[Ffmpeg-devel-irc] ffmpeg.log.20130504

burek burek021 at gmail.com
Sun May 5 02:05:01 CEST 2013


[00:00] <relaxed> How is it not specific?
[00:00] <Jorky> for instance album mettallica-ride the lightning album (mp3) to metallica-ride the lightnig album (wma) but 128k wma
[00:00] <sacarasc> The thing about that script, Jorky, is that it will do exactly what you asked on as many different albums as you want.
[00:01] <Jorky> but in what quality?
[00:01] <relaxed> Jorky: for i in *mp3; do ffmpeg -i "$i" -c:a wmav2 -b:a 128k "${i%.*}".wma; done
[00:01] <Jorky> ok
[00:01] <Jorky> now I get it
[00:01] <Jorky> thnx
[00:01] <Jorky> my native language isn't english so I need more time and different words to understand
[00:23] <satonio> hi
[01:28] <brontosaurusrex> how would i scale to say 16px X 1px and export to some sort of filmstrip vertical image?
[01:28] <brontosaurusrex> input is video
[02:10] <cypod> Hello
[02:10] <cypod> I had a question about compiling ffmpeg
[02:11] <cypod> I have build libvpx to a custom location and want to using that version instead of the system default
[02:18] <llogan> cypod: see --extra-cflags and --extra-ldflags
[02:18] <llogan> for ffmpeg
[02:19] <cypod> so would that be --extra-ldflags=-L/path/libvpx/lib ?
[02:22] <llogan> cypod: looks good to me
[02:26] <cypod> llogon : and the plug-in I'm trying to load is libvpx-v1.1.0/libvpx.so which points to libvpx.so.1.1.0
[02:42] <brontosaurusrex> how would i pipe from ffmpeg to imagemagick convert?
[02:44] <brontosaurusrex> i'd like this:
[02:44] <brontosaurusrex> ffmpeg -i in.mp4 -sws_flags neighbor -vf scale=2:2 -f image2 out-%05d.png && convert +append out-*.png -resize 1x1\! -resize 1x64\! out.png
[02:44] <brontosaurusrex> as a pipe
[02:45] <cypod> is there anyway to load the libvpx plugin without recompiling ffmpeg?
[02:45] <brontosaurusrex> cypod, is that vp8 encoder?
[02:46] <cypod> I think so, hoping to create some webm
[02:46] <brontosaurusrex> yeah, i played with that
[02:46] <brontosaurusrex> It ended up with piping from ffmpeg to vpxenc
[02:46] <brontosaurusrex> or whatever its called
[02:47] <brontosaurusrex> because vpx cli was like 123412536 chars long and i just couln't convert that to ffmpeg mappings
[02:47] <brontosaurusrex> i can find an example if you wish
[02:50] <llogan> brontosaurusrex: maybe "ffmpeg -i input -f image2pipe - | convert [input options] - [output options] ..."
[02:50] <brontosaurusrex> llogan, let me try, i think that was the first i tryed
[02:51] <cypod> where to get vpxenc ?
[02:52] <cypod> think I found it there in the build dir, yes examples please
[02:53] <brontosaurusrex> cypod, hold on
[02:56] <brontosaurusrex> cypod, a two-pass example http://paste.debian.net/2000/
[02:58] <brontosaurusrex> actually thats a sort of quality-based encode
[02:58] <brontosaurusrex> irc
[02:58] <brontosaurusrex> anyway, i remember it was a pain to figure it out
[02:59] <cypod> in that examle is vp8 the encoder or is it vpxenc?
[03:01] <cypod> was thinking it would be : vpxenc --best -o source.mp4 -w 1920 -h 1080 newfile.webm
[03:02] <brontosaurusrex> its vpxenc
[03:03] <brontosaurusrex> thats from a script
[03:03] <brontosaurusrex> ~
[03:04] <cypod> maybe get better result with -p 2
[04:38] <voidah> m
[04:38] <voidah> oops
[04:39] <voidah> is there a way to take an audio file as input (.mp3) and "shink" it so that it become of an exact specified length?
[04:39] <voidah> I have a .mp3 file that is 1m23 long, and would like to shrink it to 1:21
[04:57] <voidah> said otherwise: I would like to play my sound faster
[04:59] <voidah> :w
[04:59] <voidah> oops
[05:12] <voidah> ah https://lists.ffmpeg.org/pipermail/ffmpeg-devel/2013-April/142777.html
[05:12] <voidah> seems to be the same issue i'm having
[05:12] <voidah> aptempo might be ok finally
[05:12] <voidah> recompiling
[09:24] <samek_> Hi, I've got two video live streams put on static image and i want to sync audio with only one video (second video is without audio), how would i sync audio with correct video, since it seams it's syncing it to the second one.
[09:29] <samek_> right now i have /usr/local/bin/ffmpeg  -y   -f mpegts -i /tmp/SPOT.pipe   -f mpegts -i /tmp/PIPE.pipe   -f image2 -loop 1  -i /tmp/SIT.png   -map 0:v -map 0:a -async 2  -map 1:v -map 2:v  but's it's not syncing ok.
[09:41] <smj> is FAAC better than LAME, as it should?
[09:42] <Keshl> Depends what you mean by "better:
[09:42] <Keshl> *"
[09:43] <smj> better quality per bitrate
[09:43] <Keshl> FAAC outputs .faac files, which are lossless. Every detail you put into them is preserved and compressed, so it sounds exactly the same on the way out.
[09:43] <Keshl> However, files and bitrates are substantally larger than LAME.
[09:43] <Keshl> LAME is lossy, but it most humans will not hear a difference.
[09:43] <Keshl> Outputs .mp3 files.
[09:43] <smj> are you talking about FLAC?
[09:43] <Keshl> ..
[09:43] <Keshl> Yes, yes I am.
[09:43] <Keshl> Ignore me.
[09:43] <Keshl> >w>
[09:43] <smj> I will
[09:44] <Keshl> Danks. <É<
[09:44] <Keshl> For the record though, the standard says that h.264 uses .mp4 which uses FAAC.
[09:44] <Keshl> Just saying.
[09:44] Action: Keshl might be wrong.
[09:45] <smj> how does a file format use an encoder?
[09:45] <Keshl> ...Iunno D: -Hides in a corner- D:
[09:45] Action: Keshl isn't the smartest tatertot here.
[09:45] <TheSchaf> so i have to convert alot of mp3s from 441000 to 480000 and 128 kbit/s to 192 kbit/s and i did that using ffmpeg. is there any tips on how i can keep "quality"? i heard transcoding is bad :p
[09:46] <smj> At least you bother to type well.
[09:46] <smj> unlike me :I
[09:46] <Keshl> People who dun need to be slap'd with fish, oÉo.
[09:46] <Keshl> 'cept not mIRC fish. Them's bad. <É<
[09:48] <Mavrik> smj, most tests show that FAAC (being a reference encoder) doesn't produce significantly better output than libmp3lame
[09:48] <Mavrik> (at the same bitrate and settings)
[09:48] <smj> oh, so it's a waste of CPU
[09:48] <smj> ?
[09:48] <Keshl> Depends.
[09:48] <Mavrik> TheSchaf, why wuld you do a silly thing like that? :P
[09:48] <Mavrik> smj, depends. Rather tell us what do you want to achieve.
[09:48] <Keshl> Devices that follow standards are going to support .mp4's with FAAC in them always.
[09:48] <Keshl> it's a guarentee.
[09:49] <Keshl> They may or may not support mp3.
[09:49] <TheSchaf> Mavrik, i'm creating content for a game
[09:49] <TheSchaf> it only supports that one format :P
[09:49] <Keshl> TheSchaf: Fix the game. D:
[09:49] <TheSchaf> i dont have its source
[09:49] <Keshl> Get it D:
[09:49] <Mavrik> TheSchaf, it only supports one bitrate?
[09:50] <TheSchaf> yes
[09:50] <Mavrik> TheSchaf, that seems weard. I get supporting 48000 Hz sample rate though
[09:50] <Mavrik> *wierd
[09:50] <TheSchaf> its a music dance game
[09:50] <TheSchaf> DDR like
[09:50] <TheSchaf> so it has alot of dirty hacks to sync to audio
[09:50] <Mavrik> TheSchaf, anyway, simce you're upsampling to a certain output bitrate and samplerate there's nothiing you can do
[09:50] Action: Keshl twitches. ( http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better-than-you-at-everything.html )
[09:50] <Mavrik> you'll lose a little quality but there's no magic.
[09:51] <TheSchaf> mhh, ok
[09:51] <Keshl> basically yeah. Somehow data has to be created, that's going to be carried over to what humans hear, it's gunna make a difference.
[09:51] <Mavrik> getting original music source in CD / losless format and transcoding that would be magic though ;)
[09:51] <Keshl> There's no lossless way to do it, contrary to what common sense says.
[09:51] <Keshl> Well, from a computing perspective it is lossless, but what you hear will be different nonetheless.
[09:52] <Keshl> HopefullythatmakessenseImmagobacktoalesssmartchannelnowforaseckay<w<
[09:52] <TheSchaf> no way for me to get the music in original format
[09:53] <Mavrik> well you have no choice then
[09:55] <smj> Mavrik, I'm trying to get the best possible stream quality out of my hardware. Until today, I thought twitch.tv supported only MP3 audio, but one clip I downloaded from there had AAC audio
[09:57] <Mavrik> smj, yeah, they probably use AAC
[09:57] <Mavrik> but that has little to do with your hardware.
[09:58] <Mavrik> smj, encode audio in high enough bitrate so it sounds good and thats it
[09:58] <Mavrik> smj, you can use fdk_aac encoder (the Fraunhofer one) which is currently the best of the bunch
[09:59] <Keshl> oÉo... Well now, that's weird. Does ffmpeg handle video that barely changes from frame to frame well?
[09:59] <Mavrik> Keshl, nothing to do with ffmpeg, everything to do with the encoder and settings.
[10:00] <Mavrik> smj, but in reality, your bitrate and samplerate settings will make far greater difference than choice of mp3 or aac. Especially if you're not using ridiculusly low bitrates.
[10:01] <Mavrik> Keshl, x264 with large GOP can probably encode those quite efficiently, especially with stillimage tuning
[10:01] <Keshl> Mavrik: Kay, I'm doing "ffmpeg -r 60 -i Frame_%04d.png -i "pathto.wav" -vcodec libx264 -preset medium -crf 10 -movflags faststart -pix_fmt yuv420p OUT.mp4 -- This results in q=18 (my goal) on pretty much every frame. However, white specs randomly appear.
[10:01] <Keshl> Turning the CRF up or down seems to fix them.
[10:01] <Keshl> Just seems that, anywhere near 7-15 it adds white specs randomly.
[10:01] <smj> my CPU isn't fast enough for 720p, so I'm encoding at 480p, and I want to keep audio bitrate around 100-120, is that low?
[10:01] <Keshl> There's no white in my frames.
[10:02] <Mavrik> smj, depends on kind of audio :)
[10:02] <Mavrik> smj, we lived with 128kbps mp3s for a LONG time ;)
[10:02] <Mavrik> does it sound right? if it does, yeah, that's ok :P
[10:03] <Mavrik> Keshl, probably a question for x264 devs then.
[10:03] <Keshl> Should also mention that, during encode, ffmpeg randomly sorta freezes.
[10:03] <Mavrik> and be prepared to show a sample of input and output :)
[10:03] <Mavrik> hm.
[10:03] <Keshl> The time= suddenly climbs up /really/ fast, then holds still while frame= catches up.
[10:03] <Keshl> But the video plays fine, audio's in sync and all, just the white specs randomly appear.
[10:03] <Mavrik> Keshl, set fps on output as well.
[10:03] <Keshl> Never had to before. oÉo
[10:04] <Keshl> And what's weird is, it worked /just fine/ on similar video yesterday.
[10:04] <Keshl> No updates.
[10:05] <Keshl> Mavrik: Also, how do I do that other stuff you said, oÉo?
[10:05] <Keshl> Maybe just by chance it'll fix it, might be useful to the x264 devs to know if it does.
[10:05] <Mavrik> you say "-tune stillimage"
[10:05] <Mavrik> if you have a still image
[10:05] <Mavrik> and test that
[10:05] <Keshl> It's not /still/, it's just that most of it stays static.
[10:06] <Mavrik> anyway, sleep time.
[10:06] <Keshl> Here, sec. It'll make more sense if I be shows, oÉo.
[10:06] <Keshl> D'aww .É.
[10:07] <smj> So how do I use this... fdk_aac?
[10:08] <Fjorgynn> I just fdk_aac
[10:08] <Fjorgynn> but you must compile it yourself
[10:08] <smj> aha, --enable-libfdk-aac
[10:08] <Fjorgynn> yeah
[10:08] <Fjorgynn> and download it from git
[10:09] <Fjorgynn> if you don't have it
[10:10] <smj> https://github.com/mstorsjo/fdk-aac Is this the official one, if there is such?
[10:15] <Keshl> Very interesting, -tune stillimage fixed it.
[10:15] <Keshl> Practically doubled the fielsize, but it fixed it.
[10:15] <Keshl> *filesize
[10:17] <xxthink> how to enable aac decoding?
[10:17] <xxthink> I use this configure script, but the result says the decoder does not support aac
[10:19] <xxthink> http://pastebin.ca/2373091
[10:20] <xxthink> this is the output
[10:20] <xxthink> http://pastebin.ca/2373093
[10:21] <xxthink> I debug for about 3 hours
[10:21] <xxthink> and don't know the reason why aac decoder is not enabled
[10:31] <xxthink> close --disable-fft --disable-lpc is ok
[13:39] <xlinkz0> how can i see what PTS the first frame of the video has after i seek?
[16:43] <nilsge> greetings
[16:43] <nilsge> can I use ffmpeg to edit wav riff chunks?
[16:43] <nilsge> fmt, fact, cue, smpl and others   (see  http://www.sonicspot.com/guide/wavefiles.html )
[18:59] <dax_roc> Evening all
[19:00] <dax_roc> I'm trying to stream a mpegts to ffserver with ffmpeg -i /dev/video0 -re -vcodec copy -qp 0 -acodec copy -f mpegts tcp://$HOST:$PORT/feed1.ffm and it's failing with av_interleaved_write_frame(): Connection reset by peer
[19:01] <dax_roc> The source is a happauge hdpvr (1st gen)
[19:02] <dax_roc> If i stream via mpegts udp I can watch the stream no problem
[19:07] <dax_roc> Anyone have any suggestions why http://bpaste.net/show/rhGR3LcN8yULX1Qdpl9x/
[19:59] <smj> has overlay filter been tested with stream inputs and inconsistent frame rates? it looks a lot like it goes by the lowest one
[20:31] <dax_roc> Can I take a remote streem and feed it to a local dev and have another ffmpeg transcode it or can I do this directly ?
[21:14] <thee_l> Hey
[21:14] <thee_l> So I am wondering what signals can be used to close ffmpeg in a safe way.
[21:15] <thee_l> I hope to script some streaming to justin.tv and it would really be great it I could use the kill command to shut down ffmpeg
[21:15] <thee_l> *without worrying anything could go wrong
[21:15] <thee_l> Basically a signal equivalent to pressing 'q'
[21:16] <thee_l> anyone?
[21:18] <thee_l> anyone know of any signals that are handled like a 'q'
[21:25] <tonsofpcs> 14 maybe?
[21:25] <tonsofpcs> (just guessing)
[21:30] <thee_l> woops, sorry didn't realize you responded
[21:31] <goo_> Hi. Is there a filter in ffmpeg corresponding to Levels in Photoshop?
[21:31] <thee_l> @goo like: 'multiple' 'add' 'screen'
[21:31] <thee_l> oh wait
[21:31] <thee_l> nevermind
[21:32] <thee_l> I think imagemagick might have what you need.
[21:32] <thee_l> check it out http://www.imagemagick.org/script/index.php
[21:32] <goo_> well, I was searching for that too but i found it's blend=all_mode=multiply
[21:33] <goo_> Yes, but I was searching for something faster than imagemagick...
[21:33] <thee_l> oh, I gotcha
[21:34] <thee_l> I couldn't tell you, I don't know much about ffmpeg, but I'm pretty sure effects on single images isn't really it's specialty, I could be very wrong though
[21:34] <tonsofpcs> imagemagick is pretty fast...
[21:37] <thee_l> @tonsofpcs I guess I'm looking for a signal which is specifically used for the purpose of shutting down ffmpeg safely just like 'q'
[21:37] <goo_> yes, it's fast but for video I thought there could be something more specific.
[21:37] <thee_l> oh it's a video
[21:37] <thee_l> I thought you were talking about individual images.
[21:38] <thee_l> yeah so @tonsofpcs I am looking for something definite, thank you though
[21:39] <goo_> yes,  already tried to feed ffmpeg with Imagemagick filtered pictures but I think it's too slow
[21:39] <tonsofpcs> goo_: what processing are you trying to do?
[21:41] <goo_> I need to multiply a solid color, modify levels, brightness and contrast, overlay pictures
[21:41] <goo_> i already find how to do most of this operations but i don't find levels, onli curves
[21:47] <tonsofpcs> erm... brightness/contrast are just black/white curves...
[21:47] <tonsofpcs> brightness is the black level - higher brightness and the lowest possible level is higher; contrast is the white level - lower contrast and the highest possible level is lower
[21:51] <thee_l> I'm going... see ya, hope your processing works out goo_ and thanks anyway tonsofpcs
[21:51] <thee_l> bye
[21:52] <goo_> thank you thee_l
[21:55] <goo_> Ok, @tonsofpcs I think I need to read some theory, thank you ;)
[22:01] <tonsofpcs> goo_: that is the theory, there's nothing more to it.
[00:00] --- Sun May  5 2013


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