[Ffmpeg-devel-irc] ffmpeg-devel.log.20190327

[burek]

[01:17:31 CET] <cone-099> ffmpeg 03Decai Lin 07master:ec1e4a8baf1b: lavc/h264_levels: add MaxMBPS checking and update fate test.
[03:33:42 CET] <Cldfire> Hello all o/ I'm a student interested in the opencl video filter GSoC project and I am stopping by to ask if anyone has any recommendations for which existing CPU filter to implement in opencl (or, as the qualification task description states, any other filter) beyond simply looking through the existing CPU filters and picking one that looks reason
[03:33:42 CET] <Cldfire> ably straightforward
[03:34:21 CET] <Cldfire> I also want to make sure I'm not stepping on anyone else's toes and starting on something that's already being worked on by another applicant
[03:34:51 CET] <Cldfire> jkqxz, ping in regard to the above since you are listed as the mentor :)
[07:57:46 CET] <cone-862> ffmpeg 03Lauri Kasanen 07master:81a4719d8eaf: swscale: Remove duplicated code
[08:02:27 CET] <cone-862> ffmpeg 03Lauri Kasanen 07master:681957b88d18: swscale/ppc: VSX-optimize yuv2rgb_full
[08:45:19 CET] <cone-862> ffmpeg 03Michael Niedermayer 07master:54655623a826: avcodec/hevcdec: Avoid only partly skiping duplicate first slices
[10:37:20 CET] <thardin> this m264 guy is relentless
[10:52:52 CET] <kurosu> His bonus depends on it
[11:05:06 CET] <thardin> ooh already someone interested in AVIF
[11:06:06 CET] <JEEB> I think it's a similar mess to HEIF
[11:06:17 CET] <nevcairiel> it is HEIF
[11:06:19 CET] <JEEB> basically HEIF with the codec as AV1
[11:06:23 CET] <JEEB> yup
[11:07:06 CET] <nevcairiel> at least they didnt make a new spec entirely, but that doesnt solve the mess that is HEIF regardless
[11:07:38 CET] <JEEB> true
[11:08:47 CET] <thardin> sounds like I'm unwittingly getting myself into a bit of a mess
[11:09:54 CET] <nevcairiel> the format is just absolutely overengineered, typical example of design by comitee
[11:10:07 CET] <nevcairiel> committee*
[11:10:10 CET] <thardin> so HEIF is just another word for stuffing an H.265 I-frame in a MOV
[11:10:46 CET] <nevcairiel> if it was only so simple
[11:12:09 CET] <thardin> either way, the AVIF task is a superset of the HEIF task
[11:14:34 CET] <thardin> "Storage of still images as well as collection of images in a single container file, Storage of burst photos, Storage and efficient representation of video animations and cinemagraphs. Support for simultaneous capture of video and still images, i.e. storing still images and timed image sequences into the same file."
[11:14:39 CET] <thardin> fun
[11:15:39 CET] <nevcairiel> they also have a container-level tiling scheme, which for our component seperation is really no fun
[11:18:02 CET] <thardin> madness
[11:18:19 CET] <thardin> that kind of stuff can be done by svg
[11:39:27 CET] <thardin> so I have to guy buy an empty sim card just to register a throwaway google account. unbelievable
[11:57:08 CET] <JEEB> thardin: yea they really want your # these days >_>
[13:02:58 CET] <thardin> jokes on them, I have everything segregated into a bajillion accounts
[13:03:55 CET] <JEEB> if you use firefox you can also utilize tab containers
[13:04:04 CET] <JEEB> to limit specific sites into specific groups of tabs
[13:04:08 CET] <JEEB> which then have their own storage etc
[13:04:26 CET] <thardin> I use umatrix
[13:04:30 CET] <JEEB> :)
[13:04:41 CET] <thardin> so by default it never pulls in anything except 1st party media and css
[13:04:53 CET] <JEEB> yea, they started adding settings for that in firefox as well
[13:05:01 CET] <JEEB> content blocking, cookie etc blocking
[13:05:04 CET] <thardin> and with certain garbage sites like twitter, not even the css
[13:05:13 CET] <thardin> yeah firefox has been a lot better lately
[13:05:18 CET] <thardin> still doing some nonsense like the pocket thing
[13:05:25 CET] <thardin> and cloudflare mitm dns
[13:05:29 CET] <JEEB> I wish they'd actually advertise stuff like tab containers
[13:05:31 CET] <thardin> and drm
[13:05:36 CET] <JEEB> because that's actually a nice feature
[13:05:46 CET] <JEEB> right now it's disabled by default unless you install an add-on that requires it
[13:05:49 CET] <JEEB> :<
[13:06:08 CET] <JEEB> (and then there's add-ons that limit f.ex. facebook and google etc into their little containers)
[13:06:18 CET] <JEEB> the generic idea works without specific add-ons though
[13:06:23 CET] <JEEB> just that the feature needs to be enabled
[13:12:12 CET] <thardin> another roundabout way of doing it is having multiple users on the same machine
[13:12:18 CET] <thardin> or VMs
[13:50:25 CET] <thealakazam> Hello, I've been trying to work on the GSOC topic on getting HEIF support for ffmpeg, it mentions making a trivial muxer, what's that about
[13:55:28 CET] <thardin> thealakazam: muxer is short for multiplexer
[13:55:50 CET] <thardin> in other words the libavformat part of the output (not the codec stuff)
[13:57:04 CET] <thardin> carl should be in here
[14:00:11 CET] <thealakazam> Oh, thanks i got confused whether it should go in the codec part or format part, so it should enable me to write to a heif file, i guess
[14:00:58 CET] <thardin> are you the guy who emailed me about avif?
[14:03:10 CET] <thealakazam> no
[14:05:42 CET] <thardin> k. the formats are related
[14:06:45 CET] <thealakazam> can you clear what the trivial part means
[14:16:16 CET] <thardin> thealakazam: probably only writing an HEIF file that is a regular old static image
[14:17:11 CET] <thardin> instead of those other things HEIF can do, like multiple images, tiling, burst photos, combining video and stills etc.
[14:17:36 CET] <thardin> a demuxer would potentially have to deal with all that
[14:18:08 CET] <thealakazam> ok thanks for clarifying
[14:54:52 CET] <cone-749> ffmpeg 03Carl Eugen Hoyos 07master:6bc800dead1e: lavf/latmenc: Return the correct error for wrong codec.
[14:57:15 CET] <nevcairiel> writing files has the advantage that you get to pick which features you want to s upport
[14:57:23 CET] <nevcairiel> which can be as simple as one can make it
[14:57:42 CET] <nevcairiel> reading on the other hand has to support all features, so that files made with other tools actually work
[14:59:34 CET] <thardin> yeah
[16:30:50 CET] <nevcairiel> anyone feel like SIMDing sws yuv2nv12cX_c? my head hurts trying to think about it, it should be similar to yuv2planeX_8_c which has SIMD already
[17:41:29 CET] <BtbN> Did apple seriously just remove mjpeg support from their OS?
[17:41:41 CET] <BtbN> Os is "Motion JPEG A und B" something else?
[18:39:51 CET] <cone-749> ffmpeg 03Michael Niedermayer 07release/4.0:d34202f4f036: avcodec/truemotion2: Fix integer overflow in tm2_null_res_block()
[18:39:52 CET] <cone-749> ffmpeg 03Michael Niedermayer 07release/4.0:530286c96bd8: avformat/mov: Fix potential integer overflow in entry check in mov_read_trun()
[18:39:53 CET] <cone-749> ffmpeg 03Michael Niedermayer 07release/4.0:1d44fab8c3c4: avcodec/mpegpicture: Check size of edge_emu_buffer
[18:39:54 CET] <cone-749> ffmpeg 03Carl Eugen Hoyos 07release/4.0:c877b329054d: lavc/bmp: Avoid a heap buffer overwrite for 1bpp input.
[18:39:55 CET] <cone-749> ffmpeg 03Michael Niedermayer 07release/4.0:494ce3da24b6: avcodec/hevcdec: Avoid only partly skiping duplicate first slices
[18:39:56 CET] <cone-749> ffmpeg 03Michael Niedermayer 07release/4.0:ee66e04bc9db: Changelog: update
[18:41:28 CET] <BradleyS> BtbN: sure did
[18:41:38 CET] <BradleyS> all the more reason for oss
[19:23:39 CET] <lrusak_> jkqxz: excuse my lack of knowledge about this. but is it possible to implement a decoder that uses the hwaccel interface but requires full frames rather than slices?
[19:24:27 CET] <lrusak_> if not, is it possible to rebuild the full frame from the slices so it can be passed to the hw decoder?
[19:25:15 CET] <nevcairiel> the start_frame callback gets passed the entire frame buffer
[19:25:45 CET] <nevcairiel> but such a decoder still needs to act like any of the o ther slice decoders - that is, only decode the image, not doing any re-ordering or any of that stuff
[19:31:05 CET] <lrusak_> nevcairiel: so can i just implement start_frame and end_frame and ignore decode_params and decode_slice?
[20:47:05 CET] <philipl> lrusak_: you need to implement a stub decode_slice. You can see this being done in many of the existing hwaccels.
[20:54:07 CET] <lrusak_> philipl: thanks, I'll have a look, can you think of any specific examples?
[20:58:07 CET] <lrusak_> ah, maybe something like ff_nvdec_simple_decode_slice ??
[22:51:46 CET] <nevcairiel> BtbN: do you have any insight into how well spatial-aq/temporal-aq work in nvenc, quality wise?
[22:52:19 CET] <BtbN> better with every generation, supposedly really good starting with Turing
[22:52:38 CET] <BtbN> Like, a bunch of people claim it's better than x264 now, but I have high doubts about that.
[22:52:45 CET] <BtbN> though that's about general quality
[22:53:21 CET] <nevcairiel> beating x264 at a preset with similar speed on an average cpu is probably fine
[22:53:34 CET] <nevcairiel> but of course x264 can go slower, nvenc cant
[22:54:06 CET] <BtbN> For streaming, nvenc on Turing is really good it seems
[22:54:24 CET] <nevcairiel> i got me a 1660 now to put into my streaming server
[22:54:28 CET] <BtbN> though all the "Look how good nvenc looks" streams I have seen so far were obviously horrible.
[22:55:25 CET] <nevcairiel> just trying to fine tune nvenc settings, that is (a) for my card specifically, but also (b) for the general public
[22:55:51 CET] <nevcairiel> might need a few checkboxes maybe
[22:57:12 CET] <nevcairiel> (also, the code boilerplate just to get a nvenc session to probe capabilities is really quite a lot, so instead i hacked the local copy of ffmpeg to make it just disable unsupported features instead of error out)
[23:32:27 CET] <cone-552> ffmpeg 03Mark Thompson 07master:d0b174d7df88: configure: Do not enable both OpenCL-VAAPI interop modes simultaneously
[23:56:25 CET] <jamrial> jkqxz: take a look at my cbs patches when you can
[00:00:00 CET] --- Thu Mar 28 2019