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Re: Video editing software bounty?

Subject: Re: Video editing software bounty?
by diegocr on 2012/1/8 19:32:54

I will try to answer some questions. Diego will surely do that better that me later.

Well, i think we can add some background about the project and the unpaved road we were following.

Things started on March 2011, when mrod contacted me about the possibility of updating avcodec, and everyone who knows mrod is aware of how insistent he is ;) I agreed to take a look at it, and started trying to get the thing updated to latest lavc core, it started as something fun to do - after all my previous experience with amigift helped a lot, where i had to port a dozen of Linux's *.so as native amigaos libs/plugins - then the fun part temporarily became a tedious thing... while some codecs worked fine with minimum effort, most didn't worked at all or produced weird results, the incompatibility manifest took place... we found that dvp was using some hardcoded enums for codec definition and pixel format which broke our expectatives of a nice port (that was our thought at the time, things became worse later..) So... after implementing some "crazy stuff" to get 2008's definitions and forward to 2011's ones we got back on the right road... not for so long, since apart from the fact the ffmpeg team removed from their API the decode audio/video functions the original avcodec.library was using, we found the decoding of audio implemented on a hopefully backward-compatible way wasn't working properly... that was mostly noticeable with AC3 and some MPEGs, a kick on the balls literally since these are the most common formats as used eg on DVDs.

At this step, around two months later since we've started working on it (several hours per day, if you ask me) we got stuck... mainly due the development road we were following, since i lacked an os4 machine at the time i was cross-compiling the lib from Linux (OpenSUSE + KDevelop, i love them ;) and sending it back to mrod/elwood for the tests, which became quite frustrating to track down that audio decoding issue (changing a few lines of code and sending the lib to test, and so on and so on) Fortunately, a couple of months ago i've got an os4 machine from the loaner program, and i want to take this opportunity to thanks Troels and everyone else involved for providing my first ever os4 hardware :)

So... with a Sam at my hands things restarted well, the audio issue got properly fixed and hundred of tests made to try to achieve faster video decoding as well, with something we got nuts was with our tests with AVI (MPEG-4) and VOB/DVDs (MPEG-2) while we can achieve a "faster decoding" (aka, less cpu usage) with one of them, that involves the other being slower/weird... our thoughts as a joke was that in the worst case we can release two versions of the same lib, being one specifically for DVDs which would play them better than before, however we reached some point where the "distance" between them isn't too worse and still playing those formats/codecs better than before (still testing, though)

Our current Beta is version 53.1 based on lavc 53.0 from April 2011 - Depending on the bounty results we tend to keep the lib updated, being the next version based on the recently released 0.9.1 stable branch (53.1 is based on a GIT snapshot)

We have to mention we got a little disappointed with the nice way the ffmpeg ppl breaks their API... since its current stable version is already incompatible with the branch we've used for 53.1 and therefore we'll need to reinvent the wheel... looks like they have made more [incompatible] changes in the last year than from the 2008's branch to the 2011 used, anybody interested can check the diffs here.

Well, thank you all sincerely for supporting this bounty.

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