[Ffmpeg-devel-irc] ffmpeg.log.20141225

[burek]

[00:16] <zenny> Hi: I am getting "ALSA buffer xrun" and the audio capture to the computer not only jitters but dies in a few seconds. Please help. Whining for two days to fix this.
[00:17] <klaxa> for me that was pretty much unfixable, running pulse on top of alsa eliminates the issue
[00:18] <klaxa> if that is no option, i have no perfect answer
[00:19] <klaxa> zenny: ^
[00:19] <zenny> klaxa, I am on ubuntu 14.04, I guess pulse is running on top of alsa. It records alright with audacity, but not only with ffmpeg.
[00:19] <klaxa> use -f pulse -i default instead of -f alsa -i hw:0,0
[00:19] <zenny> klaxa: how did you resolve that?
[00:22] <zenny> just a sec
[00:29] <zenny> klaxa, -f pulse -i default worked with the built in mic in the laptop, not with the external microphone connected to the sound input of the laptop.
[00:29] <klaxa> use pavucontrol to set the record device
[00:30] <vlatkozelka> hello ... anyone knows what encoding supports playing in fast reverse ? i was making a media player with a java wrapper for ffmpeg , and the best fast reverse i could acheive was some choppy jump to postion playback ... but ive seen programs that play videos fluently in fast reverse , so i wonder if it depends on encoding and such ...
[00:30] <klaxa> there is a tab called "recording"
[00:30] <klaxa> you have to have ffmpeg running and recording to select the record device
[00:30] <Fjorgynn> :)
[00:30] <klaxa> vlatkozelka: intraframe only codecs should be good at that
[00:31] <vlatkozelka> intraframe codecs ?
[00:31] <vlatkozelka> if possible i need something that can be saved to files ( if im making sence at all )
[00:32] <vlatkozelka> atm i have mpeg2-ts  *.ts files ... what should i transcode these to ?
[00:33] <klaxa> if you can encode the videos yourself, maybe encoding to h264 with libx264 and intra-frame only coding it should work rather well
[00:33] <klaxa> try: ffmpeg -i in.ts -c:v libx264 -g 1 -c:a copy out.mkv
[00:33] <klaxa> i'm not sure if this is the most optimal thing to do
[00:33] <klaxa> the file will get a lot bigger too i think
[00:34] <vlatkozelka> well the ts files im recording myself from a udp stream
[00:35] <vlatkozelka> i can encode to whatever i want and the server is quite powerfull , also no trouble with storage
[00:35] <vlatkozelka> ill give it a try
[00:36] <zenny> klaxa: thanks, but when I plugged the external microphone and started pavucontrol it states it had two options, internal microphone and the "microphone unplugged". Chosen microphone unplugged without any results.
[00:36] <klaxa> check the input devices tab
[00:37] <zenny> In the input devices tab, there are two options, internal microphone and microphone (unplugged).
[00:38] <klaxa> well... can you record it in another way?
[00:38] <petri6890> muchos gracias
[00:38] <klaxa> you said you could record with audacity?
[00:38] <zenny> yes
[00:38] <vlatkozelka> klaxa, what is the -g for ?
[00:38] <klaxa> can you record with audacity and check pavucontrol?
[00:38] <zenny> with audacity without problem, but not with fmpeg in command line
[00:38] <klaxa> group of pictures
[00:39] <Fjorgynn> :o
[00:39] <klaxa> actually, use -g 0
[00:39] <klaxa> it says so in the manual that that is what you want
[00:39] <vlatkozelka> does it have to be mkv ?
[00:40] <klaxa> no
[00:40] <vlatkozelka> cant i .ts ?
[00:40] <klaxa> probably
[00:40] <klaxa> just try it out :)
[00:40] <vlatkozelka> i will ...
[00:40] <vlatkozelka> but my program filters out .ts files
[00:40] <vlatkozelka> now i have to plunge into source code ive written ages ago :P
[00:41] <zenny> klaxa: it was possible before I installed pavucontrol, but now audacity also cannot do so.
[00:41] <klaxa> eeh? that's weird.
[00:42] <klaxa> well unplugged kinda states that it's not plugged in (duh) but i assume you have checked all the cables already?
[00:43] <zenny> Yep, all cables are alright.
[00:48] <vlatkozelka> klaxa , thanks alot man , it worked wonders ... i just played it in fast reverse 16X clear as water :)
[00:50] <zenny> klaxa: thanks, I removed pavucontrol and it seems to have been working. Thanks a lot, man.
[01:23] <zenny> klaxa: using -f pulse -i default captures the sound for a while but gives "Alsa buffer xrun" problem again after a while.
[01:46] <zenny> while capturing with ffmpeg how does one specify the bitrate and frequency of the audio capture?
[01:50] <c_14> zenny: input or output?
[01:51] <c_14> input should be pcm, you can set freq with -ar as an input option (usually)
[02:12] <zenny> Hi, I am having problem to capture with ffmpeg. It stops capturing after a while. The ffmpeg log is at: http://pastebin.geany.org/TSq50/ Any help appreciated.
[02:21] <zenny> Hi I am having trouble to capture, ffmpeg freezes after a few minutes of capture. Detail ffmpeg log is at http://pastebin.geany.org/TSq50/ This is indeed causing irritation.
[04:16] <Jan\> how do i run the server on windows? i dont see a ffserver binary
[16:01] <Dr_Radium> what is best aac encoder
[16:02] <JEEBsv> available from ffmpeg currently the best is something you cannot distribute as binaries
[16:02] <JEEBsv> fdk-aac
[16:02] <Dr_Radium> jeebsv what is second best
[16:03] <JEEBsv> I'm actually not sure if patched ffaac or the non-distributable faac (ffaac is the internal aac encoder, and faac is a thing based on the reference implementation)
[16:03] <JEEBsv> are better :V
[16:04] <JEEBsv> ffaac is kind of OK even without the patches and can be distributed
[16:04] <JEEBsv> patched with the stuff in the longest thread on the trac it should be even better
[16:04] <Dr_Radium> which one is "aac-avcodec" ?
[16:04] <JEEBsv> that is not called like that in ffmpeg or lavc
[16:04] <Dr_Radium> what is it called
[16:04] <JEEBsv> but probably that means the "aac" encoder in lavc, which is what I called ffaac
[16:05] <Dr_Radium> The LibAV AAC encoder is now the default as FAAC has been removed.
[16:05] <JEEBsv> yes, it means ffaac then
[16:05] <JEEBsv> which is a shorthand for the libavcodec internal aac encoder
[16:05] <Dr_Radium> i am so confused
[16:05] <Dr_Radium> why the name change
[16:06] <JEEBsv> it hasn't been changed :P
[16:06] <JEEBsv> it's just that when you have multiple things doing the same format, you usually call the internal one ff*
[16:06] <Dr_Radium> libav-aac = faac ?
[16:06] <JEEBsv> no
[16:06] <JEEBsv> one f = non-distributable external library that has a wrapper in lavc
[16:07] <JEEBsv> two f = internal to libav* (-codec/-format/-whatever)
[16:08] <Dr_Radium> is x265 much better than x264 ?
[16:08] <JEEBsv> it's only somewhat better in very low bit rate scenarios, where both look bad
[16:08] <JEEBsv> and x265 just looks better than x264
[16:08] <JEEBsv> if you raise the bit rate, x264's psychovisual optimizations are still much better than x265's
[16:09] <JEEBsv> format does not equal implementation, and x264 is one damn fine implementation :3
[16:09] <Dr_Radium> what about in "constant quality" nobody uses  bitrate anymore
[16:10] <JEEBsv> there's no constant quality, but there is CRF. and I meant the scenario which is the same regardless of the rate control mode
[16:12] <JEEBsv> I'm probably going to test it again soon'ish because they made some improvements, but to be honest I'm not expecting them to beat x264 at my use cases yet :)
[16:12] <JEEBsv> that said, the very low rate scenarios do look promising
[16:13] <Dr_Radium> but h265 is superior
[16:13] <JEEBsv> yes
[16:13] <JEEBsv> as I said, format does not equal implementation
[16:13] <JEEBsv> MCW will have to work their asses off to beat x264 :P
[16:13] <JEEBsv> they will be helped by the fact that HEVC is better than AVC
[16:13] <Dr_Radium> what is mcw?
[16:13] <JEEBsv> the company doing x265
[16:14] <Dr_Radium> i see
[16:14] <JEEBsv> multicoreware
[16:14] <Dr_Radium> what about other h265 encoders?
[16:14] <JEEBsv> they are all worse than x265 at the moment
[16:14] <JEEBsv> so if you need to test HEVC, I recommend x265
[16:14] <Dr_Radium> jeebsv are you being fair or just being bias
[16:14] <JEEBsv> there is no reason for me to be biased
[16:15] <Dr_Radium> jeebsv freenode people are very bias to  freeware/opensource
[16:15] <Dr_Radium> you cannot deny that
[16:15] <JEEBsv> well yes, but unfortunately I had some friends over at video-related corps testing proprietary HEVC encoders
[16:15] <JEEBsv> so far none of them were better than x265
[16:16] <Dr_Radium> okay, what is second best then
[16:16] <JEEBsv> which is not surprising because very few proprietary AVC encoders were better than x264
[16:16] <JEEBsv> and those that were usually were really hard to get for "normal" amounts of money
[16:16] <Dr_Radium> why do you think  x264/x265 are really far ahead  compared to others then?
[16:17] <JEEBsv> x265 because everyone else just happens to suck more, with x264 it was the actual relatively quick development compared to the corporates
[16:17] <JEEBsv> x265 is pretty much corporate software, it just happens to be GPL licensed
[16:18] <JEEBsv> and to be honest I'd love it if there were alternative encoders available, proprietary or not
[16:18] <Dr_Radium> is x264 pretty much corporate software too?
[16:18] <JEEBsv> no
[16:18] <Dr_Radium> i see
[16:18] <JEEBsv> it had and still has a community
[16:18] <Dr_Radium> how did x265 became corporate but not x264
[16:19] <JEEBsv> because a company made a deal with x264 LLC to license the brand?
[16:19] <JEEBsv> and they named their encoder "x265"
[16:20] <JEEBsv> and they did also get the right to use the code if they wanted, of which they have used some
[16:28] <Dr_Radium> has vp codec caught up to x264 ?
[16:29] <JEEBsv> the vp9 format in theory is better than AVC (d'oh, it has grabbed a lot of things out of HEVC), and while in theory you could get better results with slow settings... libvpx's implementation is pretty much like the reference implementation of HEVC :P
[16:29] <JEEBsv> aka "slow as fuck"
[16:30] <JEEBsv> it also lacks any type of threading
[16:30] <Dr_Radium> i see
[16:30] <Dr_Radium> what about theora ?
[16:32] <JEEBsv> theora hasn't been developed for years
[16:32] <JEEBsv> I remember derf telling me he should fix a bug there last year, and I think that's still not fixed 8)
[16:32] <Dr_Radium> why did they stop
[16:33] <JEEBsv> theora is just not worth working on really, there are plenty of more interesting projects
[16:33] <JEEBsv> and more useful ones
[16:33] <JEEBsv> it was lagging related to MPEG-4 Part 2, and it's even more lagging related to AVC and HEVC. And even the Google VPx formats
[16:34] <Dr_Radium> VPx has really improved a lot. that number is keep increasing every year
[16:34] <Dr_Radium> google owns VPx now?
[16:34] <Dr_Radium> not ON2 ?
[16:34] <JEEBsv> Google bought On2 in like 2010 or so
[16:35] <Dr_Radium> and did google make VP better than on2 ?
[16:36] <JEEBsv> so far the only VP format that was done under Google has been VP9, and that is indeed better than VP8, but it still follows a very similar format
[16:36] <JEEBsv> you take the ISO/IEC format, then take some things out of it and modify some things for it to not be exactly the same
[16:37] <JEEBsv> with vp8 it was AVC, with vp9 it is HEVC
[16:37] <JEEBsv> and as I saw, Google really isn't interested in pushing their format outside their bubble
[16:37] <JEEBsv> one of the ways to note that is by seeing the fact that vp9 encoding never got multithreaeding
[16:38] <JEEBsv> Youtube doesn't really need it, as live video is not going to be encoded with it
[16:38] <JEEBsv> and for normal clips they just encode in parts
[16:38] <Dr_Radium> youtube doesn't use vpx ?
[16:38] <JEEBsv> they just cared enough to get the decoder somewhere, and that succeeded
[16:39] <JEEBsv> oh it does, it had to because it was a political decision
[16:39] <JEEBsv> I just said that it didn't need multithreading because it wouldn't use it (VP9) for any kind of live encoding
[16:40] <Dr_Radium> when i am watching "non live youtube video" what video codec am i watching then
[16:40] <JEEBsv> and for static file encoding they work in parts so they can just work around the lack of multithreading to a level
[16:40] <JEEBsv> most probably AVC I guess?
[16:40] <JEEBsv> at least that's what I get on my browser
[16:41] <Dr_Radium> avc ? they are not confident to use their own VPx ?
[16:41] <JEEBsv> in some cases VPx clips will get used, I guess. I could pick a VP9 clip on my chrome for some videos
[16:42] <Dr_Radium> jeebsv show me a youtube video with VP9
[16:45] <JEEBsv> https://www.youtube.com/watch?v=IBb2BIVrV7M <- I was able to play this one in VP9 on chrome, but there are also all of the AVC versions available as well
[16:45] <JEEBsv> use your favourite tool to snoop around those to see all the alternatives
[16:46] <Dr_Radium> how do you tell if that video is using vp9 ?
[16:51] <JEEBsv> in the HTML5 player there's info on that, and as I said there's plenty of applications (youtube-dl among others) that can tell you what are available
[16:54] <Dr_Radium> it's using adobe flash
[16:54] <JEEBsv> then that's AVC.
[16:55] <Dr_Radium> you just said it's vp9
[16:56] <JEEBsv> there's all versions available, and flash doesn't support VPx so guess what the site is giving you :P
[16:56] <JEEBsv> now go use something to list all the available formats, as I noted there are several tools for that
[17:44] <LiuYan> hi, where can i send feedback of ffmpeg website to ?
[17:45] <pzich> maybe something on http://ffmpeg.org/contact.html ?
[17:48] <LiuYan> pzich: that's where i came from :D
[21:55] <wag434> Hiya, is it acceptable to post superuser.com questions here? I.e. ask for advise relating to a SU question? Thanks
[22:00] <Fjorgynn> :=
[22:03] <wag434> ?
[22:21] <c_14> wag434: just ask, if someone can help you, they will
[22:22] <wag434> c_14, thanks very much
[22:22] <wag434> http://superuser.com/questions/856845/issue-streaming-ffmpeg-webcam-feed-with-ffserver
[22:23] <wag434> I think I am missing the final bit in connecting ffserver and ffmpeg - as both seem to work properly independently
[22:24] <c_14> wag434: ffmpeg -f v4l2 -i /dev/video0 http://[ffserver-ip]:[port]/feed1.ffm
[22:25] <wag434> ok, firing up ffserver, giving it a shot :)
[22:25] <wag434> thx!
[22:25] <c_14> https://trac.ffmpeg.org/wiki/Streaming%20media%20with%20ffserver
[22:27] <wag434> getting "Unknown input format: 'v4l2'"
[22:27] <wag434> yet I have v4l-utils installed
[22:27] <wag434> ffserver running
[22:27] <wag434> http://localhost:8090/stat.html looking good
[22:28] <wag434> have seen this before, ffmpeg suggests using avconv
[22:28] <wag434> didn't find related howto, i.e. connecting ffserver and avconv
[22:32] <c_14> use -f video4linux2 then
[22:33] <wag434> trying
[22:33] <c_14> oh
[22:34] <wag434> ok, I guess I am closing in
[22:34] <wag434> camera flashed for a couple of seconds
[22:34] <wag434> after that
[22:35] <wag434> Could not find input stream matching output stream #0.0
[22:35] <wag434> *** glibc detected *** ffmpeg: double free or corruption (!prev): 0x000000000124abe0 ***
[22:35] <wag434> ======= Backtrace: =========
[22:35] <wag434> long 'stack trace'
[22:36] <wag434> libvorbis and libxvidcore related
[22:36] <c_14> You're using libav, not ffmpeg. Either compile ffmpeg from FFmpeg, use a static build or ask in #libav
[22:37] <wag434> ok, thanks. will do a bit of homework on these.
[22:38] <wag434> cheers and seasons greetings
[23:14] <c_14> ribasushi: just wanted to say that I just sent the patch to the devel mailing list. Should only be a matter of time.
[00:00] --- Fri Dec 26 2014