avfilter/avf_showcwt: simplify cache handling

libavfilter/avf_showcwt.c

@@ -85,7 +85,7 @@ typedef struct ShowCWTContext {
     unsigned *index;
     int *kernel_start;
     int *kernel_stop;
-    AVFrame *cache[2];
+    AVFrame *cache;
     AVFrame *outpicref;
     AVFrame *fft_in;
     AVFrame *fft_out;
@@ -168,8 +168,7 @@ static av_cold void uninit(AVFilterContext *ctx)
     av_freep(&s->index);
 
     av_frame_free(&s->kernel);
-    av_frame_free(&s->cache[0]);
-    av_frame_free(&s->cache[1]);
+    av_frame_free(&s->cache);
     av_frame_free(&s->outpicref);
     av_frame_free(&s->fft_in);
     av_frame_free(&s->fft_out);
@@ -280,32 +279,25 @@ static int run_channel_cwt_prepare(AVFilterContext *ctx, void *arg, int jobnr, i
     ShowCWTContext *s = ctx->priv;
     const int hop_size = s->hop_size;
     AVFrame *fin = arg;
-    float *cache0 = (float *)s->cache[0]->extended_data[ch];
-    float *cache = (float *)s->cache[1]->extended_data[ch];
+    AVComplexFloat *cache = (AVComplexFloat *)s->cache->extended_data[ch];
     AVComplexFloat *src = (AVComplexFloat *)s->fft_in->extended_data[ch];
     AVComplexFloat *dst = (AVComplexFloat *)s->fft_out->extended_data[ch];
 
     if (fin) {
-        const int offset = s->hop_index;
         const float *input = (const float *)fin->extended_data[ch];
+        const int offset = s->input_padding_size - fin->nb_samples;
 
-        memcpy(&cache[offset], input,
-               fin->nb_samples * sizeof(float));
+        memmove(cache, cache + fin->nb_samples, sizeof(*cache) * offset);
+        for (int n = 0; n < fin->nb_samples; n++) {
+            cache[offset + n].re = input[n];
+            cache[offset + n].im = 0.f;
+        }
     }
 
-    if (fin == NULL) {
-        memset(&cache[s->hop_index], 0,
-               (hop_size - s->hop_index) * sizeof(float));
-    } else if (s->hop_index + fin->nb_samples < hop_size) {
+    if (fin && s->hop_index + fin->nb_samples < hop_size)
         return 0;
-    }
 
-    for (int n = 0; n < hop_size; n++) {
-        src[n].re = cache0[n];
-        src[n].im = 0.f;
-        src[n + hop_size].re = cache[n];
-        src[n + hop_size].im = 0.f;
-    }
+    memcpy(src, cache, sizeof(*src) * s->input_padding_size);
 
     s->tx_fn(s->fft[jobnr], dst, src, sizeof(*src));
 
@@ -630,8 +622,7 @@ static int config_output(AVFilterLink *outlink)
     s->outpicref = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     s->fft_in = ff_get_audio_buffer(inlink, s->fft_in_size * 2);
     s->fft_out = ff_get_audio_buffer(inlink, s->fft_out_size * 2);
-    s->cache[0] = ff_get_audio_buffer(inlink, s->hop_size);
-    s->cache[1] = ff_get_audio_buffer(inlink, s->hop_size);
+    s->cache = ff_get_audio_buffer(inlink, s->fft_in_size * 2);
     s->ch_out = ff_get_audio_buffer(inlink, s->frequency_band_count * 2 * s->ihop_size);
     s->ifft_in = av_frame_alloc();
     s->ifft_out = av_frame_alloc();
@@ -641,7 +632,7 @@ static int config_output(AVFilterLink *outlink)
     s->kernel_stop = av_calloc(s->frequency_band_count, sizeof(*s->kernel_stop));
     if (!s->outpicref || !s->fft_in || !s->fft_out ||
         !s->ifft_in || !s->ifft_out || !s->kernel_start || !s->kernel_stop ||
-        !s->frequency_band || !s->kernel || !s->cache[0] || !s->cache[1] || !s->index)
+        !s->frequency_band || !s->kernel || !s->cache || !s->index)
         return AVERROR(ENOMEM);
 
     s->ifft_in->format     = inlink->format;
@@ -983,10 +974,8 @@ static int activate(AVFilterContext *ctx)
         }
 
         if (s->hop_index >= s->hop_size || s->ihop_index > 0) {
-            if (s->hop_index) {
-                FFSWAP(AVFrame *, s->cache[0], s->cache[1]);
+            if (s->hop_index)
                 s->hop_index = 0;
-            }
 
             for (int ch = 0; ch < s->nb_channels && s->ihop_index == 0; ch++) {
                 ff_filter_execute(ctx, run_channel_cwt, (void *)&ch, NULL,