58. 34.100 > libavformat 58. 19.102 / 58. 19.102 > libavdevice 58. 4.106 / 58. 4.106 > libavfilter 7. 38.100 / 7. 38.100 > libswscale 5. 2.100 / 5. 2.100 > libswresample 3. 2.100 / 3. 2.100 > Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'atmosTest.mp4': > Metadata: > major_brand : mp42 > minor_version : 1 > compatible_brands: mp42dby1isom > creation_time : 2018-09-07T19:17:49.000000Z > Duration: 00:02:40.80, start: 0.000000, bitrate: 769 kb/s > Stream #0:0(und): Audio: eac3 (ec-3 / 0x332D6365), 48000 Hz, 5.1(side), > fltp, 768 kb/s (default) > Metadata: > creation_time : 2018-09-07T19:17:49.000000Z > handler_name : sound handler > Side data: > audio service type: main > [hls @ 0x7fbfc4825c00] Opening 'atmosTestffmpeg.m4s' for writing > [mp4 @ 0x7fbfc4827600] track 0: codec frame size is not set > Output #0, hls, to 'atmosTestffmpeg.m3u8': > Metadata: > major_brand : mp42 > minor_version : 1 > compatible_brands: mp42dby1isom > encoder : Lavf58.19.102 > Stream #0:0(und): Audio: eac3 (ec-3 / 0x332D6365), 48000 Hz, 5.1(side), > fltp, 768 kb/s (default) > Metadata: > creation_time : 2018-09-07T19:17:49.000000Z > handler_name : sound handler > Side data: > audio service type: main > Stream mapping: > Stream #0:0 -> #0:0 (copy) > Press [q] to stop, [?] for help > size=N/A time=00:02:40.76 bitrate=N/A speed= 397x > video:0kB audio:15075kB subtitle:0kB other streams:0kB global headers:0kB > muxing overhead: unknown > > When you look at the generated .m4s file, you will see ftyp, moov, followed > by a collection of sidx, moof and mdat atoms. > > > However, when I run a similar command using Apple's Tooling: > > > a45e60e46a79:Dolby ronakp$ mediafilesegmenter -a -r -s atmosTest.ec3 > Nov 12 2018 11:58:52.713: ISO fragmented mode, forcing segments to start with > I-Frame > Nov 12 2018 11:58:52.714: Processing file > /Users/ronakp/Desktop/Dolby/atmosTest.ec3 > Nov 12 2018 11:58:52.743: Wrote 0 to 578 to main.mp4 > Nov 12 2018 11:58:52.748: Wrote 578 to 959266 to main.mp4 > Nov 12 2018 11:58:52.749: segment bitrate 768.18 kbits/sec is new max > Nov 12 2018 11:58:52.756: Wrote 959266 to 1917954 to main.mp4 > Nov 12 2018 11:58:52.763: Wrote 1917954 to 2876642 to main.mp4 > Nov 12 2018 11:58:52.772: Wrote 2876642 to 3835330 to main.mp4 > Nov 12 2018 11:58:52.777: Wrote 3835330 to 4794018 to main.mp4 > Nov 12 2018 11:58:52.784: Wrote 4794018 to 5752706 to main.mp4 > Nov 12 2018 11:58:52.793: Wrote 5752706 to 6711394 to main.mp4 > Nov 12 2018 11:58:52.800: Wrote 6711394 to 7670082 to main.mp4 > Nov 12 2018 11:58:52.880: Wrote 7670082 to 8628770 to main.mp4 > Nov 12 2018 11:58:52.924: Wrote 8628770 to 9587458 to main.mp4 > Nov 12 2018 11:58:52.966: Wrote 9587458 to 10546146 to main.mp4 > Nov 12 2018 11:58:52.973: Wrote 10546146 to 11504834 to main.mp4 > Nov 12 2018 11:58:53.017: Wrote 11504834 to 12463522 to main.mp4 > Nov 12 2018 11:58:53.060: Wrote 12463522 to 13422210 to main.mp4 > Nov 12 2018 11:58:53.102: Wrote 13422210 to 14380898 to main.mp4 > Nov 12 2018 11:58:53.147: Wrote 14380898 to 15339586 to main.mp4 > Nov 12 2018 11:58:53.147: Wrote 15339586 to 15441066 to main.mp4 > Nov 12 2018 11:58:53.147: segment bitrate 768.24 kbits/sec is new max > Nov 12 2018 11:58:53.147: Unknown video dynamic range value 0 > Nov 12 2018 11:58:53.147: average bit rate is 768.21 kbits/sec - max file bit > rate is 768.24 kbits/sec > > It generates a file without any SIDX atoms; only ftyp, moov & a collection of > moof & mdat atoms. > > Why does ffmpeg do this? How hard would it be to remove this behavior from > ffmpeg? > > Thanks, > > Ronak > > > > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".