[Ffmpeg-devel-irc] ffmpeg.log.20140720

burek burek021 at gmail.com
Mon Jul 21 02:05:01 CEST 2014


[01:15] <ac_slate1> hey all. I'm building ffmpeg statically into a small project. I know ill only be using mpeg2 videos in an mpeg2 container. I've tried to compile with the basic demuxers and decoders (mpeg2video, mpeg1video, mpegvideo) and the file protocol, but I get 'Invalid data when processing input'... I cant tell what else I'd need for mpeg2 decoding/demuxing. Thanks!
[01:17] <ac_slate1> c_14: yup, http://paste.debian.net/plain/110591
[01:19] <ac_slate1> and on my distro's ffmpeg install, here is what the ffprobe output looks like http://paste.debian.net/plain/110592
[01:20] <ac_slate1> c_14: I'm not actually using the ffmpeg command line applications, but libav*. The ffprobe error matches my error from avformat_open_input
[01:24] <ac_slate1> c_14: oh ... doing `mediainfo` on it shows it's an mpeg2ps .. I havent enabled those
[01:28] <c_14> maybe also enable the mpegtsraw demuxer
[01:54] <ac_slater> c_14: I forgot the parser for mpegvideo
[01:55] <c_14> So that was it.
[02:52] <jrm> Hi.  I'm trying to do a conversion (first time).  I'm just trying to get the audio from a video, but I seem to be missing a codec.  Here's the output: http://slexy.org/view/s2HzyEpwXx and here's the output of ffmpeg -codecs: http://slexy.org/view/s20y01eA6x.  Do you have any tips?
[02:53] <c_14> You don't have an mp3 encoder.
[02:53] <c_14> Rebuild with --enable-libmp3lame or use a different output codec.
[02:56] <jrm> c_14: Thanks.  I'm not partial to mp3.  Any suggestions, so that it will play the audio on my g/f's android phone.  Open is, of course, better. :-)
[02:57] <jrm> open format that is
[03:00] <klaxa> try vorbis
[03:00] <iive> jrm: it is best if you don't recode the audio, try stream copy ( -c copy -vn )
[03:00] <iive> -vn is to disable the video.
[03:00] <iive> andoid should be able to play aac
[03:00] <klaxa> android should play aac just fine, yeha
[03:00] <klaxa> *yeah
[03:01] <c_14> ^What they said.
[03:02] <jrm> cool, thanks all :)
[04:13] <onyx> hey guys, I want to record a rtmp live stream with ffmpeg, is there  a way to record 10 mins of the live stream?
[04:13] <c_14> ffmpeg stream -t 10:00 file
[04:13] <c_14> -codec copy
[04:14] <onyx> thanks
[04:15] <onyx> so to make sure it will go something like this? "ffmpeg -i rtsp://serverip:port -acodec copy -vcodec copy -t 10:00 c:/abc.mp4"
[04:16] <sacarasc> You might have to do C:\, but yeah in theory.
[04:16] <onyx> ok, I'll give that a try!
[04:17] <onyx> question, does it use a lot of resources to record?
[04:18] <sacarasc> Not really.
[04:19] <onyx> how about transcoding that .mp4 after, lets say convert it to .flv
[04:20] <sacarasc> Depending on codecs you want to use, it could use a lot or not much at all.
[04:21] <onyx> I will just want that file to be web optimized
[04:22] <sacarasc> FLV is for flash players, not really for the web.
[04:23] <onyx> mp4 are more standar right?
[04:23] <sacarasc> If you want HTML 5, you would have to do in like 3 formats to support all browsers that support it.
[04:24] <onyx> ok, how would I go about doing that?
[05:24] <ac_slater> how the heck do I generate the doxygen?
[05:25] <ac_slater> (when compiling obviously)
[08:10] <CthUlhUzzz> Hi guys! Can I save just the audio track from remote video file, without downloading it completely?
[08:11] <sacarasc> Probably not.
[08:23] <CthUlhUzzz> sacarasc: I see, that HTTP support partial download using header 'Content-Range'. And perhaps MP4 container support it too.
[08:25] <sacarasc> When you mux things, you don't put the video at the start and the audio at the back, you put them in at the same time.
[08:34] <CthUlhUzzz> sacarasc: But I can download the audio constantly jumping from place to place? =D
[08:34] <sacarasc> [07:11:28] <sacarasc> Probably not.
[08:35] <CthUlhUzzz> sacarasc: F**k(((
[11:01] <feliwir> Mavrik?
[11:02] <feliwir> if i just want the rgba picture i can just return rgba_picture in ur code? (https://gist.github.com/izacus/26a624df7b5536191c84)
[11:50] <optix2> I don't really get the doc of the blend filter http://ffmpeg.org/ffmpeg-filters.html#blend - is it possible to change transparency/opacity of each layer or what exactly do c0_mode etc do?
[12:18] <vladtv>  help me, how encoding 25i to 50p in vlc ore ffmpeg with deinterlace yadif2x?
[12:25] <Mavrik> feliwir, I didn't really show you that code for you to copy-paste.
[12:26] <Mavrik> but to see how conversion is done for whatever you're doing.
[12:26] <feliwir> ye i know i just wanted to know if that rgba_picture is valid for use
[12:26] <feliwir> since i don't want to convert to yuv i won't use it anyways :P
[12:27] <feliwir> i just want a ordinary rgba_buffer that i can use for my gltexture
[12:28] <Mavrik> yeah, that's the rgba picture
[12:28] <Mavrik> you can even do the conversion directly into your buffer and just skip the AVPicture allocation alltogether
[12:28] <Mavrik> the loop that goes over all rects for each of colors is the important part
[12:29] <feliwir> i used to use the data directly from the rectangle
[12:29] <feliwir> but that resulted in weird code
[12:29] <feliwir> *weird texture
[12:30] <Mavrik> yeah
[12:31] <Mavrik> because in the rectangle you have only indexes of the color
[12:31] <Mavrik> and the colors are stored in data[1]
[12:31] <Mavrik> so for each pixel you need to do a lookup of color in data[1] array :)
[12:31] <Mavrik> that's what RGBA_IN macro does
[12:32] <Mavrik> optix2, it's mathemaical, you set just how you want the output generated from two images
[12:33] <Mavrik> optix2, try with all_mode=normal,all_opacity=0.8 for start
[12:38] <optix2> Mavrik: I'm actually trying to set transparency of a subitle (ssa format) and thought I could do it with blend
[13:53] <Fjorgynn> ffmpeg -i windows.wav windows.flac
[14:47] <BlackDream> See This: http://pastebin.com/PPKW2NbZ
[14:47] <BlackDream> the stream is working perfectly, though ffmpeg sometimes starts restreaming
[14:47] <BlackDream> some other times doesnt even start
[14:48] <BlackDream> if i remove flags -global_header -fflags +genpts etc etc doesnt make any change
[14:58] <Fjorgynn> :)
[16:44] <karika200> hi
[16:44] <karika200> is there any way to stream from an ip camera a h264 video in mp4 container?
[16:45] <karika200> I get alway the next error: [mp4 @ 0x2651d70]muxer does not support non seekable output
[16:47] <karika200> http://pastebin.com/bHcF1zav
[16:50] <c_14> Try adding AVOptionVideo movflags frag_keyframe
[16:58] <karika200> I added it, but didn't helped
[16:58] <karika200> This is the ffserver's output: http://pastebin.com/2frZviNS
[16:58] <karika200> I need to publish 2-3 IP cam's output to a website with html5 and as fallback solution with flash
[16:58] <karika200> so I could use webm also.. but then i need to transcode the video
[16:58] <karika200> from h264 to vp8
[16:58] <karika200> so, if any other container format is available in the mainstream browsers, that can be good for me
[16:58] <karika200> but I don't want to transcode the video from h264 :\
[17:04] <c_14> Hmm, it doesn't look like it'll work with mp4. You'll need a different format.
[17:07] <karika200> Then I have to transcode my videos.. :/
[17:07] <karika200> thx
[17:07] <karika200> Is it an ffmpeg specific thing or it's impossible to use mp4 for streaming?
[17:08] <c_14> The latter, although there are some specific hacks that can be used in certain situations. In this case the fault lies with mp4 though.
[17:09] <karika200> I see
[17:09] <karika200> ty for the help
[19:44] <kaotiko> hi
[20:05] <onyx> hey guys how do I make it to add the time of the recording to the file name?  -acodec copy -vcodec copy -t 10:00 c:/abc.mp4
[20:05] <onyx> I want it to create a file that be abc-2.mp4, abc-3.mp4, and so on...
[20:06] <c_14> You might be able to do that with the segment muxer depending on what exactly you want.
[20:11] <onyx> something like this?  -acodec copy -vcodec copy -t 10:00 c:/abc-hh:mm:ss[.mp4]
[20:15] <c_14> On windows something like -t 10:00 c:/abc-%time%.mp4 should work.
[20:15] <c_14> Can't verify because I don't have a windows though.
[20:18] <onyx> Im running on linux
[20:20] <c_14> Then what's with the c:/, anyway, just use c:/abc-`date +%H:%M:%S`.mp4
[20:23] <onyx> ok, ill try that
[20:33] <onyx> that worked!
[20:52] <onyx> thank you c_14
[20:52] <onyx> im out
[22:52] <sebgonz> Hey guys, I'm really really new to ffmpeg, but I have a question. I'm trying to reduce the size of a file. I'm using ffmpeg -i test.mp4 -c:v libx264 -preset -crf 22 output test1.mp4
[22:52] <sebgonz> however I keep getting the error: "Unable to find a suitable output format for '22'
[22:52] <sebgonz> Is that something to do with the crf?
[22:53] <c_14> You need to specify a preset.
[22:53] <c_14> -preset something -crf 22
[22:53] <sebgonz> do I have to use a preset?
[22:53] <c_14> No, but you specified the option...
[22:54] <sebgonz> Yeah, I was following something else. :) Thanks I'll give that a shot.
[22:59] <sebgonz> Do I have to specify both video and audio streams? I keep getting "Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height.
[22:59] <sebgonz> 0:1 is the audio
[23:00] <JEEB> the error is probably somewhere before that, so pastebin your whole command and output
[23:01] <sebgonz> http://pastebin.com/rT1kK9FZ
[23:01] <sebgonz> Duh... sorry guys.
[23:03] <Mavrik> uh
[23:03] <Mavrik> *tries to wrap head around that output*
[23:03] <JEEB> it's 5.1 and vo-aacenc doesn't habla that
[23:04] <JEEB> which is why [libvo_aacenc @ 051d0b00] Unable to set encoding parameters
[23:04] <JEEB> -c:a aac -strict experimental should fix that
[23:06] <sebgonz> Looks like it's working.
[23:06] <sebgonz> Thanks guys! Now to figure out how to process a whole folder. :)
[23:12] <sfan5> JEEB: wouldn't it be better to try libfdk_aac instead of the experimental aac encoder?
[23:13] <c_14> sfan5: It doesn't look like he has libfdk_aac enabled.
[23:14] <sfan5> how about recompiling?
[23:14] <sfan5> how "experimental" is the aac encoder anyway?
[23:14] <c_14> He could do that, but the internal encoder isn't that bad if you give it a high enough bitrate.
[23:14] <sfan5> doesn't it work fine?
[23:16] <sebgonz> I wonder how much faster than handbrake this is...
[23:16] <c_14> I've never seen it break anything, but I don't use AAC that much.
[23:17] <c_14> sebgonz: I'm pretty sure handbrake uses x264 as well so as long as that's the bottleneck it should be around the same speed (assuming similar settings).
[23:18] <sebgonz> Thanks guys. I really appreciate it when I can come into IRC, get help, and not feel like a total tool.
[23:28] <phingers> Hey gang, I'm trying to get started with ffmpeg, and just sequence 3 images, into a 10 second movie clip, how do I set the length each image should be displayed? I'm using ffmpeg -f image2 -i foo%03d.png -r 3 -s 640x360 output.mp4
[23:40] <phingers> okay I made it a little further after RTFM - ffmpeg -r 1/5 -i foo%03d.png -r 30 -idct h264 -pix_fmt yuv420p output.mp4 - it is still not h264 streaming though any ideas?
[23:44] <phingers> I added in an audio track, and it does stream the sound, but the image is all black
[00:00] --- Mon Jul 21 2014


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