[Ffmpeg-devel-irc] ffmpeg.log.20160731

Mon Aug 1 03:05:01 EEST 2016

[03:02:46 CEST] <medya> can you concatanate multiple .avi files and at the asme time convert outpfile to mp4
[03:03:00 CEST] <medya> so lets say you have 3 avi files, you want one mp4 file
[03:03:11 CEST] <medya> how to combine concatante and convert to mp4 at same time?
[03:19:35 CEST] <DHE> there's a concatenate input format that will assemble the inputs. see the trac wiki
[03:23:09 CEST] <medya> what is trac wiki
[03:24:17 CEST] <medya> I dont see one here https://trac.ffmpeg.org/wiki/Concatenate
[03:24:20 CEST] <medya> it is all -copy
[03:24:23 CEST] <medya> I dont want copy
[03:25:08 CEST] <DHE> then scroll down to the "different codecs" bit
[03:25:18 CEST] <DHE> also note that's codec copy, not container copy
[03:27:34 CEST] <medya> DHE thats for different codes of input
[03:27:40 CEST] <medya> all my inputs are avi
[03:27:46 CEST] <medya> I just want diffrent ouptput
[03:27:57 CEST] <medya> the doc talks about if I have bunch of files with diffrent codecs
[03:32:58 CEST] <DHE> I fear you are confusing "codec" and "container". h264, mpeg2 and sorenson are codecs. avi, mp4 and webm are containers.
[03:39:03 CEST] <medya> well I have 3 files, with avi contrainers, I want all to be concatanted into one file with h264 codec and mp4 container
[03:39:06 CEST] <medya> how can I do that?
[04:18:30 CEST] <buff3r> hi trying to satisfy the output format for a pipe
[04:18:41 CEST] <buff3r> (trying to save a png clip from a video)
[04:19:24 CEST] <buff3r> does anyone know how to specify a png for pipe:1?
[04:19:25 CEST] <bp0> satisfy = specify?
[04:19:40 CEST] <buff3r> i tried -f png_pipe but that didn't work
[04:19:44 CEST] <buff3r> yes
[04:19:50 CEST] <furq> -f image2pipe
[04:20:13 CEST] <furq> it doesn't sound like you need a pipe though
[04:20:34 CEST] <buff3r> i think that worked
[04:21:14 CEST] <buff3r> furq: yeah but i plan on using this as part of a python program
[04:21:36 CEST] <buff3r> bp0: yes specify, thanks
[04:40:28 CEST] <zumba_addict> hi folks, i ran ffmpeg -i on an mp4 and I got this - Stream #0:0(eng): Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv), 1280x720 [SAR 1:1 DAR 16:9], 139 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 29.97 tbc (default)
[04:40:38 CEST] <zumba_addict> I can't see the video but I can hear the audio loud and clear
[04:40:55 CEST] <zumba_addict> what is that format? I've never seen one like that
[04:43:14 CEST] <furq> h.265
[04:45:51 CEST] <zumba_addict> looks like i need to update mplayer to play it
[04:45:58 CEST] <zumba_addict> vlc was able to play it
[04:46:16 CEST] <zumba_addict> is it better than h.264?
[04:46:31 CEST] <bp0> in ways
[04:46:50 CEST] <zumba_addict> k
[04:55:56 CEST] <zumba_addict> WOW, https://www.youtube.com/watch?v=qL22L0mRSDs
[04:56:03 CEST] <zumba_addict> if it's true, WOW
[04:56:39 CEST] <zumba_addict> how can I check if my ffmpeg has support for hevc?
[04:57:01 CEST] <zumba_addict> I'd like to encode few clips so I can see for myself
[05:01:01 CEST] <furq> ffmpeg -version | grep x265
[05:01:49 CEST] <furq> i wouldn't get your hopes up too much
[05:12:46 CEST] <zumba_addict> why?
[05:13:02 CEST] <zumba_addict> so x265 is still experimental?
[05:13:05 CEST] <furq> it's not that much better than x264 and it's much slower
[05:13:18 CEST] <zumba_addict> slower in terms of reencoding?
[05:13:30 CEST] <furq> in terms of encoding and decoding
[05:13:38 CEST] <zumba_addict> more cpu hungry then
[05:15:49 CEST] <furq> it's about 5-10 times slower than x264 -preset veryslow if you want to see measurable gains
[05:18:05 CEST] <zumba_addict> wow, ouch
[05:18:17 CEST] <zumba_addict> not worth it then
[05:18:39 CEST] <zumba_addict> veryslow is really slow, now with 5-10 times even slower, :D
[05:21:12 CEST] <furq> it's also not widely supported yet
[05:21:37 CEST] <furq> although i guess you know that since you couldn't play it
[13:34:13 CEST] <Fyr> is it possible to create a video with alpha channel then merge this video with another?
[13:34:54 CEST] <JEEB> yes, you can overlay things
[13:52:47 CEST] <wallbroken> i tried encoding in 32 and 64 bit mode
[13:52:56 CEST] <wallbroken> total different output files i get
[13:53:12 CEST] <Fyr> JEEB, so it's possible to create text placed in half-transparent box and the put it onto an image?
[14:05:01 CEST] <JEEB> Fyr: yes although for text I would probably use ASS subtitles with custom fonts and positioning etc
[14:05:27 CEST] <Fyr> JEEB, do you have a manual for this?
[14:06:19 CEST] <JEEB> look at aegisub with regards to how create the ASS and then use the ass subtitle filter
[14:06:45 CEST] <JEEB> or just do it your way and have an overlay clip with alpha
[14:25:00 CEST] <maziar> hi
[14:26:14 CEST] <maziar> i want to stream from my hdmi to m3u8 , is it posible? **i have nginx for it
[14:26:59 CEST] <maziar> how can get input from hdmi
[14:27:42 CEST] <Fyr> JEEB, do you have an example for Title, like text lying towards camera?
[14:31:18 CEST] <maziar> Fyr would you please kindly help me ? i want to stream from my HDMI input, is it possible ?
[14:31:42 CEST] <Fyr> I've never streamed with FFMPEG.
[14:37:56 CEST] <maziar> is there any body ?
[14:38:26 CEST] <maziar> Fyr do you know how to record from hdmi
[14:38:34 CEST] <Fyr> no
[14:38:41 CEST] <Fyr> I've used only OBS.
[14:38:53 CEST] <maziar> Fyr sorry what is OBS ?
[14:39:14 CEST] <Fyr> https://obsproject.com/
[14:42:18 CEST] <maziar> is there any body know how to capture from HDMI
[15:00:01 CEST] <iive> maziar: hdmi captures are rare and expensive. are you sure you don't want to just capture the computer screen?
[15:01:05 CEST] <bencoh> blackmagic isn't *that* expensive, but ... yeah.
[15:01:30 CEST] <maziar> iive yes i want to capture input from hdmi
[15:03:18 CEST] <iive> maziar: do you have the hardware capture?
[15:03:43 CEST] <maziar> iive what do you mean ?
[15:04:18 CEST] <iive> you need some device to capture the signal.
[15:04:42 CEST] <iive> you can't do it with bare hands.
[15:05:35 CEST] <iive> screen capture is easier, because you take the image from the video card memory. but once the hdmi signal is out, you need a capture card.
[15:09:15 CEST] <iive> if you are under linux, x11grab does the screen capture. look the manual/documentation
[15:10:25 CEST] <iive> https://trac.ffmpeg.org/wiki/Capture/Desktop
[15:21:45 CEST] <jpleau> hi, I can get a AVCodecParameters struct with AVStream.codecpar. How can I get the long name of the codec?
[15:24:32 CEST] <durandal_1707> with that struct only? Pick codec id and then find its long name using codec_desc struct
[15:25:04 CEST] <durandal_1707> that one should be global
[15:25:34 CEST] <jpleau> Yes I had codec_ic, was not aware of codec_desc though
[15:25:39 CEST] <jpleau> er, codec_id*
[15:26:03 CEST] <jpleau> thanks durandal_1707
[16:14:38 CEST] <Fyr> guys, how does concatenation work if the framerates are different?
[16:42:42 CEST] <Polochon_street> Hi ! What is the standard procedure to have both AVCodec and AVCodecContext from an opened AVFormatContext ? AVCodec first, or AVCodecContext ?
[16:59:22 CEST] <cyphix> I'm using the following ffmpeg command to create gifs : ffmpeg $quiet -v warning -i lossless.mkv -i $gif_palette -lavfi "$video_options [x]; [x][1:v] paletteuse" -y $file.$ext. I would like to store this command in a file to reuse it later. But to do so, I have to remove the double quotes inside the command. But doing so, when I use it, I get "Unable to find a suitable output format for [x]. Is [x] some kind
[16:59:24 CEST] <cyphix> of expanded variable?
[17:06:14 CEST] <cyphix> nevermind, I found how to solve it!
[17:44:17 CEST] <Polochon_street> is avcodec_open2 usable with an av_find_best_stream'd codec ? It doesn't seem to work on my case :|
[18:14:03 CEST] <kdehl> Greetings.
[18:17:10 CEST] <kdehl> I want to merge two video streams into one video with the original videos shown in parallel. So far so good, this is the command I use:
[18:17:18 CEST] <kdehl> ffmpeg -i left.mp4 -i right.mp4 -an -y -filter_complex "pad=w=in_w*2[padded]; scale=544:408[right_scaled]; [padded][right_scaled]overlay=W/2" output.mp4
[18:17:24 CEST] <kdehl> It works well.
[18:18:10 CEST] <kdehl> I just wonder whether I can replace that 544:408 with a reference to the size of the video in the first filter chain?
[18:18:27 CEST] <kdehl> Pardon me if I use incorrect terminology, but I think you understand what I mean.
[18:19:42 CEST] <c_14> no, filters can only access the variables of their input. not of other filters in the graph
[18:20:24 CEST] <kdehl> Okay, thank you very much.
[18:21:00 CEST] <kdehl> On other words, I need to make a bash script in order to automate the process.
[18:25:40 CEST] <c_14> or any other scripting language, yes
[18:26:47 CEST] <kdehl> Right.
[18:28:06 CEST] <kdehl> So if I understand it correctly, the unnamed inputs in the filter graph are connected to the input streams specified by the -i parameter in the order that they are given?
[18:29:49 CEST] <c_14> Probably, but I wouldn't depend on it. It's better to explicitly name them.
[18:32:52 CEST] <kdehl> I couldn't figure out how to do that.
[18:33:34 CEST] <kdehl> Never mind.
[18:33:36 CEST] <kdehl> It's in the manual.
[18:36:03 CEST] <kdehl> Heh, I was reading a bad guide.
[19:09:45 CEST] <DelphiWorld> SUP everyone
[20:40:18 CEST] <Fyr> guys, when concatenating, I see crap in the place where supposed to be video.
[20:40:37 CEST] <Fyr> is it happening because of concatenation protocol?
[20:41:46 CEST] <Fyr> I'm concatenating the four videos, each of them has the same encoders, sample_fmt, pix_fmt, frame rate, ar.
[20:42:12 CEST] <furq> what container
[20:42:15 CEST] <Fyr> however, between the second and the third video thereis only artifacts.
[20:42:17 CEST] <Fyr> MKV
[20:42:24 CEST] <furq> you can't use the protocol for mkv
[20:42:26 CEST] <furq> use the demuxer
[20:43:27 CEST] <Fyr> furq, do you mean -f concat -i my_list.txt, as mentioned in the wiki?
[20:43:36 CEST] <furq> yes
[20:43:46 CEST] <Fyr> it's exactly what I'm doing.
[20:43:55 CEST] <Fyr> I tried MP4.
[20:44:03 CEST] <Fyr> it didn't work out either.
[20:46:54 CEST] <JEEB> concat in FFmpeg in various ways is a horrible hack, so depending on the container and other things it might fail. I think the concat filter might be the least bad alternative? it requires re-encoding of course
[20:47:03 CEST] <JEEB> because the stuff is concatenated after decoding
[20:47:24 CEST] <Fyr> I don't like re-encoding. ='(
[20:47:45 CEST] <Fyr> every file in the list is played without causing troubles.
[20:47:48 CEST] <Fyr> =/
[20:47:52 CEST] <JEEB> well then you always have to make sure that your parameter sets etc don't change
[20:48:04 CEST] <JEEB> because otherwise you can have fun when you seek into another concatenated stream
[20:48:17 CEST] <JEEB> many files only have the parameter sets either off-band or in the first IRAP
[20:48:32 CEST] <JEEB> now guess what happens when you don't pass the point where the parameter sets are
[20:48:43 CEST] <JEEB> and seek from file A to file B contents
[20:48:43 CEST] <Fyr> artifacts
[20:48:50 CEST] <JEEB> more like garbage I guess
[20:49:10 CEST] <JEEB> I guess in some cases it might not be lethal
[20:49:22 CEST] <JEEB> but then again in other cases and depending on the decoder they can be lethal
[20:49:41 CEST] <JEEB> that is why in broadcast each IRAP contains the parameter sets
[20:50:05 CEST] <JEEB> to make sure the decoder has the correct stuff at that random access point and can start playback
[20:52:43 CEST] <Fyr> change of the container did the trick.
[20:53:15 CEST] <JEEB> yeah, depending on container the timestamps or whatever can go woo-woo when it hits the next file
[20:53:58 CEST] <JEEB> in any case, concat is something that everyone wants but that is not always easy to attain properly
[20:54:22 CEST] <JEEB> thankfully I don't need the feature (yet), all my use cases have been with re-encoding so the video filter has been good enough
[20:54:23 CEST] <Fyr> if somebody is interested, MPEG-TS is way better for concatenation than MKV and MP4.
[20:54:42 CEST] <JEEB> yes, MPEG-TS seems to be one of the least awful alternatives when you are using the demuxer or the protocol
[21:53:16 CEST] <Fyr> guys, I've just performed concatenation with concat filter and found out that it produces video of crappy quality.
[21:55:03 CEST] <c_14> you probably just forgot to set video encoding options
[21:55:32 CEST] <Fyr> is it possible to set stream copying?
[21:55:41 CEST] <c_14> no
[21:56:01 CEST] <Fyr> then how do I keep the quality?
[21:56:35 CEST] <c_14> pick a decent video codec with decent quality settings
[21:56:41 CEST] <c_14> like libx264 around crf 23 or so
[23:09:19 CEST] <DelphiWorld> hey guys
[23:09:37 CEST] <DelphiWorld> please someone try to help me with vaapi? my streams are not accepted by any streaming server...
[23:10:16 CEST] <chovy> should ffmpeg process terminate when a 403 request is made for a key?
[23:16:53 CEST] <DelphiWorld> can ffmpeg be a rtsp server itself, and a client send to it?
[23:17:01 CEST] <DelphiWorld> sory but client receive from ffmpeg
[23:23:59 CEST] <DelphiWorld> furq: here?
[23:24:48 CEST] <neflux> Yo! I'm wondering how can I concat a 1 frame video generated from a still image with a video file (so that the image would be the first frame of the output video)?
[23:26:57 CEST] <DelphiWorld> this one work perfectly:
[23:26:57 CEST] <DelphiWorld> ffmpeg -i udp://@239.100.0.2:1234 -acodec libfdk_aac -ab 64k -vcodec libx264 -vb 1000k -s 640x360 -f rtsp -rtsp_transport tcp rtsp://197.140.2.6/live/almajd03
[23:28:30 CEST] <Polochon_street> what is the difference between AVCodecParameters and AVCodecContext ?
[23:32:10 CEST] <neflux> delphiWorld Ok I'm lazy but not stupid that looks too shady to me hahah
[23:32:35 CEST] <DelphiWorld> neffwhat you're talking about? :-P
[23:33:41 CEST] <neflux> I guess there were desperate enough people here that actually tried everything you gave to them hahah
[23:34:05 CEST] <DelphiWorld> LOL
[23:34:18 CEST] <DelphiWorld> my vaapi is working now
[23:34:19 CEST] <DelphiWorld> with rtsp
[23:34:21 CEST] <DelphiWorld> fuck rtmp :P
[23:34:57 CEST] <neflux> ffmpeg -loop 1 -framerate 24 -t 1 -i "image.jpg" -t 1 -f lavfi -i aevalsrc=0 -i "input.webm" -filter_complex '[0:0] [1:0] [2:0] [2:1] concat=n=2:v=1:a=1' "output.webm" ///// is giving me  No such filter: '[0:0]'
[23:38:56 CEST] <neflux> Maaan I'm just trying to change the thumbnail and I think this is the only way. Because 4chan uses the first frame to generate it.
[00:00:00 CEST] --- Mon Aug  1 2016