[Ffmpeg-devel-irc] ffmpeg.log.20150520

Thu May 21 02:05:01 CEST 2015

[05:31:31 CEST] <hmmwhatsthisdo> Suppose I have a total of 20 or so h.264 1080p30 streams. I know that bandwidth vs. CPU time aren't generally comparable resource measurements, but is it going to be a better idea to have the media server handle scaling/composition of streams, or just stream HD to clients and let them do scaling if they so choose?
[05:31:41 CEST] <hmmwhatsthisdo> (scaling/streaming would be done with ffmpeg)
[10:09:43 CEST] <acron^> hi all. quick question - i have 10,078 frames that have been extracted from a video. I am trying to reassemble it using: ffmpeg -f image2 -i "%05d.tga" -r 48 -q:v 99 -vf "scale=2320:trunc(ow/a/2)*2" 48fps.ogg. This, I believe, should give me a 48fps video - 10078/48 = 210 secs = 3.5 mins. Yet, the output video is 6m 43s...and I can see, from looking at it
[10:09:43 CEST] <acron^> that the motion is too slow...
[10:12:21 CEST] <relaxed> remove -r 48 and put -framerate 48 befoure the input
[10:12:30 CEST] <relaxed> before*
[10:13:40 CEST] <acron^>  ffmpeg -f image2 -framerate 48 -i "%05d.tga" -q:v 99 -vf "scale=2320:trunc(ow/a/2)*2" 48fps.ogg
[10:13:43 CEST] <acron^> like that?
[10:14:03 CEST] <relaxed> yes
[10:15:17 CEST] <acron^> thanks, i will try it now :)
[10:15:53 CEST] <relaxed> by default ffmpeg will use 25 fps as input for image2
[10:19:05 CEST] <acron^> ah that'd make sense
[10:19:22 CEST] <acron^> i mean, that'd add up to 6ms43s
[10:56:26 CEST] <Misan> good morning
[13:57:52 CEST] <december> Hello
[13:57:52 CEST] <december> I'm using avcodec_find_encoder(AV_CODEC_ID_MP2) to find the MP2 encoder. But i get null, so my current installed lib seems not to have the encoder included.
[13:57:52 CEST] <december> (i did the avcodec_register_all() stuff)
[13:57:52 CEST] <december> Is there a configure flag to enable MP2 Audio??
[14:11:05 CEST] <rg_> Hi, I'm just looking to confirm whether or not ffmpeg sends RTCP RRs when streaming over TCP (RTP over RTSP/TCP). Sniffing the traffic seems to indicate that it doesn't send them. Thanks!
[14:41:54 CEST] <Ajay> irc://irc.freenode.net/ffmpeg
[14:41:58 CEST] <Ajay> # ffmpeg -vcodec vp8 -i rtp://192.168.1.93:15000  -f mpeg1video -b: 400k -r 25 http://192.168.1.11:8082/url/640/480/ ffmpeg version n2.5.6-3-ga2ad7fd Copyright (c) 2000-2015 the FFmpeg developers   built on May  1 2015 13:18:01 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11)   configuration: --enable-nonfree --enable-gpl --enable-libvpx --enable-decoder=aac --enable-libx264 --enable-demuxer=mov --enable-x11grab --enable-zlib --enable-
[14:42:15 CEST] <Ajay> ffmpeg -vcodec vp8 -i rtp://192.168.1.93:15000  -f mpeg1video -b: 400k -r 25 http://192.168.1.11:8082/url/640/480/
[14:42:21 CEST] <Ajay> output::
[14:42:43 CEST] <Ajay> [rtp @ 0x25cf0e0] Unable to receive RTP payload type 100 without an SDP file describing it Input #0, rtp, from 'rtp://192.168.1.93:15000':   Duration: N/A, bitrate: N/A Codec AVOption b (set bitrate (in bits/s)) specified for output file #0 (http://192.168.1.11:8082/url/640/480/) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of so
[14:44:06 CEST] <animax> hello everybody. I am from Germany and an absolute beginner concerning ffmpeg. I want to encode image sequences into mp4 video files. if I get it right then with a command like 'ffmpeg -i image%04d.png video.mp4' ffmpeg uses a framerate 25 by itself as standard. can anyone tell me which further settings ffmpeg is using in such a case? i mean encoding method and so on. does ist use any crf...
[14:44:07 CEST] <animax> ...presets? to tell it more exactly: what would be the appropriate command "under the hood" concerning the command mentioned above?
[17:14:43 CEST] <efesto> Hi all, one quick question, is there any flag I can use in replacement of -vframes for limiting the input frames ?
[19:12:01 CEST] <robertmoore> I just installed ffmpeg on an Ubuntu system, and when trying to take an mp3 and add a xing/LAME header via ffmpeg it ends with "Encoder (codec mp3) not found for output stream #0:1"
[19:12:58 CEST] <robertmoore> http://pastebin.com/L81rmgKt
[19:13:28 CEST] <robertmoore> Sorry, that was when I tried with xing off, updating now.
[19:13:30 CEST] <llogan> you did not configure ffmpeg with support for libmp3lame
[19:13:39 CEST] <llogan> and disable-yasm is never a good idea
[19:13:47 CEST] <robertmoore> It wouldn't let me install without disable-yasm
[19:13:55 CEST] <llogan> http://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu
[19:14:06 CEST] <llogan> or simply get a static build
[19:14:12 CEST] <llogan> http://johnvansickle.com/ffmpeg/
[19:14:53 CEST] <robertmoore> Is there an uninstall script so I can start clean
[19:15:43 CEST] <llogan> for your current compiled ffmpeg?
[19:15:47 CEST] <robertmoore> yea
[19:16:27 CEST] <llogan> did you already run "make install" or "checkinstall" and do you still have the source directory?
[19:16:43 CEST] <robertmoore> Yes, make install, and I do.
[19:17:02 CEST] <llogan> go into the source directory and run "sudo make uninstall". that should be it.
[19:20:47 CEST] <robertmoore> Okay, I'll try your suggestions, thanks for your help so far.
[19:31:28 CEST] <robertmoore> llogan, I used the static binaries you provided and it "worked" but the xing headers I am expecting aren't there - although the LAME ones are - here's a pastebin.
[19:32:09 CEST] <robertmoore> http://pastebin.com/eSgPvkGR
[19:34:44 CEST] <llogan> write_xing should be enabled by default for the mp3 muxer
[19:34:50 CEST] <llogan> how do you know it's not there?
[19:37:16 CEST] <robertmoore> I did a hexdump to search for the XING keyword
[19:38:14 CEST] <relaxed> robertmoore: look at ffmpeg -h muxer=mp3
[19:38:53 CEST] <relaxed> oh, you want -write_xing 1, right?
[19:39:12 CEST] <robertmoore> yea
[19:39:42 CEST] <robertmoore> i'll try it with it flagged but as llogan said it should be defaulted on
[19:39:44 CEST] <relaxed> that's the default, -write_xing 1
[19:40:48 CEST] <llogan> i wonder if the enabled xing still causes an incorrect duration in Finder/QuickTime on OS X
[19:41:04 CEST] <llogan> #2697
[19:47:14 CEST] <robertmoore> I'm following the LAME/Xing definitions outlined here :http://gabriel.mp3-tech.org/mp3infotag.html  trying to parse for replay gain and such, but I don't see XLAME, just LAME
[19:47:14 CEST] <robertmoore> I'm pretty new to with this whole subject so maybe I'm looking for the wrong thing / expecting the wrong thing?
[19:48:45 CEST] <llogan> i really don't know much about Xing myself, so i won't be much help. maybe try ffmpeg-user mailing list
[19:49:57 CEST] <robertmoore> Bummer, okay thanks for your help.
[20:28:01 CEST] <animax> hello. I'll try again. I am an absolute beginner concerning ffmpeg. I want to encode image sequences into mp4 video files. if I get it right then with a command like 'ffmpeg -i image%04d.png video.mp4' ffmpeg uses a framerate 25 by itself as standard. can anyone tell me which further settings ffmpeg is using in such a case? i mean encoding method and so on. does ist use any crf presets? to...
[20:28:02 CEST] <animax> ...tell it more exactly: what would be the appropriate command "under the hood" concerning the command mentioned above?
[20:28:55 CEST] <llogan> i don't understand the question
[20:29:31 CEST] <llogan> oh, you want to know what other possible defaults are?
[20:29:51 CEST] <llogan> it depends on your ffmpeg build and what encoders it supports
[20:30:24 CEST] <llogan> if your build supports libx264, then it will be used for MP4 output, but if it does not then the native mpeg4 encoder will be used
[20:30:48 CEST] <llogan> libx264 then has it's own defaults such as "-crf 23 -preset medium"
[20:32:07 CEST] <llogan> as for your command, i recommend adding "-pix_fmt yuv420p" if you're going to be viewing the output in non-FFmpeg based players (but you don't need to if you're simply uploading to YouTube)
[20:32:42 CEST] <llogan> and add "-movflags +faststart" if you're viewing via progressive download
[20:32:50 CEST] <llogan> both of these are output options
[20:33:11 CEST] <llogan> im assuming your build supports libx264
[20:50:24 CEST] <animax> hello llogan. ok. my build does support libx264. for the time beeing I want to use the movie for a website header. do I then need to choose '-pix_fmt yuv420p' and '-movflags +faststart'?
[22:47:20 CEST] <rafael2k> hi people. i read about CC support in ffmpeg 2.6. Which standard is supported? I know analog TV uses one (line 21), DVB uses one, and ISDB-T uses other Closed Caption standard.
[22:47:46 CEST] <rafael2k> Closed Caption (EIA-608 / CEA-708) Decoder
[22:47:49 CEST] <rafael2k> ooops, sorry
[22:47:51 CEST] <rafael2k> ; )
[22:52:24 CEST] <rafael2k> btw, for ISDB-T the CC standard is ARIB B24
[22:52:48 CEST] <Mavrik> Hmm, any idea which defines CC in SDI?
[22:52:57 CEST] <Mavrik> (sorry for driveby questions :P )
[22:53:20 CEST] <llogan> rafael2k: i don't know but you could ask the author. Anshul Maheshwari "anshul.ffmpeg at gmail"
[22:53:23 CEST] <rafael2k> It goes in VANC
[22:54:43 CEST] <rafael2k> used you can get the CC from SDI using the capture card API
[22:55:16 CEST] <rafael2k>  s/used/usually
[22:55:33 CEST] <Mavrik> mhm, you get lines
[22:55:48 CEST] <Mavrik> but decoding those is a bit annoying since I can't get reliable info on which standard they're encoded into
[22:56:49 CEST] <rafael2k> true
[22:57:50 CEST] <Mavrik> and of course guys running the machines have no idea as well :P
[22:58:12 CEST] <rafael2k> in ISDB-T people use the ARIB B37 in SDI
[22:59:28 CEST] <rafael2k> there is already some time I player with SDI CC
[23:07:10 CEST] <iv_> hi. is it possible to stream theora video with ffserver to embed it later into <video> in html? all ffserver configurations/examples i found on internet don't work
[23:08:19 CEST] <rafael2k> you can use icecast for that
[23:09:05 CEST] <rafael2k> encode using ffmpeg and send the stream to icecast using oggfwd
[23:10:56 CEST] <rafael2k> Mavrik: CEA-708-B ?
[23:11:43 CEST] <iv_> @rafael2k: is it going to compile on raspberry?
[23:16:24 CEST] <rafael2k> iv_: you want just serve the media files in raspberry or encode them?
[23:17:31 CEST] <rafael2k> iv_: if it's just for serving the files, it's ok to do with icecast, if you want also to encode the files, rpi has not enough processing power
[23:21:07 CEST] <iv_> ok, understand. but the next question is - does icecast encode a stream? you said to encode with ffmpeg, and that's near the camera, so it's raspberry
[23:27:54 CEST] <rafael2k> iv_: no, icecast does not encode
[23:29:19 CEST] <iv_> i see, thanks
[00:00:00 CEST] --- Thu May 21 2015