[Ffmpeg-devel-irc] ffmpeg.log.20120328

burek burek021 at gmail.com
Thu Mar 29 02:05:01 CEST 2012


[00:28] <sh_t> hey are there any good references for encoding options to use for various formats ie iphone/ipad with the latest ffmpeg? ive found a lot to be outdated syntax wise
[00:42] <Wntrvnm> sh_t:  https://github.com/Wintervenom/Scripts/blob/master/video/ffmpeg/ffmpeg-android
[00:42] <Wntrvnm> sh_t:  (But take out the 'r 23.976'.)
[00:42] <Wntrvnm> * -r
[00:43] <Wntrvnm> And adjust the resolution height to 640.
[00:54] <sh_t> nice, thanks. I also found this http://www.virag.si/2012/01/web-video-encoding-tutorial-with-ffmpeg-0-9/
[00:54] <sh_t> I am curious though, what's the difference between -s and -vf scale:w:h
[00:54] <sh_t> seems that scale is more flexible since you can use -1 to maintain the aspect ratio
[00:55] <sh_t> -vf scale=w:h* sorry
[00:58] <Wntrvnm> sh_t:  «-s» doesn't maintain ratio.
[00:59] <sh_t> alright just confirming thanks :)
[01:00] <Wntrvnm> You might remove the «unsharp» filter from that, too.
[01:00] <Wntrvnm> The only reason I put that there is because it helps make things a little less blurry on small screens.
[01:02] <sh_t> i notice you use qt-faststart there
[01:02] <sh_t> im used to using MP4Box to fix the streaming issues
[01:02] <sh_t> do you have any input on that?
[01:03] <Wntrvnm> «qt-faststart» was the first one I learned about and already comes with FFmpeg.
[01:33] <sh_t> Wntrvnm: I'm finding that the -vf scale parameter is being ignored.. any idea why? http://pastebin.com/sSq5UXPz
[01:34] <sh_t> ah, a correction in the pastebin. my $DIMENSIONS is "-vf scale=-1:240"
[01:34] <sh_t> outputs the same as the source
[04:25] <realazthat> hi
[04:26] <realazthat> I got two large x264 files (1GB)
[04:26] <realazthat> I need to upload them to the net, was wondering what codec is best for lowering them to reasonable size w/o reducing quality too much
[04:26] <realazthat> (advice)
[10:20] <someone-noone> hello, i'm writing own video-player and get next problem:
[10:20] <someone-noone> my program time from time crashes on av_read_frame (some heap memory error). I'm running on windows with VS 2010
[10:21] <someone-noone> Here is how i do in ReadThread:
[10:21] <someone-noone> 1. av_read_frame
[10:21] <someone-noone> 2. av_dup_packet
[10:21] <someone-noone> 3. if video or audio packet -> push to queue , else av_free_packet
[10:21] <someone-noone> in DecodingThread (s):
[10:21] <someone-noone> 1. queue->GetPacket
[10:22] <someone-noone> 2. Decode packet
[10:22] <someone-noone> 3. av_free_packet
[10:22] <someone-noone> why can it happening?
[11:38] <sarathy> \help
[11:43] <madlag> Hi there !
[11:43] <madlag> I described here a problem with ffmpeg truncating videos yesterday.
[11:44] <madlag> It looks like I get "Enter command: <target> <time> <command>[ <argument>]" at some random time when I run ffmpeg.
[11:44] <madlag> Something like after 15 minutes of encoding.
[11:44] <madlag> What is this stuff ?
[15:17] <godfath3r_> hello, I'm facing the following issue: I playback a swf file with mplayer and it's duration is wrong. swf originally is 10 seconds but in mplayer it is 4... Any suggestions? This is my mplayers msg http://pastebin.com/XEZDrFxX I also get the same (wrong) duration when I'm trying to encode swf file to avi/mpg with ffmpeg...
[15:29] Last message repeated 1 time(s).
[17:30] <madlag> Hi.
[17:30] <madlag> I used the -d option to get over random freeze of ffmpeg, as it was maybe related to log file freeze ...
[17:31] <madlag> It works a bit better, but I have still some issues
[17:31] <madlag> For very long videos, from time to time, ffmpeg continue to accept data from input (named pipe)
[17:31] <madlag> But it stops writing anything on the output
[17:32] <madlag> (output file is a mp4 h264  file)
[17:32] <madlag> So in the end, the video is readable, but truncated.
[17:33] <madlag> Anybody ?
[17:33] <madlag> An older version of ffmpeg just worked fine for now 3 years ...
[17:34] <Mavrik> hmm
[17:34] <Mavrik> that's probably something you should report to bug tracker
[17:34] <madlag> OK.
[17:34] <madlag> Do you just have any idea of what I could try ?
[17:35] <madlag> I have disabled threading (-threads 1)
[17:35] <madlag> I have set loglevel to quiet
[17:36] <madlag> The most strange thing is that it continues accepting data, but it just throw it.
[18:44] <dv_> christ, FAAD is slow compared to the ffmpeg aac decoder
[18:44] <dv_> i expected a difference, but faad is about 7 times slower!
[18:47] <mystica555> im not certain, and i think one of the f's stands for 'fabrice', but i consider ffmpeg to be f'n fast mpeg.
[18:49] <dv_> also, faad seems to be dog slow
[18:50] <jmbc> fast forward mpeg
[19:00] <frostschutz> Is ffmpeg by any chance not good with dts? Mplayer works fine for me but ffmpeg/ffplay gives me everything on the left channel. There's a file on samples.mplayerhq.hu that gives me the same problem http://samples.mplayerhq.hu/A-codecs/DTS/lotr_5.1_768.dts - I'm using 0.10.2, btw
[19:06] <JEEB> frostschutz, I would guess that's a mixing problem rather than a decoding problem
[19:06] <JEEB> if it's a decoding problem, then a bug report is appropriate
[19:07] <JEEB> (also trying the current git HEAD is a good'ish idea)
[19:10] <ubitux> downmixing to two channels (-ac 2) seems to work with ffmpeg
[19:10] <ubitux> i'm not sure how ffplay is supposed to deal with this
[19:12] <ubitux> seems to depend on sdl config
[19:12] <frostschutz> mplayer lotr_5.1_768.dts sounds much better to me, than ffplay -ac 2 lotr_5.1_768.dts. There's water noise in the background and centered bird chirping with mplayer, ffplay only gives birds on the left.
[19:13] <ubitux> it might need a volume boost
[19:13] <frostschutz> and when I encode it to flac with ffmpeg, it sounds just as bad with mplayer
[19:13] <ubitux> oh?
[19:13] <ubitux> ok
[19:14] <ubitux> feel free to open an issue then
[19:14] <frostschutz> yes, just wondering if anyone besides me could reproduce the issue. I'm on Gentoo so it may always be my system
[19:17] <frostschutz> if it's just a matter of channel mapping I should be able to do get it right with -map_channel?
[19:18] <frostschutz> on the other hand mplayer says Selected audio codec: [ffdca] afm: ffmpeg (FFmpeg DTS) - so if it's using ffmpeg to decode the audio how can it be wrong when using ffmpeg directly *scratches head*
[19:19] <JEEB> mplayer IIRC still has its own copy of ffmpeg in its code tree
[19:19] <JEEB> could be a regression
[19:19] <JEEB> ...or something else
[19:21] <jermy> So, I haven't been near head in a while. Is it possible to use libavfilter to take video with - for example - a stereo and a mono audio stream, and mix it down to a single stereo pair whilst keeping sync with the video?
[19:28] <MStoykov> question: is there a way to embed (into the container) subtitles (from srt file for example) into webm video ?
[19:34] <JEEB> MStoykov, as far as I know webm still hasn't set itself a subtitle format
[19:35] <JEEB> it's basically matroska, so in all theory you could just mux srt or whatever there
[19:35] <JEEB> but that would then be against webm specs :D
[19:36] <MStoykov> hm QQ so .... html5 <video> is the way ?
[20:24] <sprzybilla> is there a simple way to set a PAL resolution adherent to the non-square pixel aspect ratio?
[20:45] <Hfuy> Hello
[20:45] <Hfuy> I have some videos that I want to rotate 270 degrees, or, equivalently, flip both horizontally and vertically.
[20:45] <Hfuy> Google sources differ on the best way to do this - any pointers?
[21:03] <Mista_D> I have mov with 8 mono channel tracks, how can I mix them into 1 eight channel track (PCM WAV)?
[21:15] <silverrocker> hi, can I ask my question about ffplay here aswell?
[21:17] <Hfuy> is "-vf vflip" the appropriate way to mirror something vertically? can I combine it with a horizontal flip?
[21:22] <Hfuy> Why would it complain "Error opening filters"?
[21:23] <Hfuy> Also, why would it complain "no such filter hflip" when many documents insist there is a horizontal flip filter?
[21:26] <Hfuy> It also complains "missing parameter such as bit_rate", but when I attempt to insert a -bit_rate option it claims there is no such option.
[21:28] <Hfuy> it doesn't like "width" either, despite asking for "width"
[21:30] <sprzybilla> hfuy -vf "filter=setting"
[21:30] <Hfuy> what settings do I need
[21:31] <Hfuy> it's a vertical flip (there seems to be no horizontal flip available, for some reason)
[21:31] <sprzybilla> Hfuy: ohoh sorry -vf "vflip"
[21:31] <Hfuy> I don't think that's the problem.
[21:31] <Hfuy> It's an "error opening encoder" issue
[21:32] <Hfuy> I'm after mp4 output at quality similar to the 3gp input, but I don't know what it needs.
[21:32] <Hfuy> It's expressly asking for some options that it then expressly refuses to use.
[21:33] <sprzybilla> try setting a constant bitrate like this "-b:v 4000k -minrate 4000k -maxrate 4000k -bufsize 1500k"
[21:33] <sprzybilla> there is no bit_rae parameter, bitrate is set differently depending on your desired results
[21:34] <Hfuy> Unrecognized option 'b:v'
[21:34] <sprzybilla> just use -b
[21:34] <Hfuy> Error while opening encoder for output stream #0.1 - maybe incorrect parameters
[21:34] <Hfuy> such as bit_rate, rate, width or height
[21:34] <sprzybilla> set your size with -s
[21:35] <sprzybilla> i.e. "-s 640x360"
[21:35] <Hfuy> no change
[21:35] <sprzybilla> also, look at the top of the output, is sometimes there will be another error towards the top
[21:35] <Hfuy> I love the way it's asking for options it refuses to use
[21:36] <Hfuy> http://pastebin.com/9exYN9YC
[21:37] <sprzybilla> your output needs to be at the end
[21:37] <Hfuy> Unable to find a suitable output format for 'pipe:'
[21:38] <sprzybilla> hey a new error we are making progress!
[21:38] <sprzybilla> ;)
[21:38] <Hfuy> This has to be the single most user-hostile piece of software I've ever come across.
[21:39] <Hfuy> OK, I typo'd
[21:39] <Hfuy> but if I correct the typo, we're back to "missing parameter" stuff
[21:39] <sprzybilla> poop
[21:40] <sprzybilla> oh
[21:40] <sprzybilla> take the audio out once
[21:40] <sprzybilla> -an
[21:40] <sprzybilla> [aac @ 02ef3f70]Too many bits per frame requested
[21:40] <Hfuy> I do need the audio.l
[21:41] <sprzybilla> hehe okay, then do -acodec faac -ab 96k
[21:41] <sprzybilla> if you have libfaac
[21:41] <Hfuy> I suspect I don't.
[21:42] <sprzybilla> taking the audio out would at least tell us if that was the original issue
[21:42] <Hfuy> Unknown encoder 'faac'
[21:42] <sprzybilla> yeah
[21:42] <Hfuy> It will encode with -an
[21:42] <sprzybilla> jsut do -an
[21:42] <sprzybilla> okay
[21:42] <sprzybilla> so that was the problem
[21:42] <Hfuy> Is there any way to feature-request slightly less foggy error messages?
[21:42] <sprzybilla> lol, well, there was an error in there, it was just hidden
[21:43] <sprzybilla> i think it's because the error at the bottom is ffmpeg, the errors for the libraries appear as they happen
[21:43] <Hfuy> I don't know what the 3gp file uses for audio.
[21:43] Action: Hfuy tries -acodec copy
[21:43] <sprzybilla> i.e. just use -acodec aac
[21:43] <sprzybilla> oh yeah
[21:43] <sprzybilla> that might work too
[21:43] <Hfuy> Could not write header for output file #0 (incorrect codec parameters ?)
[21:44] <sprzybilla> haha
[21:44] <sprzybilla> try aac
[21:44] <Hfuy> encoder 'aac' is experimental and might produce bad results.
[21:44] <Hfuy> Add '-strict experimental' if you want to use it.
[21:44] Action: Hfuy pounds his head against the monitor screen
[21:44] <sprzybilla> yeah, its a shitty aac encoder i think, that's why i use faac
[21:44] <sprzybilla> here
[21:44] <sprzybilla> do ffmpeg -codecs
[21:45] <sprzybilla> that will tell you which decoders/encoders you have
[21:45] <Hfuy> there are...many
[21:45] <Hfuy> Christ on a souped-up harley, this thing supports CINEPAK?
[21:45] <sprzybilla> (and all the acceptable parameters for -vcodec -acodec)
[21:45] <sprzybilla> be careful
[21:46] <sprzybilla>  DEVSD
[21:46] <sprzybilla> those letters by the name will tell you what your currently compiled ffmpeg can do
[21:46] <Hfuy> It supports cinepak, but it doesn't support mp3?
[21:46] <sprzybilla> ah - it explains what the letters mean at the top of the output if you're curious
[21:46] <Hfuy> this is hopeless!
[21:47] <sprzybilla> lol NOOOOOO, your doing an mp4 output?
[21:47] <Hfuy> Well it claims it supports mp3 for at least some opertaions.
[21:47] <sprzybilla> the most important are the first two letters
[21:48] <sprzybilla> D = decodec E = encoder
[21:48] <sprzybilla> decoder*
[21:48] <Hfuy> Why does ffmpeg not have an mp3 encoder? Isn't that a massive oversight?
[21:48] <JEEB> there's libmp3lame
[21:48] <Hfuy> there isn't, I tried that
[21:48] <JEEB> which is one of the best mp3 encoders around
[21:49] <JEEB> it means you haven't built ffmpeg with the library
[21:49] <Hfuy> I haven't built ffmpeg at all, I downloaded a binary
[21:49] <JEEB> well durr
[21:50] <JEEB> the reason why ffmpeg doesn't have encoders for anything you can see in the ogg vorbis encoder that's inside ffmpeg :P
[21:50] <JEEB> (not libvorbis)
[21:51] <Hfuy> oh, screw this noise
[21:51] <Hfuy> I'll do it in Premiere
[21:52] <Hfuy> it'll take 3 hours to go through every video file in this folder, doing it all manually, but at least it can produce output in a format invented after 1990.
[21:52] <Hfuy> DIdn't it occur to anyone that mp3 might be useful!?
[21:52] <JEEB> yes? which is why there's a decoder
[21:52] <JEEB> the encoder's not there because there's a library which you can link to ffmpeg
[21:52] Action: sprzybilla giggles
[21:53] <Hfuy> I'm not a software engineer.
[21:53] <JEEB> then you find a better compile, that's all >_>
[21:53] <sprzybilla> Hfuy: I know your pain, ffmpeg made me learn all about compiling software
[21:53] <sprzybilla> but it was worth it!
[21:53] <Hfuy> I suspect that libmp3lame doesn't work because it isn't happy with the codec parameters
[21:53] <JEEB> anyways, -acodec aac's current state should be ok at around 192k+
[21:53] <JEEB> Hfuy, is it in the codec listing?
[21:53] <Hfuy> but there's no documentation on how to give it the proper parameters.
[21:53] <JEEB> also how old is this build of yours?
[21:54] <Hfuy> let's just do LAME.
[21:55] <Hfuy> it's saying "mp4 @ 01640400]track 1: muxing mp3 at 8000hz is not supported"
[21:55] <Hfuy> but I've specified -ab 192k
[21:55] <JEEB> ah
[21:55] <JEEB> that's not bitrate
[21:55] <Hfuy> Oh, sample rate
[21:55] <JEEB> yup
[21:55] <JEEB> 441000 or 48000 should be ok, or even 22050
[21:55] <Hfuy> is it trying to match the sample rate in the input file, or something?
[21:55] <JEEB> yeah
[21:55] <JEEB> which is usually what you want
[21:55] <Hfuy> Aha.
[21:56] <Hfuy> Can I make it not?
[21:56] <JEEB> yes
[21:56] <JEEB> unfortunately I don't remember the setting for that :P
[21:56] <Hfuy> Aurrgh, the pain
[21:56] <JEEB> at least ffmpeg has a web site with most settings now
[21:56] <sprzybilla> -ar
[21:56] <sprzybilla> = samplerate
[21:56] <Hfuy> -ar
[21:57] <Hfuy> By the wibbly bits of my squeedilyspooch, it works!
[21:57] <sprzybilla> hooray!
[21:57] <sprzybilla> grats!
[21:57] <sprzybilla> feels good don't it?
[21:57] <Hfuy> No, it makes me revile and despise opensource software with a new and cutting vitriol.
[21:57] <JEEB> just make sure that whatever you're wishing to play that on likes mp3 as audio
[21:57] <JEEB> lol
[21:57] <Hfuy> How do I make it do all the files in a folder?
[21:57] <sprzybilla> now I need to figure out how to make this 720x390 video get into a standard PAL resolution/PAR with padding..
[21:58] <JEEB> Hfuy, make a batch file with a for loop?
[21:58] <JEEB> (I will take the approximation that you're on windows)
[21:58] <Hfuy> powershell I think
[21:58] <Hfuy> OK thanks folks
[21:58] <JEEB> powershell is probably less roasting for the brain
[22:34] <sprzybilla> is SAR the same thing as Pixel aspect ratio in FFMPEG lingo?
[22:37] <Tjoppen> yes. SAR = sample aspect ratio
[22:37] <Tjoppen> SAR is the proper term I think
[22:39] <sprzybilla> hrm, I have a source with square pixels, but FFMPEG reads a SAR of 1:1 and a DAR of 24:13, which shouldn't be the case according to http://en.wikipedia.org/wiki/Storage_Aspect_Ratio#Storage_Aspect_Ratio
[22:39] <sprzybilla> according to that, they should "agree"
[22:39] <sprzybilla> by agree I would assume be both 24:13
[22:40] <sprzybilla> since that would mean 24:13/24:13 = 1
[22:40] <sprzybilla> god I hate broadcast standard and their unaquare pixels
[22:40] <sprzybilla> and my typing abilities..
[22:43] <Tjoppen> erm, DAR = width/height * SAR
[22:43] <Tjoppen> some files have separate width/height + SAR in the container though. this is common with IMX50 MOVs for instance
[22:46] <sprzybilla> Tjoppen: where does pixel apect ratio fit into your equation. Again I am referencing that wikipedia article
[22:47] <sprzybilla> I need to make a video with a PAR of 16:15 for PAL
[22:47] <sprzybilla> and my source is reading differntly than I would think it should
[22:47] <sprzybilla> this is some deep stuff, and can get super confusing hehe
[22:54] <Tjoppen> 16:15 is typically 720x576. you're getting the resolution right but not the SAR?
[22:57] <sprzybilla> Tjoppen: pm'd this might get hairy ;)
[23:07] <Diogo> hi this is possible to encode video and generate thumbnails in the same command?
[23:08] <Diogo> and another question...what is the best way to detect video 3d?
[23:08] <Diogo> i'm using exiftool and mediainfo..but this is possible to detect a video 3d?
[23:08] <Diogo> thanks..
[23:27] <markatto> when I use the option `-vf scale='min(500, iw*3/2):-1'` (copy-paste out of the man page) I am getting the error `No such filter: 'iw*3/2):-1'`
[23:27] <markatto> any help?
[23:28] <frostschutz> tried without space?
[23:28] <markatto> yup
[23:28] <emerica> passed over a line this morning that said sometimes the commas may need to be escaped
[23:29] <markatto> emerica: hmm, escaping the comma seems to work
[23:29] <emerica> yay
[23:30] <markatto> except now it complains about the height not being a multiple of 2 :(
[23:33] <markatto> if the -1 height has a chance of calculating heights that are invalid for my codec it is pretty useless
[23:52] <burek> frostschutz, why `
[23:52] <frostschutz> why what?
[23:53] <burek> backtick
[23:53] <burek> can you please use pastebin.com, to show your command line and its output?
[23:58] <sprzybilla> why, with a high bitrate, would my q level be riding at 31?
[23:59] <sprzybilla> isn't that supposed to reflect the quality for availabel resources? Or am I misinterpreting?
[00:00] --- Thu Mar 29 2012


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