[FFmpeg-devel] [RFC] Frame accurate seeking

Baptiste Coudurier baptiste.coudurier
Wed Dec 30 17:59:20 CET 2009

On 12/30/09 5:25 PM, Karl Blomster wrote:
> Baptiste Coudurier wrote:
>> Hi,
>> On 12/30/09 4:07 PM, Karl Blomster wrote:
>>> Artur Bodera wrote:
>>>>> Also, feature requests do not belong on this list, and even
>>>>> for a feature request this lacks an exact description of
>>>>> _what_ you want.
>>>> Sure, unless I provide a solution, which I did:
>>>> http://github.com/lbrandy/ffmpeg-fas
>>> FFmpegSource (http://code.google.com/p/ffmpegsource) does
>>> something similar. That is, provides a simplified API that gives
>>> you frame-accurate decoding but not much else. Some people find
>>> that quite useful, but from what I read about what you actually
>>> want to do, it won't help you at all.
>>>> The use case is described here:
>>>> http://archives.free.net.ph/message/20091228.114853.066bc91b.en.html
 >>>> I'm looking for a way to split a stream into parts without decoding
>>>> it to rawvideo or transcoding 2 times. I thought it would be
>>>> feasible using gop/fps calculations, but it seems that the
>>>> time seeking is a bit "jerky" and -vframes does not help either
>>>> when you need 2 matching chunks (the second one needs to start
>>>> where the first one ended, frame-wise, and you can not seek by
>>>> frames = dead in the water).
>>> If you can accept splitting only at I(DR)-frames, mkvmerge can
>>> do this for you. You can always demux/remux back to MP4 later.
>>> :V
>> I personnally find _very rude_ to advertise for different software
>> (2 in this mail) on another software's mailing list. IMHO there
>> are way more appropriate places for advertising.
> How exactly was I "advertising" anything, and why exactly would it
> be rude to speak of software that uses ffmpeg?

I consider that mentioning FFmpegSource and mkvmerge in a mail in
ffmpeg-devel mailing list, is advertising.

> The thread starter talked about software that uses ffmpeg to do
> something ffmpeg currently doesn't do, with the aim of trying to
> integrate similar functionality into ffmpeg itself, and I provided
> him with another example of similar software.

And his request was pretty clear IMHO. He didn't not request for
FFmpegSource as far as I understand, though even if he did, it would
have been clearly _offtopic_ for ffmpeg-devel.
ffmpeg-devel mailing list is about ffmpeg development.

> Neither software can possibly be considered a replacement for ffmpeg
> (both just let you use ffmpeg in a different way), so why are you
> getting offended by this alleged "advertising"?

Hopefully, I'm not getting offended by rude behaviour, otherwise it 
would hard to live nowdays. I just wanted to mention what I felt.

> It's not like we're trying to "steal" your "market share"; it's
> actually more like we're trying to make ffmpeg better.

Well, I disagree here. The only way IMHO to make ffmpeg better is to
report bugs or send patches fixing bugs and/or implementing useful features.
IMHO creating sub-projects workarounding ffmpeg problems is only harmful.


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