[Ffmpeg-devel-irc] ffmpeg.log.20130430

burek burek021 at gmail.com
Wed May 1 02:05:01 CEST 2013


[00:59] <Guest1296> When does player i.e youtube or dailymotion player get to know to start video playback ....Is it depending on buffer size or key frames?
[01:01] <Guest1296> is that limited to number of frames or just the buffer/time
[01:02] <Mavrik> usually it starts immediately as soon as it has minimal amount of data in buffer
[01:02] <Mavrik> and enough information to start playing
[01:02] <Mavrik> it depends on player really
[01:03] <Guest1296> Ok
[01:03] <Guest1296> it is different for different players right
[01:04] <Guest1296> someone mentioned that when we at least get one key frame ...and player immidiatly start playback
[01:05] <Guest1296> i just wanted to confirm from our group is that true
[01:06] <Mavrik> Guest1296, also it depends on container and format
[01:06] <Mavrik> e.g. if you have an MP4 with MOOV atom at the end it wont play until it downloads whole file :)
[01:07] <Guest1296> correct... also inorder to extract/read moov atom even though its in beginning is little bit time consuming
[01:09] <Guest1296> Great thanks
[02:28] <voidah> hi guys
[02:29] <voidah> I'm trying to modify a little thing in x11grab
[02:30] <voidah> is there a standard way in other part of ffmpeg to change some config values at runtime?
[02:31] <voidah> or a way to check for external event
[02:31] <voidah> what I want to do is to disable mouse cursor capture/drawing depending of an external event
[04:16] <voidah> hi, I have made a small (hackish..) patch
[04:16] <voidah> I would like, if someone want, show it to a ffmpeg developer
[11:38] <kornerr> hi
[12:14] <zap0> lo
[15:00] <ElMarikon> hi guys! I am trying to find out how to set channel names for each output channel...
[15:01] <ElMarikon> if the movie allready has the tags as an input file, ffmpeg is able to just copy them, but how to initially set them?
[15:01] <ElMarikon> a list of possibilities is shown on: ffmpeg -layouts.
[15:02] <ElMarikon> I can set the layout, but not individual channel names... can s.o. help me, plz?!
[15:20] <ElMarikon> noone?
[15:22] <spaam> channel names ?:O
[15:22] <spaam> like channel 1 is called microchip_ and the second is called sacarasc ?
[15:23] <spaam> or what do you mean?
[15:23] <sacarasc> sacarasc is a silly name.
[15:24] <spaam> its hard to say...  my friend an i say "that sac-ish dude you know"
[15:26] <sacarasc> Hehe.
[15:27] <spaam> sacarasc: i dont think we will get an answer from ElMarikon :(
[15:37] <nchauvet> Hi, is it legal to redistribute a ffmpeg built (GPLv2) with fdk-aac ?
[15:39] <durandal_1707> no
[15:45] <ElMarikon> sorry, was gone for a moment...
[15:46] <ElMarikon> i am talking about channel names, like L, R, C, LF...
[15:47] <ElMarikon> with QT u can assign them for each hannel, ffmpeg can then read theam and give them on to a new target (mov)...
[15:47] <ElMarikon> but I need to know, how to initially set them WITHOUT QT...
[15:47] <ElMarikon> (because it's slow , closed and unhandy...)
[15:48] <ElMarikon> spaam
[16:21] <ElMarikon> ...and now they are all gone:-(
[16:25] <Peace-> is there a way to speed up  a video with ffplay ?
[16:32] <watcher13> Hey! I'm trying to capture a video from a Logitech C905 webcam on Raspbian with ffmpeg, but get an error from [video4linux2 @ 0x1371840] Cannot find a proper format for codec_id 0, pix_fmt -1
[16:33] <Peace-> mm
[16:33] <watcher13> I wonder, do I have to install libv4l2 or libv4l2-convert manually to get that codec?
[16:33] <Fjorgynn> I love
[16:36] <Peace-> watcher13: paste all the output with the commad
[16:36] <watcher13> avconv version 0.8.6-6:0.8.6-1+rpi1, Copyright (c) 2000-2013 the Libav developers   built on Mar 31 2013 13:58:10 with gcc 4.6.3 [video4linux2 @ 0x1371840] Cannot find a proper format for codec_id 0, pix_fmt -1. /dev/video0: Input/output error
[16:37] <Peace-> the command ?
[16:37] <watcher13> That's all
[16:37] <watcher13> Oh, sorry
[16:37] <watcher13> avconv -t 5 -f video4linux2 -s 320x240 -r 30 -i /dev/video0 -vcodec mpeg1video out.avi
[16:37] <Peace-> :) #avconv
[16:38] <Peace-> ups
[16:38] <Peace-> there is the other channel for avstuff
[16:38] <watcher13> Ok, but ffmpeg output is the same, except by deprecation warning
[16:38] <durandal_1707> Peace-: ffplay is simple media player
[16:39] <Peace-> durandal_1707: i knew
[16:40] <watcher13> Peace: I just wonder, what info you guys can extract from that output: it's absolutely non-verbose. May be I can use some flags to have ffmpeg give more info?
[16:41] <relaxed> why mpeg1 in avi?
[16:42] <durandal_1707> watcher13: this is channel for ffmpeg from FFmpeg and not from Libav, either try latest ffmpeg or ask help on Libav channel
[16:42] <relaxed> it's #libav
[16:43] <Peace-> watcher13: well the command it's not write well btw
[16:43] <Peace-> at least for what i know
[16:46] <ElMarikon> since there is sth going on here, now... my question again:
[16:47] <ElMarikon> how do i assign channel names to individual audio channels in eg. a mov file?
[16:48] <ElMarikon> ffmpeg -layouts     shows the available names, but no command to assign them to channels...
[16:48] <ElMarikon> i found out, ffmpeg can pass them through from some other file, like mov to a new file, but how to initially  set them
[16:48] <ElMarikon> ?
[16:49] <ElMarikon> anyone has a clue?
[16:49] <ElMarikon> plz!!
[16:50] <watcher13> Peace, durandal_1707: ok, but ffmpeg's output is the same, just s/avconv/ffmpeg/gc. What info can I get from ffmpeg and give to you, so that it helps?
[16:53] <durandal_1707> watcher13: i told you: the only way you can help yourself is by trying latest version
[16:53] <durandal_1707> ElMarikon: you want to remap channels?
[17:52] <ElMarikon> durandal_1707: No, #I don't need to remnap. I just need to label them...
[17:54] <durandal_1707> label what?
[18:03] <spaam> durandal_1707: the channel. so right channel will have R  and left channel will have L  and so on.
[18:05] <durandal_1707> so he have mov with each channel in separate stream?
[18:14] <watcher13> Peace, durandal_1707: Thank you.
[18:20] <ElMarikon> well--- maybe separate streams maybe in one stream...
[18:20] <ElMarikon> my point is, i have to assign a label for every channel.
[18:21] <durandal_1707> in what way? via metadata or?
[18:22] <ElMarikon> well... how ever... just need to tell ffmpeg, that my 1st channel is named: FL, 2nd channel= FR and so on...
[18:22] <ElMarikon> as I said, doing that with QuickTime is easy (via gui) and ffmpeg keeps the names, but how to initially assign them, not workling with an eyternal tool for that?!
[18:22] <smj> hey... I'm not sure, but I might have fixed the desync problem by giving frame rate as the output option instead of an input option
[18:23] <ElMarikon> smj: but then you drop/duplicate frames..
[18:23] <ElMarikon> do u want that?
[18:23] <smj> yes.
[18:23] <smj> while streaming.
[18:33] <atog> I'm using ffmpeg to record audio from a public stream at predetermined times. The content that I'm trying to capture is preceeded by a prerecorded audio cue. Do any of you know how I might compare the input stream to a copy of the cue so that I can begin recording once the cue has been played?
[18:36] <ElMarikon> atog: I don't get that... what do u wanna compare
[18:36] <atog> ElMarikon: I want to compare a live audio stream to a prerecorded cue. Once the cue is heard on the live stream I want to begin recording
[18:37] <durandal_1707> ElMarikon: there is -map_channel
[18:39] <ElMarikon> durandal_1707: thanx, but as i wrote it is not about mapping the channels, but about labeling them...
[18:39] <durandal_1707> where would be label put?
[18:41] <ElMarikon> so... I have to change this:
[18:41] <ElMarikon>     Metadata:
[18:41] <ElMarikon>       creation_time   : 2013-04-10 22:12:07
[18:41] <ElMarikon>       handler_name    : Apple Alias Data Handler
[18:41] <ElMarikon>     Stream #0:18(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32, 1152 kb/s
[18:41] <ElMarikon> to that:
[18:41] <ElMarikon>     Metadata:
[18:41] <ElMarikon>       creation_time   : 2013-04-10 22:12:07
[18:41] <ElMarikon>       handler_name    : Apple Alias Data Handler
[18:41] <ElMarikon>     Stream #0:18(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1 channels (LFE), s32, 1152 kb/s
[18:42] <ElMarikon> meaning: i have to tell ffmpeg: THIS is the LFE, that channel is the FL and so on...
[18:42] <durandal_1707> open feature request on our trac
[18:42] <ElMarikon> NO remap. I know how to do that...
[18:43] <durandal_1707> thing is that currently 1 channel is always mono
[18:43] <ElMarikon> ffmpeg can pass these labels through, but I don't know how to create them...
[18:43] <durandal_1707> how ffmpeg pass such labels?
[18:44] <durandal_1707> do you have file where it says anything different from "mono" ?
[18:47] <ElMarikon> yes.
[18:47] <ElMarikon> created by Quicktime...
[18:48] <ElMarikon> if i just map the channels to a new.mov, ffmpeg just keeps the labels.
[18:50] <durandal_1707> have link to short sample?
[18:50] <durandal_1707> i'm certainly sure this is mov feature that is missing in muxer
[18:51] <durandal_1707> because if you do -c copy it should be keept
[18:51] <durandal_1707> if not, than its missing and so open bug report
[18:55] <ElMarikon> i check that now...
[18:56] <ElMarikon> so... it keeps the label even if i change the codec and /or mapping...
[19:00] <ElMarikon> but just from mov to mov. It disappears, when i write an avi/mkv...
[19:01] <durandal_1707> because avi/mkv does not have that feature
[19:01] <durandal_1707> it seems user is not allowed to change those...
[19:05] <ElMarikon> well... u can remove them, by saying map_metadata -1
[19:06] <ElMarikon> so u're saying, options are: keep or remove, nothing else!?
[19:06] <durandal_1707> afaik they are set by "chan" tag
[19:12] <cliente> can ffmpeg dump the audio of the wmv format?
[19:15] <ElMarikon> of cause...
[19:16] <cliente> cause?
[19:16] <ElMarikon> durandal_1707: I can't find anything about that in this "chan" option...
[19:17] <durandal_1707> ElMarikon: its metadata key, and afaik not settable from muxer/user
[19:18] <durandal_1707> s/settable/ignored
[19:18] <cliente> I have been trying with vlc and the audio seem to get distorted
[19:18] <durandal_1707> ElMarikon: but try setting -channel_layout
[19:36] <ElMarikon> i did try that of cause... in several ways...
[19:36] <ElMarikon> durandal_1707: what codecs are in the file?
[20:39] <sean-w> Is there any way to convert AIFFs to MP3s while retaining metadata?
[20:40] <xlinkz0> where can i see what ffmpeg does when given a rtsp input stream?
[20:42] <ElMarikon> sean-w: you could try to mess around with the -map_metadata option...
[20:43] <ElMarikon> xlinkz0: what does it say?
[20:43] <xlinkz0> no i mean how it sends rtsp commands etc
[20:50] <ElMarikon> oh... sorry... not a single clue...
[21:03] <xlinkz0> more particularly i need to know to which RTSP command the url is used on
[21:03] <xlinkz0> or if the url is passed through the http api
[21:11] <sean-w> xlinkz0: Maybe sniff some traffic with Wireshark?
[21:24] <xlinkz0> thanks that's a good idea
[22:09] <jbwiv> guys, I'm trying to convert an mp4 to wmv. I can do this with ffmpeg and it plays fine on linux, but when I try to play it on windows, it causes wmplayer to crash. Is this a known issue?
[22:20] <otters> anyone on osx gotten sox to compile with ffmpeg support?
[22:20] <otters> this is the tail of configure output on latest sox https://gist.github.com/joelteon/8a3c0bfe4555d95c3eb1
[22:21] <durandal11707> otters: you are asking for sox help on wrong channel
[22:29] <otters> oh
[22:29] <otters> well #sox is empty
[22:30] <durandal11707> sox is even removing ffmpeg support
[22:31] <otters> then what do I use to merge two m4bs together?
[22:31] <durandal11707> what?
[22:31] <otters> what do you mean, "what"
[22:32] <durandal11707> what is m4bs?
[22:33] <otters> it's an m4a with chapters
[22:34] <durandal11707> i dont think sox supports m4a
[22:34] <durandal11707> so whatever you do can be done with ffmpeg alone
[22:35] <otters> it's an audiobook
[22:39] <otters> okay it doesn't look like there exists any program capable of concatenating two m4bs
[22:42] <tmatth> otters: http://ubuntuforums.org/showthread.php?t=1900761
[22:42] <otters> tmatth: you are the reincarnation of jesus christ
[22:43] <ElMarikon> wrong, that's me..!
[22:44] <durandal11707> same can be done with ffmpeg, there is documentation...
[22:44] <ElMarikon> well... he found his way...
[22:48] <ElMarikon> so... i still did not find a solution 4 my problem here...
[22:48] <ElMarikon> I need to label the audio channels in a mov container the right way:
[22:48] <ElMarikon> in: Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, mono, s16, 768 kb/s
[22:49] <ElMarikon> out: Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, (FL), s16, 768 kb/s
[22:49] <ElMarikon> i just don'tr get how to change the channel names...
[22:49] <durandal11707> i told you that is not currently possible, open bug if you ever want it get fixed
[22:50] <ElMarikon> where do u know that from?
[22:50] <ElMarikon> i do see it is possible.
[22:50] <ElMarikon> the only question is how...
[22:51] <otters> heh, mp4box
[22:51] <otters> it actually can't be done with ffmpeg
[22:52] <otters> which can't output m4b
[22:52] <otters> or doesn't understand how
[22:52] <ElMarikon> but it can read and pass on these tags...
[22:52] <ElMarikon> oh sorry...
[22:53] <durandal11707> ElMarikon: yes, but you cannot really control them
[22:54] <durandal11707> otters: m4b is just extension
[22:55] <otters> durandal11707: ah...that might be it
[22:56] <otters> because it can output to *.mp4 just fine >_>
[22:56] <otters> thanks
[22:59] <durandal11707> otters: its probably some extra few bytes change, i could add support for it, funny sox uses ffmpeg for m4b but ffmpeg does not even know m4b exist ...
[22:59] <otters> durandal11707: okay so ffmpeg merges the files together properly, but when I open the resulting file it thinks it's the length of the first file
[22:59] <otters> I think it might be because the chapter offsets in both tracks start at 0
[23:00] <durandal11707> what you used to merge?
[23:00] <otters> ffmpeg
[23:00] <otters> oh
[23:00] <durandal11707> but command...
[23:00] <otters> ffmpeg -i file1.m4b -i file2.m4b -y out.mp4
[23:01] <otters> hang on, tmux won't let me select all of it
[23:01] <durandal11707> but if worked with sox?
[23:01] <otters> no
[23:02] <durandal11707> so why you asked for sox help then :)))
[23:02] <otters> because i thought sox could do it
[23:02] <otters> I just tried ffmpeg and it "worked"
[23:03] <durandal11707> well there is concat demuxer
[23:03] <durandal11707> !doc
[23:14] <SeanDuncan_>  I'm trying to use x264's qpfile option through ffmpeg's 'x264opts' option but qpfile doesn't seem to be working from there. is it called something else in ffmpeg?
[23:14] <SeanDuncan_> I know there is the 'force keyframes' option but I'm looking to set frame types at a frame level
[23:17] <SeanDuncan_> the big picture of what I'm trying to do is a pass=1 with x264, with mbtree enabled, while maintaining keyframe placement of past encodes (qp file generated from past .stats files)
[23:19] <otters> https://gist.github.com/joelteon/038ea6b7317d7fef2cf2
[23:19] <otters> so all I really need to do is increment the chapter offsets and chapter numbers on the second input track
[23:20] <otters> or...something.
[23:21] <durandal11707> i dont think thats currently possible, open bug report if you want such feature
[23:21] <otters> rats
[23:24] <ElMarikon> durandal11707: if you are interested, I found the solution for my Problem: ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -channel_layout:0 FL -map_channel 0.0.1:0.1 -channel_layout:1 FR -c:a pcm_s16le tagged.mov
[23:25] <ElMarikon> that tags channel0 as F(ront)L(eft) and channel1 as F()R()
[23:25] <ElMarikon> so, no need for a bug report... thanx 2 u all!
[23:26] <ElMarikon> otters: if it helps, you can just skip the chapters...
[23:26] <ElMarikon> like: -map_chapters -1
[23:28] <durandal11707> ElMarikon: yes, i even mentioned to try with -channel_layout (but i did not pushed as i did not expect it to work)
[23:29] <otters> ElMarikon: having chapters is the whole point of m4b
[23:29] <durandal11707> ElMarikon: you could even add it to our wiki...
[23:29] <ElMarikon> well... i do not know, but maybe there is a way to export them as text file and then offset them...
[23:30] <durandal11707> for chapters i could swear you can't edit them, just remap/dump them
[23:31] <ElMarikon> durandal11707: well, I also was not sure if it works, because i fritst tried to tag as FC, which for ffmpeg is the same as mono, so I had no tag then..:-|
[23:31] <durandal11707> or even creating new ones from scratch
[23:31] <durandal11707> is not currently possible
[23:34] <ElMarikon> so, maybe it sounds funny, but handbrake has a good chapter handler and understands mp4 files... maybe it can be of help here...
[23:34] <ElMarikon> ...a little off topc, i know...
[23:34] <durandal11707> already mentioned mp4box too
[23:34] <ElMarikon> :-)
[23:35] <otters> mp4box gives me a mysterious error :)
[23:35] <otters> "Error: Bad Parameter"
[23:35] <ElMarikon> oh I just see, there is an export chapters option in handbrake, so maybe u can export, edit and then re-import...
[23:35] <ElMarikon> otters: what parameters did u specify?
[23:36] <otters> ElMarikon:
[23:36] <otters> mp4box -cat file2.m4b file1.m4b
[23:36] <otters> it says "Appeding file2.m4b" and gives me a progress bar
[23:36] <otters> then, once it hits 100%, gives me that error and exits
[23:37] <otters> Appending, actually
[23:37] <ElMarikon> and the file does not work in the end?
[23:40] <otters> it does, it has the length and chapters of the first input file but the filesize of both together
[23:41] <ElMarikon> okay... i am not sure, but don't u have to say sth like mp4box  -add file1.m4b -cat file2.m4b -new ...m4b
[23:41] <ElMarikon> ?
[23:42] <ElMarikon> and mybe -all
[23:43] <ElMarikon> sorry, -keep-all
[23:48] <ElMarikon> okay guys... i'T kindof midnight here, i am leaving... happy 1st of May, if that means sth to anyone:-)
[23:48] <SeanDuncan_> OK, I'm back.  sorry it took awhile.  here is the pastebin of what I'm trying to do http://pastebin.com/u0FYfZnT
[23:50] <ElMarikon> well...
[23:50] <ElMarikon> seems, it does not like your qpfile
[23:50] <ElMarikon> it does not even know the option...
[23:54] <SeanDuncan_> yes, I see the same.  it's just that x264 does have a option called 'qpfile' http://mewiki.project357.com/wiki/X264_Settings#qpfile
[23:54] <ElMarikon> rite, but ffmpeg seems not to pass this on to the lib...
[23:54] <SeanDuncan_> and I know the qp file is formated like the wiki says it should be
[23:54] <SeanDuncan_> oh
[23:54] <SeanDuncan_> dang
[23:55] <SeanDuncan_> that's a shame
[23:55] <ElMarikon> so, what u can do is:
[23:55] <SeanDuncan_> pipe from ffmpeg to x264?
[23:56] <ElMarikon> ffmpeg -i %vid% -vf scale=1280:720 -an -pix_fmt yuv420p -f yuv4mpegpipe -vsync 0 -v 4 - | x264 %youropts% out.mp4
[23:56] <ElMarikon> sorry, no vscale!!
[23:56] <SeanDuncan_> right
[23:56] <SeanDuncan_>  I was hoping to avoid that method
[23:56] <SeanDuncan_> totally doable, I understand
[23:57] <ElMarikon> why?
[23:57] <ElMarikon> it does not really change a thing...
[23:57] <SeanDuncan_> any idea if ffmpeg plans to allow for qpfile via x264opts?
[23:57] <ElMarikon> not a single clue, i am just assuming...
[23:58] <durandal11707> SeanDuncan_: did you make sure it actually works with x264 alone?
[00:00] --- Wed May  1 2013


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