2017-09-06 14:06 GMT+08:00 Jeyapal, Karthick <kjeya...@akamai.com>: > Hi Steven, > > I am restarting this discussion, just to conclude this thread one way or the > other. Maybe I am not thinking correctly. Here is detailed thinking, on why I > think this patch will not violate HLS spec. > >> if (target_duration <= en->duration) >> target_duration = (hls->flags & HLS_ROUND_DURATIONS) ? >> lrint(en->duration) : get_int_from_double(en->duration); > > As per the above code, target duration will be maximum of all > lrint(en->duration) when HLS_ROUND_DURATIONS is set. > >> if (hls->flags & HLS_ROUND_DURATIONS) >> avio_printf(out, "#EXTINF:%ld,\n", lrint(en->duration)); >> else >> avio_printf(out, "#EXTINF:%f,\n", en->duration); > > As per this code #EXTINF duration will be lrint(en->duration) when > HLS_ROUND_DURATIONS is set. > >>https://tools.ietf.org/html/draft-pantos-http-live-streaming-23#section-4.3.3.1 >> >>4.3.3.1. EXT-X-TARGETDURATION >> >> The EXT-X-TARGETDURATION tag specifies the maximum Media Segment >> duration. The EXTINF duration of each Media Segment in the Playlist >> file, when rounded to the nearest integer, MUST be less than or equal >> to the target duration; longer segments can trigger playback stalls >> or other errors. It applies to the entire Playlist file. Its format >> is: >> >> #EXT-X-TARGETDURATION:<s> >> >> where s is a decimal-integer indicating the target duration in >> seconds. The EXT-X-TARGETDURATION tag is REQUIRED. > > As rightly pointed by you, spec says “The EXTINF duration of each Media > Segment in the Playlist file, when rounded to the nearest integer, MUST be > less than or equal to the target duration”. With this patch this is always > true, and hence there is no violation of spec. > > Maybe I misunderstood and missing out something very obvious. Could you let > me know the situation in which this code will generate target duration lesser > than the EXTINF duration? Thanks for your help.
segment1.ts duration = 4.880000 ROUND is 5, not 4, is it? if its duration = 4.040000 ROUND is 4, the real segment1.ts duration is 4.040000, the safe one is TARGETDURATION = 5, the get_int_from_ double API can make the truely, yes, your patch can make 4.880000 to 5, and make 4.040000 to 4, all solution's TARGETDURATION is INT, but just make safe, i know the lrint API, so that is why have not use it, not i don't know lrint. > > Regards, > Karthick > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
