[Ffmpeg-devel-irc] ffmpeg.log.20140323

[burek]

[00:23] <slorbast> Hey guys, is there any way to convert a .mp3 or any other typical audio or video file to .mid? I imagine there isn't a great way to do it systematically other than recomposing a midi myself but wanted to make sure
[00:24] <klaxa> there are some programs that try to do that
[00:24] <klaxa> there isn't anyone that does it reliably well though
[00:25] <klaxa> *any one
[00:26] <slorbast> Thanks, I'll poke around and try them out and see if they work "well enough" lol
[01:06] <tabakd> I'm trying to record a stream of a x11 session seperate from the one I am in using ffmpeg. The second I leave my x11 sesion (:1) being recorded the stream freezes.
[01:42] <BtbN> tabakd, that's most likely because it stops beeing rendered at all
[01:46] <BlackFox> Greetings, quick question: I want to stream an existing video file, and I want to be able to play/pause/rewind it in realtime. Taking ffmpeg and giving it the file as input works, can I control it somehow though?
[01:50] <sacarasc> I think you'd be better off with something like VLC for that.
[01:50] <BlackFox> Hmm
[01:51] <BlackFox> I suppose I can just have ffmpeg re-route the stream from VLC
[01:52] <tabakd>  Can ffmpeg record an x11 session I'm not actually connected to?
[01:57] <clever> tabakd: if you can set DISPLAY right to connect to it, yes
[01:58] <BtbN> The problem is not that ffmpeg can't connect to it, the problem is that it stops rendering when it's not active
[01:58] <clever> yeah, thats a different problem
[01:58] <clever> i would start an Xvnc4 server instead
[01:58] <clever> then i can minimize the viewer or even DC without any impact
[01:59] <BtbN> but also loose all performance
[01:59] <clever> yeah, it depends on what he is trying to do as well
[02:03] <tabakd> yea
[02:04] <tabakd> the stream goes inactive when I leave the session
[02:05] <BtbN> yes, that's not a bug and not a problem with ffmpeg, and most likely also nothing you can fix
[02:08] <tabakd> does any other software do what I want?
[02:46] <pippin> there has been a regression in the GIF animation encoder; it no longer makes pixels that are the same from the previous frame transparent (frame mode is still combine though)
[02:49] <pippin> discovered when updating the ffmpeg patch at http://pippin.gimp.org/a_dither/ - now all of the methods; including bayer yields ~2.9M files
[07:41] <pross-au> noob question: how do i play back a 352 kHz audio file using ffplay (sdl fails to open the audio device; e.g. how do i make ffplay resample it.)
[10:26] <xhochy_> hey, I have a problem with rtmp streams where ffmpeg does not stop playing: in vlc the progressbar always stops 1/2s before the end and ffplay just outputs silence for an infinite time but the timecounter increases, the ffplay -loglevel debug log http://pastebin.com/WAANH0AD shows that a NetStream.Play.Stop is received so I'm wondering a bit why it does not
[10:26] <xhochy_> stop
[19:30] <ValdikSS> klaxa: https://trac.ffmpeg.org/ticket/3491
[20:08] <ValdikSS> klaxa: and it's solved!
[22:24] <justinfront> Hi I would like to convert EX1 sony camera footage to something I can upload to the internet and something I can use with flash player and with quick time.  I installed ffmpeg via macports and remember it was doing something but some of the links related seem to be broken, can anyone suggest how I check the current format and the best or simplest way to get it in a mac usable form using ffmpeg.
[22:25] <klaxa> ValdikSS: oh nice
[22:26] <zumba_addict> is h.265 in public?
[22:29] <jbermudes> justinfront: if you just give ffmpeg an input without instructions on what to output, it'll tell you info about the file. ffmpeg -i filename.mov etc.
[22:35] <klaxa> justinfront: if you want it to be compatible as possible, webm is probably what you want
[22:36] <klaxa> to see if it satisfies your quality needs, just encode a test segment like so: ffmpeg -i somefile.mov -t 10 somewebm.webm
[22:36] <klaxa> that will encode the first 10 seconds
[22:36] <justinfront> jbermudes thanks I have pastebinned the output maybe someone can advise the best approach, been practicing a student dance show and really want to upload something to crappy facebook private group so quality can probably go out the window.
[22:36] <justinfront> http://pastebin.com/dgavS9Qt
[22:37] <justinfront> what does -t 10 do?
[22:37] <justinfront> oh sorry did not read
[22:37] <justinfront> 10 sec
[22:37] <justinfront> Klaxa will try that
[22:38] <justinfront> I think fb probably like h264 format ie flash, webm is likely heavier and not ideal for flash which is probably what the use best if they don't have to try "fixing" my quality further.
[22:39] <klaxa> ah with flash player
[22:39] <klaxa> i read without flash player
[22:40] <klaxa> (nobody wants flash really...)
[22:41] <klaxa> justinfront: to encode to h264 read: https://trac.ffmpeg.org/wiki/x264EncodingGuide
[22:43] <justinfront> fb suggest
[22:43] <justinfront>     We recommend H.264 video with AAC audio in MOV or MP4 format
[22:43] <justinfront>     Make sure the video isn't more than 1280px wide
[22:43] <justinfront>     Try to keep your aspect ratio, or the length and width of the video, to multiples of 16px
[22:43] <justinfront>     Keep the frame rate of your video at, or below, 30fps
[22:43] <justinfront>     Use stereo audio with a sample rate of 44,100hz
[22:44] <justinfront> my video is currently 1920x1080
[22:45] <sacarasc> -vf scale 1280:-3
[22:45] <justinfront> so would I change the video in stages or try to get all the settings in one go
[22:45] <justinfront> what does the -3 mean?
[22:46] <justinfront> thanks by the way guys this is really helpful.
[22:50] <justinfront> that h264 link is not easy reading was hoping someone may have done something similar and I would not need to learn it all right now
[22:51] <sacarasc> -3 means, IIRC, scale it properly, keeping aspect ratio and divisible by 16...
[22:51] <sacarasc> I think.
[22:52] <justinfront> cool maybe I need to read the wiki some
[22:52] <klaxa> justinfront, for facebook you can probably just use -crf 21 and use whatever preset you find to have an acceptable speed
[23:04] <justinfront> Unable to find a suitable output format for 'scale' scale: Invalid argument
[23:05] <justinfront> = missing  ?   lets try
[23:07] <justinfront> -1 ?
[23:09] <sacarasc> -vf scale=1280:-3
[23:09] <sacarasc> I missed the =.
[23:09] <justinfront> Currently I have
[23:10] <justinfront> ffmpeg -i 663_0174_01.MP4 -c:v -vf scale=1280:-3 libx264 -crf 23 output.mp4
[23:10] <justinfront> is that order ok ?
[23:10] <ValdikSS> yes
[23:11] <ValdikSS> do you have interlaced video?
[23:11] <justinfront> Stream #0:0(eng): Video: mpeg2video (Main) (mp4v / 0x7634706D), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 34959 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
[23:12] <justinfront> I don't know
[23:12] <justinfront> does that tell me?
[23:12] <Jack64> justinfront: libx264 should be after -c:v , no?
[23:12] <klaxa> yeah make that: ffmpeg -i 663_0174_01.MP4 -c:v libx264 -vf scale=1280:-3 -crf 23 output.mp4
[23:13] <justinfront> [Parsed_scale_0 @ 0x7f8a10418500] Size values less than -1 are not acceptable.
[23:13] <justinfront> [Parsed_scale_0 @ 0x7f8a10418500] Failed to configure output pad on Parsed_scale_0
[23:13] <justinfront> Error opening filters!
[23:13] <Jack64> scale=1280:-1 ?
[23:13] <ValdikSS> use -1
[23:14] <ValdikSS> or keep_aspect=1
[23:14] <klaxa> that *should* come out at 1280x720 anyway
[23:14] <ValdikSS> so guys, is his video interlaced?
[23:14] <justinfront> Is this ok to add The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.
[23:14] <Jack64> use libfdk_aac
[23:15] <klaxa> ValdikSS: probably not, otherwise it wouldn't be 25 fps
[23:16] <justinfront> well I put the strict and it's doing something so guess wait and see
[23:16] <justinfront> what it looks like
[23:17] <justinfront> Do you guys often write wrappers to make it easier to select settings or use tools or is it best to just use a terminal?
[23:19] <justinfront> Also wondering if you would shoot the video in high rez and then convert like I am or would you try to set the camera up to film at the output resolution?
[23:20] <justinfront> by the way very grateful for the help thank you everyone.
[23:21] <jbermudes> justinfront: It depends on the tools. On Linux, there is a control panel for adjusting some webcam settings but ffmpeg doesn't seem to honor some of the settings
[23:21] <klaxa> if you have the storage, always record in the best quality possible
[23:24] <justinfront> looks like it is using 48 not 44 for the audio.
[23:26] <guest9184> Hello all, I am having trouble compiling ffmpeg for the Android NDK. Using these instructions http://www.roman10.net/how-to-build-ffmpeg-with-ndk-r9/comment-page-3/#comments I am able to get right up to the point where I run the .sh build script. Unfortunatly, when I run it, I get the following error:"...arm-linux-androideabi-gcc is unable to create an executable file. C compiler test failed.". And it gives many "no such file or 
[23:28] <justinfront> do you need to do something like sudo and give the script admin permission, beyond that suggestion can't help
[23:29] <justinfront> Duration: 00:04:40.00   er seems like it may take awhile its still on   00:00:31.14   :(
[23:30] <justinfront> should I kill the shell or just go off and let it run and come back to see the output
[23:33] <ValdikSS> justinfront: ffmpeg -i 663_0174_01.MP4 -c:v libx264 -preset veryfast -vf scale=1280:-1 -crf 23 output.mp4
[23:35] <justinfront> I need to add  -strict -2    or  something like   -libfdk_aac
[23:41] <Jack64> justinfront: replace -c:a aac with -c:a libfdk_aac
[23:43] <justinfront> and I can set that to 44 instead of 48?
[23:45] <Jack64> I assume you mean kHz
[23:46] <Jack64> I'm not sure, I've never tried to change the audio frequency, I just change the bitrate with -c:b 320k for example
[23:46] <justinfront> ok I can try that bitrate or is that a guess?
[23:47] <justinfront> yes kHz
[23:48] <justinfront> https://trac.macports.org/ticket/42190
[23:48] <zumba_addict> in an mp4 file, is there a atom data that I need to reposition?
[23:50] <sacarasc> Only if you want to stream it.
[23:50] <ValdikSS> justinfront: ffmpeg -i 663_0174_01.MP4 -c:v libx264 -preset veryfast -vf scale=1280:-1 -crf 23 -c:a libmp3lame -b:a 192k -ar 44100 output.mp4
[23:52] <justinfront> thanks will give that a go
[00:00] --- Mon Mar 24 2014