[Ffmpeg-devel-irc] ffmpeg-devel.log.20190212

[burek]

[02:14:56 CET] <cone-621> ffmpeg 03Jun Zhao 07master:6382d0334775: avfilter/tests/integral: Check malloc fail before using it
[02:14:56 CET] <cone-621> ffmpeg 03Jun Zhao 07master:9f33b0ed392f: avfilter/tests/integral: Fix build warning after adjust the location
[09:52:32 CET] <feliwir> Does ffmpeg have any builtin vpx encoder at all?
[09:52:49 CET] <feliwir> Which i could use to start from with vp6
[09:53:42 CET] <JEEB> I don't think, it started with VP8/9 and those are through libvpx
[09:54:10 CET] <JEEB> there used to be a separate project called xvp8, but that never got too far (and since it based on x264 it was GPL)
[10:13:54 CET] <feliwir> Hm, would it make sense to start on the more simple vpx codecs? E.g. vp3 etc.
[10:14:12 CET] <feliwir> Eventhough there probably is probably no userbase for those anymore
[10:15:55 CET] <durandal_1707> feliwir: why you need this?
[10:21:30 CET] <JEEB> durandal_1707: he wants something old game engines can play? for localization etc
[10:22:19 CET] <durandal_1707> ah, that would be non trivial :-)
[10:22:27 CET] <feliwir> durandal_1707, to encode VP6 videos for old EA game engines :) (there are actually more people than me who want that)
[10:23:15 CET] <feliwir> I contributed a bit to the vp6 decoder a couple years ago, but i guess encoding is a complete different story
[10:24:23 CET] <feliwir> But i wonder why Google never release the vp6 encoder after acquiring On2 anyways
[10:24:30 CET] <feliwir> *released
[10:28:43 CET] <JEEB> > verifying if your A/V sync is still OK after PCR+timestamps fall backwards in a broadcast stream
[10:28:46 CET] <JEEB> oh the fun
[11:00:56 CET] <atomnuker> feliwir: licenses probably
[11:02:03 CET] <feliwir> atomnuker, who is holding licenses except for Google?
[11:04:05 CET] <JEEB> I would just guess lack of care of touching those old versions of their code
[11:04:28 CET] <feliwir> well, they wouldn't need to touch it to publish it :)
[11:04:54 CET] <JEEB> even finding it is to touch it
[11:05:00 CET] <JEEB> and/or clean it up from any random crap in there
[11:05:10 CET] <JEEB> basically, to get it through legal
[11:05:31 CET] <feliwir> Hm, i don't know anyone at Google who could do that :(
[11:06:17 CET] <feliwir> Aren't some people in here employed by Google for working at libvpx?
[11:09:23 CET] <JEEB> yes, but you know - they work with *current* libvpx
[11:09:44 CET] <JEEB> I think the most we got out of that stuff (and I'm not 100% sure if it's official or not) was the VP7 spec?
[11:11:02 CET] <feliwir> Well, but i'd be suprised if Google just ditched the old On2 tools / source repositories. Not sure how the policy is there at Google, but i don't see why they wouldn't give it out
[11:15:07 CET] <JEEB> I'm probably explaining it badly :P it was never anyone's job to even take a look at the old On2 stuff. and to release something that hasn't been OK'd for release is probably a PITA anyways
[11:15:13 CET] <JEEB> welcome to enterprises
[11:16:55 CET] <feliwir> Hm, sounds stupid :) However vp3 was opensourced by On2, but still i can't seem to find any opensource encoder. I just know that Theora derived from it
[11:17:36 CET] <durandal_1707> ask google
[11:18:04 CET] <feliwir> I did ask it already
[11:18:07 CET] <j-b> Why would anyone want to produce vp6 or vp3 content?
[11:19:11 CET] <feliwir> Well, i don't know about vp3, but we need vp6 for https://github.com/OpenSAGE/OpenSAGE
[11:19:32 CET] <feliwir> Basically to create videos for old EA games, which used vp6 :)
[11:20:22 CET] <thardin> vp6 used some horrible combination of mplayer talking to the codec via RPC
[11:20:26 CET] <thardin> for encoding
[11:20:51 CET] <thardin> or perhaps it was mencoder. either way, horrifying
[11:21:55 CET] <thardin> as always, kostya is the guy to talk to about duck things
[11:24:56 CET] <feliwir> who is kostya ?
[11:25:21 CET] <durandal_1707> black magic wizard
[11:25:37 CET] <feliwir> And where can i find that wizard? :D
[11:26:26 CET] <durandal_1707> codecs.multimedia.cx
[11:29:22 CET] <jdarnley> > opensage
[11:29:41 CET] <jdarnley> If thats a remiplementation of an engine then why cant you include a better video decoder?
[11:29:49 CET] <atomnuker> ^^
[11:31:37 CET] <thardin> yeah that's what I thought too
[11:31:39 CET] <thardin> just link libvpx
[11:32:31 CET] <JEEB> you just need to somehow figure out when you need to load stuff for the original assets, and when the asset's a VP8/9 file
[11:32:54 CET] <JEEB> and yes, that would make things much simpler unless you want to make the new files load up in the actual original game
[11:32:56 CET] <thardin> if only there were some kind of set of multimedia libraries that do just that
[11:33:55 CET] <durandal_1707> comercial - bink
[11:36:36 CET] <JEEB> I still need to figure out bink2 for my chinese cartoon openings of games
[11:37:13 CET] <feliwir> @jdarnley, we use the original assets to avoid any copyright issues. We don't ship them we expect the user to have them
[11:37:45 CET] <thardin> feliwir: but then you only need a decoder
[11:38:16 CET] <feliwir> but then we'd not be compatible to the original game anymore ;)
[11:38:55 CET] <thardin> sure if you want to go the chocolate doom kind of path
[11:38:55 CET] <feliwir> We'll probably allow better codecs aswell, since we link ffmpeg anyways
[11:39:31 CET] <thardin> but you probably want to encourage people to use your libre implementation anyway
[11:39:55 CET] <feliwir> hm, it's doom indeed. But i thought since I am interested in multimedia anyways i might give it a shot
[11:40:20 CET] <thardin> you could try to write an encoder as a summer project
[11:40:38 CET] <feliwir> GSoC? Well, i'm not a student anymore 
[11:40:42 CET] <thardin> my cinepak encoder ended up being commited after all, after some improvements
[11:41:01 CET] <feliwir> Can i also participate as a normal developer?
[11:41:21 CET] <thardin> I hadn't thought of gsoc even
[11:41:28 CET] <durandal_1707> be mentor
[11:41:32 CET] <feliwir> Ah, why a summer project then? :D
[11:41:38 CET] <thardin> because summer = free time
[11:41:48 CET] <feliwir> meh, unfortunaly not true :(
[11:42:13 CET] <feliwir> durandal_1707, i don't think i could mentor anyone in ffmpeg :D
[13:06:31 CET] <JEEB> with US captions, was there any spot where they put language IDs?
[13:06:40 CET] <JEEB> since I remember there's 4 or so (?) slots
[13:39:16 CET] Action: JEEB double-blinks at mpegts_get_pcr
[13:39:26 CET] <JEEB> git grep only mentions it once and it's marked with av_unused
[13:39:35 CET] <JEEB> which silences the warning...
[15:29:57 CET] <cone-760> ffmpeg 03Jun Zhao 07master:84e7aff60816: tests/api/api-h264-test: Add AV_NOPTS_VALUE check for AVFrame.pkt_dts/pts
[15:31:09 CET] <JEEB> trying to verify discontinuity handling... not fun
[15:31:19 CET] Action: JEEB stabs streams that go backwards in time
[15:37:42 CET] <atomnuker> how dare they violate the second law of thermodynamics
[19:33:51 CET] Action: JEEB runs a static analysis pass on his thingamajig just in case
[20:04:03 CET] <cone-530> ffmpeg 03Jan Ekström 07master:4beccf400df3: lavc/libaribb24: add error handling to region handling
[20:04:04 CET] <cone-530> ffmpeg 03Jan Ekström 07master:03824afdb4a5: lavc/libaribb24: protect handled value with parenthesis in RGB_TO_BGR
[20:04:05 CET] <cone-530> ffmpeg 03Jan Ekström 07master:1ed9e8e9377d: lavc/libaribb24: add missing type struct members to AVOptions
[20:04:06 CET] <cone-530> ffmpeg 03Jan Ekström 07master:466cb4ed56a1: lavc/libaribb24: use integer math to calculate font scaling
[20:29:04 CET] <feliwir_> When adding the vp3 encoder i should probably split from vp3.c into vp3_dec.c and vp3_enc.c?
[20:29:17 CET] <feliwir_> or what are the preferences there?
[20:30:01 CET] <atomnuker> just make a vp3.h or vp3_utils.h and throw shared code in there
[20:30:29 CET] <JEEB> feliwir_: yea generally if we have a decoder and encoder they're _{enc,dec}
[20:31:12 CET] <JEEB> feliwir_: f.ex. http://git.videolan.org/?p=ffmpeg.git;a=commit;h=77f47e328800f5d7e7d1d3259a29c2eecc96daee
[20:48:21 CET] <feliwir_> I just realized that libtheora has a vp3 compability mode
[20:48:45 CET] <feliwir_> why was that never used to create vp3 encoder in ffmpeg (since we use libtheora anyways)?
[20:50:11 CET] <feliwir_> I guess noone bothered :D
[20:54:09 CET] <JEEB> most likely
[21:10:16 CET] <jamrial> theora had its use in ogg videos some 15 years ago. vp3 didn't
[21:10:38 CET] <jamrial> so probably that's why nobody bothered with an encoder for it
[21:10:56 CET] <atomnuker> fun fact: vp8 usually compresses worse than theora
[21:12:34 CET] <jamrial> vp8, or libvpx?
[21:13:50 CET] <atomnuker> libvpx, but vp8 in general
[21:14:08 CET] <feliwir_> hm, since the theora decoder was hacked into vp3.c a native theora encoder would maybe make sense aswell. But maybe someone else can do that
[21:14:25 CET] <kurosu_> what other encoder for vp8 than libvpx ? And I expect vs a heavily tuned theora encoder (Thusnelda?)
[21:14:52 CET] <kurosu_> (but then on2 could have better tuned their encoder, too)
[21:15:05 CET] <atomnuker> vp8 only had 4x4 blocks and I don't think it had segmentation, while theora had 8x8 and could change quantization on a per-block basis
[21:16:31 CET] <atomnuker> even if vp8 could change per-block quantizer its still 4x4 only so the overhead would be 4x more than 8x8
[21:16:56 CET] <kurosu_> I had to look, indeed 4x4 only
[21:17:44 CET] <kurosu_> Time to release a codec with 4CC VP8F!
[21:18:19 CET] <durandal_1707> xvc
[21:19:31 CET] <kurosu_> is that an equation where we need to solve for x ?
[21:19:43 CET] <durandal_1707> no
[21:19:53 CET] <durandal_1707> codec name
[21:44:35 CET] <feliwir_> Is there a documentation of types & functions that `should/can` be reused between codecs? 
[22:53:32 CET] <cone-530> ffmpeg 03Moritz Barsnick 07master:a84af760b809: configure: fix dependencies for mlp and truehd encoders
[00:00:00 CET] --- Wed Feb 13 2019