On Thu, Jul 7, 2016 at 12:02 PM, Ronald S. Bultje <rsbul...@gmail.com> wrote: > Hi Vignesh, > > On Thu, Jul 7, 2016 at 2:44 PM, Vignesh Venkatasubramanian < > vigneshv-at-google....@ffmpeg.org> wrote: > >> On Wed, Jul 6, 2016 at 4:50 PM, Vignesh Venkatasubramanian >> <vigne...@google.com> wrote: >> > On Fri, Jul 1, 2016 at 3:03 PM, Ronald S. Bultje <rsbul...@gmail.com> >> wrote: >> >> Hi, >> >> >> >> On Fri, Jul 1, 2016 at 5:27 PM, Vignesh Venkatasubramanian < >> >> vigneshv-at-google....@ffmpeg.org> wrote: >> >> >> >>> On Fri, Jul 1, 2016 at 12:48 PM, Ronald S. Bultje <rsbul...@gmail.com> >> >>> wrote: >> >>> > Hi, >> >>> > >> >>> > On Fri, Jul 1, 2016 at 3:29 PM, Ronald S. Bultje <rsbul...@gmail.com >> > >> >>> wrote: >> >>> > >> >>> >> Hi, >> >>> >> >> >>> >> On Fri, Jul 1, 2016 at 3:12 PM, Vignesh Venkatasubramanian < >> >>> >> vigneshv-at-google....@ffmpeg.org> wrote: >> >>> >> >> >>> >>> On Fri, Jul 1, 2016 at 11:06 AM, James Almer <jamr...@gmail.com> >> >>> wrote: >> >>> >>> > On 7/1/2016 2:53 PM, Ronald S. Bultje wrote: >> >>> >>> >> Hi, >> >>> >>> >> >> >>> >>> >> On Fri, Jul 1, 2016 at 1:40 PM, James Zern < >> >>> >>> jzern-at-google....@ffmpeg.org> >> >>> >>> >> wrote: >> >>> >>> >> >> >>> >>> >>> On Fri, Jul 1, 2016 at 10:07 AM, Carl Eugen Hoyos < >> >>> ceho...@ag.or.at> >> >>> >>> >>> wrote: >> >>> >>> >>>>> Do we have decoder support (for either vp8 or vp9) for these >> >>> files? >> >>> >>> >>>> >> >>> >>> >>>> No, only encoding and muxing. >> >>> >>> >>> >> >>> >>> >>> Seems like a feature request, but no reason to block this one >> if >> >>> the >> >>> >>> >>> vp8 one is here. >> >>> >>> >> >> >>> >>> >> >> >>> >>> >> I'm not sure I have an opinion on this... But it feels strange >> to >> >>> allow >> >>> >>> >> encoding of content we cannot decode. Being ffmpeg, how do we >> >>> recommend >> >>> >>> >> people handle the files created with this feature, if not by >> using >> >>> >>> ffmpeg >> >>> >>> >> itself? >> >>> >>> >> >>> >>> One plausible reason is that Chrome can decode this. So it will be >> >>> >>> useful for people who already have ffmpeg in their pipelines and >> want >> >>> >>> to create such files. And like James Almer mentioned, this isn't a >> >>> >>> first. VP8 Alpha has been this way too. >> >>> >> >> >>> >> >> >>> >> The fact that something is the way it is, does not prove that it is >> >>> >> therefore right, or that we should therefore continue doing it that >> way >> >>> in >> >>> >> other cases. >> >>> >> >> >>> >> So you're suggesting that it is perfectly fine for people to use >> Chrome >> >>> as >> >>> >> decoder if FFmpeg is the encoder. What if people don't have Chrome >> >>> >> installed? Or what if they want a way of UI-less batch-processing >> such >> >>> >> files, e.g. what if a service like Youtube/Vimeo wants to allow >> upload >> >>> of >> >>> >> vp8a/vp9a files without invoking Chrome for decoding? >> >>> >> >> >>> > >> >>> > Additional evidence in [1], [2]. >> >>> > >> >>> > There absolutely seems to be interest in support for vp8a/vp9a >> decoding >> >>> > outside Chrome. I'm not saying you should implement it in all >> multimedia >> >>> > frameworks ever created in human history, but doing it in one of them >> >>> (e.g. >> >>> > ffmpeg, since it already supports encoding) certainly sounds helpful? >> >>> > >> >>> >> >>> I'm not saying alpha decoder shouldn't ever be implemented in ffmpeg. >> >>> I'm just saying that it shouldn't be a reason to block this patch. :) >> >>> Sorry if i wasn't clear before. >> >> >> >> >> >> I totally understand that you would think that, since it means you don't >> >> have to do anything :). >> >> >> >> But there's an issue with this thinking. We're essentially already the >> >> dumping ground for anything multimedia-related nowadays. After all, we >> >> maintain it and keep it working (assuming basic tests), things couldn't >> get >> >> much easier than that, right? But is it actually useful to anyone? I >> mean >> >> not just useful for you, but useful to a wider set of people, at least >> in >> >> theory. >> >> >> >> If there's no decoder, I would claim that the wider utility of this >> thing >> >> is essentially zero. And that's somewhat of a concern. >> >> >> >> So, how do we get a decoder? vp8a suggests that just waiting for one to >> >> spontaneously combust out of thin air just doesn't work. So I'm >> suggesting >> >> you provide us with one. It's ok if it uses libvpx instead of ffvp8/9. >> >> Since vp8a encoding is already in, I won't ask for a vp8a decoder >> either. >> >> I'm just asking for a vp9a decoder. It might even be OK if it's >> implemented >> >> on top of ffmpeg instead of inside libavcodec (I'm not sure how others >> feel >> >> about this), i.e. just something that invokes libavformat to parse a >> webm >> >> file, create two decoders to get the yuv and a planes, and then merge >> them >> >> together into a yuva420p picture. I'm just asking for something _small_ >> and >> >> _simple_ (i.e. not "Chrome") that we can point users to when they ask >> "how >> >> do I decode vp9a files". >> >> >> >> I asked on IRC (#ffmpeg-devel) and several people concurred: >> >> >> >> <BBB> jamrial: so … I’m looking for a second opinion here, like, an >> >> independent one… am I being too hard on these guys for saying “an >> encoder >> >> needs a decoder”? >> >> <JEEB> BBB: I do tend to agree that in general it goes dec->enc, or >> both at >> >> the same time. be it a fully lavc decoder or just utilizing a decoder >> >> library >> >> <jamrial> BBB: no, you're not being hard >> >> >> >> So it seems I'm not entirely alone in this opinion within the ffmpeg >> >> developer community. >> >> >> > >> > Alright, i have a working patch for the decoder locally (i will push >> > that to the ML shortly). >> >> Here it is: http://ffmpeg.org/pipermail/ffmpeg-devel/2016-July/196403.html > > > Thanks, that resolves my concerns. >
Can you please commit this patch? Thanks! > Ronald > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel -- Vignesh _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
