[Ffmpeg-devel-irc] ffmpeg.log.20140426

burek burek021 at gmail.com
Sun Apr 27 02:05:01 CEST 2014

[01:35] <Moonlightning> I'm trying to extract the audio from an mp4 video, but it seems I'm missing an encoder.
[01:35] <Moonlightning> I'm on Ubuntu 12.04; I believe ffmpeg was installed with the OS
[01:36] <c_14> In that case you're probably using libav, see #libav for help.
[01:36] <c_14> Or download a static ffmpeg build.
[01:36] <c_14> Or compile it yourself.
[01:37] <c_14> Options, options, options
[01:38] <Moonlightning> Thanks
[01:40] <diesel420> static ftw
[02:23] <relevart> I'm streaming using ffmpeg, and get "PES packet size mismatch" warnings from time to time. I'd like to filter the packet that generates these warnings but I can't find them using pkt->flags & AV_PKT_FLAG_CORRUPT
[02:23] <relevart> pls help!
[04:57] <alexanderino> Greetings. I would like to report a potential bug: the ffmpeg implementation of vorbis decoding does not work properly [or at all] with files created with older encoders. For example, I have many files with 'vorbis_vendor = Xiphophorus libVorbis I 20020408'. foobar2000 1.3.2 [which uses the ffmpeg library] refuses to play them, while older 1.x versions causes a warbling distortion.
[04:57] <alexanderino> please let me know if there's anything i can do to help
[04:59] <klaxa> you can upload a sample and file a bugreport on the ffmpeg bugtracker: http://ffmpeg.org/bugreports.html
[05:01] <alexanderino> Thank you, klaxa. Shall do.
[05:02] <alexanderino> I only have full songs. Will this be an issue?
[05:02] <klaxa> not at all i think
[05:02] <alexanderino> ok, good
[05:02] <klaxa> thanks for bringing this up btw, i bet you are not the only one having this issue
[05:03] <alexanderino> indeed
[05:03] <alexanderino> i was chatting with the foobar2000 devs, they pointed out that it has to do with the ffmpeg library having partial support for libvorbis
[05:03] <alexanderino> with older versions that do not use ffmpeg [0.666, 0.8.3], the songs play fine
[05:04] <alexanderino> same with XMPlay 3.2, but not 3.8
[05:05] <alexanderino> i'll of course include this in the report, but foobar2000 1.3.2 [latest version] outright refuses to play the file. Here is the console output: Unable to open item for playback (ffmpeg: could not open the decoder): "O:\music\Death\(1993) Individual Thought Patterns\01 - Overactive Imagination.ogg"
[05:21] <alexanderino> tried ffplay.exe, this is the result:
[05:21] <alexanderino> [vorbis @ 00000000044f0260] partition out of bounds: type, begin, end, size, blocksize: 2, 0, 2080, 32, 1024
[05:21] <alexanderino> [vorbis @ 00000000044f0260]  Vorbis setup header packet corrupt (residues).
[05:21] <alexanderino> [vorbis @ 00000000044f0260] Setup header corrupt.
[05:22] <alexanderino> with a recently encoded file, this is output: [ogg @ 000000000453ef60] 1912 bytes of comment header remainf=0/0
[06:12] <alexanderino> report created: https://trac.ffmpeg.org/ticket/3590
[06:13] <alexanderino> the smallest file is over 4 MB, so I have uploaded the sample via FTP with a text file describing it
[06:13] <alexanderino> now i shall email the list
[06:26] <alexanderino> is ffmpeg-user the correct list to send it?
[10:33] <TheSchaf> -_- i have some videos that have a 1 pixel border on the left side
[10:34] <TheSchaf> how do i remove that while keeping the same resolution in the best way?
[10:34] <TheSchaf> i guess if i rescale the video quality will go down?
[10:35] <TheSchaf> is there a way to copy the line next to the border over the border with ffmpeg?
[15:20] <qeed> i saw a ffmpeg post saying a person was trying to add protracker mod support in gsoc 2010, did that go anywhere? i tried using ffmpeg ona a mod file  and it says Invalid data found when processing input
[15:59] <spaam> qeed: it was never commited to master :'(
[15:59] <qeed> why not
[16:02] <spaam> because it needed some fixes and it was never fixed.. :/
[16:03] <spaam> but one source say that you can compile with libgma or libmodplug to play those files. but yeah. that 3rd party.
[16:03] <qeed> i just used xmp
[16:04] <spaam> okey
[17:28] <wizbit> does anybody remember the name of tool what lets you adjust webcam settings on the terminal?
[17:28] <wizbit> my webcam is showing in black and white, but i used a terminal tool to change it to colour, i cant remember what it was
[17:39] <revolver> hi people <3
[17:40] <revolver> i was looking for a way to record audio directly from the audio card (recording the sound that is currently being reproduced)
[17:40] <revolver> I do that using Audio Hijack in MacOS and Audio Recorder in Windows
[17:40] <revolver> How could I do the same in a Linux enviroment? does ffmpeg have the proper tools to do that?
[17:49] <klaxa> you audio "driver" will have to take care of that, if you are using pulse it's pretty simple, i think it's possible with alsa, no idea how to do it with alsa really
[17:50] <klaxa> on pulse you can open the pavucontrol gui (if you don't have it, you can install it) record with ffmpeg using: ffmpeg -f alsa -i pulse -c:a libvorbis out.ogg and in the gui select "monitor of <soundcard here>" as the source for the ffmpeg recording stream in the recording tab
[19:42] <znf> Hello. I have a question related to libx264. I'm somehow getting HUGE files for something that is basically a still image with a "showwaves" filter applied on the bottom of the image. I thought that x264 should be a lot more effective at this. Could someone tip me off as to how I could reduce the filesize? I somehow think that it shouldn't require ~4000kbps for something as simple as this
[19:42] <znf> I'm running this command:
[19:42] <znf> tools\ffmpeg.exe -y -i temp\audio.mp3 -loop 1 -i temp\canvas.png -i temp\annotated.png -filter_complex "[0:a] showwaves=size=1280x100:mode=line:r=25 [wave];[1:v][wave] overlay=y=H-h:eval=init[comp];[comp][2:v] overlay=eval=init" -shortest -acodec copy -vcodec libx264 -pix_fmt yuv420p -preset ultrafast -tune stillimage -crf 19 -movflags faststart "videos\WANDERHOUSE-SUGAR.mp4"
[19:47] <klaxa> well, try increasing the crf value
[19:48] <klaxa> 19 is pretty high quality
[19:48] <znf> I did, even with 31, the file-size is still huge considering the video content
[19:48] <sacarasc> Use an actual bitrate, maybe?
[19:48] <znf> ~25minute audio file results in something like ~400mb video size
[19:54] <blippyp> znf: your problem is that you're using an ultrafast preset - this will encode the file very fast, but will create large files - change it to veryslow, slow or just leave it out entirely - You'll notice large differences in your file size
[19:54] <znf> I'll try, thanks
[19:54] <klaxa> ah yeah didn't see that even
[19:54] <blippyp> keep in mind though that you are still creating a video file - so the file is going to be much larger than your audio file, and it will take a lot longer to encode
[19:56] <blippyp> if you want to keep your video quality to near 'original' I would change your crf to 17 (this is what I always use) if you plan on re-encoding it again for something else you might want to go lower even.
[19:56] <znf> yeah, I know that
[19:56] <znf> I just thought that since less than 10% of the image changes every frame, it shouldn't really be that big
[19:57] <blippyp> no, it doesn't work like webm
[19:57] <blippyp> it will still be a large file
[19:57] <blippyp> but using a different preset other than ultrafast will show significant differences in your file size nonetheless
[19:58] <znf> mhm, I see... though 30fps encoding vs. 130fps... :-/
[19:58] <blippyp> you might be happier using webm for what you want
[19:59] <znf> but webm is slow as molasses :(
[20:00] <blippyp> it's not that bad - you'll get a much bigger investment in your file size since that's what you're complaining about
[20:00] <blippyp> it will do what you wanted
[20:00] <znf> just trying to find a sweet spot, mostly
[20:00] <blippyp> seriously, if you're using a still image for the video webm is the way to go
[20:02] <znf> blippyp, but I don't want to encode stuff at 25fps, for example. Generate a video for a 60 minute song, that's one hour of encoding
[20:02] <blippyp> then don't?
[20:02] <blippyp> change the framerate to whatever you want...???
[20:03] <znf> the showwaves filter looks bad at below 20fps, I noticed
[20:03] <blippyp> what resolution is the video?
[20:04] <znf> 720p
[20:04] <blippyp> no matter what you're going to have to give up something
[20:04] <sacarasc> znf: What's CPU do you have?
[20:04] <znf> seems crf=21 with preset=fast is still decent
[20:04] <znf> sacarasc, core i5 4440
[20:05] <blippyp> with x264 - it will encode faster (but not really that much faster) and you'll end up with much larger file size - use webm and it will encode a little slower, but you'll end up with MUCH smaller file sizes...
[20:05] <sacarasc> And lower quality.
[20:05] <blippyp> you might be able to play with the crf since the video isn't changing that much
[20:05] <znf> hmm, my build doesn't seem to have webm support
[20:05] <znf> does webm support yuv444p?
[20:06] <klaxa> no
[20:06] <klaxa> vp8 only supports yuv420p
[20:06] <znf> crap :(
[20:06] <klaxa> also, fast is still pretty bad
[20:06] <klaxa> try medium or slow
[20:06] <znf> I'm getting ~1.2mbit/s at "fast"
[20:06] <klaxa> you should generally start with medium
[20:07] <znf> also, does webm support mp3 audio?
[20:07] <klaxa> if you think you can go slower, go as slow as possible
[20:07] <klaxa> no
[20:07] <klaxa> webm supports opus and vorbis
[20:07] <znf> then that's out of the question :-/
[20:08] <znf> though, I still want to give it a try
[20:08] <znf> anyone knows of an ffmpeg build for windows with libvpx support?
[20:09] <blippyp> try the static build on ffmpeg - the linux version has it
[20:09] <znf> ah, it seems zeranoe's has it now, too
[20:09] <znf> last time I checked it didn't
[20:09] <znf> it lists support, anyway
[20:11] <znf> yeah... I'm getting 8 fps with webm
[20:12] <blippyp> let it finish though - so you can see the benefits...  ;) compare it with a x264...
[20:12] <znf> woah...
[20:13] <znf> default flags (ie: no flags passed to the decoder)
[20:13] <znf> == 3 fps
[20:13] <klaxa> are you using vp8 or vp9?
[20:13] <znf> libvpx
[20:14] <klaxa> vpx can encode both, vp8 and vp9
[20:14] <znf> I'm not sure, what's the default?
[20:15] <klaxa> i would guess vp8 because it's less complex
[20:15] <klaxa> what does ffmpeg print?
[20:15] <klaxa> also i think vp8 is single threaded by default too
[20:15] <klaxa> because multi-threaded encodes with vp8 are non-deterministic
[20:15] <znf> vp8
[20:15] <blippyp> yeah - you'd want to set the -threads
[20:16] <znf> setting -threads crashes ffmpeg :-/
[20:16] <znf> but this looks horrible http://i.imgur.com/vhdK2gS.jpg
[20:16] <klaxa> in how far?
[20:17] <znf> in me pressing enter :>
[20:17] <blippyp> not in linux it doesn't....
[20:17] <klaxa> "it crashes" is not really a good description
[20:17] <klaxa> does it segfault?
[20:17] <klaxa> does it tell you the arguments are invalid?
[20:17] <blippyp> show your command - paste it to pastebin or something
[20:17] <znf> no, it crashes with "ffmpeg has encountered an error and needs to be closed"
[20:18] <znf> tools\ffmpeg.exe -y -i temp\audio.mp3 -loop 1 -i temp\canvas.png -i temp\annotated.png -filter_complex "[0:a] showwaves=size=1280x100:mode=line:r=25 [wave];[1:v][wave] overlay=y=H-h:eval=init[comp];[comp][2:v] overlay=eval=init" -sho
[20:18] <znf> rtest -acodec libvorbis -vcodec libvpx -crf 4 -threads 4 "videos\WANDERHOUSE-SUGAR.webm"
[20:18] <znf> crap
[20:19] <blippyp> I don't see anything wrong with that - you should set a bitrate though - I think crf still wants a bitrate (-b:v) or it won't work very well
[20:19] <znf> if I use -vcodec vp9, it doesn't crash
[20:20] <klaxa> crf 4 is pretty high too btw
[20:20] <klaxa> vp9 will be slow as hell
[20:20] <blippyp> vp9 will be much slower than 8 though
[20:20] <klaxa> if you run x264 at "fast" and complain about speed, vp9 is not for you
[20:20] <znf> well, vp8 crashes when passed threads
[20:20] <blippyp> yeah crf 4 is low - with mostly a still background you should be able to get away with much higher value I'd think
[20:21] <znf> and even with -crf 4, the quality is incredibly crap
[20:21] <znf> erm, isn't lowest == better quality?
[20:21] <blippyp> that's because you didn't set a bitrate
[20:21] <klaxa> pretty much yeah
[20:21] <blippyp> it's defaulting to some crappy value
[20:21] <znf> I just set a -b:v 2000k
[20:21] <znf> and it's still low :-/
[20:21] <blippyp> that should work - I'd bet you can set it much lower though
[20:21] <klaxa> also on my server with an i7 2600 at 3.4 ghz it took 30 minutes to encode a 90 seconds video in 1080p
[20:22] <klaxa> so there's some benchmark for you, not sure you want vp9 really
[20:22] <znf> then I don't really see the point in webm :-/
[20:22] <blippyp> the final file size
[20:22] <blippyp> that's the point
[20:22] <klaxa> the point in webm is compatibility across all platforms
[20:22] <blippyp> if it's not that important to you than x264 is fine - and faster
[20:23] <klaxa> x264 gives better results than vp8
[20:50] <ChocolateArmpits> Hello, is there any command line media player that could be output piped to ffmpeg ?
[21:13] <klaxa> i think every player related to mplayer can dump the stream
[21:13] <klaxa> you can also use ffmpeg for decoding a stream
[21:59] <blippyp> znf: I did a test once to compare putting a smaller video on a much larger black background with webm to test if it would change the file size: And it didn't (or at least very little). However, I mistakenly always assumed that because those pixels did not change that this would also apply with a static 'picture' background. I have been testing it out and it appears I was wrong about that. WebM is definately not what you want - I apologize f
[22:20] <ChocolateArmpits> klaxa, I was looking to run on Windows; I want to pipe the output because ffmpeg by itself throws a lot of errors when trying to parse the broken AVI files that I want to fix. FFplay, VLC and other players have no playback problems though.
[22:30] <jarainf> ChocolateArmpits, how would ffplay manage to playback without any problems while ffmpeg throws errors?
[22:30] <jarainf> Are the errors fatal?
[22:31] <jarainf> If not, I doubt you'd get better results using a player to pipe it to ffmpeg. VLC is a beast and might be able to save something, but that's about it...
[22:31] <ChocolateArmpits> jarainf, throws a bunch of errors during encoding I think
[22:31] <ChocolateArmpits> The files were recovered from a broken sd card
[22:31] <jarainf> Could you paste it's output?
[22:31] <ChocolateArmpits> Sorry, not at work
[22:32] <jarainf> What are the errors about?
[22:34] <ChocolateArmpits> Sorry, jarainf, don't remember them exactly. I was only ready to solve it by piping output from VLC, but there's not much concrete information about that. Wasn't preparing to write down the errors
[22:35] <ChocolateArmpits> Avisynth reads the files also
[22:36] <ChocolateArmpits> If the command line for VLC won't work, then it's Avs and MediainfoCLI to extract codec information for me I guess
[00:00] --- Sun Apr 27 2014

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