[Ffmpeg-devel-irc] ffmpeg.log.20160701

Sat Jul 2 02:05:01 CEST 2016

[00:11:10 CEST] <Ultima> hello, why is it recommended to not use over 16 threads? is there limited testing using more than that?
[00:12:48 CEST] <viric> some codecs degrade in quality, on more threads. Maybe because of that
[00:13:52 CEST] <Ultima> viric: do you know if hevc is subjected to this?
[00:14:28 CEST] <viric> I guess it degrades, like h264
[00:14:41 CEST] <viric> should degrade little
[00:15:15 CEST] <Spring> viric, was actually going to ask why thread count changes the quality
[00:15:37 CEST] <Spring> testing 16 vs 4 showed differences in the encodes
[00:16:08 CEST] <viric> how do you split the encoding process to multiple threads, if all produced data per frame is dependant one on the other?
[00:16:31 CEST] <viric> by the use of some tricks, that have some degrading effect (should be little)
[00:17:12 CEST] <Spring> yeah it wasn't significant. What was significant though is 'Constant Quality' mode vs 'Constrained Quality' mode
[00:17:33 CEST] <Spring> the wiki says it will keep to a CRF quality except if it hits the max bitrate ceiling
[00:17:44 CEST] <Spring> however I haven't found this at all to be the case with VPx
[00:18:00 CEST] <viric> I don't know much details about that
[00:21:51 CEST] <Spring> I'm not sure I get the wiki at times :p I can set CRF 4 -b:v 2M and it will typically output around 9-1200kbps, whereas CRF -b:v 0 outputs at like 30000kbps.
[00:22:05 CEST] <Spring> *CRF 4 -b:v 0
[00:23:26 CEST] <Spring> wait, of course it would. M = MBit/s.
[00:24:37 CEST] <Ultima> what crf value would be considered visually lossless? around 23?
[00:57:50 CEST] <utack> Spring i would assume it ignores a bitrate of zero because it is obvious nonsense?
[00:58:23 CEST] <utack> just a guess
[00:59:55 CEST] <Spring> utack, according to the docs setting '0' is required for that mode to work, so yeah there's no artificial max.
[01:01:14 CEST] <utack> uhm..i had that happen with one encoder, can't remember which one, but ffmpeg should not require that
[01:01:47 CEST] <utack> at least last i tried i think i used just crf
[01:02:08 CEST] <Spring> it does work with CRF without it but it has different results
[01:02:28 CEST] <utack> crf 4 is pretty heavy, bitrate of 30mbit+ sounds about right
[01:03:12 CEST] <Spring> at first I assumed CRF would work without any -b:v, after reading the docs and comparing results the difference is obvious
[01:03:27 CEST] <Spring> just a quirk I suppose
[01:08:43 CEST] <HSKW> hi! i've a problem... i want to transcode an DVB ts udp from smartdvb player... ffmpeg create a lot of error like frame dropped or PMT sync... to avoid this issue i must buy an hdmi capture card and bypass HDMI video card with HDMI in capture card?
[01:11:49 CEST] <HSKW> Stream #0:0: Video: h264 (libx264) ([7][0][0][0] / 0x0007), yuv420p, 640x360 [SAR 1:1 DAR 16:9], q=-1--1, 100 kb/s, 25 fps, 1k tbn, 25 tbc
[01:12:07 CEST] <HSKW> Stream #0:0[0x200]: Video: h264 (High 4:2:2) ([27][0][0][0] / 0x001B), yuv422p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 50 tbr, 90k tbn, 50 tbc
[01:24:31 CEST] <HSKW> http://pastebin.com/BihJaLG4
[01:33:01 CEST] <Spring> are different filters separated by commas or semi-colons?
[01:33:56 CEST] <Spring> pretty sure they're semi-colons but some are related and use commads
[01:34:02 CEST] <Spring> *commas
[01:34:15 CEST] <llogan> sequential filters are separated by commas to create a filterchain. filterchains are separated by semicolons
[01:45:39 CEST] <Spring> I think I'm getting a bit stuck with how to combine a video+audio filter
[01:45:57 CEST] <Spring> -filter_complex scale=iw:ih;dynaudnorm=m=30:s=10
[01:46:29 CEST] <llogan> "[0:v]scale[v];[0:a]dynaudnorm[a]" -map "[v]" -map "[a]"
[01:47:08 CEST] <llogan> you don't have to explicitly label inputs and outputs but I prefer not to rely on defaults to avoid surprises
[01:47:32 CEST] <Spring> llogan, ooh. So where would the filter settings be placed in that format?
[01:48:03 CEST] <llogan> "[0:v]scale=640:-2[v];[0:a]dynaudnorm=m=30:s=10[a]"
[01:48:20 CEST] <llogan> scale=iw:ih will do nothing by the way
[01:48:35 CEST] <Spring> yeah, it's a conditional toggle for a batch script
[01:48:50 CEST] <Spring> so when no changes are made I set it to that
[01:51:52 CEST] <HSKW> well how i can set?
[01:52:39 CEST] <HSKW> ffmpeg -i udp://@127.0.0.1:8888  -pix_fmt yuv420p -c
[01:52:39 CEST] <HSKW> :a aac -b:a 64k -c:v libx264 -b:v 100K -vf scale=640:360 -f flv rtmp://localhost/live
[02:14:00 CEST] <Spring> llogan, so I integrated it and it runs but there's no sound. Looking at it there is an audio stream but 0kbps output. Any ideas?
[02:17:15 CEST] <Spring> llogan, this is the final 2 pass code: http://pastebin.com/Xgk5bVEF
[02:19:50 CEST] <llogan> that's not the complete console output. make sure to remove -loglevel and -hide_banner. those are useless when requesting help.
[02:23:38 CEST] <HSKW> anyone can help me : http://pastebin.com/BihJaLG4
[02:24:00 CEST] <llogan> there in no command in that pastebin link
[02:24:04 CEST] <llogan> *is no
[02:27:11 CEST] <Spring> llogan, entire console output: http://pastebin.com/WWtqGrfd
[02:27:35 CEST] <Spring> the command is outputted by the batch script so it doesn't appear in the log when beginning
[02:28:34 CEST] <llogan> the command you used to generate the console output is different than what you showed earleir
[02:30:00 CEST] <Spring> this is the output, I posted the ffmpeg command in the earlier link. The command itself is identical to the one posted earlier but without the loglevel and hidebanner options
[02:30:08 CEST] <llogan> maybe, not. it's just using two different audio encoders for each pass
[02:31:34 CEST] <Spring> I just realized something. I added the audio filter to the first pass when I have the -an switch.
[02:32:06 CEST] <Spring> would that make a difference?
[02:32:34 CEST] <llogan> i doubt you need to encode audio for the first pass.
[02:33:13 CEST] <Spring> thing is all the options are actually variables, so I'll try to make two different versions for each pass
[02:33:13 CEST] <HSKW> llogan: ffmpeg -i udp://@127.0.0.1:8888  -pix_fmt yuv420p -c
[02:33:13 CEST] <HSKW> [01:52:39] <HSKW> :a aac -b:a 64k -c:v libx264 -b:v 100K -vf scale=640:360 -f flv rtmp://localhost/live
[02:33:27 CEST] <llogan> HSKW: probably a shitty, borken input
[02:34:19 CEST] <HSKW> llogan: is an mpegts input.... in this case.. i need an HDMI capture card and loop with GPU hdmi exit??
[02:34:29 CEST] <llogan> i don't know
[02:34:32 CEST] <HSKW> all player like VLC, FFplay mpc work ok
[02:34:40 CEST] <HSKW> only if i transcode :(
[02:35:38 CEST] <vandemar> HSKW: does that need one of the bsf flags for audio to work right?
[02:36:11 CEST] <HSKW> vandemar: dont know :(
[02:36:59 CEST] <HSKW> bsf flah what mean?
[02:37:27 CEST] <vandemar> I'm not sure you need it, ts issues are a bit fuzzy for me, but https://www.ffmpeg.org/ffmpeg-bitstream-filters.html#aac_005fadtstoasc
[02:38:14 CEST] <vandemar> not relevant to the problem you pasted afaik, but worth knowing about
[02:40:01 CEST] <HSKW> vandemar: ffmpeg -i udp://@127.0.0.1:8888  -pix_fmt yuv420p -c:a aac -b:a 64k -c:v libx264 -b:v 100K -vf scale=640:360 -f flv rtmp://localhost/live
[02:40:10 CEST] <HSKW> this is the command line that run
[02:43:02 CEST] <Spring> so removed the -an (no sound) option and complex filter from the first pass, leaving just the -vf scale filter. Still no sound even though the audio channels are still embedded.
[02:43:14 CEST] <Spring> Is there a correct order to placing audio filters?
[02:45:27 CEST] <HSKW> vandemar: i think if the broken input... i must use an secondary video card exit and loop in an hdmi capure card.. and caputure the hdmi av and stream it on rtmp
[03:44:57 CEST] <Spring> got it working. Turns out I needed the audio options in both passes not just the second, at least that's the only way I got it working.
[05:52:49 CEST] <yagiza> Hello!
[05:53:37 CEST] <yagiza> Any AVOption and AVDictionary guru around?
[07:25:50 CEST] <Spring> so pass logs are saved to the location of the input file not the output file?
[07:26:53 CEST] <Spring> edit, my bad nvm.
[14:20:49 CEST] <HSKW> hello why ffmpeg is obsolete and must use avconv?
[14:21:46 CEST] <BtbN> You are a few yeard behind.
[14:21:49 CEST] <BtbN> *years
[14:22:16 CEST] <HSKW> Why?
[14:22:36 CEST] <HSKW> i've read this when launch ffmpeg on debian wheezy
[14:22:40 CEST] <BtbN> Because that misleading message was added in ancient versions of libav, and has since been removed, and replaced with ffmpeg again.
[14:23:02 CEST] <BtbN> Debian Wheezy is ancient.
[14:23:14 CEST] <HSKW> BtbN: yes but in server i must use it...
[14:23:41 CEST] <BtbN> It does not come with ffmpeg, and the libav version it comes with is equally ancient.
[14:24:02 CEST] <HSKW> BtbN: i must buy an HDMI capture card.. i would buy some PCIex card... what work very well with ffmpeg??? Blackmagic Intensity pro 4k? or some Avermedia product?
[14:24:30 CEST] <BtbN> I think the only capture cards that work on linux at all are the declink ones.
[14:24:48 CEST] <HSKW> blackmagic decklink caputure?
[14:25:34 CEST] <HSKW> Blackmagic decklink mini recorder
[14:26:04 CEST] <HSKW> are ok this?
[14:26:10 CEST] <BtbN> No idea, ask their manufacturer.
[14:26:25 CEST] <BtbN> You won't have much fun with any of them using that ancient libav version though.
[14:27:15 CEST] <HSKW> BtbN: now i've compiled an fresh ffmpeg 2016 from last source :D
[14:27:21 CEST] <HSKW> the message not appear :D
[14:27:29 CEST] <BtbN> The message was never part of ffmpeg.
[14:27:32 CEST] <BtbN> It comes from libav.
[14:27:36 CEST] <BtbN> Or rather, came.
[14:27:47 CEST] <BtbN> They indeed did remove ffmpeg after a while.
[14:27:53 CEST] <HSKW> libav is inside ffmpeg?
[14:28:04 CEST] <BtbN> libav is an entirely seperate project.
[14:28:49 CEST] <HSKW> libavutil      55. 17.103 / 55. 17.103   libavcodec     57. 24.102 / 57. 24.102
[14:28:55 CEST] <viric> libav was a spoon of ffmpeg
[14:29:02 CEST] <HSKW> this is my libav version
[14:29:09 CEST] <BtbN> No, that's your libav* versions.
[14:29:31 CEST] <BtbN> They did a good job confusing people by choosing that project name.
[14:30:16 CEST] <HSKW> BtbN: LoL... libav must compile separately?
[14:30:49 CEST] <BtbN> libav and ffmpeg can't be installed on the same system at the same time, as they install "the same" libraries.
[14:31:35 CEST] <HSKW> BtbN: ok well if i compile ffmpeg they install the lastet libav library?
[14:32:09 CEST] <BtbN> ffmpeg installs its own set of libav* libraries, if you tell it to do so.
[14:32:18 CEST] <BtbN> I'd highly recommend against doing that, it _will_ break stuff
[14:33:13 CEST] <HSKW> BtbN: i've compiled ffmpeg reading the guide on the wiki...
[14:33:30 CEST] <BtbN> As long as you didn't run make install as root, it's fine.
[14:33:43 CEST] <BtbN> just put the static binary elsewhere
[14:33:52 CEST] <HSKW> ok... done this
[14:34:49 CEST] <HSKW> now... i would a advertising on what is the best video capture card... declink that capture in raw pixel or an h264 encoding card like avermedia
[14:35:26 CEST] <BtbN> AverMedia does not have linux drivers at all.
[14:35:37 CEST] <BtbN> decklink is the only thing i know that works on linux at all.
[14:35:51 CEST] <HSKW> decklink what version? there are a lot... :(
[14:36:01 CEST] <BtbN> decklink is the ffmpeg input name
[14:36:09 CEST] <BtbN> it supports a lot of cards iirc
[14:36:46 CEST] <HSKW> DeckLink Mini Recorder ?
[14:38:45 CEST] <HSKW> BtbN: i would use this card because i've some problem with the mpegts input from an dvb-ts
[14:39:18 CEST] <HSKW> well with the vlc i can play whis mpegts and show on secondary monitor, than capture with this decklink card and ffmpeg :)
[14:39:56 CEST] <BtbN> problems while using that ancient version of avconv?
[14:41:17 CEST] <HSKW> BtbN: no lastet build... both windows or linux all same problem... wait i send the pastebin link with log of error...
[14:46:20 CEST] <HSKW> BtbN: http://pastebin.com/BihJaLG4 look
[14:47:27 CEST] <BtbN> looks like a very damaged stream
[14:49:14 CEST] <HSKW> BtbN: is from DVB
[14:49:29 CEST] <HSKW> with vlc, Mpc-hc all work ok...
[14:50:33 CEST] <HSKW> well i would use this workaround... play this stream with VLC on secondary monitor... exit with HDMI from VGA Card... input in decklink capture card and than encode and stream
[14:51:57 CEST] <BtbN> sounds like overkill. VLC also just uses libav* to plays its stuff
[14:53:49 CEST] <HSKW> BtbN: yes i know.. this is very strage. but this stream is from a professional DVB encoder ericcson
[17:07:07 CEST] <imperio_> Hi, is it possible to give an char* to an equivalent of avformat_open_input instead of a filename?
[17:07:32 CEST] <imperio_> I have the content of a video file but don't want to write on my harddrive
[17:17:13 CEST] <dbugger> Hello everyone
[17:17:33 CEST] <DHE> imperio_: you can make your own "input source" object, I believe an example shows how to do this
[17:17:45 CEST] <imperio_> DHE: really?
[17:17:48 CEST] <imperio_> that'd be awesome!
[17:17:58 CEST] <dbugger> I have an issue. I have 3 video files on my NAS, and I can see video1 and video2 on my Samsunt Smart TV, but not video3... But the streams seems to be correct... what could be wrong? This is the info data on each video: http://hastebin.com/ifidipubiy.bash
[17:18:07 CEST] <imperio_> I thought about memory map, but don't know if it's possible to map memory as a file
[17:18:25 CEST] <furq> dbugger: post the ffprobe output for each file
[17:19:34 CEST] <dbugger> furq, i dont know ffprobe, can you tell me the command I have to type?
[17:20:05 CEST] <dbugger> oh, of course, simply ffprobe video1 :)
[17:22:25 CEST] <dbugger> furq, here it is: http://hastebin.com/juyukuyipa.coffee
[17:23:45 CEST] <imperio_> DHE: found it, thanks again!
[17:28:58 CEST] <furq> dbugger: i can't see anything obvious
[17:31:47 CEST] <dbugger> furq, it is weird... I wonder why...
[17:32:30 CEST] <furq> you could maybe check mediainfo for the encoder settings
[17:32:44 CEST] <furq> smart tvs are notoriously picky though
[17:32:59 CEST] <furq> most hardware players are
[17:36:00 CEST] <dbugger> furq, mediainfo on the files?
[17:36:39 CEST] <furq> yeah
[17:36:45 CEST] <dbugger> ok, let me install it first..
[17:37:43 CEST] <dbugger> This is video1: http://hastebin.com/exeyarayiz.vhdl
[17:38:17 CEST] <dbugger> This is video2: http://hastebin.com/faburusuze.rib
[17:38:34 CEST] <furq> hastebin's format detection really is a modern marvel
[17:39:04 CEST] <dbugger> And this is video3: http://hastebin.com/besekosulo.rib
[17:39:07 CEST] <dbugger> I know XDDDD
[17:40:52 CEST] <furq> yeah i can't see any meaningful difference here
[17:41:05 CEST] <dbugger> I have no idea then... :(
[17:41:10 CEST] <furq> maybe try remuxing it into a new mkv
[17:41:15 CEST] <furq> ffmpeg -i foo.mkv -c copy bar.mkv
[17:41:59 CEST] <dbugger> i did this: "avconv -i input.mkv -cc copy output.mp4"
[17:42:02 CEST] <dbugger> It did not work
[17:42:16 CEST] <dbugger> I mean "-c", of course :)
[17:42:23 CEST] <furq> some players are picky about ac3 in mp4
[17:42:38 CEST] <furq> although it's been part of the spec since ~2008 so a new smart tv should be able to figure it out
[17:42:49 CEST] <dbugger> so you think I should try "avconc -i input.mkv -c copy output.mkv" ?
[17:42:58 CEST] <furq> it's worth a shot
[17:43:01 CEST] <dbugger> ok, let me see
[17:43:59 CEST] <dbugger> Ok, pasting. Im gonna test it
[17:45:10 CEST] <dbugger> Nothing... it did not work :(
[17:57:17 CEST] <lerner> hi, I have an iso file that contains a movie. I want to extract it to mkv or mp4. If I click on the individual pal files the image appears small, with 5 cm margins. I want to avoid that. Is ffmpeg the tool I need?
[17:57:28 CEST] <lerner> what about mkvtoolnix?
[19:30:55 CEST] <]R[> i have a flv file with audio starting late, is there a way to make ffprobe show me when ? (ie: timecode/frame #)
[19:54:16 CEST] <klaxa> ]R[: you could see if mediainfo shows something, sometimes it displays more stuff than ffprobe i think
[20:24:53 CEST] <shincodex> Hi my people
[20:25:07 CEST] <shincodex> What does the AV stand for anyways
[20:25:20 CEST] <shincodex> awful video?
[20:25:35 CEST] <shincodex> like libavcodec
[20:25:36 CEST] <shincodex> etc
[20:26:53 CEST] <__jack__> audio video ?
[20:27:06 CEST] <shincodex> you say that like its a question
[20:27:08 CEST] <shincodex> you are unsure
[20:27:21 CEST] <__jack__> that's true, I don't really know
[20:27:23 CEST] <shincodex> ffmpeg is the collection of them
[20:27:37 CEST] <shincodex> screw it
[20:27:39 CEST] <__jack__> false : they are parts of ffmpeg
[20:27:44 CEST] <shincodex> PH
[20:27:45 CEST] <shincodex> Oh
[20:27:50 CEST] <shincodex> then what should i call my thing
[20:28:01 CEST] <shincodex> AvideoStreamer : IVideoStreamer
[20:28:06 CEST] <shincodex> but then i was thinking
[20:28:19 CEST] <__jack__> your thing ? dunno what's your thing
[20:28:25 CEST] <shincodex> FFmpegStreamer as a name
[20:29:52 CEST] <klaxa> interesting
[20:29:56 CEST] <shincodex> look
[20:30:00 CEST] <shincodex> is it FFMpeg?
[20:30:02 CEST] <shincodex> ffmpeg?
[20:30:07 CEST] <shincodex> or FFmpeg
[20:30:19 CEST] <klaxa> FFmpeg
[20:30:27 CEST] <klaxa> just look at ffmpeg.org and see the title
[20:30:33 CEST] <shincodex> <redi> https://www.sgi.com/tech/stl/
[20:30:37 CEST] <shincodex> wtf wrong paste
[20:30:38 CEST] <shincodex> ah
[20:30:45 CEST] <shincodex> i forgot i cant paste from windows
[20:30:50 CEST] <klaxa> :)
[20:31:00 CEST] <shincodex> FFmpegStreamer : public IVideoStreamer
[20:58:59 CEST] <CoJaBo> Is is possible to proportionally scale down a clip without erroring out half the time?
[20:59:30 CEST] <CoJaBo> E.g., scale to 180 height, while setting width to the closest legal value
[21:07:42 CEST] <furq> CoJaBo: -vf scale=-2:180
[23:39:13 CEST] <lerner> ffmpeg -crop=out_w=in_h crop=in_h 1.mkv a.mkv < is this right?
[23:40:38 CEST] <llogan> lerner: no. what are you trying to do?
[23:41:54 CEST] <lerner> 1.mkv is a concatenation of 4 vob files (from an iso file). On the 4 sides of the screen there are 3 cm wide "margins" which I want to get rid of, so I need to recode
[23:42:02 CEST] <lerner> llogan, ^
[23:42:24 CEST] <TheDracle> I'm seeing a really strange difference in performance between an FFMPEG I built by hand, and the one I downloaded from Zeranoe.
[23:42:27 CEST] <lerner> on the manpages I found the crop section, which Im trying to use
[23:42:45 CEST] <lerner> https://ffmpeg.org/ffmpeg-filters.html#crop
[23:42:49 CEST] <TheDracle> I'm recording video/audio with gdigrab, and Zeranoe is a lot faster the moment I introduce an audio track.
[23:43:08 CEST] <TheDracle> Literally the same options for both.
[23:43:23 CEST] <TheDracle> I'm recording rawvideo, and pcm just to take encoder performance out of the mix.
[23:43:27 CEST] <llogan> lerner: ffmpeg -i zardoz.mkv -vf crop=iw-100:ih-100 -c:a copy output.mkv
[23:43:55 CEST] <lerner> llogan, I assume zardov is original file?
[23:44:01 CEST] <llogan> yes. it's a terrible movie.
[23:44:02 CEST] <TheDracle> Does anyone have any ideas on what could explain the performance difference? Perhaps something dealing with syncing the video/audio streams?
[23:44:19 CEST] <TheDracle> One big difference is Zeranoe is using pthreads- and I am using win32threads.
[23:44:22 CEST] <lerner> llogan, will that remove 100 pixels from each of the 4 sides?
[23:44:50 CEST] <llogan> it will remove 100 pixels from the width, and 100 from the height.
[23:45:15 CEST] <llogan> default is centered, so 50px from left, 50 px from top, 50 px from right, 50px from bottom
[23:45:29 CEST] <lerner> llogan, so the way to go here is to calculate and maybe get lucky finding the exat number of pixesl to get rid of...
[23:45:53 CEST] <llogan> that's one method. another is to use cropdetect to tell you
[23:46:04 CEST] <ChocolateArmpits> Is there any filter to show motion between frames ?
[23:46:20 CEST] <ChocolateArmpits> I want to produce a motion mask
[23:46:22 CEST] <lerner> llogan, is cropdetect a function in ffmpeg?
[23:47:24 CEST] <llogan> lerner: ffmpeg -i police_academy_9.mov -vf cropdetect -f null -
[23:47:27 CEST] <llogan> http://ffmpeg.org/ffmpeg-filters.html#cropdetect
[23:47:38 CEST] <lerner> aua
[23:47:42 CEST] <llogan> it will spew info about detected black area which you can feed to crop
[23:50:08 CEST] <llogan> ChocolateArmpits: maybe tblend?
[23:54:46 CEST] <ChocolateArmpits> llogan: Thanks, difference filtering could be used, but I'm not sure about how accurate the results are, should have some threshold filtering
[00:00:00 CEST] --- Sat Jul  2 2016