[Ffmpeg-devel-irc] ffmpeg.log.20151125

burek burek021 at gmail.com
Thu Nov 26 02:05:01 CET 2015


[00:12:22 CET] <sea_tui> heya everone
[00:12:41 CET] <sea_tui> maybe i have the wrong impression, but is it possible to PLAY a DVD with ffmpeg?
[00:16:39 CET] <ocrete> sea_tui: no, use a video player like VLC, etc
[00:18:04 CET] <sea_tui> ocrete, thats why i'm asking, just seen VLC is using ffmpeg as backend ;)
[00:18:32 CET] <sea_tui> but seems the dvdplay is another binary part then. thank yo
[00:18:33 CET] <sea_tui> u
[00:18:37 CET] <ocrete> sea_tui: but it uses more than ffmpeg, DVD playback is somewhat complex as it has menus, etc, it's just not playing the stream
[00:20:19 CET] <sea_tui> ocrete, well, vob files contain 'all' the streams too, and playing them directly works fine (mostly).. but anyway, question has been answered
[01:06:42 CET] <Zeranoe> Any idea what's going on here? http://paste.debian.net/plain/335694 It dies after "Opening an output file: video.wmv." with "Unable to find a suitable output format for 'video.wmv'"
[01:07:17 CET] <Zeranoe> Original command was: type "img.bmp" | ffmpeg -c:v bmp -pix_fmt bgr24 -s 1096x4202 -y -r 7.1 -f image2pipe -i - -loglevel verbose -q:v 5 -s 1280x720 -r 30.0 "video.wmv"
[01:07:43 CET] <Zeranoe> And FFmpeg was configured with: --enable-gpl --enable-version3 --disable-w32threads --disable-everything --enable-decoder=bmp --enable-encoder='wmv1,wmv2,*mpeg*,libx264,flv' --enable-demuxer=image2pipe --enable-protocol='pipe,file,data' --enable-muxer='mpeg1video,mpeg2video,mov,avi,h264,flv' --enable-parser='h264,mpeg4video,mpegvideo,bmp'
[01:15:27 CET] <c_14> Missing the asf muxer
[01:15:29 CET] <c_14> probably
[01:15:51 CET] <c_14> At least that's what ffmpeg picks for me for files with .wmv extension
[01:24:01 CET] <darktoad> Anyone having good result with -vcodec nvenc? I have a GTX960 but I get a lower fps than with a cpu only encoding :/
[01:27:54 CET] <Zeranoe> darktoad: x264 is really good
[01:30:53 CET] <Zeranoe> c_14: Good call, making progress. http://paste.debian.net/plain/335697 "Output pad "default" with type video of the filter instance "Parsed_null_0" of null not connected to any destination"
[01:32:55 CET] <Zeranoe> c_14: I'm guessing a missing filter, but I don't see it trying to use one...
[01:33:04 CET] <llogan> Zeranoe: -s
[01:33:41 CET] <Zeranoe> llogan: So a resize filter?
[01:33:50 CET] <llogan> scale
[01:33:56 CET] <darktoad> ffmpeg -re -i file.test -vcodec nvenc, I'am on 359 drivers, ffmpeg 2.8, windows 7, any idea why I get 50fps?
[01:34:19 CET] <darktoad> gtx960
[01:34:37 CET] <Zeranoe> llogan: Thanks, see anything else that might use one?
[01:35:03 CET] <llogan> there is always something else when using --disable-everything. you'll just have to keep experimenting.
[01:35:14 CET] <Zeranoe> Very true
[01:35:52 CET] <furq> darktoad: probably because you're using -re
[01:36:27 CET] <darktoad> my file is 60fps, it's for streaming purpose
[01:37:28 CET] <darktoad> can't get more than 50fps using nvenc, 60fps easily using 80% cpu, don't know what's wrong
[01:37:54 CET] <Zeranoe> llogan: Working for now, till a new feature is used. Thanks again.
[01:38:31 CET] <llogan> just curious, why are you disabling stuff?
[01:38:42 CET] <darktoad> >ffmpeg -re -i test.ts -vcodec nvenc_h264 -maxrate 8000k -bufsize 24000k -pix_fmt yuv420p -g 50 -acodec libmp3lame -b:a 128k -ac 2 -ar 44100 -f flv rtmp_url
[01:39:13 CET] <Zeranoe> llogan: Someone wants a "we use FFmpeg to do one thing, and don't want anything else" build.
[01:39:46 CET] <furq> darktoad: try -preset fast i guess
[01:40:10 CET] <furq> 1080p60 is a pretty hefty load
[01:40:41 CET] <furq> also -g 50 is probably wrong for 60fps content
[01:41:13 CET] <llogan> Zeranoe: why --enable-version3?. i don't see anything there that would need it
[01:41:17 CET] <darktoad> [nvenc_h264 @ 04740060] Preset "fast" is unknown! Supported presets: hp, hq, bd,
[01:41:17 CET] <darktoad>  ll, llhp, llhq, lossless, losslesshp, default
[01:41:51 CET] <Zeranoe> llogan: What do you mean?
[01:42:34 CET] <Zeranoe> Mainly because you go from ~30-~40 megs to ~5
[01:44:00 CET] <llogan> do they just want (L)GPL3, or was the accidentally left in there for support for libopencode*, libsmbclient, and/or libvo_?
[01:44:49 CET] <Zeranoe> llogan: Oh i see what you mean, they didn't give a reason for v3. You're probably right that with --disable-everything there isn't any GPL3 features beyond what is in 2.
[01:47:58 CET] <llogan> and for pure OCD, you should change input options -r to -framerate, pix_fmt to pixel_format, -s to -video_size (see ffmpeg -h demuxer=image2pipe)
[01:48:24 CET] <Zeranoe> llogan: I also didn't write that command, but I would.
[02:16:29 CET] <cluelessperson> Hi all.  I'm attempting to do this.   ffmpeg -ss 01:31:22 -i Ex.Machina.2015.1080p.BluRay.x264.YIFY.mp4 -to 01:32:03 -vf fps=3 screens/out%d.png
[02:16:37 CET] <cluelessperson> however, it seems to ignore the -to option
[02:16:55 CET] <c_14> When using -ss as an input option, -to becomes equivalent to -t
[02:17:06 CET] <c_14> (unless there's also a -ss in the output as well)
[02:17:16 CET] <flarunt> dont you mean your_home_movie.mp4?
[02:17:32 CET] <cluelessperson> flarunt, ?
[02:18:21 CET] <flarunt> oh didnt notice the parrot on your shoulder
[02:18:24 CET] <cluelessperson> c_14, I'll try that then,  I thought -t was time though, as in length
[02:18:32 CET] <c_14> It is
[02:18:56 CET] <cluelessperson> c_14, is there not a way to do start time and stop time?
[02:19:08 CET] <cluelessperson> or must it be start, duration?
[02:19:11 CET] <c_14> There is, but only if you use -ss as an output option
[02:19:35 CET] <cluelessperson> c_14, So as I understand it, I must use duration
[02:20:08 CET] <cluelessperson> c_14, using -ss as an output option seems to take forever to start doing anything
[02:20:20 CET] <cluelessperson> Sigh.  I must got.  Thank you for your help.
[02:20:23 CET] <cluelessperson> go
[02:20:28 CET] <cluelessperson> bbl
[02:20:34 CET] <furq> -ss as an output option decodes until the start point
[02:20:47 CET] <cluelessperson> furq, oh. ;_;
[02:21:47 CET] <cluelessperson> furq, Wait, so do I need to do   input -ss start_time -i file.mp4 -ss start_time -so stop_time output   ?
[02:23:05 CET] <cluelessperson> well, yea, I have to go, 8 minutes to get somewhere.  Thanks again.
[02:24:13 CET] <c_14> cluelessperson: no, that would seek twice
[02:35:03 CET] <sonto_lau> Hi all! I am developing a media streaming software, but I dont know how to stream the media files encoded in h264 to network(RTP) by using ffmpeg, could anyone help me or give me some tutorial about this. thanks
[02:35:43 CET] <llogan> the cli tool or via the libraries?
[02:37:48 CET] <sonto_lau> Yes, I am using libraries, but I have no idea to use them and know too few about ffmpeg.
[02:38:27 CET] <llogan> see doc/examples, and http://ffmpeg.org/doxygen/trunk/index.html, and libav-user mailing list
[02:38:43 CET] <sonto_lau> I dont know how to output the stream in RTP format.
[02:39:07 CET] <sonto_lau> thanks, I try the link
[02:43:45 CET] <utopian> Hey all, when doing a two pass encoding.. I set the bitrate of the video and audio and I notice that qscale moves between 1.6 and 2 yet never hits 0 and does not use up the bitrate I set
[02:43:47 CET] <utopian> What is that all about
[02:44:23 CET] <utopian> Yet if I all out -q 0 it, it's much higher than what I set, so as far as I can tell, it's not lack of input
[02:45:40 CET] <llogan> i'll assume mpeg4. there is possibly a -qmin being applied by default, and I don't think the MPEG* qscale starts at 0, but 1
[02:46:10 CET] <utopian> that's what I wanted to know thanks, i saw the ranges and did not know how to set them
[02:46:13 CET] <utopian> I tried with just -q and had errors
[02:46:15 CET] <utopian> -qmin thanks
[02:46:43 CET] <utopian> Yes mpeg4
[02:52:39 CET] <utopian> Erps
[03:02:11 CET] <sonto_lau> I got the error "Unable to find a suitable output format for 'rtp://172.18.104.207:8554'"  when I use "rtp://host:port" as my output filename, what should I do? thanks.
[03:07:31 CET] <llogan> sonto_lau: how to duplicate?
[03:10:05 CET] <sonto_lau> I use the example code located at http://ffmpeg.org/doxygen/trunk/transcoding_8c-example.html to open a media file and output to network. so I compiled the code and run it with the command "./transcode ./test.h264 rtp://192.168.1.4:8554"
[03:11:27 CET] <sonto_lau> I have no idea that the example code can stream the media file to network.
[03:17:35 CET] <llogan> sonto_lau: i don't know. i'm not a library user. you should probably use doc/examples/transcoding in your local source copy instead of the example in doxygen/trunk (unless your source is current and they are the same)
[03:18:19 CET] <sonto_lau> llogan: thanks a lot!
[04:10:34 CET] <cluelessperson> c_14, I'm back.   I don't understand how to make it start at a position and end at another then
[04:16:12 CET] <cluelessperson> So I'm trying to do
[04:16:13 CET] <cluelessperson> ffmpeg -ss 01:31:22 -i Ex.Machina.2015.1080p.BluRay.x264.YIFY.mp4 -to 01:32:03 -vf fps=3 screens/out%d.png
[04:16:22 CET] <cluelessperson> however, having problem with seeking/ending
[04:16:43 CET] <cluelessperson> -ss on the IN seems to work, but it doesn't STOP at the correct time
[04:16:59 CET] <cluelessperson> because -to acts as a -t
[04:17:42 CET] <relaxed> then treat it as -t
[04:18:43 CET] <cluelessperson> relaxed, I really need to do end time, or it's going to be a big PITA translating/converting it every time.
[04:19:26 CET] <relaxed> doesn't it work if -ss is after the input?
[04:19:54 CET] <cluelessperson> relaxed, maybe it does, but it seems not to do anything forever
[04:20:17 CET] <relaxed> because it decodes to that point instead of seeking
[04:20:19 CET] <cluelessperson> relaxed, I sat there for 60 seconds, and it didn't show any progress and no output files were created.
[04:20:33 CET] <cluelessperson> relaxed, yes, I think so.  So should I sit there for hour+?
[04:21:08 CET] <relaxed> you can file a bug report (or add to one) while you wait
[04:28:07 CET] <relaxed> cluelessperson: did you try with both -ss and -to before the input?
[04:28:47 CET] <cluelessperson> relaxed, I think I did and it didn't work, I'll try again
[04:28:49 CET] <furq> is anyone in here keeping count of how often people accidentally incriminate themselves
[04:29:23 CET] <furq> it would make a nice infographic
[04:29:44 CET] <cluelessperson> furq, Sorry, did I incriminate myself?
[04:29:48 CET] <cluelessperson> of what
[04:29:58 CET] <relaxed> nobody cares
[04:30:19 CET] <furq> i expect somebody cares
[04:30:27 CET] <furq> it may not be anyone in here
[04:30:45 CET] <cluelessperson> furq,   I'm just going along with it.  But you hvae to prove how I got it, that I don't already own it, that it's illegal in my country, that it was ME that downloaded it, and that the distribution source wasn't legal. :P
[04:30:57 CET] <furq> i don't have to do any of that
[04:31:17 CET] <cluelessperson> furq, Actually, you do.  I'm innocent until proven guilty.
[04:31:34 CET] <furq> yeah but i don't care
[04:32:07 CET] <relaxed> this isn't #ffmorals
[04:32:13 CET] <furq> i just find it amusing
[04:42:39 CET] <cluelessperson> anyway yeah
[04:44:21 CET] <cluelessperson> relaxed, I get the error, using -to as in
[04:44:22 CET] <cluelessperson> Option to (record or transcode stop time) cannot be applied to input file Ex.Mac                     hina.2015.1080p.BluRay.x264.YIFY.mp4 -- you are trying to apply an input option                      to an output file or vice versa. Move this option before the file it belongs to.
[04:46:42 CET] <pepee> I don't get it, how is imgur able to convert files so fast?
[04:46:56 CET] <cluelessperson> pepee, how is imgur fast?
[04:47:17 CET] <cluelessperson> pepee, it takes like 10 seconds, so I imagine it's done on submission?
[04:47:19 CET] <pepee> cluelessperson, upload a 2MB gif and see by yourself
[04:49:11 CET] <furq> i uploaded a 3.5MB gif and it took more than 10 seconds
[04:50:28 CET] <furq> it took about one second converting it with ffmpeg
[04:50:30 CET] <pepee> how much of that time was the upload itself?
[04:50:46 CET] <furq> i started counting when it ticked over to "upload complete"
[04:51:50 CET] <furq> actually i take that back, it took about four seconds to webm with ffmpeg
[04:52:05 CET] <furq> with one thread on a core 2 duo
[04:52:42 CET] <pepee> right, it was fast here, too. I thought converting gifs would be slower
[04:53:35 CET] <pepee> I uploaded one from a website, it took like 1 second after the upload process, I think... and it also shows a preview
[04:54:12 CET] <pepee> furq, did you see the bug report? https://trac.ffmpeg.org/ticket/5033
[04:56:32 CET] <pepee> turns out the aac bug was fixed in the git version... mostly, but that wasn't the cause of the difference in length of the videos
[04:57:12 CET] <furq> yeah it was happening to me with mp3 when i first noticed it
[05:12:15 CET] <pepee> furq, I'm stupid... I didn't notice, this also happens with webms, too
[05:12:27 CET] <furq> yeah i mentioned it happens with mkv
[05:12:46 CET] <pepee> you shoul write that in the bug report
[05:13:03 CET] <pepee> I guess the problem is -shortest ? I don't remember, are you mixing images too?
[05:13:17 CET] <furq> yeah
[05:14:13 CET] <furq> http://sprunge.us/JYOS
[05:14:23 CET] <furq> the first one is out by ~6 seconds, the second one is out by about a second
[05:15:38 CET] <furq> and it gets worse at lower framerates
[09:25:50 CET] <licson> Hello! I'm having some problems with ffmoeg working with NVENC
[09:28:13 CET] <licson> After I successfully compiled ffmpeg with NVENC support, there are errors below
[09:28:16 CET] <licson> [nvenc_h264 @ 0x22c7a20] CreateInputBuffer failed
[09:29:36 CET] <licson> I have search about posts that said there is not enough video RAM but that should not happen
[09:30:54 CET] <licson> P.S. I'm using Ubuntu 14.04 and installed the 346.46 drive on EC2 g2.2xlarge instances
[09:36:05 CET] <fritsch> isn't the driver ultra old @ licson ?
[09:36:30 CET] <fritsch> we are always > 352
[09:36:42 CET] <fritsch> for the long live branch
[09:48:56 CET] <licson> fritsch: I'm having trouble on installing NVIDIA's drivers so I use a pre-built image that has the old version of driver
[10:38:57 CET] <srikanth> Hi all ..
[10:40:51 CET] <Guest90218> I am trying to identify the most commonly used encoders/decoders of ffmpeg
[10:41:21 CET] <Guest90218> so that I can work on doing performance optimization on ppc64le platform
[10:42:57 CET] <Guest90218> can you please help me, by providing the list of most commonly used encoders/decoders of ffmpeg
[11:09:02 CET] <Guest90218> Hi merzo...
[11:10:54 CET] <Guest90218> I looking for list of most commonly used encoders/decoders of ffmpeg, so that I can work on doing performance optimization of those encoders/decoders on ppc64le platform ...
[11:20:19 CET] <DHE> generally the most common codecs are the ones available on youtube... VP-9, H264, and maybe others..
[11:30:58 CET] <Guest90218> could you please elaborate on this, actually I am looking out for atleast list of ten most commonly used encoders/decoders of ffmpeg .. including audio/video/subtitles...
[11:33:23 CET] <JEEB> many encoders actually used are external projects
[11:33:27 CET] <JEEB> like libx264 or libvpx
[11:33:51 CET] <JEEB> decoder-wise, I'd say h264, hevc, mpeg2video, mpeg4
[11:34:08 CET] <JEEB> maybe ffv1 and utvideo too
[11:34:25 CET] <JEEB> vp9 I guess
[11:43:15 CET] <Guest90218> thanks so much for the inputs
[11:43:48 CET] <Guest90218> pls list any other widely used encoders/decoders apart from the above list
[11:44:35 CET] <Guest90218> i would be grateful if someone gives me details of how to find the de/encoders available on youtube.. are they listed on some page in the site?
[12:11:38 CET] <derjanni> Hello! I want to use ffplay in my application. With mplayer there is something like the -wid parameter that allows me to have mplayer draw in my XWindow. Is there something comparable for ffplay?
[13:47:02 CET] <c_14> cluelessperson: write a script that takes a from and a to timestamp and turns it into a duration (that's how I handle it)
[17:17:17 CET] <Zeranoe> What muxer is used in: ffmpeg -y -r 15.9 -f image2pipe -i pipe:.bmp  -vcodec mpeg4  -q:v 5  -s 1280x720 -r 30.0 "video.mp4"
[17:27:50 CET] <JEEB> Zeranoe: mp4 derivatives are in libavformat/movenc
[17:28:05 CET] <JEEB> or well, I should say "mov derivatives"
[17:30:56 CET] <Zeranoe> JEEB: Thanks, working now.
[18:10:14 CET] <hero_biz> hi guys.
[18:10:19 CET] <hero_biz> a small question
[18:10:31 CET] <hero_biz> i have encoded an flac audio with this command:
[18:10:53 CET] <hero_biz> ffmpeg -i a.flac -c:a libfdk_aac -vbr 5 a.aac
[18:11:29 CET] <hero_biz> in middle of encoding I noticed that flac file had some meta data, about album,...
[18:11:49 CET] <hero_biz> but it seems my encode will drop those meta data.
[18:12:04 CET] <hero_biz> is there anyway to keep those meta data when encoding to aac?
[18:19:37 CET] <durandal_1707> aac format afaik doesn't allow metadata
[18:20:25 CET] <hero_biz> then I need to use m4a?
[18:20:42 CET] <hero_biz> m4a container?
[18:21:04 CET] <durandal_1707> I guess
[18:21:52 CET] <hero_biz> ok,ty info
[18:32:18 CET] <hero_biz> should i add a -c:v none option too?
[18:38:36 CET] <furq> hero_biz: -vn
[18:39:17 CET] <thebombzen> you could also try using -map
[18:40:03 CET] <hero_biz> i used -map_metadata 0 -id3v2_version 3 and .mka file.
[18:40:19 CET] <hero_biz> everythign ok now. i guess lol.
[19:58:17 CET] <prelude2004c> hey guys.. question is there some way to have ffmpeg keep writing segmented files out even if input has stopped ( eg. udp ) or , insert something else while input is out ?
[20:17:33 CET] <ented> Hello folks,  I am trying to develop stuff with libav.
[20:18:10 CET] <ented> Well ffmpeg C interface
[20:18:45 CET] <ented> Not on those heretics library :)
[20:21:25 CET] <ented> I need to do offline video processing and play frames backward. Clearly h264 playing backwards is almost impossible. Is it good strategy to try seek backwards to earlier keyframe and decode frames until current frame?
[20:22:07 CET] <c_14> Look at what the reverse filter does
[20:22:29 CET] <c_14> Then cut it up into pieces so you don't OOM
[20:23:52 CET] <c_14> But seeking back to the last keyframe doesn't sound like the worst idea.
[21:20:13 CET] <basisbit> I love ffmpeg. just had to say it :)
[22:20:43 CET] <cbsrobot> cluelessperson and c_14: I guess you need to add -copyts after the input file
[22:21:58 CET] <cbsrobot> if you seek with -ss in front of the input file and do not set the -copyts option, the timestamp starts at 0 and your -to option is useless
[22:25:51 CET] <arpu> hello does anyone have an simple node http server that exapts ffmpeg http output?
[22:36:39 CET] <MrJohnson> Hello, I have a bunch of mp4s already encoded using h264. These mp4s only have one channel of audio (left). I'm looking to duplicate the left channel into the right channel without re-encoding/compressing the video. I assume this is something ffmpeg can handle?
[22:45:32 CET] <durandal_170> Yes, for video use -c:v copy
[22:51:37 CET] <furq> MrJohnson: you can create a mono audio stream with -map_channel and -ac
[00:00:00 CET] --- Thu Nov 26 2015


More information about the Ffmpeg-devel-irc mailing list