avconv.c:1471: error: Null Dereference
  pointer `vstats_file` last assigned on line 1461 could be null and is dereferenced by call to `fprintf()` at line 1471, column 9.

avconv.c:1452:1: start of procedure do_video_stats()
1450. }
1451. 
1452. static void do_video_stats(AVFormatContext *os, OutputStream *ost,
      ^
1453.                            int frame_size)
1454. {

avconv.c:1460:10: Taking true branch
1458. 
1459.     /* this is executed just the first time do_video_stats is called */
1460.     if (!vstats_file) {
               ^
1461.         vstats_file = fopen(vstats_filename, "w");
1462.         if (!vstats_file) {

avconv.c:1461:9: 
1459.     /* this is executed just the first time do_video_stats is called */
1460.     if (!vstats_file) {
1461.         vstats_file = fopen(vstats_filename, "w");
              ^
1462.         if (!vstats_file) {
1463.             perror("fopen");

avconv.c:1462:14: Taking true branch
1460.     if (!vstats_file) {
1461.         vstats_file = fopen(vstats_filename, "w");
1462.         if (!vstats_file) {
                   ^
1463.             perror("fopen");
1464.             exit_program(1);

avconv.c:1463:13: 
1461.         vstats_file = fopen(vstats_filename, "w");
1462.         if (!vstats_file) {
1463.             perror("fopen");
                  ^
1464.             exit_program(1);
1465.         }

avconv.c:1464:13: Skipping exit_program(): empty list of specs
1462.         if (!vstats_file) {
1463.             perror("fopen");
1464.             exit_program(1);
                  ^
1465.         }
1466.     }

avconv.c:1468:5: 
1466.     }
1467. 
1468.     enc = ost->st->codec;
          ^
1469.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1470.         frame_number = ost->frame_number;

avconv.c:1469:9: Taking true branch
1467. 
1468.     enc = ost->st->codec;
1469.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
              ^
1470.         frame_number = ost->frame_number;
1471.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality / (float)FF_QP2LAMBDA);

avconv.c:1470:9: 
1468.     enc = ost->st->codec;
1469.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1470.         frame_number = ost->frame_number;
              ^
1471.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality / (float)FF_QP2LAMBDA);
1472.         if (enc->flags&CODEC_FLAG_PSNR)

avconv.c:1471:9: 
1469.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1470.         frame_number = ost->frame_number;
1471.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality / (float)FF_QP2LAMBDA);
              ^
1472.         if (enc->flags&CODEC_FLAG_PSNR)
1473.             fprintf(vstats_file, "PSNR= %6.2f ", psnr(enc->coded_frame->error[0] / (enc->width * enc->height * 255.0 * 255.0)));
