[Ffmpeg-devel-irc] ffmpeg-devel.log.20181130

[burek]

[01:38:20 CET] <cone-395> ffmpeg 03Jun Zhao 07master:b87063c06dde: lavc/libaomenc: Add a maximum constraint of 64 encoder threads.
[01:41:56 CET] <atomnuker> eh? but libaom can't use threads atm to encode, can't it
[01:42:03 CET] <atomnuker> there's no row_mt option
[02:33:51 CET] <jkqxz> atomnuker:  Tiles.
[02:35:08 CET] <jkqxz> I think most of the people asking for the tiles option were wanting it so they could use multiple threads for encode.
[02:38:31 CET] <atomnuker> yeah, I tried setting tile cols/rows just a few days ago, didn't work, still singlethreaded
[02:42:10 CET] <jkqxz> Odd - it works for me.  (Maybe there are some weird additional conditions somewhere for it to be used.)
[02:53:08 CET] <atomnuker> -b:v 0 -crf 30 -tiles 2x2 on a normal 720p video
[02:56:33 CET] <jkqxz> For me that pegs a single core only most of the time, but goes above it in bursts.
[02:58:34 CET] <jkqxz> It you use a 4K input, it uses four cores a lot of the time.
[02:59:22 CET] <jkqxz> (With some single core only time too.)
[03:00:06 CET] <atomnuker> not here though, and it uses 6 gigs of memory up front for 4k video
[03:02:02 CET] <jkqxz> Oh well.  I've no idea then.
[03:03:03 CET] <jamrial> atomnuker: make sure to use a recent git snapshot and not 1.0.0
[03:05:35 CET] <atomnuker> ah, that probably explains it, afaik arch is still on 1.0 without any asm
[09:40:34 CET] <cone-900> ffmpeg 03Steven Liu 07master:ba71ebbbfa16: avformat/dashdec: add subtitle stream support
[10:54:53 CET] <cone-900> ffmpeg 03Zhong Li 07master:518b963d2c99: lavc/qsvenc: enable ICQ and ICQ_LA on Linux
[10:54:54 CET] <cone-900> ffmpeg 03Zhong Li 07master:ac0bcd6b6194: lavc/qsvenc: add forced_idr option
[10:54:55 CET] <cone-900> ffmpeg 03Linjie Fu 07master:67cdfcf694f8: lavc/qsvenc: assert uninitialized pict_type
[16:30:09 CET] <cone-988> ffmpeg 03Paul B Mahol 07master:f09bbb8f087d: avformat/ac3dec: always skip junk bytes before sync bytes
[20:01:11 CET] <tytyt> Hey guys, I have a few questions so please bear with me: 
[20:01:41 CET] <tytyt> 1. I'm not specifically using FFmpeg would I still be able to ask a question about the AOMedia built source? 
[20:01:52 CET] <kierank> ask in #aomedia
[20:02:01 CET] <tytyt> ffs Thanks so much Kie! 
[20:02:49 CET] <tytyt> For viewing AV1 image files, what should I use? I set the params in Chrome but still can't see them with encoded ffmpeg 
[20:03:30 CET] <tytyt> And last question, is the the proper flags to export a single image (.avif) in FFMpeg? `ffmpeg -i test.png -c:v libaom-av1 -crf 0 -b:v 0 -strict experimental test2.png`
[20:07:59 CET] <durandal_1707> no
[20:11:05 CET] <tytyt> Ouch, do you mind pointing me to the right direction (or the line to use) ;) thanks! 
[20:12:01 CET] <durandal_1707> no
[20:12:24 CET] <durandal_1707> unsupported
[20:13:26 CET] <tytyt> Images are unsupported? 
[20:13:33 CET] <durandal_1707> no
[20:13:48 CET] <tytyt> My heart, 
[20:14:11 CET] <tytyt> Okay, we'll is there a hack? Convert to avi then to a single image?
[20:14:45 CET] <durandal_1707> doable
[20:15:07 CET] <tytyt> Thanks so much! 
[20:36:14 CET] <durandal_1707> avif is not supported currently in any kind in ffmpeg
[20:42:21 CET] <tytyt> Okay, what about a single frame (image) that is encoded as AV1? 
[20:43:52 CET] <nevcairiel> The AVIF file format is not directly supported by ffmpeg, even though its based on mp4, other restrictions apply, and a dedicated tool would likely do a better job at it - and also integrate encoding, I suppose
[20:46:33 CET] <gnafu> Hopefully more will become available once the spec is finalized.  I would imaging it wouldn't be terribly hard to add AVIF output to ffmpeg once there's a final spec, right?
[20:46:41 CET] <gnafu> s/imaging/imagine/
[20:46:56 CET] <nevcairiel> if its as crazy as HEIF, then keep hoping =P
[20:47:04 CET] <durandal_1707> haha
[20:47:12 CET] <jamrial> tytyt: single frame av1 can be decoded just fine
[20:47:22 CET] <jamrial> and encoded
[20:47:30 CET] <gnafu> nevcairiel, durandal_1707: Aah, I suppose.
[20:47:39 CET] <gnafu> nevcairiel, durandal_1707: But a guy can dream ;-D.
[20:47:43 CET] <jamrial> output it to mp4, mkv, ivf or whatever
[20:53:12 CET] <tytyt> "tytyt: single frame av1 can be decoded just fine" I'm asking for encoding. Was hoping to encode a png or webp file :/
[20:54:48 CET] <jamrial> if you mean converting a png into an AV1 still frame, then as i said, you can do that too
[20:55:11 CET] <thardin> is there a still image av1 thingy yet, like webp and bpg?
[20:55:36 CET] <nevcairiel> AVIF
[20:55:54 CET] <durandal_1707> why not AV1F?
[20:55:58 CET] <tytyt> `if you mean converting a png into an AV1 still frame, then as i said, you can do that too` how?
[20:56:22 CET] <tytyt> Everything I've looked at won't allow me to encode a png. 
[20:56:25 CET] <tytyt> Just raw video. 
[20:56:32 CET] <thardin> what durandal_1707 said
[20:56:36 CET] <thardin> also cool
[20:56:41 CET] <thardin> av1p maybe
[20:57:07 CET] <durandal_1707> ffmpeg -i input.png -c:v libaom out.ivf
[20:57:49 CET] <tytyt> The only way I was able to export was like this: `ffmpeg -i test.png -c:v libaom-av1 -crf 0 -b:v 0 -strict experimental test2.png`
[20:57:59 CET] <tytyt> Are you sure that is encoding?
[20:58:11 CET] <thardin> wut, you can put it in a .png?
[20:58:17 CET] <nevcairiel> no, you cant put any codec in a png
[20:58:23 CET] <tytyt> _yeah I was just doing tests_
[20:58:24 CET] <durandal_1707> why you use png extension?
[20:58:30 CET] <tytyt> Just a test, 
[20:58:39 CET] <tytyt> I have since switched it. 
[20:58:57 CET] <tytyt> But talking to the guys in #aomedia I still don't think it offers encoding from a png. 
[20:58:59 CET] <tytyt> Are you sure? 
[20:59:17 CET] <thardin> why would that matter in this context?
[20:59:38 CET] <durandal_1707> aomedia probably accepts raw when writes avif
[20:59:57 CET] <tytyt> They are AOMedia doesn't support avif. 
[21:00:03 CET] <tytyt> *saying
[21:00:11 CET] <tytyt> And everything I have tried supports that. 
[21:00:19 CET] <tytyt> So I don't see how ff does either. 
[21:00:23 CET] <gnafu> Not so much "doesn't support" as it's not finalized.  Nothing to support yet, basically ;-).
[21:00:47 CET] <tytyt> lol
[21:00:50 CET] <tytyt> Fair
[21:01:32 CET] <durandal_1707> ffmpeg -i test.png -c:v libaom-av1 test2.ivf ?
[21:02:39 CET] <tytyt> ffmpeg -i test.png -c:v libaom-av1 -crf 43 -b:v 0 -cpu-used 4 -strict experimental test.mp4
[21:03:43 CET] <thardin> uhm, mp4 is like very strict with codecs
[21:06:00 CET] <jamrial> thardin: it supports av1
[21:06:19 CET] <thardin> really? huh
[21:06:39 CET] <jamrial> it's the container youtube uses to serve av1 even
[22:13:30 CET] <tytyt> Is there a flag for threads used on encoding? 
[22:17:07 CET] <Easyfab> tytyt: did you know about av1 in HEIF ? see here https://github.com/strukturag/libheif/tree/avif ? maybe as gnafu said, you need to wait final AVIF spec
[22:17:36 CET] <tytyt> No I didn't thanks so much! 
[22:18:11 CET] <gnafu> tytyt: You can use '-tile-columns [some number]' and '-threads [max number of threads]'.
[22:18:48 CET] <gnafu> tytyt: For example, '-tile-columns 4 -threads 16' would be a max of 16 tile columns and 16 threads.
[22:18:57 CET] <gnafu> Easyfab: Ooh, interesting.
[22:19:38 CET] <tytyt> Yeah doesn't really speed up the encode, 
[22:19:55 CET] <tytyt> I thought it was -threads but it doens't have it in the -help. 
[22:20:00 CET] <tytyt> Thanks! 
[22:31:25 CET] <gnafu> For one image I tried, using '-tile-columns 4 -threads 16' ended up being ~2x as fast (but still very slow).  That's on a 4-core little Pentium, though.
[22:31:58 CET] <gnafu> Probably better to just do a lot of single-threaded parallel encodes.
[00:00:00 CET] --- Sat Dec  1 2018