[Ffmpeg-devel-irc] ffmpeg.log.20130807

[burek]

[00:45] <meekohi> Does anyone know if it is possible/impossible to do this operation using ffmpeg's existing filters? http://pastebin.com/51mcTShT
[00:47] <llogan> meekohi: can you explain in english what you want to achieve?
[00:47] <meekohi> llogan: take the greyscale value at each pixel, and use it to adjust the saturation of the RGB channels at that same pixel.
[00:48] <meekohi> Basically I can't figure out how to grab the greyscale value and then use it when doing some math on the original channels
[00:48] <meekohi> I was almost thinking I might have to output a greyscale version of the video then combine them somehow?
[00:52] <llogan> i don't have an example for you, but did you refer to the current list of video filters? http://ffmpeg.org/ffmpeg-filters.html#toc-Video-Filters
[00:52] <meekohi> llogan: I did indeed, have been trying to find a combination that makes it work.
[00:53] <mark4o> meekohi: did you try lut, or maybe even haldclut?
[00:54] <meekohi> mark4o: out can't access the other channels while working on each channel unfortunately. Will look into Haldclut
[00:55] <meekohi> Haldclut looks like in only supports fixed color lookup tables -- unfortunately saturation is a function of the greyscale value (so it isn't a simple lookup table)
[00:56] <mark4o> haldclut can take any combination of r, g, and b into consideration so that shouldn't be an issue
[00:57] <meekohi> mark4o: Ahhhh okay I see what you mean, duh. Thanks this looks promising.
[00:57] <mark4o> it is normally fixed but can cover every color
[00:57] <mark4o> and I think it actually doesn't have to be fixed, can be a movie
[06:47] <mkvsynth> how do I find the framerate when using ffmpeg libraries?
[06:47] <mkvsynth> I have a formatContext and a codecContext
[08:03] <kcm1700> I want to associate AVPacket with the returned AVFrame from avcodec_decode_video2. since the decoders can produce delayed frames, it's not trivial how to associate them. what's the proper way?
[08:06] <kcm1700> mkvsynth: can you access to the AVStream structures which belong to the format context? I think AVStream has one.
[08:13] <mkvsynth> I think AVRational?
[08:18] <mkvsynth> avg_frame_rate?
[08:27] <mkvsynth> got it. in the format context you find the video stream and then use avg_frame_rate
[09:25] <Datalink> blah, I'm back...
[09:41] <Datalink> http://illogicallabs.com/paste/00000006.txt anyone know why I'd have an input/output error on this?
[11:10] <Martijnvdc> i'm trying to set up a decoder for a microphone, but after decoding, the data is corrupt. The raw packets from the audio device do contain valid PCM data though.
[11:10] <Martijnvdc> pastebin.com/T17gjUX6
[11:10] <Martijnvdc> would this be a bug, or am i doing something wrong?
[11:10] <Mavrik> um
[11:10] <Mavrik> why are you even decoding if you have PCM data?
[11:11] <Martijnvdc> because i need an AVFrame instead of an AVPacket
[11:13] <viric> I remember having issues with that... and finding out why.
[11:14] <viric> Martijnvdc: check my init_input: http://viric.name/cgi-bin/ring/artifact/30b92f876e91c1e719923c43c24930798e55e702
[11:14] <viric> and process_input
[11:15] <viric> I remember troubles initialising the contexts.
[11:20] <Martijnvdc> viric: thank you!
[11:20] <viric> this code works :)
[11:21] <viric> I suffered making it. hehe. it's the only thing I ever wrote with ffmpeg
[13:13] <axgb> Hi
[13:13] <axgb> What command would I use to convert a whole folder and the subfolders of music from mp3 to ogg
[13:18] <Martijnvdc> viric: thanks a lot man. thanks to your example, it now works perfectly
[13:19] <Martijnvdc> i don't know what exactly caused the corruption, but at least it now works :D
[13:35] <elkng> I have some video that coded video with "camtasia" codec and audio with "pcm_s16le, 12000 Hz, 1 channels, s16, 192 kb/s", and the audio sounds really poor, and a very little huming noise, is there some filter that can improve its quality ?
[13:36] <elkng> because watching that video for some period of time became really annoying
[13:36] <vad_> 12000 Hz means you will only get sounds up to 6 kHz.
[13:37] <vad_> IOW, someone chose really poor encoding settings
[13:38] <karlox> hi all
[13:38] <elkng> I mean to make it little softer, the only sound is voice its some recording of desktop video with commentary, and that voice sounds like really old radio from 30s, its quite brute for ears to hear
[13:40] <karlox> there is a way to undestand why when i play video fom an ip camera i receave the massege : corrupted macroblock specially on heavy network traffic
[13:42] <vad_> karlox: if the camera sends the stream in realtime to you, and the network is congested, it may have to drop frames because there's no space to write them anywhere
[13:42] <karlox> and there is a way to drop this frame so i don't display video damaged
[13:42] <vad_> so use it.
[13:43] <elkng> vad_: "chose really poor encoding settings", at least that way 26 minutes are 55Mb in size, very efficient
[13:43] <vad_> elkng: for 192kbit/s, you would get wonderful audio if encoded as MP3 or MP4AAC, even multichannel at that.
[13:43] <karlox> vad_, are you talking about network device or opertive system?
[13:43] <vad_> karlox: any component can and must drop something if buffers are full
[13:43] <elkng> s/opertive/aperture
[13:44] <karlox> vad_, may i drop this frame? The image with this error is terrible to diplay!
[13:45] <karlox> vad_, i'm trying with ffplay
[13:59] <Mavrik> elkng, the problem is that the audio is already destroyed
[14:02] <elkng> Mavrik: shouldn't there be filters for that purpose to restore quality ?
[14:02] <elkng> or make it softer or something
[14:02] <Mavrik> there's nothing to restore
[14:02] <Mavrik> you have all frequencies over 6kHz missing
[14:16] <viric> Martijnvdc: perfect :)
[14:16] <viric> Martijnvdc: I hope you write something very good and gpl
[14:49] <Martijnvdc> viric: it will be gpl :)
[15:37] <karlox> i have a lot of rtp missed  warnings also with negative number (RTP: missed -52283 packets) where i can investigate to find the cause of this warnings
[15:53] <karlox> in ffplay the option -fflags discardcorrupt can be used to drop frame this kind of error: error while decoding MB 44 26
[15:53] <karlox> ?
[17:04] <BoR0> hi. are there any examples of using FFmpeg with DirectSound? ffplay uses SDL for audio, but I need DirectSound in this specific case. I have one implementation but it generates a little white noise when I play it
[17:31] <mcbonz> Hey guys, which one is the currently best video codec supported by ffmpeg?
[17:56] <meekohi> What's the difference between "-q:v 1" and "-qscale 1" ?
[18:27] <microchip_> mcbonz: libx264
[18:28] <microchip_> meekohi: it's the same... -q:v 1 is the newer way of specifying it, -qscale  is the older way
[18:28] <meekohi> microchip_: Ah great, thanks!
[18:54] <karlox> i'm alway stuck with dropping frame to avoid to display artifact image....
[18:54] <karlox> i can't found the right option in ffplay!
[19:07] <WhiteNight_> Hi, how can I convert an RGB image to YUV420 using sws_scale? (I get the RGB image with glReadPixels(), as an char-array)
[20:55] <zap0> which yuv ?
[21:15] <Mista_D> anyway to copy gop structure of the source file?
[21:47] <Mr_E-> Is there no way to make ffmpeg use the english tagged audiotrack always as default if source has multiple language tracks (dvb input)
[21:48] <Mr_E-> Somewhat like what vlc's --audio-language=blah does
[21:59] <Mr_E-> Haha pretty simple, -alang eng always thought that was for setting output metadata ^^
[22:10] <SirCmpwn> can I get ffmpeg to just dump information about a file without doing anything to it
[22:11] <Mr_E-> ffmpeg -i file
[22:11] <Mr_E-> does just that
[22:11] <Mr_E-> :)
[22:44] <phr3ak> how could I avoid verbose/progress messages if I run ffmpeg in a cron job?
[22:47] <viric> -v loglevel ?
[22:50] <phr3ak> what do you think -v 0 ?
[22:50] <viric> no idea.
[23:16] <relaxed> phr3ak: you could log it all to a file somewhere with, ffmpeg -i .... output 2>/path/to/ffmpeg.log
[23:26] <beastd> phr3ak: you can try -loglevel quiet if you want to see nothing really or -loglevel warning or something in between. the log levels are described in the manual if you are curious.
[00:00] --- Thu Aug  8 2013