I have a hls playlist playlist.m3u8 file where the url's of all the chunks are there.
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:10,
01-0.ts
#EXTINF:10,
01-1.ts
#EXTINF:10,
01-2.ts
#EXTINF:10,
01-3.ts
#EXTINF:10,
01-4.ts
#EXTINF:10,
01-5.ts
#EXTINF:10,
01-6.ts
#EXTINF:10,
01-7.ts
Even if I change the media sequence no to , say 5, it always plays from the start. Is there anyway that I can play the content from any given point i.e not always from the start ? Please help me.
If you want to keep all the segments in the playlist you can use the optional tag #EXT-X-START:TIME-OFFSET=<seconds>. This is available in version 6 of the protocol.
Source: https://datatracker.ietf.org/doc/html/draft-pantos-http-live-streaming-12#section-3.4.16
Related
Update:
I have a video player in browser which plays mp4 videos though websocket. The player only supports mp4 file. When i checked normal mp4 fiels does not play in the player, a mp4 file with a "moovflags faststart " will only play on that player. For a allready stored file , this will work properly.
But In case of an livestream(RTSP), using ffmpeg will only work once the RTSP connection has terminated since the "moovflags faststart " flags will work once a connection has terminated properly.
Hope the above statements makes more sense.
Due to this behavior, am checking if there is any way to get the moovflasg at first or something
I am having RTSP live source and i need it to convert the RTSP to a mp4 file which has moov flags in the begining of the file.
I have checked with openrtsp to take a mp4 dump of the rtsp, but it only adds moov flags and other info on the footer of the mp4(onlky when openrtsp has closes the rtsp stream).
Ffmpeg has " -movflags faststart" to move the footer info to the header of the mp4 container.
Since i am having a RTSP live source, the video data will be comming back to back and there wont be any termination. The above ffmpeg command only works once the rtsp stream has terminated.
Is there any way we can make a mp4 container which contains the mp4 footer info present in the header itself so that i can use it for a live source?
EDIT #1
I have video player which plays mp4 video files , it only support playback of a recorded mp4 file which is createtd using "-movflags faststart" , normal mp4 files does not play in that.
This is the player
https://github.com/sonysuqin/WasmVideoPlayer.
Since i am tryng to stream live video to the player, its not possible to use movflags faststart.
The mp4 header can not be added to the file before it is complete. It’s not possible because of how mp4 files are structured. The header needs to know the frame type, timestamp, size, and file offset of every frame in the file. That can’t be known until the file is complete. You can not stream an mp4 while it is being created. You need to use a protocol such as HLS or DASH to accomplish this.
I want to fetch hls video segments by time interval.
Suppose I have seg1.m4s / seg2.m4s ..., and each seg is 1 minutes long and size is 10000 bytes.
If I want to play from 1:30 ~ 3:30, it means the hls would start from middle of seg2 to middle of seg4.
This why I would need to dynamic generate m3u8 list and EXT-X-BYTERANGE.
However I encounter some problem.
Here is my m3u8 list now
#EXTM3U
#EXT-X-VERSION:7
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:VOD
#EXT-X-ALLOW-CACHE:YES
#EXT-X-MAP:URI="init.mp4",
#EXTINF:30.0,
#EXT-X-BYTERANGE:5000#5000,
seg2.m4s
#EXTINF:60.0,
seg3.m4s
#EXTINF:30.0,
#EXT-X-BYTERANGE:5000#0,
seg4.m4s
#EXT-X-ENDLIST
It would play only seg2.m4s and stop.
the question is:
in different level playlist who have the same sequence number, MUST they present the same content(e.g. both level1-fileSequence2.ts, level2-fileSequence2.ts duration is 10:00:00-10:00:10) ?
OR for thest different level's ts file, if they present the same period content, must they have the same sequence number?
playlist
#EXTM3U
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=150000,RESOLUTION=416x234, \
CODECS="avc1.42e00a,mp4a.40.2"
level1.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=240000,RESOLUTION=416x234, \
CODECS="avc1.42e00a,mp4a.40.2"
level2.m3u8
level1.m3u8
#EXTM3U
#EXT-X-TARGETDURATION:10
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:1
#EXTINF:10,
level1-fileSequence1.ts
#EXTINF:10,
level1-fileSequence2.ts
level2.m3u8
#EXTM3U
#EXT-X-TARGETDURATION:10
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:2
#EXTINF:10,
level2-fileSequence2.ts
#EXTINF:10,
level2-fileSequence3.ts
Not necessarily, for both questions.
As a quick note, the name of the file doesn't matter at all. From the HLS specification:
A client MUST NOT assume that segments with the same Media Sequence
Number in different Variant Streams or Renditions have the same
position in the presentation; Playlists MAY have independent Media
Sequence Numbers. Instead, a client MUST use the relative position
of each segment on the Playlist timeline and its Discontinuity
Sequence Number to locate corresponding segments.
Source: HLS Draft
I have an HLS playlist of type EVENT. It has the #EXT-X-PLAYLIST-TYPE:EVENT tag. The playlist is not finished. It does not have an #EXT-X-ENDLIST tag.
When I play the playlist in Quicktime, it doesn't allow me to seek around. Since this is an event playlist, all the previous segments are available. Quicktime should have everything it needs to seek back.
I have tried this on OS X 10.6 and Maverick and the problem occurs. I have also tried this on an old iPad running iOS 5. On iOS 5 the problem doesn't occur.
Here is the playlist itself:
#EXTM3U
#EXT-X-VERSION:6
#EXT-X-ALLOW-CACHE:NO
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:EVENT
#EXT-X-START:TIME-OFFSET=0,PRECISE=NO
#EXT-X-TARGETDURATION:10
#EXTINF:10,
live_robocop_hd-rate_01_6512.ts
#EXTINF:10,
live_robocop_hd-rate_01_6513.ts
#EXTINF:10,
live_robocop_hd-rate_01_6514.ts
#EXTINF:10,
live_robocop_hd-rate_01_6515.ts
# ... more segments here ...
I have an album stored as a list of gapless m4a files, ripped from CD. I need to stream the album gaplessly over HTTP Live Streaming, and the user must be able to "jump in" at the start of any track. For now, my only client is AVPlayer on iOS.
I can segment the tracks individually using Apple's mediafilesegmenter tool. For each track, this produces one .m3u8 playlist file and several .aac segment files, each ~10 seconds in duration except for the last.
The m3u8 playlist for Track 1 looks like this:
#EXTM3U
#EXT-X-TARGETDURATION:11
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:10.001,
segment0.aac
#EXTINF:9.983,
segment1.aac
...
#EXTINF:3.231,
segment23.aac
#EXT-X-ENDLIST
I can combine these m3u8 playlist files into one master m3u8 file for the album:
#EXTM3U
#EXT-X-TARGETDURATION:11
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:10.001, // begin track 1
segment0.aac
#EXTINF:9.983,
segment1.aac
...
#EXTINF:3.231,
segment23.aac
#EXT-X-DISCONTINUITY
#EXTINF:10.001, // begin track 2
segment24.aac
#EXTINF:9.983,
segment25.aac
...
#EXTINF:6.845,
segment46.aac
#EXT-X-DISCONTINUITY
#EXTINF:10.001, // begin track 3
segment47.aac
#EXTINF:9.983,
segment48.aac
...
#EXTINF:8.012,
segment80.aac
#EXT-X-ENDLIST
It will play through the whole album, but it isn't gapless. Notice the DISCONTINUITY tag between each track (without it, the player hangs forever). This introduces a small gap between tracks, maybe 300 milliseconds.
How can I create segments that flow into each other with no discontinuity?
You can concatenate the AAC files before using the mediafilesegmenter tool on the combined AAC file.
The following ffmpeg command might generate the output file.
ffmpeg -i "concat:input1.aac|input2.aac|input3.aac" -c copy output.aac
It's possible you'll need to remux the aac files to mpeg2ts files before concatenation, and then remux the mpeg2ts file to AAC.