avfilter/af_headphone: Don't allocate unused element in array

The headphone filter uses an array with as many elements as the
filter has inputs to store some per-input information; yet actually it
only stores information for all inputs except the very first one (which
is special for this filter). Therefore this commit modifies the code to
remove this unused element.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavfilter/af_headphone.c

@@ -52,7 +52,7 @@ typedef struct HeadphoneContext {
     int ir_len;
     int air_len;
 
-    int nb_inputs;
+    int nb_hrir_inputs;
 
     int nb_irs;
 
@@ -76,10 +76,10 @@ typedef struct HeadphoneContext {
     FFTComplex *data_hrtf[2];
 
     AVFloatDSPContext *fdsp;
-    struct headphone_inputs {
+    struct hrir_inputs {
         int          ir_len;
         int          eof;
-    } *in;
+    } *hrir_in;
     uint64_t mapping[64];
 } HeadphoneContext;
 
@@ -99,8 +99,6 @@ static void parse_map(AVFilterContext *ctx)
     char *arg, *tokenizer, *p;
     uint64_t used_channels = 0;
 
-    s->nb_inputs = 1;
-
     p = s->map;
     while ((arg = av_strtok(p, "|", &tokenizer))) {
         uint64_t out_channel;
@@ -120,9 +118,9 @@ static void parse_map(AVFilterContext *ctx)
     }
 
     if (s->hrir_fmt == HRIR_MULTI)
-        s->nb_inputs = 2;
+        s->nb_hrir_inputs = 1;
     else
-        s->nb_inputs = s->nb_irs + 1;
+        s->nb_hrir_inputs = s->nb_irs;
 }
 
 typedef struct ThreadData {
@@ -318,7 +316,7 @@ static int check_ir(AVFilterLink *inlink, int input_number)
         av_log(ctx, AV_LOG_ERROR, "Too big length of IRs: %d > %d.\n", ir_len, max_ir_len);
         return AVERROR(EINVAL);
     }
-    s->in[input_number].ir_len = ir_len;
+    s->hrir_in[input_number].ir_len = ir_len;
     s->ir_len = FFMAX(ir_len, s->ir_len);
 
     return 0;
@@ -432,8 +430,8 @@ static int convert_coeffs(AVFilterContext *ctx, AVFilterLink *inlink)
         }
     }
 
-    for (i = 0; i < s->nb_inputs - 1; av_frame_free(&frame), i++) {
-        int len = s->in[i + 1].ir_len;
+    for (i = 0; i < s->nb_hrir_inputs; av_frame_free(&frame), i++) {
+        int len = s->hrir_in[i].ir_len;
         float *ptr;
 
         ret = ff_inlink_consume_samples(ctx->inputs[i + 1], len, len, &frame);
@@ -521,23 +519,25 @@ static int activate(AVFilterContext *ctx)
     FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);
     if (!s->eof_hrirs) {
         int eof = 1;
-        for (i = 1; i < s->nb_inputs; i++) {
-            if (s->in[i].eof)
+        for (i = 0; i < s->nb_hrir_inputs; i++) {
+            AVFilterLink *input = ctx->inputs[i + 1];
+
+            if (s->hrir_in[i].eof)
                 continue;
 
-            if ((ret = check_ir(ctx->inputs[i], i)) < 0)
+            if ((ret = check_ir(input, i)) < 0)
                 return ret;
 
-            if (ff_outlink_get_status(ctx->inputs[i]) == AVERROR_EOF) {
-                if (!ff_inlink_queued_samples(ctx->inputs[i])) {
+            if (ff_outlink_get_status(input) == AVERROR_EOF) {
+                if (!ff_inlink_queued_samples(input)) {
                     av_log(ctx, AV_LOG_ERROR, "No samples provided for "
-                           "HRIR stream %d.\n", i - 1);
+                           "HRIR stream %d.\n", i);
                     return AVERROR_INVALIDDATA;
                 }
-                    s->in[i].eof = 1;
+                s->hrir_in[i].eof = 1;
             } else {
                 if (ff_outlink_frame_wanted(ctx->outputs[0]))
-                    ff_inlink_request_frame(ctx->inputs[i]);
+                    ff_inlink_request_frame(input);
                 eof = 0;
             }
         }
@@ -606,7 +606,7 @@ static int query_formats(AVFilterContext *ctx)
         if (ret)
             return ret;
     } else {
-        for (i = 1; i < s->nb_inputs; i++) {
+        for (i = 1; i <= s->nb_hrir_inputs; i++) {
             ret = ff_channel_layouts_ref(stereo_layout, &ctx->inputs[i]->outcfg.channel_layouts);
             if (ret)
                 return ret;
@@ -654,19 +654,19 @@ static av_cold int init(AVFilterContext *ctx)
 
     parse_map(ctx);
 
-    s->in = av_calloc(s->nb_inputs, sizeof(*s->in));
-    if (!s->in)
+    s->hrir_in = av_calloc(s->nb_hrir_inputs, sizeof(*s->hrir_in));
+    if (!s->hrir_in)
         return AVERROR(ENOMEM);
 
-    for (i = 1; i < s->nb_inputs; i++) {
-        char *name = av_asprintf("hrir%d", i - 1);
+    for (i = 0; i < s->nb_hrir_inputs; i++) {
+        char *name = av_asprintf("hrir%d", i);
         AVFilterPad pad = {
             .name         = name,
             .type         = AVMEDIA_TYPE_AUDIO,
         };
         if (!name)
             return AVERROR(ENOMEM);
-        if ((ret = ff_insert_inpad(ctx, i, &pad)) < 0) {
+        if ((ret = ff_insert_inpad(ctx, i + 1, &pad)) < 0) {
             av_freep(&pad.name);
             return ret;
         }
@@ -721,7 +721,7 @@ static av_cold void uninit(AVFilterContext *ctx)
     av_freep(&s->data_hrtf[1]);
     av_freep(&s->fdsp);
 
-    av_freep(&s->in);
+    av_freep(&s->hrir_in);
     for (unsigned i = 1; i < ctx->nb_inputs; i++)
         av_freep(&ctx->input_pads[i].name);
 }