[Ffmpeg-devel-irc] ffmpeg.log.20150928

Tue Sep 29 02:05:01 CEST 2015

[03:43:55 CEST] <pinPoint> i'm curious about ffmpeg and prores. How was it possible to create a prores option when it is not open?
[03:45:43 CEST] <c_14> Implementing the format spec?
[03:45:50 CEST] <c_14> That or reverse engineering a working encoder.
[03:45:52 CEST] <pinPoint> yes.
[03:46:02 CEST] <pinPoint> I mean it is not open from apple is it?
[03:46:34 CEST] <pinPoint> reversing a codec is insane no?
[03:46:41 CEST] <c_14> Been done before.
[03:47:19 CEST] <pinPoint> I've haven't spent much time in prores space but does it look good in production environment?
[03:47:49 CEST] <waressearcher2> what is that "prores" ?
[03:48:03 CEST] <c_14> It's a video codec
[03:48:11 CEST] <waressearcher2> better than V9 ?
[03:48:18 CEST] <waressearcher2> or h264
[03:48:30 CEST] <waressearcher2> or its proprietary from apple
[03:48:39 CEST] <c_14> It's main use is with high bitrates for post-processing.
[03:48:42 CEST] <c_14> Not for good compression.
[03:49:24 CEST] <pinPoint> c_14: indeed. waressearcher2 it is really good.. good colors too
[03:49:46 CEST] <pinPoint> hence the use of it in production for Post work and colorspace.
[03:49:56 CEST] <c_14> It's meant for use-cases where rawvideo is too big, and other codecs lose too much information or take too much time.
[03:50:00 CEST] <pinPoint> waressearcher2: it is an apple thing
[03:50:56 CEST] <pinPoint> waressearcher2: I got an example if you want to see. Its a color graded file but you can see it. I think. :)
[03:51:08 CEST] <waressearcher2> no need
[03:51:39 CEST] <pinPoint> ok
[03:52:35 CEST] <pinPoint> c_14: I'm suprised nobody out there has come up with something just as good. I mean there is DNxHD, CinemaDNG, R3D Raw
[03:52:53 CEST] <c_14> As good as prores?
[03:53:30 CEST] <pinPoint> yes
[03:53:49 CEST] <pinPoint> the only problem is editing in windows without support.
[03:54:08 CEST] <c_14> tbh, I usually either encode directly to H.264 or use a lossless codec
[03:54:26 CEST] <pinPoint> btw, I took those HEVC .mp4/.mkv files to work and they fly well on Samsung UHD and Vizio UHD with sound finally.
[03:54:35 CEST] <c_14> If you need support in $video_application, utvideo is supported almost everywhere.
[03:54:55 CEST] <pinPoint> Finally, I can grab 4k videos of off youtube and convert to hevc and flash drive those things for demos
[03:57:43 CEST] <pinPoint> utvideo?
[03:58:04 CEST] <pinPoint> c_14: what lossless codec do you go for usually?
[03:58:42 CEST] <pinPoint> utvideo is lossless. I see
[03:59:18 CEST] <c_14> If what I'm using has lavc support ffv1. Had the best speed/compression tradeoff in my tests.
[05:11:19 CEST] <pinPoint> so is AAC also a reversed version too?
[05:11:59 CEST] <c_14> Think there's an open spec for that one.
[05:12:09 CEST] <pinPoint> open spec?
[05:12:21 CEST] <c_14> And you can learn from the other implementations.
[05:12:24 CEST] <pinPoint> I used -strict experimental.. is that what that is?
[05:12:38 CEST] <waressearcher2> can ffmpeg use CUDA or opencl for encoding ?
[05:12:44 CEST] <c_14> A spec you can get your hands on without belonging to some ominous association or paying sums of money.
[05:12:53 CEST] <waressearcher2> will it be some day ?
[05:13:37 CEST] <c_14> waressearcher2: besides some minor x264 optimization, no. (and one or 2 video filters)
[05:15:08 CEST] <waressearcher2> are there plans for full support ?
[05:15:20 CEST] <waressearcher2> I mean can you imagine reusing thouthands CUDA cores for encoding ?
[05:15:24 CEST] <c_14> It's not worth it for encoding. Might be worth it for some filters.
[05:15:28 CEST] <c_14> *usually not worth it
[05:15:44 CEST] <waressearcher2> by the way what is the reason it doesn't use GPU ? CUDA is available like for years
[05:17:03 CEST] <waressearcher2> but there are video cards that are specificaly for video processing, like "Sony Vegas" can use "geforce 570" features to speed up encoding, does it uses some specific features and not CUDA ?
[05:17:19 CEST] <pinPoint> would cuda/opencl even help much?
[05:17:26 CEST] <c_14> Those are usually special chips on the graphics cards.
[05:17:34 CEST] <c_14> Whatever they're called
[05:17:36 CEST] <pinPoint> my hexa cranks to fulltime when I push some x265 out
[05:17:36 CEST] <c_14> eh
[05:17:45 CEST] <waressearcher2> can ffmpeg use them or isit driver specific ?
[05:17:56 CEST] <pinPoint> c_14: "get your hands on" oh boi.
[05:17:58 CEST] <waressearcher2> pinPoint: what is hexa ?
[05:18:03 CEST] <pinPoint> hexacore
[05:18:14 CEST] <waressearcher2> pinPoint: 8 core ?
[05:18:21 CEST] <pinPoint> 6
[05:18:22 CEST] <c_14> waressearcher2: nvenc & related hwaccels
[05:20:02 CEST] <pinPoint> c_14: is the reason that its better for rendering instead? on my premiere the cuda does come online. It's still dealing with video so ffmpeg can never do it?
[05:21:08 CEST] <c_14> The GPU is good for doing millions of small operations simultaneously, encoding video doesn't usually fit that bill
[05:23:06 CEST] <pinPoint> ah
[05:23:22 CEST] <waressearcher2> cracking passwords ?
[05:24:32 CEST] <pinPoint> from what's on the net, yes.
[05:24:45 CEST] <pinPoint> like a 8 way sli titans
[05:24:51 CEST] Action: pinPoint shudders
[05:27:55 CEST] <pinPoint> c_14: have you messed around with prores ffmpeg encodes and tested them on a final cut X timeline? Where they compliant without fcp complaining?
[05:28:43 CEST] <c_14> Haven't personally tried it, but they should be compliant.
[05:30:02 CEST] Action: pinPoint thinks of a tutorial article
[05:34:48 CEST] <waressearcher2> "8 way sli titans", one even cheap smartphon will be as powerful as that thing
[05:34:55 CEST] <waressearcher2> one day
[05:35:20 CEST] <waressearcher2> 13:32 here
[05:37:38 CEST] <pinPoint> in the afternoon. cool
[05:37:41 CEST] <pinPoint> :)
[05:38:11 CEST] <pinPoint> waressearcher2: one day but GPUs will be just as ahead.
[05:38:13 CEST] <Nosomy> CUDA encode?
[05:38:16 CEST] <Nosomy> lol
[05:38:20 CEST] <pinPoint> :D
[05:38:39 CEST] <Nosomy> "Best Quality" [/ironic mode off]
[05:38:53 CEST] <waressearcher2> 13:36
[05:38:57 CEST] <waressearcher2> wait for it
[05:39:05 CEST] <pinPoint> l33T
[05:40:55 CEST] <Nosomy> Cuda Implementation last time i saw is a s***, maybe today it can be improved .
[05:41:03 CEST] <waressearcher2> 13:38 ta-da-a
[05:41:29 CEST] <pinPoint> Nosomy: opencl?
[05:41:50 CEST] <Nosomy> nop, before opencl.
[05:42:02 CEST] <pinPoint> libx264 crf 23 is good, libx265 crf 23 is even better?
[05:43:40 CEST] <pinPoint> that hevc is making the cpu purr
[05:43:51 CEST] <pinPoint> water cooled fans are whirrin
[05:43:55 CEST] <Nosomy> crf 23 is medium good.
[05:44:09 CEST] <Nosomy> i prefer crf 20.5
[05:44:11 CEST] <pinPoint> on libx265 its better though
[05:44:21 CEST] <c_14> You can't compare the crfs between x264 and x265. They're not meant to measure the same "quality".
[05:44:55 CEST] <pinPoint> that is why I think on x265 a crf 23 is actually better than just good.
[05:45:28 CEST] <waressearcher2> what is crf ?
[05:45:52 CEST] <Nosomy> control rate  factor
[05:46:02 CEST] <pinPoint> http://slhck.info/articles/crf
[05:46:14 CEST] <pinPoint> Constant
[05:46:37 CEST] <Nosomy> c_14 and VQMCalc avs plugin?
[05:46:44 CEST] <Nosomy> lol
[05:47:31 CEST] <c_14> Isn't that just a psnr?
[05:48:03 CEST] <Nosomy> Based on VQM work from Watson and Feng Xiao.
[05:49:59 CEST] <pinPoint> i have to admit, libx265 compression is just amazing.
[05:50:27 CEST] <pinPoint> I know hevc is not cheap but the compression levels are just insane
[05:50:31 CEST] <Nosomy> but hevc have cpu use cost to decode
[05:50:59 CEST] <pinPoint> the tv's do it just fine. I've tested a few of them
[05:51:13 CEST] <pinPoint> from a usb flash drive
[05:54:07 CEST] <pinPoint> I just went from a 346.08MB to 102MB with x265. o_O
[06:03:54 CEST] <Nosomy> reencode?
[06:04:02 CEST] <Nosomy> or the source is lossless?
[06:05:10 CEST] <pinPoint> webm       3840x1620  DASH video 17346k , VP9, 24fps, video only, 346.07MiB
[06:05:38 CEST] <pinPoint> combined it with  m4a        audio only DASH audio  255k , m4a_dash container, aac  @256k (44100Hz), 8.92MiB
[06:06:09 CEST] <pinPoint> i don't think its lossless, its from youtube. https://www.youtube.com/watch?v=xyIAV5YVjA4
[06:14:09 CEST] <Nosomy> lossy...
[06:14:35 CEST] <Nosomy> For UHD youtube use VP9?
[06:14:48 CEST] <Nosomy> lol
[06:15:18 CEST] <pinPoint> its either that or mp4
[06:15:35 CEST] <pinPoint> so I started with a larger file hopefully a bit more quality that the small mp4
[06:16:16 CEST] <Nosomy> More bitrate isn't always more quality
[06:16:29 CEST] <Nosomy> depends of codec
[06:16:29 CEST] <pinPoint> file size
[06:16:41 CEST] <pinPoint> how about this one?  mp4        5120x2700  DASH video 24998k , 30fps, video only, 506.46MiB
[06:17:14 CEST] <Nosomy> maybe very good.
[06:17:27 CEST] <Nosomy> don't see the video.
[06:17:36 CEST] <pinPoint> https://www.youtube.com/watch?v=nRt4Duf7GoI
[06:18:27 CEST] <pinPoint> Nosomy: mp4 vs webm
[06:18:53 CEST] <Nosomy> for decode or encode?
[06:19:14 CEST] <pinPoint> youtube->mkv
[06:19:27 CEST] <Nosomy> video complexity rules the encodes bitrates.
[06:20:07 CEST] <Nosomy> for encode i prefer h264, is more fast to encode.
[06:20:24 CEST] <Nosomy> for decode, vp9 hevc h264 is ok to this
[06:20:53 CEST] <pinPoint> these videos end up on a uhd tv displays for demo
[06:21:08 CEST] <pinPoint> either .mp4/mkv container(h265)(aac)
[06:21:25 CEST] <Nosomy> vp9 is slow like hevc to encode.
[06:21:46 CEST] <Nosomy> youtube using vp9 is funny...
[06:22:02 CEST] <pinPoint> they have been for quite a while now
[06:22:04 CEST] <pinPoint> since v8
[06:22:09 CEST] <pinPoint> now v10 is rolling around
[06:23:36 CEST] <Nosomy> normally youtube streaming i don't reencode.
[06:24:15 CEST] <pinPoint> Nosomy: i know but they won't play back on uhd tv displays. The manufactures have really locked it down.
[06:24:16 CEST] <Nosomy> is not recommended, if you looks quality
[06:24:27 CEST] <pinPoint> they want hevc with aac for UHD video, nothing less
[06:24:40 CEST] <pinPoint> i have tried Samsung/vizio/sharp/lg
[06:25:18 CEST] <waressearcher2> what hard ware youtube uses to encode all those videos when you upload them ?
[06:25:35 CEST] <pinPoint> their servers probably
[06:25:52 CEST] <Nosomy> batching ffmpeg with fast presets.
[06:25:57 CEST] <Nosomy> lol
[06:25:59 CEST] <waressearcher2> something i7 ?
[06:26:10 CEST] <pinPoint> try Xeons
[06:26:21 CEST] <pinPoint> 2x12Core Xeons or better
[06:26:23 CEST] <waressearcher2> they use normal CPU that average gaming PC has, right ?
[06:27:05 CEST] <pinPoint> the editors I've read run on 2x12core Xeons on 128GB RAM, 2way sli Titan X ++
[06:27:50 CEST] <waressearcher2> why they have Titan, they use CUDA ?
[06:28:56 CEST] <pinPoint> the editing programs use it. Premiere, Avid, Final Cut(hackintosh)
[06:29:16 CEST] <pinPoint> its for 3K,4K,5K,6K video
[06:30:15 CEST] <waressearcher2> that Titan thing has only 12GB memory, do you think its all NVIDIA can do or they just don't want to go ahead of themselves ?
[06:30:27 CEST] <Nosomy> time is expensive for an encode video to youtube, youtube using vp9 is very funny.
[06:31:15 CEST] <waressearcher2> its like 40hours videos uploaded per minute
[06:31:47 CEST] <pinPoint> Nosomy: actually the list is different, let me link you. http://pastebin.com/vcxnHePb
[06:31:56 CEST] <waressearcher2> or 40 minutes every second
[06:38:19 CEST] <Nosomy> Well, what should I see?
[06:40:16 CEST] <pinPoint> they have like different formats for just one video. its weird how youtube works
[06:40:25 CEST] <pinPoint> that's all from one video
[06:40:37 CEST] <pinPoint> and bandwidth sizes too
[06:42:36 CEST] <waressearcher2> is xvid still in use nowadays ?
[06:42:46 CEST] <Nosomy> youtube processing video is so little funny, out the demos them, every video uploading going to bad quality.
[06:42:51 CEST] <pinPoint> for nonhd yes.
[06:43:10 CEST] <Nosomy> warezs yet use xvid
[06:43:22 CEST] <waressearcher2> why would someone need nonhd and for how long do you think xvid will be used ?
[06:43:39 CEST] <Nosomy> more 8~10 years
[06:43:47 CEST] <Nosomy> i think
[06:45:11 CEST] <Nosomy> why would someone need nonhd? ans: preference
[06:46:25 CEST] <Nosomy> nowadays h264 is good enough for encode video.
[06:46:48 CEST] <Nosomy> including nonhd
[06:49:23 CEST] <pinPoint> indeed
[06:51:55 CEST] <Nosomy> xvid encoding looks likes a hispter video encoder, only overcome if guy used dirac, dirac is too so old.
[06:55:33 CEST] <Nosomy> ans2: xvid is compatible with old dvd\vcd players.
[06:58:34 CEST] <Nosomy> while there is old DVD\VCD player working, going to exist xvid encoding
[07:39:42 CEST] <razzledazzle> Can anyone see this paste? http://pastie.org/private/w6ksuwbnxqqihjcoxprnza
[07:41:22 CEST] <razzledazzle> Not able to understand what the starting duration has to do with the partial file issue, it even doesn't work when ss is set to 0.
[07:41:49 CEST] <razzledazzle> Works well without pipe but pipe is mandatory as streams are being used to pass in data
[11:28:09 CEST] <razzledazzle> please help, posted a question: http://superuser.com/questions/979144/unable-to-trim-piped-video-stream-with-ffmpeg
[11:53:17 CEST] <relaxed> razzledazzle: mp4 isn't the best container for piping
[11:56:40 CEST] <razzledazzle> I'm actually developing for Android and generally they support mp4, even the camera there produces in mp4
[17:11:36 CEST] <sine`> I have this audio clip in amr format amr_nb samr 8000htz mono 12/kbs
[17:12:05 CEST] <sine`> whenever I convert it to any format it is distorted with compression peaks etc, but playing it back on windows is fine without conversion
[17:12:22 CEST] <sine`> what would be the best way to preserve the audio but have it in wav/editor friendly format
[17:14:28 CEST] <sine`> its ok i fixed it
[18:55:56 CEST] <millican> Is ffmpeg no longer in the Debian (8) repos? I must be going blind.
[18:56:41 CEST] <BtbN> I don't think it was ever in there?
[18:57:38 CEST] <BtbN> 9 should have it though
[18:57:57 CEST] <millican> I didn't know there was a 9.
[18:58:08 CEST] <BtbN> Well, the one after 8 is usualy 9 ;)
[18:58:22 CEST] <relaxed> yeah, it's in unstable now
[18:58:34 CEST] <BtbN> No, testing has 2.7
[18:58:41 CEST] <BtbN> Well, of course it's also in unstable
[18:59:01 CEST] <millican> I may adjust my sources.list temporarily or compile it.
[18:59:16 CEST] <relaxed> millican: or http://johnvansickle.com/ffmpeg/
[18:59:51 CEST] <millican> relaxed: Thanks.
[19:33:52 CEST] <pinPoint> sine`: how did you fix it?
[19:34:14 CEST] <pinPoint> you got the ffmpeg command? :D just curious. bbl
[20:09:35 CEST] <Djerkaf> Hello! I'm copying the left audio channel to the right using -filter_complex "pan=stereo|c0<c0|c1<c0" but the audio quality doesn't seem to stay the same as the original. Is there any way to change the default quality into original quality?
[20:13:48 CEST] <c_14> Djerkaf: what's the rest of your command
[20:13:53 CEST] <c_14> It's probably encoding settings
[20:18:39 CEST] <Djerkaf> "C:\path\ffmpeg.exe" -i "L:\path\input.mp4" -filter_complex "pan=stereo|c0<c0|c1<c0" -map 0:v -c:v copy -shortest "L:\path\output.mp4"
[20:19:08 CEST] <waressearcher2> at first I thought why do you use "escape" symbol, then I realised its windows path
[20:19:19 CEST] <c_14> How new is your version?
[20:19:32 CEST] <c_14> Anyways, https://trac.ffmpeg.org/wiki/Encode/AAC
[20:19:54 CEST] <Djerkaf> 2.2.2
[20:20:32 CEST] <c_14> If you're using the builtin aac encoder you might want to update to recent git, lots of improvements have been added.
[20:38:36 CEST] <Djerkaf> Tried adding -c:a libvo_aacenc -vbr 1 but that "-vbr 1" seems to be completely ignored as it should be low quality and still is at a steady 128 kbit throughout the whole clip
[20:40:19 CEST] <Djerkaf> (CBR)
[20:48:45 CEST] <Nosomy> try -q:a 1
[21:06:10 CEST] <Djerkaf> Nosomy: Still CBR 128
[21:10:14 CEST] <Axydlbaaxr> Hi, good people of #ffmpeg. I'd like to know how I can configure ffserver so that it will stream video from a file in a "live" style. By that, I mean I want the server to start streaming from the file from the beginning at t=0 when the server is launched. Then when a client connects to it at t=5, the client will receive video starting at 5 seconds in, and clients connecting later will also...
[21:10:16 CEST] <Axydlbaaxr> ...get the video already in progress. Instead of the current way I'm seeing it work, where each connection starts the video from the beginning, I want each connection to join the stream already in progress as though the source video file were a live source.
[21:22:03 CEST] <fffelix> Hi, I want to transcode a stream (mp3) to a lower quality (for mobile). the standard -i input output creates a recording, but I want ffmpeg to "forget" everything thats older than ~10 seconds from the stream. Is this possible with ffmpeg?
[21:23:51 CEST] <fffelix> It should be a continous stream, but instead of the 128kbit/s mp3 a 12kbit/s opus (for mobile streaming) and kind of keep the file to a given size/length
[21:32:45 CEST] <ChocolateArmpits> fffelix: by stream you mean a file or an actual live streaming audio, like an internet radio station ?
[21:33:27 CEST] <fffelix> ChocolateArmpits: an actual stream that is provided via an mp3
[21:35:28 CEST] <ChocolateArmpits> fffelix: what do you mean by "forget" ? to only output silence until a specific time?
[21:38:35 CEST] <fffelix> ChocolateArmpits: I want to transcode the stream to a smaller opus stream, bc the station only offers 128kbit/s which is too much for my mobile plan, so I want to transcode it. When I use ffmpeg i xyz.mp3 xyz.opus it generates a recording, but I want to create a second stream with anoter codec/bitrate
[21:39:06 CEST] <ChocolateArmpits> fffelix: yes I understand that fully
[21:39:16 CEST] <ChocolateArmpits> but what does the "forget" part mean in your plan
[22:18:18 CEST] <Djerkaf> Hello71, I see that you've had a similar problem, remember if you solved it? https://mplayerhq.hu/pipermail/ffmpeg-devel-irc/2014-February/001947.html
[22:27:27 CEST] <woopdeedoodaa> Hey does anyone have experience with the nvenc encoder? I've build it from source and can encode video with it (no errors) but the colour range is limited, blacks are crushed and look washed out. Anyone know how to specify full colour range (0-255) with nvenc? I can provide examples if the would help
[22:29:10 CEST] <Nosomy> nvidia color range problem
[22:35:36 CEST] <woopdeedoodaa> So is that a hardware limitation or the codec implementation?
[22:58:32 CEST] <frenda> Hey there
[22:59:47 CEST] <frenda> May you take a look at this 10-sec video: http://uploadkon.ir/fl/dd/76929 and let me know if ffmpeg can capture the screen by zooming in/out to the zone that the curser is acting via shortcut keys; (in linux realm)
[23:01:49 CEST] <fffelix> ChocolateArmpits: sorry, that was very unspecific. I want to create another stream, not a recording that writes every bit from when i started the ffmpeg.
[23:20:53 CEST] <Hello71> Djerkaf: don't remember
[23:21:18 CEST] <Hello71> Djerkaf: maybe try reordering the options or using "vbr:v" or something
[23:24:41 CEST] <Djerkaf> Alright
[00:00:00 CEST] --- Tue Sep 29 2015