[Ffmpeg-devel-irc] ffmpeg.log.20130804

burek burek021 at gmail.com
Mon Aug 5 02:05:01 CEST 2013


[00:01] <CentRookie> cant you list all`and then simply record by trial and error?
[00:02] <CentRookie> as long as you dont have like 10 cards, you will figure out
[00:02] <CentRookie> which device has which sream
[01:50] <brad_c6> Hello, When I am am decoding audio (in my case a pcm_s16le wav file). Should the header be removed after the decode. As when I encode I get a pop noise at the beginning on the audio. Is this the old header? Thank You
[01:58] <agnar_> What might cause this? -- Whenever I try to seek during playback, it seeks to the beginning
[02:11] <klaxa> no i-frames could cause that
[02:11] <klaxa> the lack of i-frames
[03:38] <brad_c6> I think I may have got it, in an AVFormatContext the buf_ptr is the start of the PCM data? So to know the bytes to skip (to avoid the PCM header) I do pointer arithmetic of AVFormatContext buf_ptr - buffer?
[04:20] <Carraway> hi folks - I have a question about using multiple video filter arguments
[04:21] <Carraway> I want to run both -vf pp=al and -vf "scale="800:trunc(ow/a/16)*16"
[04:21] <Carraway> stackoverflow told me I can put both vfs in quotes and separate each argument with a semi-colon, but the issue is that scale is already in quotes
[04:29] <Justanotheruser> Is there anyone active here tonight?
[05:56] <Carraway> Seems like not really
[05:58] <klaxa> Carraway: try: -vf "pp=al, scale=800:trunc(ow/a/16)*16"
[05:58] <klaxa> at least that's the syntax in the online documentation
[05:59] <Carraway> That worked! Fantastic.
[05:59] <Carraway> Must be too tired to tell the difference between a comma and a semicolon
[05:59] <klaxa> :)
[09:11] <hayuto> can anyone tell me what was the option for ffmpeg to kind of works like anty alias for low bitrate movies?
[14:48] <hikenboot> hello I have used ffmpeg -i "s and d.MTS" -r 1 -f image2 stillshots2/%05d.png to break a video down that has a lot of green, but ffmpeg is turning it very green and on the redish side is there an easy fix to devide up the video and maintain the original color balance?
[14:50] <hikenboot> s/devide/divide
[14:51] <hikenboot> oops wasnt logged in at the risk of a repeat here is the question again
[14:51] <hikenboot> hello I have used ffmpeg -i "s and d.MTS" -r 1 -f image2 stillshots2/%05d.png to break a video down that has a lot of green, but ffmpeg is turning it very green and on the redish side is there an easy fix to devide up the video and maintain the original color balance?
[15:35] <durandal_1707> hikenboot: what you use to view images?
[15:35] <durandal_1707> you are probably doing yuv->rgb->yuv conversion
[16:08] <voltagex> can I ask rtmpdump questions in here?
[16:28] <recover_> Hello. Does anyone know if it is possible to figure out the size of a .ts file just by looking at the headers inside the file?
[16:29] <recover_> Say I got a partial ts file and I want to know the size it was supposed to be..
[16:32] <evdw87> recover_: I hope this might help you http://mediaarea.net/en/MediaInfo
[16:36] <recover_> I tried MediaInfo, but I couldn't find anything conclusive... I think that maybe taking the bitrate of each stream, times total seconds, divide by 8, plus the size of all headers, should be a good estimate
[16:36] <recover_> but I need it in bytes and mediainfo prints kbps, so I need to make my own program...
[17:19] <recover_> Can I have ffmpeg print the bitrate in bps instead of kbps?
[17:59] <klaxa> multiply by 1024?
[18:08] <hikenboot> how do i do  ffmpeg -i "s and d.MTS" -r 1 -f image2 stillshots2/%05d.png changed so that it doesnt do a yuv->rgb->yuv conversion ?
[19:05] <hikenboot> ok i will ask it in a different way how do I determine the current encoding format?
[19:06] <hikenboot> for color
[19:33] <hikenboot> well figured it out with trial and error thanks
[20:25] <Aethelstan> Hi I'm new to ffmpeg, how can I use an H.265 encoder if I downloaded it from the official website (http://xhevc.com/en/downloads/downloadCenter.jsp) ?
[20:26] <klaxa> probably not at all atm
[20:27] <klaxa> you will have to use the distributed binary you got and feed it some kind of raw format, most accept yuv4mpeg
[20:28] <klaxa> oh especially since it's a windows only binary
[20:28] <klaxa> (well and a mac version)
[20:30] <Aethelstan> By distributed binary do you mean ffmpeg.exe or the h265 dll?
[20:32] <klaxa> the h265.dll if you got one even... i doubt you can just use it with ffmpeg
[20:32] <Aethelstan> I do have one, so I'll try using it directly thanks!
[20:33] <klaxa> you can't execute a .dll though
[20:33] <klaxa> actually no idea how to use this encoder :|
[20:33] <sacarasc> Didn't the BBC release a 265 executable?
[20:34] <klaxa> maybe someone else knows something, so maybe stay a little longer
[20:34] <klaxa> there was an open source h265 encoder on bitbucket https://bitbucket.org/multicoreware/x265/overview
[20:35] <klaxa> people complained it uses cmake though
[20:35] <Aethelstan> what is cmake?
[20:39] <Aethelstan> the readme says "The encoder filter is a Transform Filter, with an input Pin and an output Pin. The input Pin supports two media types: MEDIASUBTYPE_IYUV and MEDIASUBTYPE_YV12. The output Pin supports the media type MEDIASUBTYPE_HM91, which is a user-defined type, indicating bitstreams compatible with HM9.1." although I'm not sure what that means exactly
[22:10] <braincracker> if you need a 230V power cable, you can be sure the one you have will have a 90 deg plug on it, and is bent in wrong direction that will not fit
[22:18] <parshap> Does anyone know why simply copying out an MP3 would work fine when writing to a file but fail when piping out to pipe:1? I'm doing `ffmpeg -i test.mp3 -codec copy -f mp3 pipe:1 > piped.mp3` which results in a bad file. See full demonstration: https://gist.github.com/parshap/d2d1da189d6ebe236f9c
[23:19] <Witchsong> How can I set the default flag of a subtitle track?
[23:19] <Witchsong> Currently all my subtitle tracks in a MKV are set as default.
[23:49] <Eduard_Munteanu> Hi. Any idea if/how ffprobe can tell me whether an mp3 file is CBR or VBR-encoded?
[23:50] <sacarasc> If it's not exactly 32, 56, 64, 96, 112, 128, etc bitrate, it's VBR. :p
[23:51] <Eduard_Munteanu> sacarasc: hm, I'd like to be sure, it's causing problems in a car media player
[23:51] <sacarasc> `mediainfo` will definitely tell you.
[23:51] <Eduard_Munteanu> Thanks, I'll try that, I've seen other mentions of it.
[23:53] <Eduard_Munteanu> (I've been rather happy with ffprobe so far, I guess mediainfo might deal with pretty-printing all those internals better)
[23:55] <sacarasc> mediainfo would look something like this: http://pastebin.com/g2iQRb0N
[00:00] --- Mon Aug  5 2013


More information about the Ffmpeg-devel-irc mailing list