ffmpeg | branch: master | Muhammad Faiz <mfc...@gmail.com> | Mon Sep 14 16:23:58 2015 +0700| [145c5a99783c750f169d366db971dbde2244fd7f] | committer: Michael Niedermayer
avfilter/avf_showcqt: change fft left-right separation This simplifies the code Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=145c5a99783c750f169d366db971dbde2244fd7f --- libavfilter/avf_showcqt.c | 56 +++++++++++++++++---------------------------- 1 file changed, 21 insertions(+), 35 deletions(-) diff --git a/libavfilter/avf_showcqt.c b/libavfilter/avf_showcqt.c index 472520c..8f06752 100644 --- a/libavfilter/avf_showcqt.c +++ b/libavfilter/avf_showcqt.c @@ -68,8 +68,7 @@ typedef struct { AVFrame *outpicref; FFTContext *fft_context; FFTComplex *fft_data; - FFTComplex *fft_result_left; - FFTComplex *fft_result_right; + FFTComplex *fft_result; uint8_t *spectogram; SparseCoeff *coeff_sort; SparseCoeff *coeffs[VIDEO_WIDTH]; @@ -125,8 +124,7 @@ static av_cold void uninit(AVFilterContext *ctx) for (k = 0; k < VIDEO_WIDTH; k++) av_freep(&s->coeffs[k]); av_freep(&s->fft_data); - av_freep(&s->fft_result_left); - av_freep(&s->fft_result_right); + av_freep(&s->fft_result); av_freep(&s->coeff_sort); av_freep(&s->spectogram); av_freep(&s->font_alpha); @@ -345,11 +343,10 @@ static int config_output(AVFilterLink *outlink) s->fft_data = av_malloc_array(fft_len, sizeof(*s->fft_data)); s->coeff_sort = av_malloc_array(fft_len, sizeof(*s->coeff_sort)); - s->fft_result_left = av_malloc_array(fft_len, sizeof(*s->fft_result_left)); - s->fft_result_right = av_malloc_array(fft_len, sizeof(*s->fft_result_right)); + s->fft_result = av_malloc_array(fft_len + 1, sizeof(*s->fft_result)); s->fft_context = av_fft_init(s->fft_bits, 0); - if (!s->fft_data || !s->coeff_sort || !s->fft_result_left || !s->fft_result_right || !s->fft_context) + if (!s->fft_data || !s->coeff_sort || !s->fft_result || !s->fft_context) return AVERROR(ENOMEM); #if CONFIG_LIBFREETYPE @@ -541,43 +538,32 @@ static int plot_cqt(AVFilterLink *inlink) int font_height = (FONT_HEIGHT/2) * video_scale; /* real part contains left samples, imaginary part contains right samples */ - memcpy(s->fft_result_left, s->fft_data, fft_len * sizeof(*s->fft_data)); - av_fft_permute(s->fft_context, s->fft_result_left); - av_fft_calc(s->fft_context, s->fft_result_left); - - /* separate left and right, (and multiply by 2.0) */ - s->fft_result_right[0].re = 2.0f * s->fft_result_left[0].im; - s->fft_result_right[0].im = 0; - s->fft_result_left[0].re = 2.0f * s->fft_result_left[0].re; - s->fft_result_left[0].im = 0; - for (x = 1; x <= fft_len >> 1; x++) { - FFTSample tmpy = s->fft_result_left[fft_len-x].im - s->fft_result_left[x].im; - - s->fft_result_right[x].re = s->fft_result_left[x].im + s->fft_result_left[fft_len-x].im; - s->fft_result_right[x].im = s->fft_result_left[x].re - s->fft_result_left[fft_len-x].re; - s->fft_result_right[fft_len-x].re = s->fft_result_right[x].re; - s->fft_result_right[fft_len-x].im = -s->fft_result_right[x].im; - - s->fft_result_left[x].re = s->fft_result_left[x].re + s->fft_result_left[fft_len-x].re; - s->fft_result_left[x].im = tmpy; - s->fft_result_left[fft_len-x].re = s->fft_result_left[x].re; - s->fft_result_left[fft_len-x].im = -s->fft_result_left[x].im; - } + memcpy(s->fft_result, s->fft_data, fft_len * sizeof(*s->fft_data)); + av_fft_permute(s->fft_context, s->fft_result); + av_fft_calc(s->fft_context, s->fft_result); + s->fft_result[fft_len] = s->fft_result[0]; /* calculating cqt */ for (x = 0; x < VIDEO_WIDTH; x++) { int u; - FFTComplex l = {0,0}; - FFTComplex r = {0,0}; + FFTComplex v = {0,0}; + FFTComplex w = {0,0}; + FFTComplex l, r; for (u = 0; u < s->coeffs_len[x]; u++) { FFTSample value = s->coeffs[x][u].value; int index = s->coeffs[x][u].index; - l.re += value * s->fft_result_left[index].re; - l.im += value * s->fft_result_left[index].im; - r.re += value * s->fft_result_right[index].re; - r.im += value * s->fft_result_right[index].im; + v.re += value * s->fft_result[index].re; + v.im += value * s->fft_result[index].im; + w.re += value * s->fft_result[fft_len - index].re; + w.im += value * s->fft_result[fft_len - index].im; } + + /* separate left and right, (and multiply by 2.0) */ + l.re = v.re + w.re; + l.im = v.im - w.im; + r.re = w.im + v.im; + r.im = w.re - v.re; /* result is power, not amplitude */ result[x][0] = l.re * l.re + l.im * l.im; result[x][2] = r.re * r.re + r.im * r.im; _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
