[Ffmpeg-devel-irc] ffmpeg.log.20140614

[burek]

[01:09] <waressearcher2> I used command "ffmpeg some_stuff_here 2>&1 > out.txt" but it still outputs on the screen, is there an option for ffmpeg to output everything to file ?
[01:10] <c_14> What you're looking for is ffmpeg tthththt 2&>1 > out.txt
[01:10] <c_14> the location of the & is wrong
[01:16] <waressearcher2> no, its not wrong
[01:16] <waressearcher2> &1 is the thing
[01:16] <waressearcher2> I always do 2> and &1 are two things
[01:16] <waressearcher2> check "man bash"
[01:17] <c_14> hmm, you're right
[01:17] <c_14> guess my bash knowledge is a bit funky
[01:17] <c_14> ffmpeg test >& out.txt works though
[01:18] <sacarasc> ffmpeg blah &> cheese.txt
[01:19] <waressearcher2> sacarasc: the "&> cheese.txt" is quite the same as "2>&1 > cheese.txt"
[01:20] <sacarasc> http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO-3.html
[01:20] <waressearcher2> but actually &> works
[01:21] <waressearcher2> yes, I usually use &> in stead of 2>&1 but that time I kind of forgot
[05:15] <Cykon> Anyone have any idea about my C++ piping problem as described here http://ffmpeg.zeranoe.com/forum/viewtopic.php?f=15&t=2021&e=0#p6896
[05:39] <waressearcher2> c_14: you here ?
[05:39] <waressearcher2> ffmpeg -f concat -i list_all.txt -i ../../_5/all.ac3 -ab 320k -ar 44100 -ac 2 -acodec libmp3lame -vcodec h264 -vb 3000k -s 1280x720 -r 30 -vf "fade=out:24900:360" -y -f avi out_all_2.avi
[05:39] <waressearcher2> that is the output of that command http://sprunge.us/QFGg
[05:39] <waressearcher2> I use that command to make file out_all_2.avi and it should be 14:02 long, now if I use mplayer on my PC it shows it is 14:02 long, correct one, but if I use ffprobe to check it's length it says its 15:07 long and also if I upload it on youtube it does show it is 15:07 long and after 14:02 there is black scree, where is the problem ? it should be
[05:40] <waressearcher2>  14:02 long there is no more video, mplayer shows it right, why youtube thinks its 15:07 ? also when I upload it on youtube it says "we can't recognize video codec and audio codec" but they still process the video ?
[05:42] <another> i guess c_14 is asleep
[05:42] <waressearcher2> give me another c_14
[05:44] <waressearcher2> anyone else ?
[05:45] <Cykon> You can call me whatever you want if you figure out why ffmpeg stops sending data to my windows pipe :)
[05:46] <waressearcher2> can I call you with "C" word ?
[05:46] <waressearcher2> "Cykon"
[05:46] <Cykon> Well, the code is in C, so you sure can!
[05:46] <waressearcher2> it will be long long word or even double float word
[05:47] <Cykon> lol
[05:47] <Cykon> This is getting frustrating -.- I wrote the same thing in python and it worked just fine... port it to C and it only sends over half a frame and then sends no data after
[05:49] <waressearcher2> imagine if ffmpeg was written in python, how fast it could've been ? 20x slower ?
[05:51] <Cykon> Lol
[05:51] <Cykon> I'm trying to pipe raw rgb 24 data in, edit it, and pipe it back out
[05:51] <Cykon> Piping in and out worked fine in python... but man
[05:51] <Cykon> imagine trying to edit it...
[05:52] <Cykon> In my C code piping data out works completely fine... but the input pipe stops reading after like 40k bytes
[05:53] <waressearcher2> there are #c and #programming
[05:54] <Cykon> Yeah, I might have to try hopping over there soon.
[05:59] <Cykon> Hmm, changing the output to rgb8 and data is coming through now
[06:07] <Cykon> ffmpeg.exe -i testvid.avi -f rawvideo -pix_fmt rgb8 -
[06:07] <Cykon> anyone see anything wrong with this? Should take testvid.avi and output it in the raw in rgb8 into stdout?
[06:50] <Cykon> Hmmm.... it seems even a pipe I wrote from scratch stops sending data through after some time
[08:57] <Cykon> When ffmpeg delivers a sample downstream to a pipe, does it wait until that data is read until it sends a new chunk of data?
[08:57] <Cykon> or does the pipe keep filling up
[11:41] <erle-> is there a way to tell ffmpeg that it should just encode but stop when a certain size is reached/
[11:41] <erle-> ?
[11:41] <erle-> for example: i specify input video, codecs and bitrate
[11:41] <erle-> and then it starts
[11:41] <erle-> and it should just cut the video at 5MB size
[12:28] <c_14> waressearcher2: The reason the resulting video is 15:06.10 long is because ffmpeg is detecting the length of the ac3 stream to be 15:06.10
[12:30] <c_14> erle-: If you manually set the bitrate you can calculate duration = size / bitrate and then use -t duration
[12:31] <c_14> waressearcher2: you can add -shortest to the output options and ffmpeg will stop encoding when the end of the shortest input (in this case the video) is reached.
[13:15] <erle--> c_14, it is obvious, that I can do that, but that is not what I want
[13:17] Action: c_14 just found -fs it looks like that should do what you want
[13:24] <erle--> c_14, thanks, i will try
[13:25] <erle--> c_14, it is exactly what i was looking for
[14:01] <waressearcher2> strange I can't find "-preset" in "man ffmpeg" but if I use ffmpeg with option "-preset ultrafast" it understands it
[14:02] <c_14> It's in ffmpeg-codecs under libx264
[14:02] <waressearcher2> but I also tryed search in "man ffmpeg-all", not here but should be that man page should contain all information
[14:03] <waressearcher2> not in "man ffmpeg-codecs" also
[14:03] <c_14> Just go into man ffmpeg-codecs, search for libx264 and scroll down a bit.
[14:03] <c_14> It's listed as preset not -preset
[14:04] <waressearcher2> but there is no keyword "ultrafast"
[14:05] <c_14> The actual presets are listed in x264 --help
[14:05] <JEEB> preset is a libx264 (and libx265 now) specific option
[14:05] <JEEB> basically if you set an unknown preset there, it's not ffmpeg that will bark at you, but the libx264 library
[14:05] <JEEB> because it's all built in there
[14:06] <JEEB> http://mewiki.project357.com/wiki/X264_Settings#preset
[15:37] <Fyr> guys! how to get ffmpeg to make two-pass encoding?
[15:37] <Fyr> I set -pass 2, but get error:
[15:37] <Fyr> "Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height"
[15:38] <Fyr> if I run the program without it, it goes normally.
[15:39] <Fyr> (h264)
[16:00] <Fyr> I recompiled ffmpeg, nevertheless it can't load cpu more than 900%.
[16:22] <bornpilot1> would using CRF and b:v together be defeating the purpose of CRF? I am guessing that I should use either one or the other?
[16:23] <BtbN> they are mutualy exclusive
[16:24] <BtbN> crf means a constant quality while adjusting the bitrate. cbr means a constant bitrate while adjusting the quality.
[16:24] <BtbN> crf is able to take some hints, like max bitrate, though
[16:25] <BtbN> where it stops increasing the quality at some point
[16:36] <bornpilot1> BtbN so if I use minrate and maxrate without bitrate and use CRF I should each image should be consistently good based on the bitrate range?
[16:37] <BtbN> well, if there is a lot of movement and it hits the max rate quality will still degrade
[16:37] <BtbN> and a min rate doesn't make much sense for vbr
[16:39] <bornpilot1> So, if I understand CRF it will provide a consistent looking image for each frame based on the the potential of the maxrate?
[18:10] <Kiliko> When i cut of start and the end with 3-6 seconds, but now when i play my video i need to wait 2-3 seconds untill i get a picture. How can do so ill have picture from the start of my video? i run ffmpeg with "-ss 4 -tt 90 -vcodec copy -acodec copy"
[18:11] <c_14> First of all, -tt isn't a valid option. Do you mean -t or -to?
[18:11] <Kiliko> ops, it should be just "-t"
[18:12] <c_14> try using -ss as an input option
[18:14] <c_14> But, since you're stream copying ffmpeg can only cut at vframes, so the accuracy of the cut will change depending on the source
[18:18] <Kiliko> c_14: Is it posiable to recode it with the same video codec format/settings and etc?
[18:20] <c_14> If you know the settings, yes. But if you're using a lossy codec, you will lose quality even if it isn't noticeable.
[19:32] <_genuser_> hello people
[19:34] <_genuser_> I'm trying to extract a video stream from an mp4 (x264 video) to another *.mp4 container. and ffmpeg gives me an error. is this not possible?
[19:35] <_genuser_> http://dpaste.com/1PPZ1G4
[19:36] <_genuser_> in this example. I change the output to .h264 to see if it change. even when I have .mp4 as extension for the outptu file, it says the same thing.
[19:39] <c_14> I think the problem is that ffmpeg can't determine the video stream's resolution or display aspect ratio.
[19:39] <_genuser_> even if you tell it to just copy it?
[19:40] <c_14> apparently so
[19:41] <_genuser_> original generated by handbrake. So possible they both write mp4 headers out differently.
[19:42] <_genuser_> ln #20 also seems problematic.
[19:43] <c_14> I think 40 is the issue, but if you put both lines together I'd assume there's something wrong with the original file/stream.
[19:44] <_genuser_> c_14: thanks. :) I guess this file is not process-able then. :)
[19:44] <c_14> You can always try reencoding and manually setting a dar or something.
[19:44] <_genuser_> dar?
[19:45] <sfan5> display aspect ratio
[19:45] <_genuser_> I originally convert is using handbrake where I set dimensions, fps, etc. --keep-display-aspect -w 720 -l 480 --display-width 720
[19:46] <_genuser_> I know those are handbrake options and mean nothing for ffmpeg. Just saying I thought I controlled like a dictator.
[19:47] <_genuser_> oh wait, let me try to set dimensions in ffmpeg manually if itallows
[19:47] Action: _genuser_ goes to read the output of ffmpeg -h
[19:48] <sfan5> man ffmpeg is probably more helpful
[19:50] <_genuser_> windows world.
[19:50] <_genuser_> well I do have ffmpeg on a linux machien too. so nm.
[19:50] <c_14> https://ffmpeg.org/ffmpeg.html
[19:50] <c_14> You can also use the online docu.
[19:54] <_genuser_> heh, no go. shouldn't have deleted the source. :)
[19:55] <_genuser_> x264 is indeed pretty crappy for editing. converted original with extra space in in front and behind the vide.
[19:55] <_genuser_> and decided to chop it in ffmpeg using -ss and -t and audio is off. which trigger this de-merging and re-merging effort.
[20:08] <_genuser_> found it.
[20:09] <_genuser_> I think ffmpeg craps the dimensions when doing an -ss on a video/audio feed both.
[20:09] <_genuser_> otherwise, it's been working on the source just fine extracting the video alone.
[20:10] <c_14> works just fine for me
[20:12] <_genuser_> 1) I generated mp4 (x264/aac) in handbrake. 2) If cut if in ffmpeg using ffmpeg -i <file> -ss 00:09:50 -t 00:20:03 .... 3) audio was off. 4) I tried to extra just the first and it gave the error we saw above.
[20:12] <_genuser_> so I cange it to
[20:12] <_genuser_> 1) handbrake 2) extra video alone, 3) extract audio alone, 4) cut each -ss -t, 5) cut audio again to align it with source 6) merge into single mp4 container.
[20:13] <_genuser_> sorry for the horrible typos. My wireless keyboard batts are going out. dropping letter, adding extras....
[20:16] <c_14> I just took some random video I had lying around and did `ffmpeg -ss 50 -t 200 -i video.mp4 -codec copy out.mp4' and the resolution stayed fine
[20:17] <_genuser_> and you can further process it in ffmpeg to let's say extract the vid only?
[20:18] <c_14> `ffmpeg -i tmp.mp4 -codec copy -an video.mp4' works just fine
[20:20] <_genuser_> interesting. this is the specific scenario that broke on my machine.
[20:20] <_genuser_> as long as I was able to fix it using more chopping, eh?
[20:21] <c_14> Maybe handbrake is generating corrupt output? Have you tried it with an mp4 not generated with handbrake?
[20:22] <_genuser_> well, I extracted video only from a handbrake generated mp4. And ffmpeg worked just fine and extract the video alone. And then audio along separately. both in mp4 containers.
[20:22] <_genuser_> so for that bit ffmpeg didn't have trouble recognizing the necessary resolution, etc.
[20:23] <_genuser_> but hndebrake does have it's own problems. an update has fixed a bug that used to bug me. and broken what used to work before. requiring manual intervention on conversions.
[20:23] <_genuser_> I can't just seem to put in place a script that can convert all my recordings quickly and efficiently.
[20:23] <c_14> Why are you using handbrake to convert? You could just use ffmpeg.
[20:26] <_genuser_> I spent lot of time testing and finding just the right handbrake options so that there's a really nice quality mp4 (x264) file generated that doesn't interlace or have blurs around fast motions.
[20:26] <_genuser_> I just haven't spent the time to figure out how to map those options in ffmpeg. And just using plain ole x264 has generated lesser quality files. e.g.:
[20:26] <waressearcher2> how to flip image or invert it upsidedown ?
[20:27] <_genuser_> ffmpeg -i file.wtv -vcodec h264 -acodec aac output.mp4.
[20:27] <_genuser_> also all my windows binaries do not support h264 conversion. only copy/decoding. I can compile my own on linux with enabled x264 and the quality didn't match.
[20:27] <c_14> waressearcher2: look at the -vf vflip
[20:28] <waressearcher2> found it -vf "hflip"
[20:28] <waressearcher2> that pesky youtube blocking my video world wide so I need a fast solution
[20:29] <c_14> _genuser_: pretty sure the static ffmpeg builds have x264
[20:29] <c_14> also, all handbrake does is pass the options to x264 which ffmpeg can do as well
[20:29] <_genuser_> c_14: all my win binaries show D V D never E when doing ffmpeg -codecs
[20:30] <c_14> http://ffmpeg.zeranoe.com/builds/ <- these ones have x264
[20:30] <_genuser_> c_14: but I'll try to download latest ffmpeg binary for windows. And do a quick map of options. if it just passes them along they might be exactly the same
[20:30] <_genuser_> c_14: yeah, I was really thinking of setting a build environment on windows to compile it myself one day. but those will do.
[20:31] <_genuser_> I used to have a build environment but that machien HD went out.
[20:31] <c_14> -x264opts is probably what you want. IIRC handbrake used to (maybe still does) have a tab that listed what x264 options everything broke down to
[20:31] <_genuser_> c_14: didn't use the GUI much. just used the docs to find what I wnated and spent hours, lol.'
[20:35] <_genuser_> c_14: nice, this one does. I thought I had downloaded this one before too. but may not have checked it on this one.
[22:13] <vtorri> hey
[22:14] <vtorri> is it normal that ffmpeg 2.2.2 and 2.2.3 releases do not appear on the main page ?
[22:27] <llogan> vtorri: it should have been done. probably by michael or me, but the download pages always have the newest release info.
[22:28] <llogan> i'll try to remember to update the news too next time
[22:30] <llogan> vtorri: there's also the FFmpeg twitter if you prefer that for getting release news (although a few of the releases for the older branches were missed).
[22:31] <vtorri> llogan: ok
[22:34] <llogan> vtorri: and of course the obligitory note that general users are usually recommended to use ffmpeg from git head instead of a release
[22:36] <vtorri> ok
[23:42] <waressea1cher2> can ffmpeg combine 4 videos with size of 640x360 into one 1280x720 ?
[23:42] <waressea1cher2> 2x2
[23:43] <c_14> https://trac.ffmpeg.org/wiki/FilteringGuide#multipleinputoverlayin2x2grid
[23:43] <c_14> a variation of that should do the tric
[23:47] <c_14> *trick
[23:59] <llogan> waressea1cher2: i just updated that example to be easier to read, hopefully.
[00:00] --- Sun Jun 15 2014