[FFmpeg-devel] [PATCH] lavfi: add ff_all_channel_layouts internal symbol

Stefano Sabatini stefano.sabatini-lala at poste.it
Sat Sep 10 09:45:16 CEST 2011


On date Saturday 2011-09-10 03:46:23 +0200, Michael Niedermayer encoded:
> On Sat, Sep 10, 2011 at 02:01:27AM +0200, Stefano Sabatini wrote:
[...]
> > > AVFilterFormats *avfilter_all_channel_layouts(void)
> > > {
> > >     static int64_t cls[] = {
> > > #define A(x) (x), (x)|AV_CH_LOW_FREQUENCY
> > > #define B(x) A(x|AV_CH_FRONT_CENTER), A(x|AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT), A(x|AV_CH_FRONT_CENTER|AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT)
> > > #define C(x) B(x), B(x|AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT), B(x|AV_CH_BACK_CENTER)
> > > #define D(x) C(x), C(x|AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT)
> > >         D(0), D(AV_CH_STEREO_LEFT|AV_CH_STEREO_RIGHT)
> > >     };
> > > 
> > >     for (i = 0; i < FF_ARRAY_ELEMS(cls); i++) {
> > >         if (get_channel_layout_nb_channels(cls[i]) > 8) {
> > >             cls[i]=AV_CH_FRONT_CENTER;
> > >         }
> > >     }
> > >     return avfilter_make_format64_list(cls);
> > > }
> > 
> > My problem is that I need the list as an int64_t list (for use in the
> > audio sink). I could of course convert the formats list to int64_t,
> > but would be awkward. That's why I proposed a static int64_t array.
> 
> Both your code and mine use a static int64_t array and convert it with
> avfilter_make_format64_list()
> 
> the for() loop in mine is just there because we dont support >8
> channels ATM, that would be remvoed once that is fixed.
> 
> Please elaborate on what the problem is

I need the list to be *public*, so I can use it in code like this:

            enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16, -1 };
            const int packing_fmts[] = { AVFILTER_PACKED, -1 };
            const int64_t *chlayouts = avfilter_all_channel_layouts_int64;
            AVABufferSinkParams *abuffersink_params = av_abuffersink_params_alloc();
            abuffersink_params->sample_fmts = sample_fmts;
            abuffersink_params->packing_fmts = packing_fmts;
            abuffersink_params->channel_layouts = chlayouts;

            ret = avfilter_graph_create_filter(&sink, abuffersink,
                                               inout->name, NULL,
                                               abuffersink_params, lavfi->graph);
            av_free(abuffersink_params);
            if (ret < 0)
                goto end;

-- 
FFmpeg = Forgiving Fostering Marvellous Pitiful Elaborated Guide


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