[Ffmpeg-devel-irc] ffmpeg.log.20120323

burek burek021 at gmail.com
Sat Mar 24 02:05:02 CET 2012


[00:00] <jhericurl> which aac encoder is best to use with ffmpeg?
[00:02] <sacarasc> Use neroAacEnc separately. It's better than anything you can use in ffmpeg.
[00:03] <bcoudurier> it's closed source
[00:03] <bcoudurier> jhericurl, vo-aacenc IIRC but I may be wrong
[00:03] <jhericurl> why would you be wrong?
[00:04] <bcoudurier> I didn't recently follow
[01:19] <macmichael01> I have a python script that extracts frames and creates a thumbnail for an uploaded video. The problem is that I perform the operation from the command line which is a bad approach. pyffmepg seems to be broken when new os versions come out. Is there another option that I could use for making calls in a non-hackish way.
[01:36] <YellowOnion> how do I stream to two different IPs? without re encoding twice?
[01:37] <YellowOnion> this is the current console output: http://paste.pocoo.org/show/569799/
[02:08] <MrJones> hello
[02:12] <MrJones> avcodec_decode_audio3() fails for me with a negative return value. a subsequent av_strerror() yields: Operation not permitted
[02:13] <MrJones> however, I have no idea which operation it attempted that might have failed
[02:38] <YellowOnion> why is everything to do with RGB to YUV conversion completely screwed?
[02:39] <YellowOnion> there's serious amounts of corruptions in my image
[02:39] <YellowOnion> http://i.imgur.com/HxjP8.png
[02:39] <YellowOnion> the original youtube video: http://www.youtube.com/watch?v=ZCh7ABIPhZs
[03:00] <YellowOnion> the screen capture software has a built in scaler and that works fine, even on nearest neighbour it looks better
[03:20] <con> Hello. I'm trying to cut a FLV file with ffmpeg, using the options: -ss 1708 -t 513 -acodec copy -vcodec copy
[03:21] <con> The resulting file works on some players, but bugs on some others. More importantly, when I analyse my output with ffmpeg, the duration is still the original duration.
[03:21] <con> Also, the video stream is described as: Stream #0.0: Video: [0][0][0][0] / 0x0000, 1099 kb/s, 1k tbr, 1k tbn, 1k tbc
[03:21] <con> Where the original stream is described as: Stream #0.0: Video: flv, yuv420p, 512x288, 1099 kb/s, 25 tbr, 1k tbn, 1k tbc
[03:22] <con> How would I make ffmpeg generate some 'decent' metadata (or just copy the original), so for example VLC might not bug on the cut file?
[03:23] <con> Using the option -dcodec copy didn't work.
[03:35] <con> Full output: http://pastebin.com/yfuq742w
[03:36] <YellowOnion> ok so it's specially bgra to yuv420p that's broken to heven hell, if I convert to rgba first it works fine
[03:51] <jhericurl> i have tools to change aspect-ratio of a video of  wmv and avi without reencoding.  anybody know a way to do that with .mp4/.mkv
[04:14] <sam3> hi, i want to build static ffmpeg. how i configure
[12:21] <globus> How can I use the ffmpeg-api to stream over rtp x264 encoded NALUs ? Only streaming not encoding.
[12:22] <MarcWeber> Is it possible to extract dvd title strings in some way?
[12:23] <JEEB> MarcWeber, I don't think there are strings to begin with for titles/chapters :)
[12:26] <MarcWeber> talking about dvd menu titles, sry. Probably you're rigt. I couldn't find any tool.
[12:30] <JEEB> Yes, those are just timestamps
[12:30] <JEEB> the text you see on the menus etc. is just pictures :P
[12:30] <JEEB> no way of extracting them
[12:42] <Onkeltem> I have 2 webm files with VP8 video and OGG audio. How can I contact them?
[17:13] <crepererum> Hi. Is there a way to extract subtitles from a m4v file (stream is mov_text, tx3g) including time stamps using ffmpeg?
[17:35] <cyclist_2> Hello, there! I am trying to stream a video using the protocol rtmp; I got the following command to achieve this: "ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream"; but I am getting the error message "no such file or directory"; could it be because my version of ffmpeg is not configured with the build "enable-librtmp"? How can I check it and -- if possible -- make it to work? I am using the latest build for Windows [executable]
[17:55] <faraway> hi, does anyone know how to to trancode to mpeg2video so that it will run in wmp audio works, but for the movie i only see artifacts
[18:21] <cybro> Hi, I try to capture my screen and audio (from pulse) with x11grab and my audio is allways out of sync :(
[18:30] <vivienschilis> Hi, anyone succeeded to make a segmented MPEGTS using -vn (audio only) and the segment format?
[18:30] <vivienschilis> it works well for video outputs but not for audio
[18:31] <vivienschilis> it generates only one segment
[19:48] <IamTrying> I am having this nonstop ffmpeg error, any idea why does it happening? It never almost happen when i do local to local test, but happening when i am doing location1 to location2
[19:48] <IamTrying> https://gist.github.com/2173707
[19:51] <burek> IamTrying,
[19:51] <burek> can you please use pastebin.com, to show your command line and its output?
[19:51] <burek> what you have provided is not an ffmpeg output
[19:52] <burek> cybro, did you solve your problem?
[19:53] <burek> cyclist_2, do you actually have file named "myfile" located on your hard disk?
[19:54] <burek> crepererum, yes
[19:54] <burek> you can use -scodec copy I think
[19:54] <burek> and mux it into the original container
[19:54] <burek> (also use -an -vn to discard audio/video data)
[19:55] <burek> but somehow I have a feeling you are trying to export it as SRT file or similar
[19:56] <burek> if that's the case, you could try just ffmpeg -i input -an -vn -scodec ass out.ass
[19:57] <cybro> burek if i press q on my terminal and stop the capture the audio is out of sync but if if i stop it with ctr +z the audio is ok but in vlc or smplayer the seek bar is static a 0 but the video is playing
[19:58] <burek> cybro
[19:58] <burek> can you please use pastebin.com, to show your command line and its output?
[19:59] <cybro> ok
[20:01] <cybro> http://pastebin.com/ePLxeUat
[20:02] <burek> cybro, why do you use so much h264 options?
[20:02] <burek> why don't you use presets/tunes
[20:03] <burek> also this "-preset ultrafast -crf 0" is not gonna give you what you want :)
[20:04] <cybro> ok , but the audio even with -crf  0 it's still the same with the q
[20:05] <crepererum> burek : "ffmpeg -i iput.m4v -an -vn -scodec ass out.ass" give me the following output/error: http://pastebin.com/32BGFmVd
[20:05] <cyclist_2> burek: no, that is just an example; I assure you I am using the right filepath to the file when using ffmpeg; I found that example on the pages "http://ffmpeg.org/trac/ffmpeg/ticket/138" and "http://ffmpeg.org/ffplay.html#SEC44"; tell me what you think, if you will, please, but I am almost convinced that I must get the "librtmp" included and enabled in my version of ffmpeg; the problem is I went for  the easy option and instaled the executa
[20:07] <relaxed> crepererum: ffmpeg -i input -map 0:s -c copy -f ass out.ass
[20:11] <crepererum> "ffmpeg -i input.m4v -map 0:s -c copy -f ass out.ass" gives me: http://pastebin.com/vQgaexEC
[20:12] <cybro> burek, :) ok with ctrl+c and not ctrl+z i have seek bar in vlc
[20:14] <cybro> but unfortunatelly :( out of sync
[20:16] <relaxed> crepererum: try, ffmpeg -i input.m4v -map 0:s -c ass -f ass out.ass
[20:17] <burek> crepererum, ffmpeg doesn't understand that subtitle codec
[20:17] <relaxed> I'm not sure if you can convert mov_text -> ass
[20:17] <burek> maybe you didnt compile ffmpeg to support that kind of codec
[20:19] <crepererum> I will look on configure options later and will recompile it
[20:20] <crepererum> recoding to out.mp4 using "-scodec copy" does not change the subtitle (vlc shows subs in input.m4v and out.mp4 correctly)
[20:20] <burek> cyclist_2, you can easily check it with ffmpeg -protocols
[20:21] <burek> if you have rtmp, everything is ok
[20:21] <burek> can you please use pastebin.com, to show your command line and its output?
[20:21] <burek> crepererum, what exactly is your goal
[20:23] <crepererum> to extract the subs to use it as input for a machine learning algorithm for speech recognition (so I need the text and the timestamps)
[20:25] <IamTrying> burek, i have been testing this latest ffmpeg implementation where they have implementation of `ffdec_h264 `  http://cgit.freedesktop.org/gstreamer/gst-ffmpeg  (i know its not ffmpeg tool because i am having a different type of input source therefore). I just wanted to understand what that error was getting caused by. Very confusing because in local it works only..
[20:26] <burek> crepererum, well -scodec copy then and open the output in notepad or hex editor
[20:26] <burek> and analyze the output
[20:26] <burek> or remux that codec into another (more familiar) format
[20:26] <burek> like i don't know, mkv, flv
[20:26] <burek> something
[20:27] <burek> type ffmpeg -formats and find the most suitable for your project
[20:27] <crepererum> burek, I will be back later, thank you for your ideas
[20:27] <burek> :beer:
[20:30] <burek> IamTrying, well, I'm not sure, but it looks like your input is invalid
[20:30] <burek> or the decoder has bugs
[20:31] <IamTrying> Hmm, that is the only cause could be.
[20:32] <IamTrying> burek, I have also tested SMPTE color bars (not only one input source, but too many random sources, all ends up to same).
[20:33] <IamTrying> Too many random input sources: SMPTE color bars, Files source, Image source, RTSP source, USB camera source , Desktop screen source, RFB source all same result.
[20:34] <burek> I honestly dont know what are you talking about :(
[20:41] <cyclist_2> burek: I checked it and found them there *and* enabled when I run ffmpeg [as "--enable-librtmp"]; but upon runing the command: "C:\ffmpeg-git-1eabd71-win32-static\bin\ffmpeg.exe -re -i "C:\Documents and Settings\user\My Documents\VIdeo file.flv" -f flv "rmtp://live.justin.tv/app/live_streaming-key" [N.B.: the username, filename and live-key have been changed for this question, but I am using the right ones]; I still get the error message: "
[20:42] <IamTrying> burek, i mean when you have mentioned `my input is invalid` that i compared with input sources such as file source or other sort of sources. But all ended with the same error. So you must be correct that all the decoders are broken or bugs.
[21:19] <cyclist_2> burek: I got it! you will not believe me, but my mistake was of just one letter: instead of "rtmpt", I was using "rmtp"...; well, the stream is very laggy at the moment, but that solution I will work out some other time; for now, I am very satisfied to discover that my build of ffmpeg on my Windows system can, indeed, stream videos to a website; thanks a bunch for your help!
[21:27] <burek> cyclist_2, :beer: :)
[21:28] <burek> IamTrying, well, you can try using plain ffmpeg
[21:28] <burek> from latest git
[21:28] <burek> to see if the bug is still there
[21:28] <burek> if it is, you could report it, so it can be fixed
[21:28] <cyclist_2> burek: see you next time; I am off now  o/
[21:28] <burek> or if the bug isn't there anymore, that means that the project, you are using, is using an old version of ffmpeg/libav
[21:28] <burek> so it contains that bug
[21:28] <burek> o/ :)
[21:35] <MrJones> hello
[21:36] <MrJones> when avcodec_decode_audio3 (to which I pass a buffer pointer through an AVPacket, not a file handle or anything, and which outputs to another buffer) returns "Operation not permitted", what does that mean? I can only think of a possible meaning for that in the context of file access
[21:37] <burek> did you read the source code for avcodec_decode_audio3, MrJones ?
[21:41] <MrJones> I did, but it doesn't do much and I cannot spot the source of that error. do you think it should be insightful in regards of that or why are you suggesting it?
[21:41] <MrJones> I read the doxygen documentation but it doesn't say much about errors.. neither do the few lines of source about that error
[21:42] <MrJones> however, I just spot a difference to the decode encode example... it constructs a new codec context instead of using the one of the original format context's stream
[21:42] <MrJones> so I probably need to do the same
[23:45] <MrJones> burek: so any idea why I might be getting that error?
[23:46] <MrJones> rewrote the other part with the codec context to do it as in that example, but the avcodec_decode_audio3 error remains
[23:48] <elkng> is there video compressing method that inserts few black lines in every frame ?
[23:50] <burek> MrJones, I don't know, I just suggested to look into the source code directly
[23:50] <burek> because it is very hard to keep up with documentation for source code
[23:50] <burek> I mean the code changes always, so it is really too much of a job to comment it appropriately
[23:50] <burek> so, your best bet is to look into the source code and try to figure out what is happening
[23:51] <burek> using a debuger or something
[23:51] <burek> elkng, what exactly is your goal?
[00:00] --- Sat Mar 24 2012


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