ffmpeg roll of source to mar 9 version...

patched-ffmpeg-mt/libavutil/fifo.c

 /*
  * a very simple circular buffer FIFO implementation
  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
  * Copyright (c) 2006 Roman Shaposhnik
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
@@ skipping 60 matching lines @@
         av_fifo_generic_read(f, f2->buffer, len, NULL);
         f2->wptr += len;
         f2->wndx += len;
         av_free(f->buffer);
         *f= *f2;
         av_free(f2);
     }
     return 0;
 }
 
+// src must NOT be const as it can be a context for func that may need updating (like a pointer or byte counter)
 int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
 {
     int total = size;
     do {
         int len = FFMIN(f->end - f->wptr, size);
         if(func) {
             if(func(src, f->wptr, len) <= 0)
                 break;
         } else {
             memcpy(f->wptr, src, len);
@@ skipping 28 matching lines @@
 }
 
 /** Discard data from the FIFO. */
 void av_fifo_drain(AVFifoBuffer *f, int size)
 {
     f->rptr += size;
     if (f->rptr >= f->end)
         f->rptr -= f->end - f->buffer;
     f->rndx += size;
 }