[FFmpeg-devel] [PATCH 15/25] avfilter/af_headphone: Avoid intermediate buffers II

[Andreas Rheinhardt]

When the headphone filter is configured to perform its processing in the
frequency domain, it allocates (among other things) two pairs of
buffers, all of the same size. One pair is used to store data in it
during the initialization of the filter; the other pair is only
allocated lateron. It is zero-initialized and yet its data is
immediately overwritten by the content of the other pair of buffers
mentioned above; the latter pair is then freed.

This commit eliminates the pair of intermediate buffers.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
 libavfilter/af_headphone.c | 33 +++++++--------------------------
 1 file changed, 7 insertions(+), 26 deletions(-)

diff --git a/libavfilter/af_headphone.c b/libavfilter/af_headphone.c
index 359174d4b4..fb6af7a966 100644
--- a/libavfilter/af_headphone.c
+++ b/libavfilter/af_headphone.c
@@ -371,8 +371,6 @@ static int convert_coeffs(AVFilterContext *ctx, AVFilterLink *inlink)
     int nb_irs = s->nb_irs;
     int nb_input_channels = ctx->inputs[0]->channels;
     float gain_lin = expf((s->gain - 3 * nb_input_channels) / 20 * M_LN10);
-    FFTComplex *data_hrtf_l = NULL;
-    FFTComplex *data_hrtf_r = NULL;
     FFTComplex *fft_in_l = NULL;
     FFTComplex *fft_in_r = NULL;
     int offset = 0, ret = 0;
@@ -439,9 +437,9 @@ static int convert_coeffs(AVFilterContext *ctx, AVFilterLink *inlink)
             goto fail;
         }
     } else {
-        data_hrtf_l = av_calloc(n_fft, sizeof(*data_hrtf_l) * nb_irs);
-        data_hrtf_r = av_calloc(n_fft, sizeof(*data_hrtf_r) * nb_irs);
-        if (!data_hrtf_r || !data_hrtf_l) {
+        s->data_hrtf[0] = av_calloc(n_fft, sizeof(*s->data_hrtf[0]) * nb_irs);
+        s->data_hrtf[1] = av_calloc(n_fft, sizeof(*s->data_hrtf[1]) * nb_irs);
+        if (!s->data_hrtf[0] || !s->data_hrtf[1]) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
@@ -488,10 +486,10 @@ static int convert_coeffs(AVFilterContext *ctx, AVFilterLink *inlink)
 
                 av_fft_permute(s->fft[0], fft_in_l);
                 av_fft_calc(s->fft[0], fft_in_l);
-                memcpy(data_hrtf_l + offset, fft_in_l, n_fft * sizeof(*fft_in_l));
+                memcpy(s->data_hrtf[0] + offset, fft_in_l, n_fft * sizeof(*fft_in_l));
                 av_fft_permute(s->fft[0], fft_in_r);
                 av_fft_calc(s->fft[0], fft_in_r);
-                memcpy(data_hrtf_r + offset, fft_in_r, n_fft * sizeof(*fft_in_r));
+                memcpy(s->data_hrtf[1] + offset, fft_in_r, n_fft * sizeof(*fft_in_r));
             }
         } else {
             int I, N = ctx->inputs[1]->channels;
@@ -529,10 +527,10 @@ static int convert_coeffs(AVFilterContext *ctx, AVFilterLink *inlink)
 
                     av_fft_permute(s->fft[0], fft_in_l);
                     av_fft_calc(s->fft[0], fft_in_l);
-                    memcpy(data_hrtf_l + offset, fft_in_l, n_fft * sizeof(*fft_in_l));
+                    memcpy(s->data_hrtf[0] + offset, fft_in_l, n_fft * sizeof(*fft_in_l));
                     av_fft_permute(s->fft[0], fft_in_r);
                     av_fft_calc(s->fft[0], fft_in_r);
-                    memcpy(data_hrtf_r + offset, fft_in_r, n_fft * sizeof(*fft_in_r));
+                    memcpy(s->data_hrtf[1] + offset, fft_in_r, n_fft * sizeof(*fft_in_r));
                 }
             }
         }
@@ -540,20 +538,6 @@ static int convert_coeffs(AVFilterContext *ctx, AVFilterLink *inlink)
         av_frame_free(&s->in[i + 1].frame);
     }
 
-    if (s->type == FREQUENCY_DOMAIN) {
-        s->data_hrtf[0] = av_calloc(n_fft * s->nb_irs, sizeof(FFTComplex));
-        s->data_hrtf[1] = av_calloc(n_fft * s->nb_irs, sizeof(FFTComplex));
-        if (!s->data_hrtf[0] || !s->data_hrtf[1]) {
-            ret = AVERROR(ENOMEM);
-            goto fail;
-        }
-
-        memcpy(s->data_hrtf[0], data_hrtf_l,
-            sizeof(FFTComplex) * nb_irs * n_fft);
-        memcpy(s->data_hrtf[1], data_hrtf_r,
-            sizeof(FFTComplex) * nb_irs * n_fft);
-    }
-
     s->have_hrirs = 1;
 
 fail:
@@ -561,9 +545,6 @@ fail:
     for (i = 0; i < s->nb_inputs - 1; i++)
         av_frame_free(&s->in[i + 1].frame);
 
-    av_freep(&data_hrtf_l);
-    av_freep(&data_hrtf_r);
-
     av_freep(&fft_in_l);
     av_freep(&fft_in_r);
 
-- 
2.20.1