libavfilter/fifo.c:190: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer`.

libavfilter/fifo.c:143:1: Parameter `ctx->priv->allocated_samples`
141. }
142. 
143. static int return_audio_frame(AVFilterContext *ctx)
     ^
144. {
145.     AVFilterLink *link = ctx->outputs[0];

libavfilter/fifo.c:181:23: Assignment
179. 
180.         while (s->buf_out->audio->nb_samples < s->allocated_samples) {
181.             int len = FFMIN(s->allocated_samples - s->buf_out->audio->nb_samples,
                           ^
182.                             head->audio->nb_samples);
183. 

libavfilter/fifo.c:181:13: Assignment
179. 
180.         while (s->buf_out->audio->nb_samples < s->allocated_samples) {
181.             int len = FFMIN(s->allocated_samples - s->buf_out->audio->nb_samples,
                 ^
182.                             head->audio->nb_samples);
183. 

libavfilter/fifo.c:187:13: Assignment
185.                             s->buf_out->audio->nb_samples, 0, len, nb_channels,
186.                             link->format);
187.             s->buf_out->audio->nb_samples += len;
                 ^
188. 
189.             if (len == head->audio->nb_samples) {

libavfilter/fifo.c:190:17: Call
188. 
189.             if (len == head->audio->nb_samples) {
190.                 avfilter_unref_buffer(head);
                     ^
191.                 queue_pop(s);
192. 

libavfilter/buffer.c:74:1: <LHS trace>
72. }
73. 
74. void avfilter_unref_buffer(AVFilterBufferRef *ref)
    ^
75. {
76.     if (!ref)

libavfilter/buffer.c:74:1: Parameter `ref->buf->refcount`
  72. }
  73. 
  74. void avfilter_unref_buffer(AVFilterBufferRef *ref)
      ^
  75. {
  76.     if (!ref)

libavfilter/buffer.c:78:11: Binary operation: ([0, +oo] - 1):unsigned32 by call to `avfilter_unref_buffer` 
  76.     if (!ref)
  77.         return;
  78.     if (!(--ref->buf->refcount))
                ^
  79.         ref->buf->free(ref->buf);
  80.     if (ref->extended_data != ref->data)
