libavcodec/utils.c:393: error: Null Dereference
  pointer `buf` last assigned on line 383 could be null and is dereferenced at line 393, column 5.

libavcodec/utils.c:375:1: start of procedure avcodec_default_release_buffer()
373. }
374. 
375. void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
     ^
376.     int i;
377.     InternalBuffer *buf, *last;

libavcodec/utils.c:379:5: 
377.     InternalBuffer *buf, *last;
378. 
379.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
         ^
380.     assert(s->internal_buffer_count);
381. 

libavcodec/utils.c:380:5: 
378. 
379.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
380.     assert(s->internal_buffer_count);
         ^
381. 
382.     if(s->internal_buffer){

libavcodec/utils.c:382:8: Taking true branch
380.     assert(s->internal_buffer_count);
381. 
382.     if(s->internal_buffer){
            ^
383.     buf = NULL; /* avoids warning */
384.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize

libavcodec/utils.c:383:5: 
381. 
382.     if(s->internal_buffer){
383.     buf = NULL; /* avoids warning */
         ^
384.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
385.         buf= &((InternalBuffer*)s->internal_buffer)[i];

libavcodec/utils.c:384:9: 
382.     if(s->internal_buffer){
383.     buf = NULL; /* avoids warning */
384.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
             ^
385.         buf= &((InternalBuffer*)s->internal_buffer)[i];
386.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:384:14: Loop condition is false. Leaving loop
382.     if(s->internal_buffer){
383.     buf = NULL; /* avoids warning */
384.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
                  ^
385.         buf= &((InternalBuffer*)s->internal_buffer)[i];
386.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:389:5: 
387.             break;
388.     }
389.     assert(i < s->internal_buffer_count);
         ^
390.     s->internal_buffer_count--;
391.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];

libavcodec/utils.c:390:5: 
388.     }
389.     assert(i < s->internal_buffer_count);
390.     s->internal_buffer_count--;
         ^
391.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
392. 

libavcodec/utils.c:391:5: 
389.     assert(i < s->internal_buffer_count);
390.     s->internal_buffer_count--;
391.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
         ^
392. 
393.     FFSWAP(InternalBuffer, *buf, *last);

libavcodec/utils.c:393:5: 
391.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
392. 
393.     FFSWAP(InternalBuffer, *buf, *last);
         ^
394.     }
395. 

void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
    int i;
    InternalBuffer *buf, *last;
    assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
    assert(s->internal_buffer_count);
    if(s->internal_buffer){
    buf = NULL;
    for(i=0; i<s->internal_buffer_count; i++){
        buf= &((InternalBuffer*)s->internal_buffer)[i];
        if(buf->data[0] == pic->data[0])
            break;
    }
    assert(i < s->internal_buffer_count);
    s->internal_buffer_count--;
    last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
    FFSWAP(InternalBuffer, *buf, *last);
    }
    for(i=0; i<4; i++){
        pic->data[i]=NULL;
    }
    if(s->debug&FF_DEBUG_BUFFERS)
        av_log(s, AV_LOG_DEBUG, "default_release_buffer called on pic %p, %d buffers used\n", pic, s->internal_buffer_count);
}
['void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){\n    int i;\n    InternalBuffer *buf, *last;\n    assert(pic->type==FF_BUFFER_TYPE_INTERNAL);\n    assert(s->internal_buffer_count);\n    if(s->internal_buffer){\n    buf = NULL;\n    for(i=0; i<s->internal_buffer_count; i++){\n        buf= &((InternalBuffer*)s->internal_buffer)[i];\n        if(buf->data[0] == pic->data[0])\n            break;\n    }\n    assert(i < s->internal_buffer_count);\n    s->internal_buffer_count--;\n    last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];\n    FFSWAP(InternalBuffer, *buf, *last);\n    }\n    for(i=0; i<4; i++){\n        pic->data[i]=NULL;\n    }\n    if(s->debug&FF_DEBUG_BUFFERS)\n        av_log(s, AV_LOG_DEBUG, "default_release_buffer called on pic %p, %d buffers used\\n", pic, s->internal_buffer_count);\n}']