libavcodec/utils.c:363: error: Null Dereference
  pointer `buf` last assigned on line 353 could be null and is dereferenced at line 363, column 5.

libavcodec/utils.c:346:1: start of procedure avcodec_default_release_buffer()
344. }
345. 
346. void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
     ^
347.     int i;
348.     InternalBuffer *buf, *last;

libavcodec/utils.c:350:5: 
348.     InternalBuffer *buf, *last;
349. 
350.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
         ^
351.     assert(s->internal_buffer_count);
352. 

libavcodec/utils.c:351:5: 
349. 
350.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
351.     assert(s->internal_buffer_count);
         ^
352. 
353.     buf = NULL; /* avoids warning */

libavcodec/utils.c:353:5: 
351.     assert(s->internal_buffer_count);
352. 
353.     buf = NULL; /* avoids warning */
         ^
354.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
355.         buf= &((InternalBuffer*)s->internal_buffer)[i];

libavcodec/utils.c:354:9: 
352. 
353.     buf = NULL; /* avoids warning */
354.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
             ^
355.         buf= &((InternalBuffer*)s->internal_buffer)[i];
356.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:354:14: Loop condition is false. Leaving loop
352. 
353.     buf = NULL; /* avoids warning */
354.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
                  ^
355.         buf= &((InternalBuffer*)s->internal_buffer)[i];
356.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:359:5: 
357.             break;
358.     }
359.     assert(i < s->internal_buffer_count);
         ^
360.     s->internal_buffer_count--;
361.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];

libavcodec/utils.c:360:5: 
358.     }
359.     assert(i < s->internal_buffer_count);
360.     s->internal_buffer_count--;
         ^
361.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
362. 

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

libavcodec/utils.c:363:5: 
361.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
362. 
363.     FFSWAP(InternalBuffer, *buf, *last);
         ^
364. 
365.     for(i=0; i<4; i++){
