[Ffmpeg-devel-irc] ffmpeg.log.20150731

burek burek021 at gmail.com
Sat Aug 1 02:05:01 CEST 2015

[02:07:15 CEST] <bwilson> When running ffmpeg on a mac, Im attempting to list supported/connected devices with `ffmpeg -f avfoundation -list_devices true -i ` but I get Unrecognized option 'list_devices.
[02:07:22 CEST] <bwilson> using the binary release from the main site
[02:07:29 CEST] <bwilson> anyone run into this?
[02:07:53 CEST] <bwilson> according to the docs, thats how to do it https://trac.ffmpeg.org/wiki/Capture/Webcam
[02:09:14 CEST] <chungy> Did you use the curly quotes on the command line?  Try using straight " quotes only.
[02:09:42 CEST] <bwilson> no, thats just my irc client. :)
[02:10:11 CEST] <bwilson> it looks like the binary release isnt build with avfoundation nor qtkit?
[02:10:16 CEST] <bwilson> s/build/built/
[02:10:46 CEST] <chungy> I don't use Mac, but the "" thing stood out to me.
[02:17:36 CEST] <c_14> bwilson: if you check the configure line, you can see that qtkit is disabled and avfoundation isn't enabled
[02:18:43 CEST] Action: bwilson built with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
[02:18:44 CEST] Action: bwilson   configuration: --prefix=/Volumes/Ramdisk/sw --enable-gpl --enable-pthreads --enable-version3 --enable-libspeex --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-avfilter --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-filters --enable-libgsm --enable-libvidstab --enable-libx265 --disable-doc --arch=x86_64 --enable-runtime-cpudetect
[02:21:24 CEST] <c_14> Can you check ffmpeg -devices?
[02:21:29 CEST] <c_14> Should be listed there if it's compiled in.
[05:57:13 CEST] <k_sze> Hello.
[05:57:42 CEST] <k_sze> Is the entropy in the image data supposed to have a huge effect on the encoding speed of the x264 and ffv1 codecs?
[05:58:09 CEST] <k_sze> disregarding I/O, that is.
[07:26:29 CEST] <satinder> Hi , Dear friends can we detect vocals with ffmpeg in any mp4 video ? if yes then how ? anybody have any idea about that ??
[08:44:44 CEST] <harisk92> good morning
[08:48:31 CEST] <harisk92> I'm using ffmpeg to output hls and I'm trying to create my own hls playlist with the chunks that were created.But I'm having the hard time with getting duration of chunks so I came to ask you a bit about how does ffmpeg writes chunks to storage does he starts and finish writing one chunk or in the same time he's writing to 2 different chunks
[10:08:05 CEST] <satinder>  Hi , Dear friends can we detect vocals with ffmpeg in any mp4 video ? if yes then how ? anybody have any idea about that ??
[11:03:21 CEST] <mathieu> I have a problem building ffmpeg from source with the --enable-shared flag
[11:03:41 CEST] <mathieu> It errors with: /usr/bin/ld: libavutil/color_utils.o: relocation R_X86_64_32S against `.rodata' can not be used when making a shared object; recompile with -fPIC
[11:03:41 CEST] <mathieu> libavutil/color_utils.o: error adding symbols: Bad value
[11:03:41 CEST] <mathieu> collect2: error: ld returned 1 exit status
[11:07:36 CEST] <JEEB> mathieu: it means that some of the dependencies aren't built with PIC
[11:08:29 CEST] <mathieu> but then the enable-shared option doesnt work at all in ffmpeg?
[11:08:46 CEST] <JEEB> it most definitely does work
[11:08:54 CEST] <JEEB> as in, in general
[11:09:32 CEST] <JEEB> if you have before this built ffmpeg from those sources, then make sure that you have the source directory clean (you can use out-of-source compilation or git clean to clean it all up)
[13:02:46 CEST] <niknok> hi! I have a content which has 2 audio languages I was able to tag each audio track with its proper language but everytime I am adding a language metadata to an audio track...the video stream got the same metadata language metadata
[13:06:44 CEST] <KarlFranz> Knowing your exact procedure would help.
[13:19:43 CEST] <niknok> here is the command I used http://pastebin.com/C0abkSSq
[13:28:59 CEST] Action: KarlFranz checks
[13:36:33 CEST] <AlicanC> Instead of using '-an', can I disable audio using '-c:a none' or something like that?
[13:37:16 CEST] <KarlFranz> Is there a reason for doing that?
[13:38:34 CEST] <AlicanC> I am generating the ffmpeg command programatically (JavaScript). I would like to be able to `-c:a ${codec}` without having an if statement to check if `codec` is none and then do '-an' instead.
[13:38:46 CEST] <AlicanC> Just trying to make my cod 0.62% cleaner.
[13:38:50 CEST] <AlicanC> *code
[17:39:10 CEST] <nyuszika7h> is it possible to use the Intel QuickSync encoder with ffmpeg?
[17:43:52 CEST] <durandal_1707> you mean qsv thing?
[19:41:40 CEST] <diegoviola> I want to convert a mp4 file to mkv and attach a subtitle to it, how do I go in doing this?
[19:41:45 CEST] <diegoviola> can I do it with ffmpeg?
[19:41:50 CEST] <diegoviola> I don't want to re-encode
[19:43:43 CEST] <pzich> never done it, but maybe something like ffmpeg -i input.mp4 -i subtitle.srt -c copy output.mkv ?
[19:47:58 CEST] <JEEB> you couldn't be able to -c copy it
[19:48:06 CEST] <JEEB> you would have to convert the srt to 3gpp subtitles
[19:48:14 CEST] <JEEB> which is probably something like mov_text in ffmpegspeak
[20:16:29 CEST] <chungy> srt works perfectly fine in a mkv container
[20:36:45 CEST] <AAA> hey all. has anyone successfully compiled ffmpeg with the qsv codec? (Intel Media SDK)
[20:37:39 CEST] <BtbN> I'm sure at least the people who sent the patches have.
[20:38:11 CEST] <BtbN> I didn't feel like digging through Intels stuff, so i gave up when they wanted me to sign up just to download the sdk.
[20:38:32 CEST] <AAA> it's a mess and the docs aren't super helpful
[20:38:58 CEST] <AAA> make: *** [libavcodec/qsvenc.o] Error 1
[20:40:01 CEST] <AAA> mfxVideoParam has no member named mfx
[21:04:03 CEST] <niknok> is it possible to mux in a subtitle using ffmpeg?
[21:05:43 CEST] <chungy> yes
[21:09:21 CEST] <niknok> I will try to mux in an Arabic subtitle...do i need to specify that the subtitle is in Arabic?
[21:09:59 CEST] <c_14> No
[21:10:13 CEST] <c_14> You can tag it as such to make it easier to tell in the muxed file.
[21:11:16 CEST] <niknok> ok thanks I will try to make 1
[21:12:38 CEST] <chungy> "-metadata:s:s:0 language=ara" would be a way in mkv to tag it as Arabic, but it's not strictly required.
[21:13:01 CEST] <chungy> the colon syntax reads odd, but it's stream:subtitle:0 (0 being the first subtitle stream)
[21:25:42 CEST] <niknok> the samples of command line I had read on the web are for mp4 and mkv files...i guess it is the same with a ts file
[21:32:44 CEST] <niknok> speaking of language tags...I had tried earlier to add tags in audio streams. I just do not know why it also add a tag in the video stream
[23:12:06 CEST] <diegoviola> how do I convert a mp4 file to mkv and also include a srt as part of the stream?
[23:12:33 CEST] <c_14> ffmpeg -i mp4 -i srt -c copy -map 0 -map 1 out.mkv
[23:12:57 CEST] <diegoviola> I don't know what -map will do
[23:13:23 CEST] <diegoviola> looking at the man page
[23:13:29 CEST] <c_14> Makes sure all streams from the first file are copied as well as the subtitle stream
[23:14:04 CEST] <diegoviola> thanks
[23:14:14 CEST] <diegoviola> is that optional though?
[23:14:53 CEST] <diegoviola> I mean, won't ffmpeg do that already if I don't specify -map?
[23:15:47 CEST] <c_14> IT picks 1 audio, 1 video, and 1 subtitle stream by default.
[23:15:51 CEST] <c_14> If you have more, it's dropped.
[23:16:04 CEST] <diegoviola> ok
[23:16:20 CEST] <diegoviola> I only have 1 mp4 and 1 srt
[23:16:25 CEST] <c_14> s/it's/they're/
[23:16:59 CEST] <c_14> But the mp4 might have several audio streams.
[23:17:13 CEST] <diegoviola> it works, thanks
[23:17:22 CEST] <diegoviola> c_14: it has only 1 audio stream
[23:17:35 CEST] <c_14> Then you don't need the maps
[23:18:09 CEST] <diegoviola> ok so the maps are useful when you have more than 1 subtitle / audio stream?
[23:18:33 CEST] <c_14> yep
[23:18:49 CEST] <diegoviola> thanks a lot
[23:18:52 CEST] <diegoviola> got it
[00:00:00 CEST] --- Sat Aug  1 2015

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