[Ffmpeg-devel-irc] ffmpeg.log.20140706

[burek]

[08:48] <Dark-knight> where is Zeranoe these days?
[09:53] <Dark-knight> i have a question
[09:53] <Dark-knight> can an MP4 file support more than one audio stream
[09:54] <Dark-knight> say... if i want to watch a video in english and then switch it over to Spanish halfway through the movie?
[10:12] <Dark-knight> i will ask my question again tomorrow
[10:12] <Dark-knight> good day
[11:33] <MarcelvanLeeuwen> Hi!
[11:34] <MarcelvanLeeuwen> if im correct a dts track is not possible in a mp4 /m4v container?
[11:34] <MarcelvanLeeuwen> and also pgs subs?
[11:34] <MarcelvanLeeuwen> Im asking bcause Im not completly sure...
[11:36] <sacarasc> I am pretty sure pgs subs aren't allowed. Not sure about DTS.
[11:37] <MarcelvanLeeuwen> okay then its better to stick with mkv
[11:38] <MarcelvanLeeuwen> I tried the - threads 0 parameter but had no luck
[11:39] <MarcelvanLeeuwen> Cpu usage is still at 15 -20%
[11:43] <MarcelvanLeeuwen> Ive searched for awhile but there is no easy way to convert subtitles to a format mp4/m4v containers allow?
[11:47] <sacarasc> Did you do something like: ffmpeg -threads 0 -i largeinput.mkv -threads 0 other options output.mkv ?
[11:47] <sacarasc> MarcelvanLeeuwen: SubRip or Subtitle Edit (both Windows) should be able to do it.
[11:50] <MarcelvanLeeuwen> Ive tried different options. Im not sure if I put it directly after FFmpeg. I will try&
[11:51] <MarcelvanLeeuwen> Im not on Windows.., heard of both progs.
[11:52] <sacarasc> IIRC, though, PGS are bitmap streams, so after OCRing them, you'll have to check them. \o/
[11:52] <MarcelvanLeeuwen> pfff, that is a lot of work
[11:53] <MarcelvanLeeuwen> and not a guarantee that its faultless
[11:54] <MarcelvanLeeuwen> then the only easy way is to stick with the mkv container
[11:54] <MarcelvanLeeuwen> accepts more formats&
[12:18] <MarcelvanLeeuwen> Also mkv workt great with Plex
[12:20] <MarcelvanLeeuwen> http://pastebin.com/3zQ3un0K
[12:21] <MarcelvanLeeuwen> I use these setting to encode a movie. Somebody any positive criticism?
[14:09] <waressearcher2> is there a way to cut out part of the video ? say the video is 1280x720 and I want square 640x480 from 100,100 to 740x580
[14:10] <waressearcher2> from 100,100 to 740,580 coordinates
[14:10] <sacarasc> -vf crop.
[14:11] <sacarasc> http://ffmpeg.org/ffmpeg-all.html 37.13 on there, and there are examples just after.
[14:11] <sacarasc> But it should be -vf crop=740:580:100:100 I think.
[14:12] Action: debianuser thinks that would be -vf crop=640:480:100:100
[14:13] <sacarasc> Oh, yeah.
[14:13] <sacarasc> Sorry. :D
[14:13] <sacarasc> I've not cropped a video in ages.
[14:13] <waressearcher2> sacarasc: crop=640:480:100:100
[15:09] <zap0> i have some PNG i manage to encode into a MP4.   but the MP4 will not play in web browsers :(
[15:09] <zap0> what voodoo is needed to make a web compatible MP4?
[15:12] <sacarasc> Which browser are you using?
[15:12] <sacarasc> Not all browsers support everything.
[15:13] <zap0> chrome and opera.
[15:14] <sacarasc> Opera doesn't support MP4 on non-mobile.
[15:14] <zap0> ok chrome then.
[15:15] <sacarasc> Are you sure it's Chrome, and not Chromium? Chromium on *nix you have to install a plug in, on other OSs it's unsupported.
[15:15] <Hello71> "mp4" isn't a format
[15:15] <Hello71> http://diveintohtml5.info/video.html
[15:15] <sacarasc> Hello71: It's MPEG4 video in an MPEG4 container.
[15:15] <sacarasc> MP4 is fine to say/.
[15:17] <Hello71> xvid == x264?
[15:18] <zap0> i just don't care what stuff is called....  i want play a video in chrome and optionally opera.
[15:18] <Hello71> then use youtube
[15:18] <zap0> go away troll.
[15:19] <Hello71> mucho raeg
[15:19] <sacarasc> zap0: Opera support VP8 in WebM... Chrome should support everything.
[15:19] <Hello71> all I'm saying is if you don't care about anything, use youtube
[15:20] <Hello71> if you want useful help, articulate your concerns in a useful manner
[15:20] <zap0> ok, so where can i find some ffmpeg settings that make a MP4 that will play in chrome
[15:23] <relaxed_> zap0: maybe, ffmpeg -h muxer=mp4|less
[15:23] <relaxed_> are you using -movflags faststart ?
[15:24] <zap0> me?
[15:24] <relaxed_> yes
[15:24] <zap0> i'm just trying to make a short video, for a browser.
[15:25] <zap0> it's not for "streaming"  per-se    the video will be small/short.  i imagine the browser will load it entirtly before it plays
[15:25] <relaxed_> add -movflags faststart after the input and see if it makes any difference
[15:26] <relaxed_> if that doesn't work pastebin.com your command and all its output
[15:28] <relaxed_> why do you would want to play files locally using a web browser?
[15:29] <zap0> who said anything about locally
[15:29] <relaxed_> I wrongly assumed
[15:59] <debianuser> zap0: I'm curious, how do you want to show it in browser? E.g. do you want to use it with some flash player, or do you want to put it in <video> tag, or maybe you want to <embed> it, or just put <a href=> link pointing to the file?
[15:59] <debianuser> I'm asking because the easiest way for you _may_ be something like: ffmpeg -i file.mp4 file.swf
[16:02] <zap0> nope.   i want mp4 or ogg or webm that i can play in chrome or opera.  in html5.  in a <video> tag.
[16:03] <sfan5> zap0: this might be helpful: https://blog.mediacru.sh/2013/12/23/The-right-way-to-encode-HTML5-video.html
[16:10] <zap0> sfan5, it was not.
[16:11] <sfan5> no?
[16:11] <zap0> it made an mp4.   but it still doesn't play in the browser.
[16:14] <debianuser> It also says how to create "webm" and "ogv"...
[16:14] <debianuser> And the wiki page: https://en.wikipedia.org/wiki/HTML5_video has a table saying, that "ogv"(theora) and "webm"(vp8) should be supported.
[16:23] <zap0> the irony...     chrome plays none of these:  mp4, webm, ogg.     opera plays the webm.
[16:24] <sfan5> the container format says nothing
[16:24] Action: debianuser can't believe chrome can't play webm, but has no chrome around to test...
[16:25] <sfan5> it depends on what codecs are used
[16:25] <sfan5> (except for webm; webm is always vp8 and vorbis)
[16:38] <zap0> chrome is being a bitch it seems.... now it's suddenly playing webm
[16:39] <zap0> i think it thinks it can play mp4 or ogg,  and then just fails.
[16:39] <sfan5> can you paste the ffprobe output for your mp4 and ogg files?
[16:40] <zap0> i'm using command line from  that page above...  ffmpeg -i image%d.png -vcodec libx264 -pix_fmt yuv420p -profile:v baseline -preset slower -crf 18 -vf "scale=trunc(in_w/2)*2:trunc(in_h/2)*2" -movflags faststart movie.mp4
[16:41] <sfan5> that might generate different files based on the versions of libraries and other things
[16:41] <sfan5> the ffprobe output shows what was actually encoded
[16:42] <zap0> i don't have ffprobe,  is  ffmpeg -i x.mp4  OK ?
[16:44] <zap0> sfan5 http://pastebin.com/5RybWPyE
[16:45] <sfan5> a 96x72 video
[16:45] <sfan5> is that right?
[16:46] <Chocola2> Does anyone know why a faststart header set with Mp4box is about half the size of a one set with ffmpeg ?
[16:47] <zap0> sfan5, yes.  it's small.
[16:48] <zap0> ChocolateArmpits, why does it matter?
[16:48] <sfan5> zap0: that file looks ok, it should play fine; can you paste the output for your .ogg file?
[16:51] <zap0> lol.. i had .ogg  in the html, it's .ogv in the filesystem.    chrome and opera now do ogv.
[16:52] <zap0> still can't get mp4 working in chrome or opera.   that might just be cause they don't support it
[16:53] <zap0> ok, so webm and ogv seem to be working..    given a choice which is typically better?
[16:56] <sacarasc> zap0: Are you sure it was Chrome and not Chromium?
[16:57] <zap0> Google Chrome web browser ver 35.0...  for desktop Windows.
[16:57] <sacarasc> http://en.wikipedia.org/wiki/HTML5_video#Browser_support
[16:57] <sacarasc> That shows what everything should support.
[16:57] <sacarasc> H264 in MP4 is the best supported, but further up the page, you can see a bit of code to have different files for different browsers.
[16:58] <zap0> firefox (desktop windows)  played the mp4.    opera and chrome did not.
[17:13] <ChocolateArmpits> zap0, well to a 3 hour long video it means having to loading the header less prior to watching
[17:14] <ChocolateArmpits> With ffmpeg the header is around 6megabytes, while with mp4box's faststart it's around 3.4 megs
[17:14] <zap0> ChocolateArmpits, oh.. what sizes are we talking about?
[17:14] <zap0> ah.
[17:14] <zap0> that is significant.
[17:15] <ChocolateArmpits> I was checking sizes with AtomicParsley if that matters
[17:28] <zap0> my ogv encoding looks terrible..  even when -q is changed to lower values
[17:29] <sacarasc> Theora is poo.
[17:29] <zap0> i'm starting to believe so
[17:30] <zap0> even at -q 1 is aweful
[17:31] <zap0> at -Q 31 it's better..  have i got this backwards?
[17:31] <zap0> isn't -q 1 (better)    -q 31 worse?
[17:31] <sacarasc> It varies with codec, IIRC.
[17:33] <zap0> it varies so much some of them are backwards?
[17:34] <sacarasc> I think so.
[17:34] <zap0> that is quite a retarded situation
[17:36] <Hello71> try https://trac.ffmpeg.org/wiki/x264EncodingGuide etc
[17:43] <debianuser> zap0: It's even worse. Different codecs has different ranges, e.g. for libaac it's recommended -q:a 330
[17:46] <zap0> i upgrade my retard comment to football hooligan retarded.
[17:54] <debianuser> For ogv/theora it seems to be (worst)0..10(best)
[18:22] <zap0> ok thats it...upgrade to Fox News presenter retarded.
[19:12] <stick__> hi
[19:13] <stick__> Is there a way to use "detectvolume" filter with php5-ffmpeg ?
[19:16] <sacarasc> That thing is ridiculously old, out of date and generally poo.
[19:17] <stick__> So what's the alternative ?
[19:17] <sacarasc> Use system() or whatever.
[19:20] <stick__> I tried this : shell_exec("ffmpeg -f lavfi -i amovie=video.mp4, volumedetect");
[19:20] <stick__> But how can I get the result (median volume in db) through php ?
[19:32] <sacarasc> stick__: How would you do it for any other program?
[19:32] <sacarasc> Get the output.
[19:40] <stick__> The output always returns -91db
[20:28] <Dark-knight> i have a question
[20:28] <Dark-knight> can an MP4 file support more than one audio stream
[20:28] <Dark-knight> say... if i want to watch a video in english and then switch it over to Spanish halfway through the movie?
[20:29] <ChocolateArmpits> Just insert more audio tracks
[20:32] <Dark-knight> that didn't answer my question
[20:32] <Dark-knight> let me reprash
[20:33] <sfan5> mp4 supports multiple audio streams IIRC
[20:33] <Dark-knight> if i remux a .mkv with 3 audio streams and a subtitle track, would that work with a .mp4 container and if so, what is the command line?
[20:33] <c_14> ffmpeg -i blah.mkv -map 0 -codec copy out.mp4
[20:34] <Dark-knight> -map 0 copys all the streams right? including the subtitles?
[20:34] <c_14> yes
[20:34] <Dark-knight> ok thanks
[20:35] <sfan5> -map 0 is mainly there for copying attachments too, isn't it?
[20:35] <c_14> It's mainly there if you just want everything.
[20:35] <Dark-knight> what audio/subtitle streams are compatible with a mp4 container?
[20:36] <c_14> https://en.wikipedia.org/wiki/Mp4#Data_streams
[20:43] <MarcelvanLeeuwen> my tv has a maxbitrate of 25Mbps so i wat to use -maxrate 25000 do you also need to set -bufsize if so which value do i need?
[20:50] <ChocolateArmpits> maxrate doesn't describe the maximum bitrate, but how much data is allowed to pass to coded picture buffer per every second
[20:50] <ChocolateArmpits> So to use maxrate it's also important to use bufsize and vice versa
[20:51] <ChocolateArmpits> If only one is described or both aren't then the encoder will decide for itself how much to use
[20:51] <ChocolateArmpits> At least in the case of x264
[20:58] <MarcelvanLeeuwen> so is it usefull to use this to not exceed 25Mbps?
[21:00] <Dark-knight> does it affect the output video at all if i put -copyts in the command line even though the video doesn't have de-sync issues?
[21:26] <Fjorgynn> this is awesome :D
[21:30] <Dark-knight> someone please answer my question
[21:30] <ChocolateArmpits> MarcelvanLeeuwen: Actually it can exceed 25mbps even if set to 25
[21:30] <ChocolateArmpits> You also have to take into account overhead and audio track
[21:31] <ChocolateArmpits> So setting video track to 25mbps will most definitely give you an overall bitrate higher than 25 in the final file
[21:32] <ChocolateArmpits> I suggest to drop a few megabits from the average bitrate
[21:32] <ChocolateArmpits> and not use maxrate of bufsize at all
[21:32] <ChocolateArmpits> or*
[21:33] <ChocolateArmpits> Outside of a set of specific scenarios, like coding for internet streaming or hardware decoding, there's no need to define them
[21:34] <ChocolateArmpits> really
[21:38] <MarcelvanLeeuwen> so you suggested not to use maxrate and bufsize but then encode with ABR and not with CRF
[21:40] <ChocolateArmpits> well in this case it would be psuedo-constant bitrate
[21:41] <MarcelvanLeeuwen> thus add -b:v 20000k
[21:41] <ChocolateArmpits> Do a one pass -b:v
[22:08] <Peter_Occ> I'm trying to decrease the quality of the capture I'm getting from my camera. Why isn't qscale having any effect? Is it placed wrong.?  ffmpeg -f mjpeg -r 8 -i http://@192.168.0.7/video/mjpg.cgi -qscale 10 -r  10 /var/www/html/mcamip/videominute10.mp4
[22:10] <Fjorgynn> :)
[22:13] <stick__> can't find the proper command to get the average audio volume from a video file ... does anyone know ?
[22:15] <Dark-knight> does it affect the output video at all if i put -copyts in the command line even though the video doesn't have de-sync issues?
[22:15] <Dark-knight> the reason im asking is because i want to know if i should just leave -copyts in all of my command line codes just in case the video DOES have a de-sync problem?
[23:25] <Dark-knight> ill ask again tomorrow
[00:00] --- Mon Jul  7 2014