+int ffio_realloc_buf(AVIOContext *s, int buf_size)
+{
+ uint8_t *buffer;
+ int data_size;
+
+ if (!s->buffer_size)
+ return ffio_set_buf_size(s, buf_size);
+
+ if (buf_size <= s->buffer_size)
+ return 0;
+
+ buffer = av_malloc(buf_size);
+ if (!buffer)
+ return AVERROR(ENOMEM);
+
+ data_size = s->write_flag ? (s->buf_ptr - s->buffer) : (s->buf_end - s->buf_ptr);
+ if (data_size > 0)
+ memcpy(buffer, s->write_flag ? s->buffer : s->buf_ptr, data_size);
+ av_free(s->buffer);
+ s->buffer = buffer;
+ s->orig_buffer_size = buf_size;
+ s->buffer_size = buf_size;
+ s->buf_ptr = s->write_flag ? (s->buffer + data_size) : s->buffer;
+ if (s->write_flag)
+ s->buf_ptr_max = s->buffer + data_size;
+
+ s->buf_end = s->write_flag ? (s->buffer + s->buffer_size) : (s->buf_ptr + data_size);
+
+ return 0;
+}
+