[Ffmpeg-devel-irc] ffmpeg.log.20200127

[burek]

[13:51:33 CET] <funnybunny2> Is it true that av_register_all is deprecated? https://github.com/leandromoreira/ffmpeg-libav-tutorial/issues/29 The docs don't say that. If I remove the call my program doesn't work
[13:57:05 CET] <ritsuka> funnybunny2: which version of ffmpeg are you using?
[13:59:05 CET] <funnybunny2> ritsuka: Looks like 3.4.6, but I want to use the latest version. I guess Ubuntu comes with an old version
[13:59:33 CET] <funnybunny2> I should switch my code to link against my own compiled version
[14:02:46 CET] <funnybunny2> The documentation for avformat_alloc_context should also be updated to say what the function returns
[14:35:34 CET] <funnybunny2> Why can avcodec_open2 fail?
[14:36:03 CET] <funnybunny2> The documentation doesn't say it returns an AVERROR and I don't know what sort of error message to print
[14:42:52 CET] <DHE> funnybunny2:  static char errstr[1024];  int errstatus = av_strerror(avcodec_open2_error_return, errstr, sizeof(errstr)-1); if (errstatus < 0) printf("Unknown error\n"); else printf("Error message: %s\n", errstr);
[14:43:53 CET] <funnybunny2> DHE: ?
[14:46:16 CET] <DHE> av_strerror will convert an error return code to a user/dev friendly string. this is the code I use (sorta) to make use of it.
[14:47:25 CET] <funnybunny2> DHE: I know that, but the documentation for avcodec_open2 doesn't say it returns an AVERROR. Looking at the source code, it actually does. But if it didn't, I wouldn't just want to print Unknown error
[14:49:12 CET] <funnybunny2> I'd like the documentation to be updated so I can trust the function will not be changed. The documentation is unclear. I guess I'm just supposed to treat the source code as the documentation and assume there is no stability to ffmpeg
[14:51:13 CET] <DHE> that's not the right way to describe it. AVERROR is a macro. AVERROR(errno) is its intended usage if an errno code is appropriate, else there are a variety of AVERROR_xxx constants
[17:34:54 CET] <JaredCE> i've used ffmpeg to split a file up... how might i use it to recombine the file?
[17:39:42 CET] <klaxa> concat muxer?
[17:39:58 CET] <klaxa> https://trac.ffmpeg.org/wiki/Concatenate#demuxer
[17:40:02 CET] <klaxa> *demuxer
[17:43:09 CET] <JaredCE> klaxa that looks like it
[21:51:48 CET] <LFSVeteran> more a generic C question.... AVAudioFifo has a field nb_buffers, how to reference nb_buffers if I have AVAudioFifo **fifo ?
[22:02:22 CET] <klaxa> is **fifo->nb_buffers invalid? i think so, then you may need brackets? like *(*fifo)->nb_buffers ?
[22:02:39 CET] <klaxa> err... *parenthesis
[22:10:20 CET] <LFSVeteran> I still get the error "dereferencing pointer to incomplete type 'AVAudioFifo' {aka 'struct AVAudioFifo'}"
[22:12:09 CET] <DHE> oh that. it's an abstract type. use av_audio_fifo_size() and/or av_audio_fifo_space()
[22:12:09 CET] <c_14> isn't it just (*fifo)->nb_buffers ?
[22:12:22 CET] <c_14> or that
[22:12:38 CET] <LFSVeteran> also tried
[22:12:50 CET] <c_14> you tried av_audio_fifo_size ?
[22:13:57 CET] <LFSVeteran> it's not just this I want , I have also other vars in **var form I want to check
[22:14:50 CET] <LFSVeteran> hence I'm searching for a generic solution
[22:23:22 CET] <c_14> in general it should be (*ptr)->field https://gcc.godbolt.org/z/m5KoG8
[22:28:51 CET] <LFSVeteran> ypedef struct AVAudioFifo AVAudioFifo;
[22:29:08 CET] <LFSVeteran> there seems not to be a real struct
[22:29:22 CET] <LFSVeteran> at least the fields are not defined
[22:29:48 CET] <LFSVeteran> can't find other definition of it in the headers
[22:29:54 CET] <c_14> then it's private
[22:30:13 CET] <c_14> and any access to its members is through av_ functions
[22:31:17 CET] <LFSVeteran> checking relevant functions...
[00:00:00 CET] --- Tue Jan 28 2020