Re: [Libav-user] Getting to grips with ffmpeg
On 6 February 2012 09:32, Nicolas George nicolas.geo...@normalesup.org wrote: L'octidi 18 pluviôse, an CCXX, John Dexter a écrit : If you're going to make such assertions please back them up. My research into dynamic linking of (L)GPL libraries finds multiple explicit claims that distribution of the library source code is _not_ required if I haven't modified the original, according to LGPL section 6, specifically 6b. (http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html linked from ffmpeg legal page). As pointed out by someone else, 6b covers the case where you do not distribute the library at all, you distribute only the application, and rely on the user to provide a suitable version of the library, probably by already having it on their system. Theoretically, the (L)GPL requires you to distribute the source code, even if it was just compiled and not modified. A lot of projects will not take it amiss if you do not distribute unmodified sources, provided you meet the other requirements, especially the prominent notice. In other words, they are interested in your enhancements to the code, not in hogging your bandwidth. People in ffmpeg are more strict about the requirements because there have been problems in the past. Please also note that 6c is more risky than it appears, and more risky than 6a: with 6a, you only need to provide the source code to the people you distributed the product, that is just a few megabytes in one corner on your installation medium. With 6c, you must provide the source code to whoever asks, because the offer can be transmitted from one person to another, outside your control. Thanks Nicholas and Phil... obviously I have no problem providing source if asked to, and in putting the license in my redistributable. I read somewhere that including a link to where users could download the source themselves can be counted as distributing the source? I was very surprised by claims it's a requirement, simply because none of the LGPL libraries I've used have ever mentioned it in the case of dynamic linking. I found this discussion: http://teem.sourceforge.net/lgpl.html - search for the interesting part. Obviously only one person's view of it, but it seemed to make sense. Thanks again. John. ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
John Dexter jdxsolutions@... writes: obviously I have no problem providing source if asked to, You misunderstand: If you don't want to accompany your binary distribution with the corresponding source code, you have to add a legally binding written offer that you will provide the source code on request. This may have been useful at a time when there was no internet but expensive discs, to save you from that burden nowadays, we recommend you to ... and in putting the license in my redistributable. I read somewhere that including a link to where users could download the source themselves can be counted as distributing the source? ... do exactly this as explained on http://ffmpeg.org/legal.html (because we think you can argue that the corresponding sources accompany the binary distribution both if you distribute them together in the same installation package and also if you provide the sources as a separate link next to the download link for your installer. If you don't trust me on this because you interpret accompany differently then you will have to add the source code to the installer, remember I am not a native speaker.) I was very surprised by claims it's a requirement, simply because none of the LGPL libraries I've used have ever mentioned it in the case of dynamic linking. Please read http://www.gnu.org/licenses/gpl-faq.html#UnchangedJustBinary and for the sake of our discussion assume that it was written by the very same person who wrote the license. Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
Carl Eugen Hoyos cehoyos@... writes: I read somewhere that including a link to where users could download the source themselves can be counted as distributing the source? ... do exactly this as explained on http://ffmpeg.org/legal.html (because we think you can argue that the corresponding sources accompany the binary distribution both if you distribute them together in the same installation package and also if you provide the sources as a separate link next to the download link for your installer. Or in other words: I assume that would count as offering equivalent access to the source code. Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
John Dexter jdxsolutions@... writes: 2. I had some concerns reading about the legal side, GPL and LGPL. Our software is totally closed source and while we use LGPL libraries, it sounded like some parts of ffmpeg are GPL-only. Will this realistically affect me It is your choice if you compile FFmpeg with support for GPL-parts (which makes the whole library GPL and forbids linking against your proprietary application) or without. So only you know if it affects you or not. (Or in other words: It will only affect you if you want H264 encoding but are not willing to buy a commercial x264 license.) Please consider reading the License Compliance Checklist on http://ffmpeg.org/legal.html and if you think anything is not clear on this page, please report! Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
On 5 February 2012 16:38, Carl Eugen Hoyos ceho...@ag.or.at wrote: John Dexter jdxsolutions@... writes: 2. I had some concerns reading about the legal side, GPL and LGPL. Our software is totally closed source and while we use LGPL libraries, it sounded like some parts of ffmpeg are GPL-only. Will this realistically affect me It is your choice if you compile FFmpeg with support for GPL-parts (which makes the whole library GPL and forbids linking against your proprietary application) or without. So only you know if it affects you or not. I was aware some parts are GPL only and you can compile without those parts... but the legal page doesn't say which, and whether they 'matter'. But you follow on with (Or in other words: It will only affect you if you want H264 encoding but are not willing to buy a commercial x264 license.) So is that the only major restriction? It sounds fairly major since I'm fairly sure our client demands H264 as the primary format. It's hardly part of ffmpeg I know, but any clarification what I can['t] do here would be awesome so I can clearly explain why (if) I can't provide what they consider the standard. Feel free to direct me elsewhere to discuss that topic. Please consider reading the License Compliance Checklist on http://ffmpeg.org/legal.html and if you think anything is not clear on this page, please report! Since you mention it, I would prefer a list of what I MUST do and a list of what you PREFER I do, in terms of open-source etiquette :) Thanks! ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
(Or in other words: It will only affect you if you want H264 encoding but are not willing to buy a commercial x264 license.) Sorry, I need to ask about that in more detail after more thought. There are 2 separate issues here it seems... 1. Whether I can use ffmpeg libraries to encode H264 without making my entire application GPL? 2. Whether I need to pay for a H264 license Is the situation I can use ffmpeg L-GPL if I pay for a H264 license, but without buying that license I can only use H264 for full GPL? Or am I totally misunderstanding the situation? John. ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
John Dexter jdxsolutions@... writes: Please consider reading the License Compliance Checklist on http://ffmpeg.org/legal.html and if you think anything is not clear on this page, please report! Since you mention it, I would prefer a list of what I MUST do and a list of what you PREFER I do, in terms of open-source etiquette :) (Not being a native speaker, I wonder if there is some insult hidden in this sentence...) The list contains all things you have to do afaict, and some things that really make a lot of sense if you trying to fulfil the requirements of the LGPL (as opposed to trying very hard not to fulfil its concept and getting away with it). Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
On 5 February 2012 18:42, Carl Eugen Hoyos ceho...@ag.or.at wrote: Carl Eugen Hoyos cehoyos@... writes: The list contains all things you have to do afaict, and some things that really make a lot of sense if you trying to fulfil the requirements of the LGPL (as opposed to trying very hard not to fulfil its concept and getting away with it). [About http://ffmpeg.org/legal.html ] I just saw that above is of course not true for point 2 (use dynamic linking) but since using static linking makes conforming to the LGPL more difficult I think it clearly counts as good advice. That page includes distribute the ffmpeg source code. IIRC that's *not* a requirement for LGPL? There is no hidden insult, I am simply remarking a legal page should clearly differentiate between what is a legal requirement from the license, and what is considered polite. If we start adding what we *want* to what is mandatory, we end up confusing people. ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
John Dexter jdxsolutions@... writes: [About http://ffmpeg.org/legal.html ] That page includes distribute the ffmpeg source code. IIRC that's not a requirement for LGPL? It is a crystal-clear requirement. Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
On 6 February 2012 03:03, Carl Eugen Hoyos ceho...@ag.or.at wrote: John Dexter jdxsolutions@... writes: [About http://ffmpeg.org/legal.html ] That page includes distribute the ffmpeg source code. IIRC that's not a requirement for LGPL? It is a crystal-clear requirement. If you're going to make such assertions please back them up. My research into dynamic linking of (L)GPL libraries finds multiple explicit claims that distribution of the library source code is _not_ required if I haven't modified the original, according to LGPL section 6, specifically 6b. (http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html linked from ffmpeg legal page). John. ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
[Libav-user] Getting to grips with ffmpeg
Hello all, I develop software (C++ using wxWidgets for Mac and Windows) which does 3D rendering (using Ogre3D) and we want to allow users to record a video as they work. ffmpeg was recommended in a couple of places but to be honest, it looks quite big and scary so before committing to using it, I have two starter questions I hope you can help me with... 1. How hard is it to learn to use the library to programatically create videos where each frame is basically just a 2D texture? Do I have to learn a lot about the library or can I just use it with a handful of API calls? I know it's a subjective question, but when you were noobs how easy was it to get started? 2. I had some concerns reading about the legal side, GPL and LGPL. Our software is totally closed source and while we use LGPL libraries, it sounded like some parts of ffmpeg are GPL-only. Will this realistically affect me 3. codecs. As a user of various video-conversion tools, I have always found them confusing and awkward. How does ffmpeg handle them - will my users have to install codecs (or rely on my app doing so for them through an installer script), or do you take the approach of bundling codecs so my users can just unzip my app onto their PC and it works? That's it for now. I'll try to come up with tougher questions next time. Thanks, John. ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Getting to grips with ffmpeg
2012/2/4 John Dexter jdxsoluti...@gmail.com: Hello all, I develop software (C++ using wxWidgets for Mac and Windows) which does 3D rendering (using Ogre3D) and we want to allow users to record a video as they work. ffmpeg was recommended in a couple of places but to be honest, it looks quite big and scary so before committing to using it, I have two starter questions I hope you can help me with... I also was scary about it when started (a year ago). But now i can say that i didn't find any (opensource or proprietary) libraries that are so mature and widely functional as ffmpeg libs. This project looks #1 in automated audio\video processing for me :) 1. How hard is it to learn to use the library to programatically create videos where each frame is basically just a 2D texture? Do I have to learn a lot about the library or can I just use it with a handful of API calls? I know it's a subjective question, but when you were noobs how easy was it to get started? It's hard if you don't know anything about structure of media files. It's easy just to use it when you have learned that. There're some code examples - in sources tree, and elsewhere. Documentation is mostly inside includable headers. 2. I had some concerns reading about the legal side, GPL and LGPL. Our software is totally closed source and while we use LGPL libraries, it sounded like some parts of ffmpeg are GPL-only. Will this realistically affect me I'm not keen on that, so i skip this question. Sorry. 3. codecs. As a user of various video-conversion tools, I have always found them confusing and awkward. How does ffmpeg handle them - will my users have to install codecs (or rely on my app doing so for them through an installer script), or do you take the approach of bundling codecs so my users can just unzip my app onto their PC and it works? You have to compile ffmpeg libs by yourself, all codecs are be compiled into it. Then just distribute libs with your application. Or link it statically into your app. (Of course, if you're allowed to do it all, with respect to license terms.) On linux it is possible also to rely on libs installed by distro's packaging system. -- Andrey Utkin ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
