[Ffmpeg-devel-irc] ffmpeg.log.20130129

burek burek021 at gmail.com
Wed Jan 30 02:05:02 CET 2013


[01:59] <njbair> am I doing something wrong or is libvpx waaaaay slower than libx264?
[02:05] <juanmabc> isn't vpx = very poor experience ?
[02:05] <juanmabc> ;P
[04:06] <Miesco> Chrome doesn't support ogg, how do I convert a .ogg to a webm vorbis?
[04:11] <Miesco> Wait I think I know: ffmpeg -i file.ogg -acodec vorbis file.webm
[04:16] <Miesco> I think wikipedia and w3c got Chrome's codec support wrong for <audio>.  Chrome doesn't support ogg...
[05:55] <saju> how to convert 2k video file to 4k
[06:09] <praveenmarkandu> hi. how come this command doesnt make my file twice as large? or twice as long?
[06:09] <praveenmarkandu> ffmpeg -i "concat:bigbuckbunny1080p.mov|bigbuckbunny1080p.mov" -c copy bigbuckbunny1080p_double.mov
[06:30] <relaxed> praveenmarkandu: ffmpeg's concat is limited. Try mkvmerge, then copy back to mov if you need that container.
[07:21] <praveenmarkandu> ok. i tried mencoder. seems to work
[07:21] <praveenmarkandu> relaxed, what do you mean by limited?
[08:15] <LorentzFactor> is there a way to use the original video stream while reencoding the audio stream?  It'll take forever if it has to reencode both with all the files I'm trying to convert :\
[08:16] <klaxa> you can copy the video stream with -c:v copy
[08:16] <LorentzFactor> ah
[08:19] <LorentzFactor> thanks that's like 300% faster
[08:19] <LorentzFactor> 3000%*
[08:21] <Youka> Is there a way to use ffmpeg in msvc9? building it is just possible with msvc10 ('wrong C compiler' error) and using this library in msvc9 causes errors because of double definitions of f.e. _sopen
[08:36] <Miesco> Hi
[08:37] <Miesco> Anyone want to know the beautifulness that ffmpeg just trancoded: ftp://miesco.is-a-geek.org/soundcloud/dont%20know%20shawnsvocals.webm
[08:37] <Miesco> Dats a song I wrote
[09:12] <frostywolf> hi
[09:13] <frostywolf> i need some help with a ffmpeg command
[09:14] <CruX|> h265 is supported by ffmpeg ?
[09:15] <frostywolf> i'm trying to get padding to work on a file. Downscaling widescreen to 4:3, from 1280x720 to 720x540 (therefore the actual video should be 720x405, so the padding command is 720:540:0:67:black right?
[09:16] <JEEBsv> CruX|: smarter from the libav project is working on a hevc / H.265 decoder
[09:16] <JEEBsv> the specification isn't even finished yet
[09:31] <praveen> wait, so libav libaries are still used in FFMPEG?
[09:31] <praveen> eventhough they have forked?
[09:33] <JEEB> praveen, libav's changes are being merged into ffmpeg, yes?
[09:34] <praveen> JEEB, ok. thanks.
[09:34] <praveen> this may seem like a flame bait question
[09:35] <praveen> but i want to know, why would one use libav over ffmpeg or vice versa
[09:35] <JEEB> there are plenty of write-ups from either side on that (´
[09:35] <JEEB> ubitux has a blog entry, lu_zero from gentoo has another...
[09:35] <praveen> im guessing since im on #ffmpeg it is a loaded question
[09:36] <praveen> ok. will search
[09:36] <praveen> are changes from FFMPEG being merged into libav? or are they generally ahead?
[09:37] <JEEB> some changes from ffmpeg are cherry-picked into libav
[09:37] <JEEB> like lately the gbrp stuff
[09:38] <praveen> ok cool
[09:56] <jeje> Hi to all ;-)
[09:56] <jeje> I have a question about using swscale lib
[09:58] <jeje> when calling sws_getContext, the function can have a sws_flags parameters but I don't understand ther difference between each one . We also can set it to NULL. If someone can explain me please.
[09:59] <jeje> for informations I use swscale to convert and resize an YUV420 image (H264 decoding by FFMPEG) to an RGB32 image displayed on screen
[10:02] <jeje> I think it can change the speed of the swscale operation, but is one sws_flags is better than another one?
[10:26] <praveen> is there a maximum file size ffmpeg can handle?
[10:27] <Mavrik> hmm... not really
[10:27] <Mavrik> it's more of a container support question
[11:36] <frostywolf> i'm trying to get padding to work on a file. Downscaling widescreen to 4:3, from 1280x720 to 720x540 (therefore the actual video should be 720x405, so the padding command is 720:540:0:67:black right?
[12:45] <venom200> Anyone knows how to set pixel aspect ratio in FFmpeg?
[12:56] <venom200> Please answer - how to set PAR - Pixel Aspect Ratio in FFmpeg.
[12:58] <durandal_1707> read documentation first
[13:00] <relaxed> hmm, ffmpeg has -sar but not the setsar filter?
[13:00] <durandal_1707> ffmpeg _have_ setsar filter
[13:01] <durandal_1707> setsar           V->V       Set the pixel sample aspect ratio.
[13:04] <venom200> I tried with setsar=1, but did not work.
[13:05] <venom200> Here is the complete cli I used: http://pastebin.com/B9cxpqMC
[13:08] <durandal_1707> venom200: do you understand what word complete mean?
[13:08] <durandal_1707> paste full uncut output
[13:10] <venom200> Here it is: http://pastebin.com/ALuX6yqM
[13:11] <durandal_1707> venom200: please read documentation
[13:11] <durandal_1707> how to use setsar filter
[13:11] <venom200> I am sorry. I am not familiar with setsar.
[13:12] <durandal_1707> can you read documentation?
[13:12] <venom200> Yes. Where can I find that?
[13:12] <durandal_1707> at ffmpeg.org
[13:12] <venom200> Thanks If setsar is fully documented, I will read that. Thanks
[13:22] <guest361> does -aspect option work for input file?
[13:26] <durandal_1707> depends, usualy it is read from container/stream
[13:30] <klaxa> http://aws.amazon.com/elastictranscoder/ <-- i wish they would post more than "720p and not 720p"
[13:31] <klaxa> oh wait they do
[13:33] <klaxa> mh not much more than "we use H264/AAC/MP4" i guess one would have to sign up to take a closer look
[14:02] <brontosaurusrex> when muxing two streams (one video + one audio) i'd like that the final stream has duration of the shortest one, was there a command for that?
[14:03] <mateo`> brontosaurusrex: -shortest ?
[14:04] <brontosaurusrex> mateo`: really? cool
[14:18] <guest361> do I have to re-encode to modify DAR ?
[14:43] <JEEB> in ffmpeg, do -maxrate and -bufsize only limit the video or all tracks within the encode?
[15:12] <foxlover> Hello everyone! Just want to know which ffmpeg version the CLI option -print_format appeared, was it 0.9 with json, compact and csv support or was yet before that? Readed the changelogs, but they don't helped much... thank you in advance!
[15:15] <durandal_1707> foxlover: with JSON output
[15:16] <durandal_1707> so 0.9
[15:37] <foxlover> durandal_1707: Thank you for your help! :)
[15:56] <Guest32954> Hi, I use av_new_packet to allocate and initialize my AVPAcket with the PADDINGSIZE (IE: dwImageSize+FF_INPUT_BUFFER_PADDING_SIZE)
[15:56] <Guest32954> but when I do a av_free_packet, it doesn't free the buffer of the AVPacket
[15:56] <Guest32954> How can I free the buffer of the AVPacket?
[15:57] <Guest32954> Do I need to call a av_freep (packet.data[0]) before?
[16:09] <Guest32954> even if I call av_destruct_packet, my memory grow up
[16:39] <Demon_Fox> Can you mux multiple files together with ffmpeg easily?
[16:39] <Demon_Fox> I am going to reword that
[16:40] <Demon_Fox> Can you easily mux multiple files together with ffmpeg?*
[16:40] <Demon_Fox> or
[16:40] <Demon_Fox> Can one easily mux multiple files together with ffmpeg?*
[16:40] Action: Demon_Fox should have got that right the first time.
[16:42] <sacarasc> Demon_Fox: So you have multiple streams or make the video longer?
[16:42] <Demon_Fox> more like
[16:42] <Demon_Fox> One audio stream and one video stream
[16:42] <JEEB> that's simple
[16:42] Action: Demon_Fox did not know
[16:42] <sacarasc> http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20concatenate%20%28join,%20merge%29%20media%20files
[16:43] <JEEB> ffmpeg -i input1 -i input2 -map 0:v -map 0:a -c copy out.file
[16:43] <JEEB> two inputs
[16:43] <JEEB> map the video from the first one, audio from the second one
[16:43] <sacarasc> Oh, right.
[16:43] Action: sacarasc goes back to bed.
[16:44] <Demon_Fox> thanks
[16:44] <JEEB> -map input_nr:track_nr or track_type
[16:45] <JEEB> selects a track
[16:45] <JEEB> and adds it to output (overrides any automatic selection before then)
[16:50] <Demon_Fox> thanks once again
[16:52] <someone-noone> Hello! When I want to read data from bufffer using read callback putted in avio_alloc_context(), my program is always crashing exactly here: http://cekirdek.pardus.org.tr/~ismail/ffmpeg-docs/aviobuf_8c-source.html#l00899
[16:53] <someone-noone> why can it be?
[16:55] <someone-noone> found problem, my buffer wasn't allocated with av_malloc
[16:56] <teratorn> if it bad to use timestamps with negative values?
[16:57] <Demon_Fox> JEEB, This may sound rude, but are you from japan. I want to know because I would like to know how polite to be before I get rude.
[16:59] <Demon_Fox> In some cultures trying to be as polite as possible can make me rude.
[16:59] <JEEB> I have lived in Japan but I am from Finland >_>
[17:00] <Demon_Fox> JEEB, Thanks, I needed how polite I needed to be about one of the most helpful IRC users
[17:01] <Demon_Fox> for one of the*
[17:04] <paltman> anyone know what this means? [libx264 @ 0x9c5a720] err{or,}_recognition separate: 1; 1
[17:06] <Demon_Fox> Strange error, maybe the people in #x264 can help.
[17:12] <paltman> also getting some errors with dvvideo, but it looks like it might have been a regression that was fixed back in march https://ffmpeg.org/trac/ffmpeg/ticket/1042
[17:12] <paltman> as my build is previous to that
[17:13] <paltman> as i am getting Unsupported bit depth: 0 as well
[17:13] <paltman> in trying to transcode dvvideo to x264
[17:13] <paltman> going to recommend my client upgrade ffmpeg to latest
[17:45] <sam_> ffmpeg doesnt accept profile options passing to libxx264
[17:46] <sam_> i had tried profile:v at command line it works but passing through configuration doesnt
[18:37] <beastd> heh, good i looked into the archive. ffserver-user mailing list will be shutdown and merged with ffmpeg-user
[19:44] <Miesco> Do you have to pay royalties for mp3 encoding/decoding in software that is free?
[19:46] <JEEBsv> Miesco: software licenses and possible licenses for formats etc. are completely separate. If you see that a company wants you to get a license to deal with a certain format, and a lawyer tells you that it is valid in your country then it's better to follow it :P
[19:46] <JEEBsv> I think MPEG-1 Layer 3 audio was licensed by fraunhofer?
[19:47] <Miesco> http://mp3licensing.com/royalty/
[19:47] <Miesco> Im looking at that
[19:49] <JEEBsv> oh, technicolor? Noted
[19:49] <JEEBsv> anyways, IANAL and I can't tell you if you *have* to pay those royalties
[19:49] <JEEBsv> that's better to be left to the lawyers
[19:49] <JEEBsv> or just do a decision by yourself
[19:53] <Miesco> its 1.25 for decoding mp3 in your app, what if its a $1 app on the android market, doesn't make sense
[19:54] <llogan> shows .75 for mp3
[19:54] <llogan> who uses mp3pro?
[20:03] <Miesco> llogan: Okay so I would have to pay $0.75?
[20:28] <llogan> Miesco: probably, but apparently licensing agencies are still in the year 2000 and don't have an "app" pricing structure.
[20:28] <JEEBsv> usually e-mailing them about it helps, at least it seems to have helped some people when licensing AAC
[20:29] <JEEBsv> if they really don't want to bulge then you'll have to decide whether you want to pay or not
[20:57] <barque> ((unsigned int)pFormatCtx->duration)/(float)AV_TIME_BASE is not giving me the correct duration of a video
[20:57] <barque> is there some better way of getting the duration?
[20:57] <barque> or do I have to maybe re-encode it to get a better duration?
[20:58] <barque> I've also tried multiplying by time_base but I think that also gives me bad values
[20:58] <barque> AVFractional time_base
[20:59] <JEEBsv> in most such cases you haven't dealt with timestamps correctly, although I have no idea how well libavformat can give you the length with various container formats
[20:59] <JEEBsv> some have timestamps for all frames
[20:59] <barque> timestamps?
[20:59] <JEEBsv> others just plain don't and stuff gets very roughly approximated
[20:59] <barque> on packets?
[21:00] <barque> no I mean I'm trying to get the duration before reading packets
[21:00] <barque> do I have to read packets to get a decent duration?
[21:00] <barque> the timestamps are actually on the mark
[21:00] <barque> very accurate
[21:00] <barque> I've logged them
[21:02] <JEEBsv> no idea, but I wouldn't expect libavformat's checks always give you the correct length... but I will bet that you most probably are doing something weird if the format is such where libavformat can give you a relatively straightforward duration, for example forgetting to normalize the timestamps (duration and its time_base)
[21:02] <barque> the packet timestamps are pefect.... what I'm trying to do to get duration is : ((unsigned int)pFormatCtx->duration)/(float)AV_TIME_BASE
[21:03] <barque> here's how I get packet timestamps : (float)(packet.pts * av_q2d(pCodecCtx->time_base));
[21:03] <barque> gives me fractional seconds on the mark
[21:03] <barque> I've tried multiplying duration by av_q2d(pCodecCtx->time_base)
[21:03] <JEEBsv> I have no idea what AV_TIME_BASE is but it sounds like some nonchanging constant, not sure if that's a good idea
[21:03] <barque> but gives me a rather large number
[21:04] <barque> 47k some such
[21:04] <barque> as *if* it was in milliseconds
[21:04] <barque> actual video length is 43 seconds
[21:05] <JEEBsv> what's your format btw?
[21:05] <barque> so I don't know if just dividing things by 1000 on my own is a good idea
[21:05] <barque> Theora/OGG
[21:05] <JEEBsv> uh-oh
[21:05] <JEEBsv> have fun is all I can say
[21:05] <barque> hah, there's no way eh?
[21:05] <JEEBsv> does command line ffmpeg give you a length?
[21:05] <barque> let me see
[21:05] <JEEBsv> nah, I'm going to expect a PEBKAC first :P
[21:08] <barque> it gives me perfect duration
[21:09] <JEEBsv> ok
[21:09] <barque> I'm doing pre-reads and using custom seeks and stuff
[21:09] <barque> callbacks
[21:09] <JEEBsv> not sure if libavformat by default does the exact same checks with the exact same amount of file... but at least it's a hint towards the fact that you might be having a PEBKAC
[21:10] <barque> So I'm not computing things correctly?
[21:10] <JEEBsv> the most general thing is that the user forgets to normalize his timestamps (in this case, duration) to whatever he's expecting or whatever :V
[21:10] <barque> ok
[21:10] <JEEBsv> I'm pretty sure you're not supposed to be using any define like AV_TIME_BASE
[21:11] <barque> yeah I used the other one
[21:11] <barque> gives me a large number
[21:11] <barque> (still)
[21:14] <JEEBsv> ok...
[21:14] <JEEBsv> http://www.ffmpeg.org/doxygen/trunk/structAVFormatContext.html#ad0ea78ac48f5bb0a15a15c1c472744d9
[21:18] <barque> yeah apparently http://www.sebastianroll.de/TableTopDoc/video_texture_8cpp-source.html is doing the same\
[21:21] <JEEBsv> also since I guess both the timestamp and timescale are int64_t, I recommend you make sure whatever you cast the values into can hold the end result values
[21:21] <barque> ok
[21:21] <barque> maybe I'll cast as the very very end
[21:22] <barque> because it obviously finally needs to fit
[21:22] <barque> I don't have godly large videos
[21:38] <barque> for duration I'm getting 477051922
[21:38] <barque> AV_TIME_BASE is 1000000
[21:38] <barque> but the length of the video is 43.3 seconds
[21:38] <barque> not 477 seconds
[22:06] <sam__> how to force ffmpeg to decode using baseline profile by default it goes with high  and add following parameter dont know how
[22:06] <barque> bleh re-encoding of the same thing fixed the issue :/
[22:06] <sam__> rc=abr  mbtree=1  bitrate=479  ratetol=1.0 /
[00:00] --- Wed Jan 30 2013


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