[Ffmpeg-devel-irc] ffmpeg.log.20161012

[burek]

[00:45:26 CEST] <qubodup> hello, is it possible to do a wipe transition with ffmpeg? GIF animation of what I mean: http://i.giphy.com/YBnXdwgJkb7LW.gif
[00:46:41 CEST] <qubodup> -filter_complex "[0:v]crop=w=t*200:h=1080:x=0:y=0:keep_aspect=0:exact=1[cropout];[1:v][cropout]overlay[out]" -map '[out]' unfortunately fails, apparently because of trying to use "t" to define "w" and also "exact" seems to not work even though it's in the docs
[01:14:59 CEST] <yaymuffins> Hello
[01:16:37 CEST] <yaymuffins> I try to extract a frame from a couple of videos as an image, they are disorganized so I'd like to extract the title card and use it to rename appropriately
[01:17:21 CEST] <yaymuffins> the issue is, I would need to seek "in reverse" to be sure that the timing is right for each video
[01:19:36 CEST] <yaymuffins> specifying a time minus the end position, instead of the default time + start position
[01:33:11 CEST] <plujon> ffmpeg -i foo.ogv foo.tls # creates a tls that vlc can play, but hls.js can not
[01:34:04 CEST] <plujon> s/tls/ts/
[01:34:59 CEST] <plujon> I know next to nothing about video encoding.  How can I create a foo.ts that an html5 player such as hls.js can process?
[01:36:30 CEST] <furq> -c:v libx264 -c:a aac
[01:36:54 CEST] <furq> or -i foo.ogv foo.mp4
[01:36:58 CEST] <furq> you can just play that in a video tag
[01:39:49 CEST] <plujon> furq: That incantation works!  Thanks!
[01:40:02 CEST] <plujon> (I'm specifically trying to test hls.js)
[04:51:57 CEST] <kuroro> hello, im interested in getting a motion vector data in text or parsable format. is there a way I can modify the following command to do that?
[04:52:00 CEST] <kuroro> ffmpeg -flags2 +export_mvs -i input.mp4 -vf codecview=mv=pf+bf+bb output.mp4
[04:54:43 CEST] <FlyingJester> How do I pass AVOptions to an encoder?
[06:22:28 CEST] <thelamer> does anyone know how to create a mosaic from a multi program transport stream ? (udp input)
[06:23:54 CEST] <thelamer> IE I can define a single stream "-i udp://127.0.0.1:6910 -map i:0x44c" but map is on the output so I cannot use filter_complex to define multiple inputs off the single UDP port
[06:25:27 CEST] <thelamer> general concept for the multi program out to a file http://pastebin.com/raw/9yjwiczB
[11:30:06 CEST] <Kadigan_KSB> Hey. I was wondering -- can ffmpeg be used to recover a file on damaged optical media?
[11:30:29 CEST] <Kadigan_KSB> Like, if I could tell it to simply insert blank (black/silence) where the damaged portions are, or to skip them after n retries or somesuch...?
[11:30:51 CEST] <Kadigan_KSB> The source material is in .flv container, h264/aac.
[11:35:47 CEST] <tdr> Kadigan, try recoverig the media using cdparanoia or similar first?
[11:39:30 CEST] <Kadigan_KSB> I'm attempting photorec, we'll see.
[11:46:48 CEST] <furq> time to break out the toothpaste
[11:54:16 CEST] <Kadigan_KSB> The disc actually has fairly localized damage, but I think it extends well into the reflective area.
[11:54:33 CEST] <Kadigan_KSB> Which is to say, no amount of grinding will help, ever.
[12:00:02 CEST] <nonex86> i remember some guys tried to "fix" scratches on disc by putting it to refrigerator for some time
[12:35:46 CEST] <cluelessperson> Hi all, what's a simple command to view my webcam on screen?
[13:23:33 CEST] <senyai_> Hi! ffmpeg log says "If you want to help, upload a sample of this file to ftp://upload.ffmpeg.org/incoming/", well, the ftp is not up.
[13:46:44 CEST] <senyai_> Anyone here responsible for ftp://upload.ffmpeg.org ?
[15:16:28 CEST] <ubitux> any lossless audio codec supported in mp4 in mind?
[15:16:36 CEST] <ubitux> (not alac for mov, i'm looking for mp4)
[15:16:52 CEST] <ubitux> pcm s16, alac nor flac are supported
[15:32:02 CEST] <c_14> mpeg4-als, but ffmpeg doesn't encode that
[15:58:17 CEST] <nonex86> does the version of libvpx matter? i build ffmpeg with libvpx 1.6, static build on windows and got an error: [libvpx @ 0000007CE9B090C0] v1.6.0
[15:58:17 CEST] <nonex86> [libvpx @ 0000007CE9B090C0] Failed to initialize encoder: ABI version mismatch
[15:58:39 CEST] <c_14> You have to link against the version you built against
[15:59:09 CEST] <nonex86> well, i link it againts 1.6 libs i built myself :/
[15:59:28 CEST] <nonex86> ill check once more
[15:59:36 CEST] <kepstin> my guess is that the build is using the wrong headers (maybe an old version)
[16:00:57 CEST] <nonex86> yeah, this is more likely...
[16:05:21 CEST] <nonex86> kepstin: yeah, thats it, i found headers from previouse version, thanks for pointing!
[16:05:54 CEST] <nonex86> god, now i have to rebuild it several times :D
[18:28:54 CEST] <furkan> hi, ffplay has an option "-fflag nobuffer", is it possible to set this flag with ffmpeg as well?
[18:29:13 CEST] <furkan> *-fflags nubuffer
[18:30:56 CEST] <DHE> it wouldn't be of a lot of use because most [good] codecs will also buffer by default, and there are quality/bitrate penalties under certain situations for not using them
[18:34:25 CEST] <furkan> all i'm doing is saving an audio stream to disk, but sometimes after maybe about an hour of streaming, it seems to skip a frame... not sure why that happens, i thought maybe the buffer fills up
[18:35:24 CEST] <DHE> why would it? the disk would be fast enough to keep up with the network stream.
[18:35:27 CEST] <furkan> no errors in the console though, so i'm not sure really
[18:35:41 CEST] <DHE> unless something causes ffmpeg to block long enough that the network layer itself is dropping packets
[18:36:31 CEST] <furkan> true... i'm not really sure how i could debug it, but just had that random thought
[18:37:02 CEST] <furkan> didn't spend too much time on it, because priorities lol
[19:03:39 CEST] <SchrodingersScat> I record some streams with multiple machines just in case of things like that.  1/10 of my captured data seems to error, so I run 6 machines.
[20:35:42 CEST] <blue_misfit> I'm seeing some conflicting info on this, but if I have a 60p input and want ffmpeg to make a 30p output via throwing away half the frames (i.e. the equivalent of SelectEven() in AviSynth) how should I do this?
[20:38:11 CEST] <agrathwohl> I've always done this by setting frame rate i.e. `-r 24000/1001` and then setting `-vsync 1`
[20:38:24 CEST] <agrathwohl> I'd also be very interested to learn if this is the right way or wrong way to do it
[20:54:40 CEST] <kuroro> is there a video player that lets me see the video frame-by-frame or at least tell which frame # im currently in?
[20:57:19 CEST] <DHE> frame number isn't always available. I use mpv, it lets you get millisecond timestamps on the OSD
[20:57:47 CEST] <SchrodingersScat> I've been using mpv too, . to step forward a frame
[20:58:23 CEST] <kuroro> ic. whats osd?
[20:58:48 CEST] <kuroro> how come there's no open source equivalent of something like this for h264?
[20:58:49 CEST] <kuroro> http://www.elecard.com/assets/images/products/screenshots/hevc-analyzer/0_main_thumbnails_stream_decoded_buffer.png
[21:00:09 CEST] <kuroro> anyway, i'll give mpv a try as well
[21:01:22 CEST] <furq> blue_misfit: -vf fps=30
[21:01:22 CEST] <SchrodingersScat> that looks pretty fancy
[21:01:47 CEST] <furq> kuroro: on-screen display
[21:03:15 CEST] <kuroro> it just found this as well - https://github.com/lheric/GitlHEVCAnalyzer
[21:05:37 CEST] <SchrodingersScat> kuroro: neat
[21:06:17 CEST] <DHE> kuroro: See https://trac.ffmpeg.org/wiki/Debug/MacroblocksAndMotionVectors
[21:06:43 CEST] <furq> neat
[21:06:48 CEST] <kuroro> yeah, i saw that yesterday
[21:07:01 CEST] <kuroro> but id be great to see what exact frame im currently in, and see the numbers
[21:07:36 CEST] <kuroro> raw numbers (currently using the ./extract_mvs and i wanna map it to the ffmpeg -flags2 +export_mvs output)
[21:18:55 CEST] <SchrodingersScat> wow, that's great, the arrows are amazing, what's that used for?
[21:23:13 CEST] <lasser> Hello! I desperately try to stream live content to Youtube via ffmpeg. Nothing seems to work, and I fear, that the most interfering factor is me. I don't beliebe that there are errors in ffmpeg or YT but only in my way to get it right.
[21:30:36 CEST] <kuroro> SchrodingersScat: i think its used by b-frames and p-frames for decoding. im not sure if my terminology is correct, but way i understand its kind of a "diff" between frames but containing direction information
[21:31:41 CEST] <DHE> "motion compensation"
[21:31:55 CEST] <DHE> I think that's the technical tetrm
[21:31:57 CEST] <DHE> term
[21:32:57 CEST] <Mavrik> Basically instead of writing the image data for next frame, only the vector describing where that block of picture has moved is saved.
[21:33:07 CEST] <Mavrik> So basically you store two numbers instead of whole block
[21:33:28 CEST] <Mavrik> Since cameras tend to pan and moved in linear way a lot that's very efficient :)
[21:34:11 CEST] <DHE> after all, MPEG stands for 'Motion Picture' Encoding Group :)
[21:36:38 CEST] <TD-Linux> kuroro, also check out http://aomanalyzer.org/
[21:36:55 CEST] <TD-Linux> (it'll take a bit to load, and if you want to see motion vectors, you need to step past the first frame of course)
[21:41:44 CEST] <lasser> I need a little help in shaping the right ffmpeg command.
[21:42:52 CEST] <lasser> for now I'm using "$ ffmpeg -f mjpeg -i Bilder/schwalben_klein.jpg -re -f mp3 -i "rockboxbackup/Hörspiele/Uni Auditorium - Physik - Vorlesung von Harald Lesch - Quantenmechanik.mp3" -preset veryfast -flags +global_header -ar 44100 -ab 128k -s 320x240 -vcodec h264 -pix_fmt yuv420p -g 20 -vb 250k -profile:v baseline -r 10 -strict -2 -f flv "rtmp://a.rtmp.youtube.com/live2/MyStreamID"
[21:43:07 CEST] <lasser> just for testing...
[21:43:10 CEST] <Mavrik> lasser, people will be happy to help you, but you'll have to pastebin the command and output somewhere.
[21:43:16 CEST] <Mavrik> And then say what the exact problem is.
[21:43:42 CEST] <furq> lasser: does that correctly output to a file or piped to a player
[21:44:01 CEST] <furq> it doesn't look like you're looping the input jpeg
[21:50:23 CEST] <kuroro> TD-Linux: looks pretty cool. is that your project?
[21:50:51 CEST] <TD-Linux> kuroro, mbx wrote it, but I do work on the video codec it's analyzing
[21:51:39 CEST] <kuroro> nice
[21:51:54 CEST] <lasser> Mavrik, sorry, here it is: http://pastebin.com/EwjFz17S
[21:52:37 CEST] <Mavrik> hrmf.
[21:52:46 CEST] <Mavrik> And the issue you're seeing?
[21:53:11 CEST] <furq> lasser: like i said, you're not looping the input jpeg
[21:54:08 CEST] <furq> get rid of -f mjpeg and add -loop 1 in its place
[21:54:17 CEST] <furq> you probably also want to use aac audio for youtube
[21:54:25 CEST] <lasser> YT seems to get some data, but the live stream does not start.
[21:54:59 CEST] <lasser> furq: ok, I'll try that, one moment, please
[21:55:16 CEST] <furq> add -shortest as well
[21:55:27 CEST] <Mavrik> Also set FPS to 30
[21:55:31 CEST] <Mavrik> not 10
[21:56:10 CEST] <furq> 10 should work but yeah, try it anyway
[21:56:14 CEST] <furq> mp3 should work as well
[21:58:54 CEST] <lasser> woaaah, i can see and hear something. That was fast, guys...
[21:59:55 CEST] <lasser> -loop 1 did the trick
[22:00:01 CEST] <furq> also there's no reason to pass -vb 250k if it's a single repeated frame
[22:00:06 CEST] <furq> the actual bitrate should be much lower than that anyway
[22:05:26 CEST] <lasser> THANK YOU!
[22:10:26 CEST] <benbro> is it safe to run it even if there is no audio channel?
[22:10:28 CEST] <benbro> ffmpeg -i in.mp4 -c:a copy -c:v copy -movflags +faststart out.mp4
[22:10:46 CEST] <benbro> I want to move the flags to the start without re-encoding
[22:11:08 CEST] <BtbN> Then use qt-faststart
[22:11:48 CEST] <benbro> BtbN: part of ffmpeg or separate?
[22:13:14 CEST] <kuroro> btw: i finally found a video player that displays frame number
[22:13:20 CEST] <kuroro> https://support.apple.com/kb/DL923?locale=en_US
[22:13:25 CEST] <kuroro> quicktime player (version 7)
[22:13:51 CEST] <kuroro> http://superuser.com/a/543045 shows how to do it
[22:13:55 CEST] <benbro> BtbN: my command is wrong? I want to avoid installing another tool
[22:14:22 CEST] <BtbN> -c copy is enough. But it pointlessly remuxes the entire file.
[22:15:21 CEST] <benbro> BtbN: qtfaststart is a python tool?
[22:16:08 CEST] <benbro> BtbN: without reencoding remuxing will probably won't take too long
[22:16:23 CEST] <BtbN> it still moves a lot of data around and potentialy causes issues.
[22:16:44 CEST] <BtbN> And i think the movflag faststart just internally calls qt-faststart after it's done writing the file.
[22:16:52 CEST] <BtbN> So just call it on the original file.
[22:18:14 CEST] <benbro> BtbN: I'll do that. I see qt-faststart is part of the ffmpeg package on ubuntu
[22:18:25 CEST] <benbro> the python package is not needed here
[22:18:48 CEST] <kuroro> yay! i found something interesting
[22:19:39 CEST] <kuroro> if there's a sudden change in scene, there would be no motion vector information for that frame
[22:19:50 CEST] <benbro> BtbN: can qt-faststart work inplace? or do I have to create another file?
[22:20:14 CEST] <kuroro> i.e. person a talking, next frame shows person b talking. (sudden shift, no motion vector)
[22:20:22 CEST] <kuroro> could be used to find breakpoints
[22:20:42 CEST] <BtbN> benbro, pretty sure it needs a new file
[22:20:48 CEST] <benbro> BtbN: thanks
[22:21:06 CEST] <BtbN> kuroro, isn't that because encoders usually auto-detect scene changes and insert an I frame?
[22:23:16 CEST] <kuroro> hmm, not sure, let me check if that frame is an iframe
[22:23:18 CEST] <kuroro> i frame
[22:23:26 CEST] <furq> anecdotally, moving the moov atom takes longer than remuxing
[22:23:40 CEST] <furq> especially if you make the mistake of trying to run several jobs in parallel on hard disks
[22:29:33 CEST] <kuroro> BtbN: oh interesting, yeah your right
[22:29:52 CEST] <kuroro> so basically, can you also breakpoints of an video via the presence of an I frame?
[22:29:57 CEST] <kuroro> a video*
[22:30:09 CEST] <kuroro> find breakpoints
[22:31:04 CEST] <kuroro> looks like it works
[22:31:07 CEST] <kuroro> this is awesome
[22:32:54 CEST] <cynar> hi all. Does anyone know where i can get more info on libdc1394 module in ffmpeg? https://www.ffmpeg.org/ffmpeg-devices.html#toc-libdc1394
[22:34:26 CEST] <cynar> I'm trying to get a stream of some sort from a point grey usb 3.0 camera. The easy options all didn't work, and ffmpeg has just enough info to suggest it can be done, but not enough to point me to how.
[22:42:50 CEST] <c_14> cynar: I just read the source, it'll always pick the first camera it finds and you can set video_size, pixel_format and framerate
[22:46:27 CEST] <okarusty> hi, i'm having some issues with ffmpeg attempting to get two of my ip cameras to stream to youtube (neither video sources provide an audio input, which is why i'm using the nullsrc=).  http://pastebin.com/p1fgzmB8
[22:46:39 CEST] <okarusty> ffmpeg eventually stops with:
[22:46:39 CEST] <okarusty> [flv @ 0x7fa7f7800600] Failed to update header with correct duration.A dup=0 drop=63 speed=   0x
[22:46:42 CEST] <okarusty> [flv @ 0x7fa7f7800600] Failed to update header with correct filesize.
[22:50:51 CEST] <cynar> c_14: hate to be a total noob, could you give me an example of how it should look? I've always found ffmpeg awesome, but a little opaque.
[22:52:19 CEST] <c_14> cynar: ffmpeg -video_size 1280x720 -pixel_format yuv420p -framerate 30 -i 0 out.mkv
[22:52:24 CEST] <c_14> should probably do it
[22:55:47 CEST] <cynar> ok, that gives me a error: 0: No such file or directory
[22:56:24 CEST] <c_14> okarusty: you probably want to use the hstack filter, the deinterlace option is deprecated use the yadif filter (or one of the other deinterlacing filters), you're not setting a video bitrate anywhere so it'll default to crf 23 (which may fluctuate to much for streaming). Don't know why it's giving that error though. Your version of ffmpeg might be old
[22:57:55 CEST] <c_14> cynar: is this dc1394-1 or dc1394-2?
[22:58:33 CEST] <cynar> not sure tbh
[22:58:58 CEST] <c_14> Well, the only one that references the filename is -1 so it's pbobaly that
[22:59:28 CEST] <cynar> been using libdc1394, but i'm well out of my depth already.
[23:02:21 CEST] <c_14> Do you happen to know the name of your dma device file?
[23:03:57 CEST] <cynar> ?
[23:05:01 CEST] <cynar> might have also found an additional problem. my copy of ffmpeg wasnt compiled with the flag enabled. attempting to compile it now. Will get back if it doesn't fix it, if that's ok?
[23:05:14 CEST] <c_14> sure
[23:07:30 CEST] <cynar> thanks for your help already as well. :)
[23:09:59 CEST] <benbro> when compiling ffmpeg from source, am I supposed to get a qt-faststart binary?
[23:10:02 CEST] <benbro> because I don't se it
[23:11:02 CEST] <furq> make qt-faststart
[23:12:24 CEST] <benbro> furq: ok. it's "make tools/qt-faststart"
[23:12:37 CEST] <benbro> do I need only the binary or also the .so?
[23:12:55 CEST] <benbro> I mean the qt-faststart.o file too?
[23:13:01 CEST] <furq> you don't need the .o
[23:14:07 CEST] <benbro> furq: I'm getting ffmpeg and ffmpeg_g binaries
[23:14:11 CEST] <benbro> what is _g?
[23:14:17 CEST] <furq> debug symbols
[23:15:01 CEST] <benbro> thanks
[23:15:15 CEST] <okarusty> c_14: thanks i'll play around these options you suggested.
[23:21:54 CEST] <benbro> furq: where can I find the binaries after running make?
[23:22:03 CEST] <benbro> and how do I install qt-faststart after make?
[23:45:37 CEST] <okarusty> c_14: i managed to get it working with those options you suggested, thanks!  all i wanted to do was make sure this was possible, and definitely was (https://youtu.be/ruO2GXDUdnM), time to donate!
[00:00:00 CEST] --- Thu Oct 13 2016