[FFmpeg-devel] [PATCH] Common ACELP code & G.729 [1/7] - filters

[RAFAEL JHONNY GOMEZ AGUILAR]

> Date: Tue, 6 May 2008 23:24:38 +0700> From: voroshil at gmail.com> To: ffmpeg-devel at mplayerhq.hu> Subject: Re: [FFmpeg-devel] [PATCH] Common ACELP code & G.729 [1/7] - filters> > On Mon, May 5, 2008 at 3:42 AM, Michael Niedermayer <michaelni at gmx.at> wrote:> > On Sun, May 04, 2008 at 01:19:10PM +0700, Vladimir Voroshilov wrote:> > > On Sat, May 3, 2008 at 7:23 PM, Michael Niedermayer <michaelni at gmx.at> wrote:> > > > On Sat, May 03, 2008 at 03:24:54PM +0700, Vladimir Voroshilov wrote:> > > > > Michael Niedermayer wrote:> > > > [...]> > > > > +void ff_acelp_convolve_circ(> > > > > + int16_t* fc_out,> > > > > + const int16_t* fc_in,> > > > > + const int16_t* filter,> > > > > + int subframe_size)> > > > > +{> > > > > + int i, k;> > > > > +> > > > > + memset(fc_out, 0, subframe_size * sizeof(int16_t));> > > >> > > > > +> > > > > + /* Since there are few pulses over all subframe (i.e. almost all> > > >> > > > > + fc_in[i] are zero, in case of G.729D it is only two non-zero> > > > > + samples of total 40), it is faster to swap two loops and process> > > > > + non-zero samples only. This will reduce number of multiplications> > > >> > > > > + from 40*40 to 2*40 for G.729D */> > > >> > > > doesnt ff_acelp_fc_enchance_harmonics() increase the number of non 0> > > > elements above 2 ?> > >> > > Perhaps i misspelled sentence.> > > I meant that using swapped loops with checking for non-zero will> > > require 2*40 multiplications,> >> > The sentance is fine.> > What i meant is that ff_acelp_fc_enchance_harmonics() can increase the number> > of non zero samples above 2. Or do i miss somehing that prevents this?> > This is exactly what this filter intended to do.> It get buffer with few pulses and smooth them over all subframe.> In reference code it is caller "pitch_shrp" ("pitch sharpening" i guess).> >nooooooooooo jodannnnnnnnnnnnnnnnnnnnn> >> >> > > while using not swapped loops without check will require 40*40 multiplications.> > > 2*40 is exact in case when "in" and "out" are different buffers (and> > > this is required!)> > > since "in" buffer is not touched in loop> > >> > > I'll be thankful for correct and clean english phrase.> > >> > > [...]> > >> > > > > + */> > > > > +void ff_acelp_weighted_filter(> > > > > + int16_t *out,> > > > > + const int16_t* in,> > > > > + const int16_t *weight_pow,> > > > > + int filter_length);> > > >> > > > > +> > > > > +/**> > > > > + * \brief high-pass filtering and upscaling (4.2.5 of G.729)> > > >> > > > just G729 ? or is it also used by others?> > >> > > AMR (according to spec) uses mostly same filter (same formula, but> > > filter coefficients differs in 5th sign).> > > In fixed-point implementation all filter coefficients are equal.> > > I'll add clarification in next update.> >> > ok> > I've made a try :)> See patch.> > > > > -- > Regards,> Vladimir Voroshilov mailto:voroshil at gmail.com> JID: voroshil at gmail.com, voroshil at jabber.ru> ICQ: 95587719
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