[Ffmpeg-devel-irc] ffmpeg.log.20130127

burek burek021 at gmail.com
Mon Jan 28 02:05:01 CET 2013


[00:00] <ulatekh> kdenlive didn't recognize .nut
[00:01] <ulatekh> huffyuv with .mov produced garbage output!  It was kind of entertaining...I might use it later if I need brightly colored static for an effect :-)
[00:04] <ulatekh> HuffYUV and a Matroska container produces a clip that identifies itself as progressive, i.e. the interlacing info was lost.
[00:07] <beastd> ulatekh: might be easier to tackle the problem the other way around. e.g. try to find a list / set  of formats kdenlive accepts, then try to see what of those can be generated by ffmpeg and is sufficiently compressed.
[00:08] <beastd> ulatekh: you might need to find out what kdenlive uses to read the files to come to a somewhat complete answer
[00:08] <ulatekh> I have an open request on kdenlive-devel for a list of supported formats.  I wasn't able to figure out how that was determined by reading the source code.
[00:10] <ulatekh> FFV1 and a Matroska container produces a clip that identifies itself as progressive, i.e. the interlacing info was lost.  I guess I can add that to my bug report.  At least I have one container format & two pixel formats working for my raw video.
[00:16] <ulatekh> Score!  "-vcodec ffv1" and a .mov container preserved interlacing AND was accepted by kdenlive!  Hot dog, we have a weiner!
[00:17] <wind_> Hi all, i am trying to burn or add subtitles to an avi file i am doing this: ffmpeg -i video.avi -vf subtitles=subtitle.srt out.avi , but  in the output i am not getting any subtitle
[00:25] <Keyboard_Warrior> ulatekh, in a more perfect world
[00:25] <Keyboard_Warrior> interlacing would never have existed
[00:25] <Keyboard_Warrior> and it definitly never would have been including in any modern day digital formats
[00:25] Action: Keyboard_Warrior cries his eyes out
[00:27] <ulatekh> Yeah, well, that's what my miniDV camcorder produces, and it's what DVD-video uses, so I gotta deal with it...and so should ffmpeg :-)
[00:27] <beastd> wind_: can you show us the full output of your command on pastebin?
[00:28] <wind_> yeah sure give me 5 min
[00:29] <Keyboard_Warrior> ulatekh, dvd can be progressive
[00:29] <Keyboard_Warrior> dvd supports soft-interlacing or whatever the technical term i
[00:32] <ulatekh> I've never gotten 24000/1001 fps DVDs to work on all players...several of them stutter horribly on such input.
[00:33] <ulatekh> AFAIK, interlacing exists because of 1950s TV-camera technology.
[00:34] <Keyboard_Warrior> ulatekh, theres a broadcast/bandwidth issue
[00:34] <Keyboard_Warrior> aswell
[00:34] <Keyboard_Warrior> ulatekh, dvd players SHOULD support soft-telecine
[00:34] <wind_> Here it is: http://pastebin.com/embed_js.php?i=wmsEjiTD
[00:35] <Keyboard_Warrior> http://en.wikipedia.org/wiki/Telecine#Soft_and_hard_telecine ulatekh
[00:36] <Keyboard_Warrior> ulatekh, but yeah, even today, interlacing is a big part of our lives.
[00:36] <Keyboard_Warrior> the h264 standard has a TON of provisions for interlacing
[00:36] <Keyboard_Warrior> including a special encoding mode to allow interlacing on indiidual macroblocks
[00:38] <ulatekh> Ah yes..."soft telecined" is what I produce if I'm encoding the video from raw input.  mpeg2enc does 3:2 pulldown.  The last time I checked, ffmpeg didn't do soft telecine.
[00:39] <ulatekh> Oh...I mean 2:3 pulldown...duh
[00:45] <beastd> wind_: seems sth goes wrong. how does the playback look if you replace ffmpeg with ffplay and drop out.avi from that line?
[00:45] <Keyboard_Warrior> ulatekh, soft telecine is where the actual video data is progressive but theres flags in the video file explaining how to telecine it
[00:45] <Keyboard_Warrior> HARD telecine is where the actual videodata is progressive, but you apply a 2:3 pulldown to make it interlaced before encoding
[00:46] <Keyboard_Warrior> ofcourse, both these are different from actual interlaced content
[00:46] <Keyboard_Warrior> http://mod16.org/hurfdurf/?p=12 ulatekh
[00:47] <ulatekh> "mpeg2enc -p" produces soft telecine...sorry about my sloppiness with terms.
[00:50] <wind_> beastd: i run the command on a laptop where the screen is broken and on my local laptop i haven't ffplay
[00:52] <beastd> oh
[00:53] <wind_> any other tip ?
[00:54] <beastd> wind_: sorry. can't think very clearly atm. but wait a bit. maybe sth comes to mind
[01:03] <wind_1> i am trying with the mencoder now
[01:07] <beastd> wind_1: wind_1
[01:07] <beastd> wind_1:  maybe a problem with your fonts/fontconfig ?
[01:08] <wind_1> how to troubleshoot ?
[01:09] <beastd> wind_1: btw what language is the text contained in your srt file?
[01:09] <wind_1> Greek
[01:27] <beastd> wind_1: could be the chars you need are not in the font that got selected. maybe try to edit a copy of the subtitle file to contain some lating characters in e,g, the first sub. then use that as input and see if the latin part got rendered
[01:35] <wind_1> ok i ll try this tomorrow thank you , good night
[10:55] <Fjorgynn> what is H.265?
[10:55] <Fjorgynn> http://techcrunch.com/2013/01/25/h265-is-approved/
[11:01] <Fjorgynn> käften
[11:01] <Fjorgynn> So what should we think about this?
[12:55] <antonello> hallo i must use swr_convert but my RUN FAILED ..... I don't know why . I have encoder and decoderContex and i set encoder parameters by decoder parametrs , after alloc the SwrContext using the two context . My code is http://pastebin.com/GXjjcWNP line 440-458
[15:47] Last message repeated 1 time(s).
[16:24] <saste> antonello, did you have a look at doc/examples/resampling.c?
[16:24] <saste> you use of the API is fishy to me
[16:25] <saste> for example you open the encoder, *then* you set fields on it
[16:25] <saste> that should be avoided, unless you know what you're doing
[16:26] <saste> also audio samples buffers are tricky to deal with, that's why i pointed to the example
[17:08] <wind_> Trying to burn subtitles using ffmpeg didn't work: http://pastebin.com/G5xPmzCp#. However trying to play it with ffplay it complains "fontconfig: Selected font isnot the requested one: 'Liberation Sans != 'Arial' " and the movie playes with subtitles
[17:08] <wind_> Any idea ?
[17:12] <saste> wind_, that seems regular font-mess, not strictly related to ffmpeg code
[17:12] <klaxa> the error message is actually just a warning
[17:12] <klaxa> ... or not?
[17:13] <saste> also as klaxa wrote it is a warning, so you *may* be able to burn the subs, more or less
[17:13] <wind_> Yeah it could be a warning but the final output avi fle doesn't contain any subtitles...
[17:14] <klaxa> i get those messages a lot with mplayer2, however the fonts appear correct nonetheless
[17:14] <wind_> i want to burn the subtitles in order to play the movie on the TV from a USB disk and not using any player like VLC or mplayer
[19:11] <killown> actually I am using this ffmpeg -f alsa -ac 2 -i pulse -f x11grab -s hd1080 -r 24 -i :0.0 -vcodec libx264 -preset ultrafast -an -y video.mkv -acodec pcm_s16le -b:a 48000k -vn  -y audio.mkv  to grab x11, what could I do to encode it in 1080p and making ffmpeg requires less I/O  and CPU?
[19:16] <killown> I guess the problem is the preset
[19:17] <killown> using -preset fast would requires less I/O and more CPU
[19:17] <killown> rather than ultrafast
[22:33] <simon___1> exit
[00:00] --- Mon Jan 28 2013


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