[Ffmpeg-devel-irc] ffmpeg.log.20170807

burek burek021 at gmail.com
Tue Aug 8 03:05:01 EEST 2017


[00:32:21 CEST] <furq> is there no way to select stream type with -map 0:m
[00:32:45 CEST] <furq> doing -map 0:v -map 0:m:language:eng and getting two video streams is a whole lot of fun
[01:51:02 CEST] <markmedes2> So, I found the problem. Apparently I have either a file system corruption or a bad block on the disk. I couldn't copy the file from the usb drive to my computer
[02:32:36 CEST] <jerkey> is it possible to cut a clip from an .mkv that does not start on a keyframe?
[02:34:28 CEST] <JEEB> that has two different readings
[02:34:59 CEST] <JEEB> 1) you want to cut a clip from a matroska file that doesn't start with an IRAP
[02:35:11 CEST] <JEEB> 2) you want to cut a clip that doesn't start with an IRAP from a matroska file
[02:36:27 CEST] <jerkey> i have a movie, i want to cut ten seconds from it, but it will only give me an output that starts at the nearest keyframe (IRAP?) to the -ss ##:##:## i give it
[02:36:39 CEST] <jerkey> i want to cut from a specific second, and it refuses to do that
[02:38:08 CEST] <JEEB> IRAP is a convenient term that was added in the HEVC spec that is an umbrella term for all types of pictures that a decoder can start decoding after random access (RA)
[02:38:54 CEST] <JEEB> since you can either have an IDR picture (all intra + references are to be reset), open GOP intra picture that is a random access point etc.
[02:39:10 CEST] <JEEB> but in general if you cut somewhere that is not an IRAP your result will not be decode'able
[02:39:42 CEST] <JEEB> so you either need to re-encode a part in the beginning until the first GOP ends where you end up
[02:39:59 CEST] <JEEB> or you use something like mp4 edit lists to get the player to throw away initial frames
[02:40:32 CEST] <JEEB> you might test the latter with itsoffset or so
[02:40:37 CEST] <jerkey> ok i am willing to re-encode, do i need to use an edit list file instead of the -ss parameter?
[02:40:38 CEST] <JEEB> (and outputting to mp4)
[02:40:48 CEST] <JEEB> re-encode is something you'll have to do manually
[02:41:04 CEST] <JEEB> in two parts and using parameters that lead to similar enough parameter sets
[02:41:23 CEST] <JEEB> (otherwise you need to make sure at least the latter part of the thing has parameter sets all over the thing
[02:41:42 CEST] <JEEB> anyways, it's almost four here so I'm dropping out
[02:42:49 CEST] <jerkey> ok thanks JEEB
[03:23:37 CEST] <relaxed> furq: it's mapping the same video stream twice?
[03:23:53 CEST] <furq> yeah
[03:24:08 CEST] <furq> it's not a big deal, i just picked the audio stream by number
[03:24:15 CEST] <furq> but i can imagine some batch use cases where that would be really annoying
[03:24:36 CEST] <relaxed> I tried the same options on some anime and it mapped only audio, ass, and one video stream
[03:24:54 CEST] <furq> usually the video stream doesn't have a language tag
[03:24:58 CEST] <furq> but evidently for this file it does
[03:25:21 CEST] <relaxed> right, I don't know why it would have a language set
[03:25:37 CEST] <furq> i've seen someone else with this problem with audio and subtitle streams though
[03:26:35 CEST] <relaxed> in ffmpeg's defense, isn't it giving you what you asked for?
[03:26:42 CEST] <furq> yeah it is
[03:26:55 CEST] <furq> which is why there should be a way to specify a stream type with m
[03:29:54 CEST] <relaxed> right, something like -map 0:m:a,s:language:eng
[03:32:36 CEST] <relaxed> maybe -map 0:a:m:language:eng -map 0:s:m:language:eng would make more sense
[03:39:51 CEST] <relaxed> what was the problem with audio and subtitle streams?
[03:42:21 CEST] <relaxed> furq: you meant the same issue?
[03:45:01 CEST] <furq> yeah
[04:32:52 CEST] <markmedes2> Guys, what's the matter here? I used the option -ec with the flag deblock
[04:32:55 CEST] <markmedes2> Codec AVOption ec (set error concealment strategy) specified for output file #0 (/home/user/Desktop/encoded/kingsman.avi) is not an encoding option.
[04:36:45 CEST] <relaxed> markmedes2: command?
[04:37:28 CEST] <markmedes2> relaxed, time ffmpeg -i /home/user/Desktop/to_encode/KINGSMEN.mts -filter:v scale="640:trunc(ow/a/2)*2" -map 0:0 -map 0:1 -map 0:2 -vcodec libx264 -crf 20 -c:a aac -err_detect ignore_err -ec deblock /home/user/Desktop/encoded/kingsman.avi
[04:42:41 CEST] <relaxed> I think that's a decoding option
[04:43:34 CEST] <markmedes2> hmmm
[04:43:43 CEST] <relaxed> place it before the input
[04:43:44 CEST] <markmedes2> why it was working before?
[04:43:50 CEST] <markmedes2> ah ok
[04:44:04 CEST] <markmedes2> still... why it was working before just fine?
[04:45:05 CEST] <markmedes2> nevermind, now it's working, thank you
[04:45:40 CEST] <relaxed> you're welcome
[04:45:47 CEST] <markmedes2> One more thing: Is there a way to re-encode using libmp3lame and keep audio in sync with video?
[04:46:15 CEST] <relaxed> why wouldn't be in sync?
[04:46:30 CEST] <relaxed> it be*
[04:46:46 CEST] <markmedes2> idk, re-encoded videos with lame are completely out of sync
[04:47:37 CEST] <relaxed> just libmp3lame?
[04:47:46 CEST] <markmedes2> yes
[04:48:00 CEST] <markmedes2> I found this: https://superuser.com/questions/1042988/ffmpeg-audio-out-of-sync-when-transcoding-demuxing-from-dv
[04:48:09 CEST] <markmedes2> but it's too complicated and I don't understand
[04:48:43 CEST] <markmedes2> and not lame related
[04:50:20 CEST] <relaxed> it's off from the start?
[04:50:33 CEST] <markmedes2> yes
[04:50:47 CEST] <relaxed> try -async -1
[04:51:27 CEST] <markmedes2> k
[05:02:35 CEST] <markmedes2> relaxed, I found something. About 1 minute into the movie there is a quick glitch in the video, it's lost for a few seconds. So maybe that's why it's desyncing?
[05:03:11 CEST] <relaxed> yeah, could be
[05:09:43 CEST] <markmedes2> relaxed, the audio track doesn't suffer from the glitch, maybe I can make the video sync to the audio?
[05:11:52 CEST] <relaxed> with a damaged file you might be out of luck
[05:12:51 CEST] <markmedes2> oh well, I give up, thank you bro
[07:17:39 CEST] <xacktm> anyone have issues with nvenc or can get nvenc to work?  I get a "Cannot init CUDA" when I try to capture the screen https://bpaste.net/show/b6dc126a1354
[10:59:38 CEST] <whald> hi! i'm having trouble to let configure pick up my libva (which is installed in a non-standard location). here's my current state of affairs: https://pastebin.com/PE9dDRH5
[11:00:04 CEST] <whald> can s.o. help me figure out why the include directory is not picked up?
[11:02:42 CEST] <furq> whald: PKG_CONFIG_PATH is printed in config.log, check that to make sure it's picking that up
[11:04:06 CEST] <whald> furq, cat ffbuild/config.log | grep PKG_CON gives "PKG_CONFIG_PATH='/home/trem/mdi/playground/lib/pkgconfig'", looks good to me
[11:06:34 CEST] <BtbN> whald, I don't think the libva checks use pkgconfig
[11:06:47 CEST] <BtbN> you need to set the lib and include path yourself in extra-cflags/ldflags
[11:06:58 CEST] <whald> BtbN, ahhh, that's interesting!
[11:07:07 CEST] <whald> BtbN, i'll give it a spin, thanks
[11:09:05 CEST] <darsain> hey guys, will "-map 0:s" select all subtitle streams?
[11:12:57 CEST] <furq> yes
[11:22:35 CEST] <Mavrik> From the first input file :)
[11:23:06 CEST] <darsain> yes yes, I got it. ty :)
[11:23:53 CEST] <darsain> also is there a way how to specify only a video video stream? I have an mkv file where there are 4 video streams, out of which 3 are mjpeg images
[11:24:41 CEST] <darsain> I could do -map 0:v:0, but what if video won't be the first stream?
[11:24:54 CEST] <BtbN> 0:v will always match the first video stream.
[11:25:13 CEST] <darsain> I thought 0:v will match all video streams from 1st file, no?
[11:51:01 CEST] <whald> BtbN, PS: using extra-cflags/ldflags did the trick, thanks! :-)
[13:39:19 CEST] <papi> Hello
[13:39:36 CEST] <papi> Does anyone have experiences with nginx rtmp module?
[15:25:37 CEST] <Bear10> does anyone know how I could decode a jpeg within a filter to get its raw contents?
[15:54:39 CEST] <JEEB> y/23
[16:36:03 CEST] <papi> Hello
[16:36:10 CEST] <papi> Can some1 help me with following issue?
[16:36:11 CEST] <papi> https://groups.google.com/forum/#!topic/nginx-rtmp/vWzKHt3ya9Q
[16:40:31 CEST] <relaxed> papi: first thing to try is a recent version of ffmpeg
[16:41:44 CEST] <papi> I use last version in debian:jessie
[16:41:50 CEST] <papi> It should be very stable version
[16:41:51 CEST] <papi> or not?
[16:43:42 CEST] <relaxed> not. I recommend compiling a recent version or using https://www.johnvansickle.com/ffmpeg/
[16:45:15 CEST] <papi> I tried to compile ffmpeg, but it is very complicated
[16:45:28 CEST] <papi> Too many flags in configure...
[16:45:59 CEST] <relaxed> then use my static build :)
[16:47:59 CEST] <papi> I'll try... ty :)
[16:49:30 CEST] <papi> Hmmmm... my version is 3.2.5 and newest is 3.3.7
[16:49:35 CEST] <papi> I think it's not too old
[16:59:06 CEST] <papi> Can you tell me how to compile your static build pls?
[16:59:54 CEST] <papi> @relaxed
[17:03:12 CEST] <papi> Ignore prev message :D
[17:03:16 CEST] <papi> I am dumb D
[17:03:17 CEST] <papi> :D
[17:04:12 CEST] <papi> Output of your static ffmpeg: https://pastebin.com/nurBnYHs
[17:07:56 CEST] <relaxed> maybe that's why the older build was not working?
[17:08:48 CEST] <relaxed> I don't have any experience with ffmpeg + nginx streaming, sorry
[17:09:53 CEST] <papi> Ok..... I don't think it's problem of older build. Your build won't send play command
[17:12:23 CEST] <Bear10> just going to try one more time incase someone missed it, does anyone know does how I could decode a jpeg within a filter to get its raw contents?
[17:18:14 CEST] <relaxed> Bear10: In a filter? Would this work --> ffmpeg -i input.jpg -f rawvideo output.raw
[17:18:47 CEST] <Bear10> relaxed: not quite, we're trying to change the input.jpg on the fly for livestreams like OBS allows you to change the inputs
[17:19:19 CEST] <Bear10> so I thought one approach would be in the code to create a custom filter and decode at will a specific jpg, however thats resulting a lot more difficult than i imagined
[19:35:47 CEST] <pgorley> hi, does the h264 decoder have a settings to drop frames that contain artifacts?
[20:28:11 CEST] <gwohl> On FFmpeg nightly build, the HEVC decoder is presenting errors like `Could not find ref with POC 340` when streaming adaptively over HTTP but not when decoding that same stream locally. Remotely, decoding gets very distorted with lots of blocking and color artifacts, but nothing bad occurs during local decode. Can anyone point to a likely cause?
[20:34:52 CEST] <Shawn_> Hello. I'm converting a MOV to WebM and the translucency does not look the same. For some reason, the WebM is letting much more of the background through. Any ideas what could cause this?
[20:35:55 CEST] <klaxa> translucency? i don't think vp8/vp9 supports transparent pixels?
[20:36:02 CEST] <furq> vp8 does
[20:36:29 CEST] <klaxa> well color me surprised
[20:36:35 CEST] <furq> oh apparently vp9 does as well
[20:36:45 CEST] <Shawn_> Here is some info: https://developers.google.com/web/updates/2013/07/Alpha-transparency-in-Chrome-video
[20:37:16 CEST] <furq> what pixel format is the mov
[20:37:43 CEST] <furq> if it's rgba or something then maybe swscale is just doing a dodgy conversion
[20:40:13 CEST] <Shawn_> It's Apple QuickTime RLE Video if that helps. How can I check to see if it's RGBA?
[20:40:19 CEST] <furq> ffprobe
[20:40:59 CEST] <furq> it must be argb though because that's the only pixel format qtrle supports with alpha
[20:43:40 CEST] <Shawn_> Here is the output of the FFProbe: https://pastebin.com/AQMZgs78
[20:44:33 CEST] <furq> maybe try -sws_flags dst_range=full
[20:44:51 CEST] <Shawn_> I'll give that a try!
[20:51:06 CEST] <Shawn_> @furq: Getting an error: https://pastebin.com/UV5aeeTi
[21:25:30 CEST] <papi> Hello guys
[21:25:39 CEST] <papi> FFmpeg cannot play RTMP stream from nginx
[21:25:47 CEST] <papi> With VLC I have no problems
[21:25:54 CEST] <papi> I am using FFmpeg 3.2.5
[21:25:57 CEST] <papi> Any solution?
[21:27:05 CEST] <JEEB> test latest master?
[21:27:20 CEST] <JEEB> if it still doesn't work provide a sample RTMP stream and post an issue on trac
[21:41:53 CEST] <nahsi> guys, i'm using mpdecimate filter to get the correct framerate from ~30 fps silent movie which originally was 14-16. The result is very impressive, but not without drawbacks. It drops black frames. There are very little of those frames in the beginning only. How can I tell it not to drop completely black frames?
[21:58:36 CEST] <lacrymology> question: ffserve serves live streams, right? like.. the client doesn't have any control over what it's getting?
[21:59:05 CEST] <lacrymology> I'm trying to find a way to cast to my chromecast that supports seeking
[21:59:07 CEST] <JEEB> lacrymology: ffserver is something that nobody will be able to help you with, so do not look at it
[21:59:21 CEST] <lacrymology> JEEB: lol. ok, but why
[21:59:45 CEST] <JEEB> because it's a thing that has never even been understood by most people. and it seemingly isn't really great at what it does
[22:01:28 CEST] <lacrymology> :)
[22:02:21 CEST] <pgorley> lacrymology: use vlc if you need a streaming server
[22:04:07 CEST] <lacrymology> pgorley: I haven't been able to make it work as I want. Ideally I'd be able to control the stream (pause, seek) either by commands from the client or by just doing it on the server and have the client not break
[22:06:39 CEST] <pgorley> lacrymology: i've never had those issues with vlc, but i wasn't doing anything other than a few tests with it
[22:07:58 CEST] <lacrymology> pgorley: how do you control playback?
[22:09:07 CEST] <pgorley> lacrymology: you should ask the guys at #videolan instead, i haven't fiddled with vlc for months
[22:09:37 CEST] <pgorley> but iirc i would just move the slider to seek in the file
[22:10:45 CEST] <pgorley> don't remember anything breaking
[22:21:00 CEST] <Shawn_> Furq, are you still there? I can't get the -sws_flags to work (https://pastebin.com/UV5aeeTi)
[22:22:23 CEST] <Shawn_> The WebM transparency is working with the exception of partial opacity (i.e. a ghost hand with the background showing through). The ghost hand is letting much more of the background threw than the MOV.
[22:22:37 CEST] <Shawn_> through*
[22:23:24 CEST] <Shawn_> For the parts that are 100% transparent, no issues.
[23:06:21 CEST] <abdul> Hi, im trying to play a v5zap dvbc/annex_a captured stream by using ffmpeg. FFmpeg says 'could not find codec parametersvq=    0KB sq=    0B f=0/0' when i play hd channels but on public free hd channels it works normaly! so is there a special codec needed or something?
[23:25:30 CEST] <timofonic> Hello
[23:26:18 CEST] <timofonic> Does ffmpeg supports DCP? https://en.wikipedia.org/wiki/Digital_Cinema_Package
[23:26:47 CEST] <JEEB> MXF is supported, composition XML not
[23:42:01 CEST] <timofonic> JEEB: Oh, why no? :(
[23:42:08 CEST] <timofonic> JEEB: Any hopes?
[23:42:45 CEST] <JEEB> now the real question is, do you /require/ the info that's in the XML. in libavformat itself
[23:43:02 CEST] <JEEB> I've had some clips in DCP format and I just ignored the XML
[23:43:16 CEST] <JEEB> load video, load audio, know how the flying fuck the audio was mixed
[23:43:20 CEST] <JEEB> and off you go
[23:44:09 CEST] <timofonic> JEEB: It's just for convenience in a projection room, just looking for a friend. I'm not a usual consumer of DCP
[23:44:20 CEST] <JEEB> well the problem with that stuff then
[23:44:29 CEST] <JEEB> is the fact that software jpeg2000 decoding is *slow*
[23:44:40 CEST] <JEEB> you can already play the MXF Files together with mpv or so
[23:44:44 CEST] <JEEB> or VLC
[23:44:55 CEST] <JEEB> VLC even has support for the XML I think if you're a lazy person like that
[23:45:21 CEST] <timofonic> JEEB: Oh, interesting :)
[23:46:32 CEST] <timofonic> JEEB: Now I'm having a really weird HDD error. Going to ask elsewhere. Thanks a lot
[23:52:19 CEST] <abdul> can it be a receiver hardware problem? the decoder supports HVEC but not h264/h265
[23:54:23 CEST] <abdul> my tv can handle all these streams without any decoder or in germany called 'hd card'
[00:00:00 CEST] --- Tue Aug  8 2017


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