libavcodec/utils.c:365: error: Null Dereference
  pointer `buf` last assigned on line 355 could be null and is dereferenced at line 365, column 5.

libavcodec/utils.c:348:1: start of procedure avcodec_default_release_buffer()
346. }
347. 
348. void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
     ^
349.     int i;
350.     InternalBuffer *buf, *last;

libavcodec/utils.c:352:5: 
350.     InternalBuffer *buf, *last;
351. 
352.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
         ^
353.     assert(s->internal_buffer_count);
354. 

libavcodec/utils.c:353:5: 
351. 
352.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
353.     assert(s->internal_buffer_count);
         ^
354. 
355.     buf = NULL; /* avoids warning */

libavcodec/utils.c:355:5: 
353.     assert(s->internal_buffer_count);
354. 
355.     buf = NULL; /* avoids warning */
         ^
356.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
357.         buf= &((InternalBuffer*)s->internal_buffer)[i];

libavcodec/utils.c:356:9: 
354. 
355.     buf = NULL; /* avoids warning */
356.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
             ^
357.         buf= &((InternalBuffer*)s->internal_buffer)[i];
358.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:356:14: Loop condition is false. Leaving loop
354. 
355.     buf = NULL; /* avoids warning */
356.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
                  ^
357.         buf= &((InternalBuffer*)s->internal_buffer)[i];
358.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:361:5: 
359.             break;
360.     }
361.     assert(i < s->internal_buffer_count);
         ^
362.     s->internal_buffer_count--;
363.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];

libavcodec/utils.c:362:5: 
360.     }
361.     assert(i < s->internal_buffer_count);
362.     s->internal_buffer_count--;
         ^
363.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
364. 

libavcodec/utils.c:363:5: 
361.     assert(i < s->internal_buffer_count);
362.     s->internal_buffer_count--;
363.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
         ^
364. 
365.     FFSWAP(InternalBuffer, *buf, *last);

libavcodec/utils.c:365:5: 
363.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
364. 
365.     FFSWAP(InternalBuffer, *buf, *last);
         ^
366. 
367.     for(i=0; i<4; i++){
