avconv.c:1460: error: Null Dereference
  pointer `vstats_file` last assigned on line 1450 could be null and is dereferenced by call to `fprintf()` at line 1460, column 9.

avconv.c:1441:1: start of procedure do_video_stats()
1439. }
1440. 
1441. static void do_video_stats(AVFormatContext *os, OutputStream *ost,
      ^
1442.                            int frame_size)
1443. {

avconv.c:1449:10: Taking true branch
1447. 
1448.     /* this is executed just the first time do_video_stats is called */
1449.     if (!vstats_file) {
               ^
1450.         vstats_file = fopen(vstats_filename, "w");
1451.         if (!vstats_file) {

avconv.c:1450:9: 
1448.     /* this is executed just the first time do_video_stats is called */
1449.     if (!vstats_file) {
1450.         vstats_file = fopen(vstats_filename, "w");
              ^
1451.         if (!vstats_file) {
1452.             perror("fopen");

avconv.c:1451:14: Taking true branch
1449.     if (!vstats_file) {
1450.         vstats_file = fopen(vstats_filename, "w");
1451.         if (!vstats_file) {
                   ^
1452.             perror("fopen");
1453.             exit_program(1);

avconv.c:1452:13: 
1450.         vstats_file = fopen(vstats_filename, "w");
1451.         if (!vstats_file) {
1452.             perror("fopen");
                  ^
1453.             exit_program(1);
1454.         }

avconv.c:1453:13: Skipping exit_program(): empty list of specs
1451.         if (!vstats_file) {
1452.             perror("fopen");
1453.             exit_program(1);
                  ^
1454.         }
1455.     }

avconv.c:1457:5: 
1455.     }
1456. 
1457.     enc = ost->st->codec;
          ^
1458.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1459.         frame_number = ost->frame_number;

avconv.c:1458:9: Taking true branch
1456. 
1457.     enc = ost->st->codec;
1458.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
              ^
1459.         frame_number = ost->frame_number;
1460.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality / (float)FF_QP2LAMBDA);

avconv.c:1459:9: 
1457.     enc = ost->st->codec;
1458.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1459.         frame_number = ost->frame_number;
              ^
1460.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality / (float)FF_QP2LAMBDA);
1461.         if (enc->flags&CODEC_FLAG_PSNR)

avconv.c:1460:9: 
1458.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1459.         frame_number = ost->frame_number;
1460.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality / (float)FF_QP2LAMBDA);
              ^
1461.         if (enc->flags&CODEC_FLAG_PSNR)
1462.             fprintf(vstats_file, "PSNR= %6.2f ", psnr(enc->coded_frame->error[0] / (enc->width * enc->height * 255.0 * 255.0)));
