[Ffmpeg-devel-irc] ffmpeg.log.20130621

burek burek021 at gmail.com
Sat Jun 22 02:05:01 CEST 2013


[00:04] <dagerik> sacarasc: 15min
[00:10] <dagerik> -preset ultrafast increased the encoding speed
[06:09] <axorb> hey guys, I'm trying to generate HLS segments on the fly but I'm having trouble getting them to play back nicely with each other
[06:11] <axorb> the segmenter is supposed to run though an entire file and generate all parts at once, but I'm trying to add seek support so the user can generate a part that hasn't been visited yet
[06:12] <axorb> basically, ffmpeg -i input.mov -ss 30 -t 10 output-3.ts
[06:13] <axorb> I want to know if there is something fundamentally flawed with this concept, or if I have to keep trying different settings until VLC/JWPlayer can play my stream properly
[06:13] <axorb> At part boundries JWPlayer stops video (but audio continues), while VLC skips a few seconds of content
[06:17] <axorb> it may seem like a weird approach but I cannot access the file until the user visits the page (so can't pre-encode), and I'd like to add seek support
[06:24] <axorb> NEVERMIND, FINALLY FIGURED IT OUT
[06:24] <axorb> #EXT-X-DISCONTINUITY
[06:25] <elkng> fix your shift key
[06:26] <axorb> sorry, I spent two days on this
[07:04] <t4nk315> hey
[07:06] <t4nk315> avformat_alloc_output_context2(&oc, NULL, "hls", filename);  now how to change the ffmpeg parameters like time wrap list_size
[07:15] <vulture> maybe look for functions that can take an options dictionary
[07:34] <t4nk315> avformat_alloc_output_context2(&oc, NULL, "hls", filename);  now how to change the ffmpeg parameters like time wrap list_size ?
[07:34] <t4nk315> using it to mux audio and video streams .
[08:04] <mootsadog> Hello all
[08:05] <mootsadog> I hope I'm not wasting anyone's time with a dumb question, but it's 1am and I have a throbbing headache, so I'm kinda crossing my eyes at the documentation
[08:06] <mootsadog> I use OS X and need to do a yadif deinterlace on a 50i MPEG2 stream file to make a 50p result.
[08:08] <mootsadog> I'm having trouble figuring out how to tell ffmpeg to filter to an output file. Absolutely nothing else about the video needs to change, just deinterlace 50i -> 50p.
[08:35] <mootsadog> oh yeah, i can tell this is going to do an awesome job. i'm missing something, though, because the output appears to be heavily compressed
[08:36] <mootsadog> Unfortunately the aforementioned headache has overcome me and i have to call it a night. I'll be back around in the morning
[09:11] <vulture> mootsadog: ffmpeg's default is to use very poor quality... you gotta up the bitrate generally to a sane amount
[09:12] <vulture> dunno why the default is set to "bad"
[09:14] <bencc1> I have live RTMP stream which I want to convert to mp3 and broadcast to several clients
[09:15] <bencc1> do I need to call ffmpeg for each connected client or can I use the same mp3 output stream for several clients?
[09:16] <vulture> once
[09:18] <bencc1> vulture: ffmpeg is not a TCP server, right?
[09:18] <bencc1> so I need to pass the mp3 stream to a media server?
[09:28] <vulture> sure
[09:28] <vulture> idk
[09:31] <bencc1> idk?
[09:32] <bencc1> what will be the output? constant stream of packets of mp3 to stdout?
[09:36] <vulture> it has a large variety, whatever you tell it
[09:37] <vulture> I dont know your options.....
[09:37] <t4nk315> avformat_alloc_output_context2(&oc, NULL, "hls", filename);  now how to change the ffmpeg parameters like time wrap list_size
[09:37] <vulture> t4nk315: [00.15.17] <vulture> maybe look for functions that can take an options dictionary
[09:38] <vulture> if you cant find it through one of the context structures
[09:39] <t4nk315> cant find it
[09:40] <vulture> how do you normally specify those parameters
[09:42] <t4nk315> i know how to specify those in  ffmpeg command in  terminal
[09:43] <t4nk315> need to know where to specify it in the Context
[09:44] <vulture> how do you specify them in ffmpeg
[09:45] <vulture> afaik you pass complex options like that through a dictionary
[09:45] <vulture> just search through the context structures for "dict" and surely you'll find structures or functions that take them
[09:45] <t4nk315> k
[09:47] <t4nk315> i coud only find a pointer to option
[09:47] <t4nk315> inside the avclass
[09:53] <xlinkz0> does anyone have experience with receiving a stream from rtmpd ( crtmpserver ) ?
[10:16] <praveenmarkandu> is it better to launch multiple ffmpeg processes or launch just one with multiple file outputs?
[10:24] <t4nk734> hi
[10:30] <Mavrik> praveenmarkandu, one with multiple outputs will make sure you only decode the file once :)
[11:21] <t4nk315> hey
[11:21] <Mavrik> g'day.
[11:22] <t4nk315> I changed the dbl value in the hls_time option in the hls class but no effect
[13:06] <StaRetji1> howdy folks, a quick question if someone can help
[13:07] <StaRetji1> I installed a lot of ffmpeg x264 on ubuntu servers for encoding
[13:07] <StaRetji1> but yesterday I tried again and after installation, I am getting "Unknown encoder 'libx264' even though x264 is compiled, ffmpeg compile with x264
[13:08] <StaRetji1> is there a known bug in git and what could I be doing wrong if I follow guide to the letter, as I always did
[13:09] <JEEB> you are most probably just running the wrong binary
[13:09] <JEEB> `which ffmpeg`
[13:11] <StaRetji1> /usr/local/bin/ffmpeg
[13:12] <JEEB> that looks like a location for a custom build, now it starts sounding like you didn't get ffmpeg compiled with libx264 after all :D
[13:13] <JEEB> `ffmpeg -codecs:v | grep "x264"`
[13:14] <JEEB> ..or you didn't install the ffmpeg binary with libx264 linked in :)
[13:17] <StaRetji1> thank you JEEB http://pastebin.com/gVjWXhvZ
[13:17] <StaRetji1> I was following https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide
[13:17] <StaRetji1> to the work
[13:17] <JEEB> so yeah, that ffmpeg has no x264 linked in
[13:18] <JEEB> also I think that guide now compiles the binary to your home
[13:18] <JEEB> check if you have an ffmpeg binary in ~/bin
[13:23] <StaRetji1> I checked, I have ffplay only
[13:23] <StaRetji1> on ~/bin
[13:24] <StaRetji1> so, I will try to remove all and try again, even though I tried 2 times already :/
[13:26] <JEEB> when you get to configuring ffmpeg itself, just make sure you check the configure script's output :P
[13:26] <JEEB> it should tell you whether or not you have libx264 found and enabled
[14:01] <determinant> hello.
[14:03] <determinant> i want to decode a flac file to wav format and output to stdout from which neroAacEnc can read directly.
[14:03] <determinant> but i don't know how. can anybody help me?
[14:10] <JEEB> ffmpeg -i welp.flac -f wav -
[14:10] <JEEB> something like this
[14:10] <JEEB> I would guess
[14:11] <durandal_1707> use pipe protocol
[14:19] <Mavrik> o yuch
[14:19] <Mavrik> ffmpeg stagefright support is totally broken
[14:20] <StaRetji1> Thx JEEB, I am doing it all over from the begining
[14:20] <StaRetji1> I hope will be okay this time, will watch every bit :)
[14:20] <StaRetji1> btw, should I compile x264 with make or make fprofiled
[14:21] <StaRetji1> will fprofiled give better performance, as I run several ffmpeg threads at the same time
[14:22] <JEEB> you need raw video for fprofiled, and the performance boost you possibly get from fprofiling is very small
[14:22] <JEEB> so just compile and install
[14:22] <StaRetji1> roger that
[14:23] <StaRetji1> thanks once again Jeeb, I am very grateful
[14:25] <LordDoskias> hello, i'm oppening an mpeg2 stream and avformat lib prints this :  mpeg_decode_postinit()
[14:25] <LordDoskias> several times, but in the end i do receive the expected output
[14:25] <LordDoskias> is this something i should be worried about?
[14:27] <durandal_1707> Mavrik: what is broken?
[14:28] <Mavrik> it doesn't even compile for starters and afterwards it expects to be linked to 2.x stagefright lib and after that it's buggy :)
[14:45] <esperegu> anyone has a working example ffserver config for me to create a rtsp stream from a ffmpeg audio stream?
[15:01] <StaRetji1> omg JEEB, clean install, no error, ffmpeg was showing libx264 in enabled encoders, but still the same Unknown encoder 'libx264'
[15:01] <StaRetji1> it was step by step followed in the guide
[15:01] <JEEB> calm down
[15:01] <JEEB> pastebin config.log
[15:01] <StaRetji1> lol
[15:01] <JEEB> and make sure you have tried to run the compiled binary
[15:02] <StaRetji1> config.log, let me look for it
[15:02] <JEEB> as in, you're in the directory where you ran configure and make, and then run dot-slash-ffmpeg
[15:02] <JEEB> ./ffmpeg
[15:02] <JEEB> and try looking at its -codecs:v list for x264
[15:02] <StaRetji1> ffmpeg 2>&1 | head -n1
[15:02] <StaRetji1> ok
[15:03] <JEEB> just make sure you ran the binary you just configured and built
[15:09] <StaRetji1> yes, you are absolutely right
[15:09] <StaRetji1> on new machine, clean, there is ffmpeg in /root/bin/
[15:10] <StaRetji1> and it works :/
[15:12] <JEEB> that isn't what I asked
[15:12] <JEEB> also why the hell are people using ffmpeg as root :s
[15:12] <JEEB> christ
[15:14] <StaRetji1> hate typing sudo lol
[15:16] <JEEB> you should only need root when installing the binary, if and only if you want to install it under a spot that is unavailable to normal users
[15:16] <JEEB> you should not need it when compiling ffmpeg (or its dependencies), nor when using
[15:17] <JEEB> and yes, I usually have a screen window open that has root rights, but I most definitely don't run random crap as root
[15:17] <JEEB> but enough of that, have fun and I don't even know what you've done or doing
[15:18] <StaRetji1> thanks man, whole time I as running wrong ffmpeg (which I was not aware it is installed with apt-get)
[15:19] <StaRetji1> that's why I got unknown libx264
[15:34] <determinant> JEEB: thanks.
[15:57] <xreal> Is this okay to get the flv and transport the stream to mp4?  http://fixee.org/paste/o5vjcyt
[16:40] Last message repeated 1 time(s).
[17:24] <norbert_> hi, question: I'm trying to transcode/re-encode a 25 fps .mod to a 60 fps .mp4; this works fine if I don't use -deinterlace but I need to get rid of the interlaced scan-lines; when I use the following (that is, add -deinterlace), the video speeds up (I don't understand why): ./ffmpeg -r 25 -i in.mod -b 4000k -ab 160k -r 60 -acodec libvo_aacenc -deinterlace out.mp4
[17:24] <norbert_> any suggestions?
[17:24] <norbert_> ffmpeg version N-54023-g6fe419b
[17:25] <norbert_> crazy version number :)
[17:41] <norbert_> wait, I probably need to use it on the input stream
[17:43] <norbert_> will try that; if unsuccessful I'll ask again to see if someone's around; bye
[20:02] <tatshwork> i'm wondering if my encode messed up because i'm getting a strange error with MP4Box
[20:02] <vulture> blame sm5!
[20:03] <tatshwork> what are you doing here :P
[20:03] <tatshwork> when i use MP4Box, i get this error
[20:03] <tatshwork> [avc-h264] invalid nal_size (106456)? Skipping 106452 bytes to reach next start code\n[avc-h264] error: no start code found (2147650100 bytes read out of 7264192457) - leaving
[20:03] <tatshwork> and the mp4 comes out to be 2.6 GiB instead of 6.8 GiB + audio
[20:05] <llogan> why are you using MP4Box?
[20:06] <vulture> tatshwork: I wanted to try to resolve a ffmpeg api problem but apparently it's a design flaw of the library =/
[20:06] <tatshwork> llogan, what do you suggest?
[20:07] <tatshwork> the format of the x264 file is rawvideo (-f rawvideo)
[20:50] <bencc> I'm trying to connect to a local rtmp stream with
[20:50] <bencc> ffmpeg -loglevel debug -i rtmp://127.0.0.1/audio/test -f test.mp3
[20:50] <bencc> the server sends the first handshake response but ffmpeg gives me
[20:50] <bencc> Cannot read RTMP handshake response
[21:20] <knIOO> Quick question, I'm converting uncompressed AVIs down to mkv using x264, currently the command I'm using is basically file.avi -acodec copy -vcodec libx264 -crf 23 out.mkv -- is there any way you guys would recommend improving this for rendering performance?
[21:20] <knIOO> there are so many settings to play with
[21:22] <sacarasc> For encoding speed or playing speed?
[21:23] <knIOO> encoding speed - the video is getting uploaded to a video sharing website and being retranscoded again :(
[21:24] <llogan> knIOO: note that, depending on your input, your output may not be yuv420 and therefore retarded players won't like it.
[21:24] <knIOO> llogan: it's just going to Youtube basically
[21:24] <llogan> i'd change -crf 23 to -crf 18
[21:25] <llogan> and if you want to encode faster then use a faster preset
[21:25] <llogan> https://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide
[21:25] <knIOO> so really crf and preset are the only two settings I need to play with?
[21:25] <knIOO> as in none of the other stuff like trellis or anything like that will significantly impact encoding performance/file size
[21:26] <llogan> the presets deal with that
[21:26] <knIOO> Makes sense, thanks!
[21:26] <llogan> YouTube counts as a retarded player.
[21:27] <llogan> so show your console output to verify that your output is yuv420p, or simply add "-pix_fmt yuv420p" or "-vf format=yuv420p" to be safe
[21:27] <knIOO> I don't think it is funny you should mention that, I seem to remember FRAPS being dumb about that
[21:28] <knIOO> I'll add that to the script though just to be sure, thanks for that!
[21:28] <llogan> i haven't checked YouTube in a while, so maybe it is better lately
[21:30] <xreal> Is this okay to get the flv and transport the stream to mp4?  http://fixee.org/paste/o5vjcyt
[21:55] Action: moot_ returms, wondering if anybody's feeling froggy to help figure out the double-deinterlacing issue he mentioned last night
[21:56] <vulture> was the issue just the speed being better? or what
[22:04] <mootsadog> vulture: i want to go from 50i -> 50p
[22:04] <mootsadog> using yadif with defaults, i get 50i -> 25p
[22:05] <mootsadog> i tried setting r: 50 but it appears to either double frames or just remain at 25p
[22:05] <vulture> is there a deinterlacing algorithm you can set to double lines ?
[22:06] <mootsadog> that's what i'm wondering
[22:09] <llogan> you're parobably using yadif=1 which creates one frame for each field
[22:09] <mootsadog> in the end, what i'm trying to do is go from 50i source material to 24p results
[22:10] <mootsadog> hm, i suppose maybe there's a yadif=2 then?
[22:10] <mootsadog> i'm totally new to ffmpeg
[22:11] <llogan> wait, i've confused myself. using yadif=1 should double the frame rate... i missed your 50i -> 25p
[22:11] <mootsadog> using yadif defaults gives me a 25p output
[22:11] <llogan> see the docs: http://ffmpeg.org/ffmpeg-filters.html#yadif-1
[22:12] <mootsadog> thanks, i hadn't been able to find that previously
[22:12] <mootsadog> sounds like yadif=1 is my winner
[22:14] <xreal> Is this okay to get the flv and transport the stream to mp4?  http://fixee.org/paste/o5vjcyt
[22:31] <mootsadog> llogan: unfortunately the yadif=2 appears to be producing frame-doubled output
[22:41] <mootsadog> can i use yadif 2x with ffmpeg?
[22:46] <xreal> Is this okay to get the flv and transport the stream to mp4?  http://fixee.org/paste/o5vjcyt
[22:49] <burek> xreal, when remuxing, you usually want to keep all your streams intact, so I would advise you to use: ffmpeg -i input.flv -map 0 -c copy output.mp4
[22:49] <burek> btw, you might check http://www.ffmpeg.org/ffmpeg-all.html#rtmp
[22:49] <xreal> burek: but my commandline does the same, normally?
[22:49] <xreal> burek: I think of a generic use :)
[22:50] <burek> and probably use "rtmp_live" too
[22:50] <burek> xreal, you never know until you try and see :)
[22:51] <xreal> burek: rtmp_live means: 1h download time? :)
[22:54] <burek> i dunno, never used rtmp :)
[22:57] <xreal> burek: I'm pretty sad, ffmpeg loses the metadata from rtmp
[22:59] <burek> what do you mean it loses? did you tell ffmpeg to keep it? :)
[23:00] <xreal> burek: how can I ?
[23:02] <burek> try using "-c copy -map 0" instead of "-c:a copy -c:v copy"
[23:06] <xreal> ok
[23:06] <xreal> burek: But I think, librtmp is wrong somehow. rtmpdump works perfectly, ffmpeg only with -re
[23:07] <burek> try using google to see some of ffmpeg rtmp examples, to get a clue how to properly use it
[23:14] <xreal> burek: I did. It download fine, but not faster than realtime. It breaks after 10 seconds.
[23:20] <burek> xreal, if you are viewing a live stream
[23:20] <burek> it's already real-time
[23:20] <burek> you can't read it faster than it arrives
[23:20] <burek> so using -re is pointless
[23:20] <burek> it only makes sense to use with file inputs
[23:20] <xreal> it's no livestream.
[23:22] <burek> http://ffmpeg.org/ffmpeg.html
[23:22] <burek> ctrl+f '-re '
[23:30] <dichotoPangea> Hey people, I've been having some trouble recording my screen with ffmpeg, anyone tell me what all this noise means?  http://pastebin.com/7s7kMADA
[23:30] <vulture> maybe you need to run as root? idk
[23:31] <dichotoPangea> I've run ffmpeg for recording without root before, but I'll try. O.o
[23:32] <dichotoPangea> Nope, same output.
[23:35] <dichotoPangea> Does anyone know an actual command that'll just record my desktop? I don't even need audio.
[23:35] <vulture> I dont use linux sorry :D
[23:36] <sacarasc> dichotoPangea: It means that you're not using ffmpeg, but avconv which is part of Libav.
[23:37] <sacarasc> ^ Read that.
[23:37] <dichotoPangea> flv format would be nice also.
[23:39] <dichotoPangea> Or somewhere I could learn such a command?
[23:41] <llogan> dichotoPangea: we only support ffmpeg here.
[23:41] <dichotoPangea> I'm /trying/ to use ffmpeg.
[23:42] <llogan> by ffmpeg, i don't mean the fake version from libav
[23:42] <llogan> https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide
[23:43] <llogan> or ask in #libav
[00:00] --- Sat Jun 22 2013


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