[FFmpeg-cvslog] avfilter/af_surround: allow non-power of 2 win_size

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Nov 16 23:41:31 2022 +0100| [a640b2874ac8ce21c8dfdf992b3b4d23afe14117] | committer: Paul B Mahol

avfilter/af_surround: allow non-power of 2 win_size

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a640b2874ac8ce21c8dfdf992b3b4d23afe14117
---

 libavfilter/af_surround.c | 47 ++++++++++++++++++++++-------------------------
 1 file changed, 22 insertions(+), 25 deletions(-)

diff --git a/libavfilter/af_surround.c b/libavfilter/af_surround.c
index 9baea2dbef..6632385a54 100644
--- a/libavfilter/af_surround.c
+++ b/libavfilter/af_surround.c
@@ -113,7 +113,6 @@ typedef struct AudioSurroundContext {
     float *lfe_mag;
     float *mag_total;
 
-    int buf_size;
     int rdft_size;
     int hop_size;
     AVTXContext **rdft, **irdft;
@@ -286,7 +285,7 @@ static int config_input(AVFilterLink *inlink)
         float scale = 1.f;
 
         ret = av_tx_init(&s->rdft[ch], &s->tx_fn, AV_TX_FLOAT_RDFT,
-                         0, s->buf_size, &scale, 0);
+                         0, s->win_size, &scale, 0);
         if (ret < 0)
             return ret;
     }
@@ -296,20 +295,20 @@ static int config_input(AVFilterLink *inlink)
 
     set_input_levels(ctx);
 
-    s->window = ff_get_audio_buffer(inlink, s->buf_size * 2);
+    s->window = ff_get_audio_buffer(inlink, s->win_size * 2);
     if (!s->window)
         return AVERROR(ENOMEM);
 
-    s->input_in = ff_get_audio_buffer(inlink, s->buf_size * 2);
+    s->input_in = ff_get_audio_buffer(inlink, s->win_size * 2);
     if (!s->input_in)
         return AVERROR(ENOMEM);
 
-    s->input = ff_get_audio_buffer(inlink, s->buf_size + 2);
+    s->input = ff_get_audio_buffer(inlink, s->win_size + 2);
     if (!s->input)
         return AVERROR(ENOMEM);
 
-    s->lowcut = 1.f * s->lowcutf / (inlink->sample_rate * 0.5) * (s->buf_size / 2);
-    s->highcut = 1.f * s->highcutf / (inlink->sample_rate * 0.5) * (s->buf_size / 2);
+    s->lowcut = 1.f * s->lowcutf / (inlink->sample_rate * 0.5) * (s->win_size / 2);
+    s->highcut = 1.f * s->highcutf / (inlink->sample_rate * 0.5) * (s->win_size / 2);
 
     return 0;
 }
@@ -329,7 +328,7 @@ static int config_output(AVFilterLink *outlink)
         float iscale = 1.f;
 
         ret = av_tx_init(&s->irdft[ch], &s->itx_fn, AV_TX_FLOAT_RDFT,
-                         1, s->buf_size, &iscale, 0);
+                         1, s->win_size, &iscale, 0);
         if (ret < 0)
             return ret;
     }
@@ -340,13 +339,13 @@ static int config_output(AVFilterLink *outlink)
 
     set_output_levels(ctx);
 
-    s->output_out = ff_get_audio_buffer(outlink, s->buf_size + 2);
-    s->output = ff_get_audio_buffer(outlink, s->buf_size + 2);
-    s->overlap_buffer = ff_get_audio_buffer(outlink, s->buf_size * 2);
+    s->output_out = ff_get_audio_buffer(outlink, s->win_size + 2);
+    s->output = ff_get_audio_buffer(outlink, s->win_size + 2);
+    s->overlap_buffer = ff_get_audio_buffer(outlink, s->win_size * 2);
     if (!s->overlap_buffer || !s->output || !s->output_out)
         return AVERROR(ENOMEM);
 
-    s->rdft_size = s->buf_size / 2 + 1;
+    s->rdft_size = s->win_size / 2 + 1;
 
     s->x_pos = av_calloc(s->rdft_size, sizeof(*s->x_pos));
     s->y_pos = av_calloc(s->rdft_size, sizeof(*s->y_pos));
@@ -1222,19 +1221,17 @@ fail:
         return AVERROR(EINVAL);
     }
 
-    s->buf_size = 1 << av_log2(s->win_size);
-
-    s->window_func_lut = av_calloc(s->buf_size, sizeof(*s->window_func_lut));
+    s->window_func_lut = av_calloc(s->win_size, sizeof(*s->window_func_lut));
     if (!s->window_func_lut)
         return AVERROR(ENOMEM);
 
-    generate_window_func(s->window_func_lut, s->buf_size, s->win_func, &overlap);
+    generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);
     if (s->overlap == 1)
         s->overlap = overlap;
 
-    for (i = 0; i < s->buf_size; i++)
-        s->window_func_lut[i] = sqrtf(s->window_func_lut[i] / s->buf_size);
-    s->hop_size = FFMAX(1, s->buf_size * (1. - s->overlap));
+    for (i = 0; i < s->win_size; i++)
+        s->window_func_lut[i] = sqrtf(s->window_func_lut[i] / s->win_size);
+    s->hop_size = FFMAX(1, s->win_size * (1. - s->overlap));
 
     allchannels_spread(ctx);
 
@@ -1246,14 +1243,14 @@ static int fft_channel(AVFilterContext *ctx, AVFrame *in, int ch)
     AudioSurroundContext *s = ctx->priv;
     float *src = (float *)s->input_in->extended_data[ch];
     float *win = (float *)s->window->extended_data[ch];
-    const int offset = s->buf_size - s->hop_size;
+    const int offset = s->win_size - s->hop_size;
     const float level_in = s->input_levels[ch];
 
     memmove(src, &src[s->hop_size], offset * sizeof(float));
     memcpy(&src[offset], in->extended_data[ch], in->nb_samples * sizeof(float));
     memset(&src[offset + in->nb_samples], 0, (s->hop_size - in->nb_samples) * sizeof(float));
 
-    for (int n = 0; n < s->buf_size; n++)
+    for (int n = 0; n < s->win_size; n++)
         win[n] = src[n] * s->window_func_lut[n] * level_in;
 
     s->tx_fn(s->rdft[ch], (float *)s->input->extended_data[ch], win, sizeof(float));
@@ -1285,11 +1282,11 @@ static int ifft_channel(AVFilterContext *ctx, AVFrame *out, int ch)
 
     memmove(s->overlap_buffer->extended_data[ch],
             s->overlap_buffer->extended_data[ch] + s->hop_size * sizeof(float),
-            s->buf_size * sizeof(float));
-    memset(s->overlap_buffer->extended_data[ch] + s->buf_size * sizeof(float),
+            s->win_size * sizeof(float));
+    memset(s->overlap_buffer->extended_data[ch] + s->win_size * sizeof(float),
            0, s->hop_size * sizeof(float));
 
-    for (int n = 0; n < s->buf_size; n++)
+    for (int n = 0; n < s->win_size; n++)
         ptr[n] += dst[n] * s->window_func_lut[n] * level_out;
 
     ptr = (float *)s->overlap_buffer->extended_data[ch];
@@ -1418,7 +1415,7 @@ static int process_command(AVFilterContext *ctx, const char *cmd, const char *ar
     if (ret < 0)
         return ret;
 
-    s->hop_size = FFMAX(1, s->buf_size * (1. - s->overlap));
+    s->hop_size = FFMAX(1, s->win_size * (1. - s->overlap));
 
     allchannels_spread(ctx);
     set_input_levels(ctx);