avconv.c:1283: error: Null Dereference
  pointer `vstats_file` last assigned on line 1273 could be null and is dereferenced by call to `fprintf()` at line 1283, column 9.

avconv.c:1264:1: start of procedure do_video_stats()
1262. }
1263. 
1264. static void do_video_stats(AVFormatContext *os, OutputStream *ost,
      ^
1265.                            int frame_size)
1266. {

avconv.c:1272:10: Taking true branch
1270. 
1271.     /* this is executed just the first time do_video_stats is called */
1272.     if (!vstats_file) {
               ^
1273.         vstats_file = fopen(vstats_filename, "w");
1274.         if (!vstats_file) {

avconv.c:1273:9: 
1271.     /* this is executed just the first time do_video_stats is called */
1272.     if (!vstats_file) {
1273.         vstats_file = fopen(vstats_filename, "w");
              ^
1274.         if (!vstats_file) {
1275.             perror("fopen");

avconv.c:1274:14: Taking true branch
1272.     if (!vstats_file) {
1273.         vstats_file = fopen(vstats_filename, "w");
1274.         if (!vstats_file) {
                   ^
1275.             perror("fopen");
1276.             exit_program(1);

avconv.c:1275:13: 
1273.         vstats_file = fopen(vstats_filename, "w");
1274.         if (!vstats_file) {
1275.             perror("fopen");
                  ^
1276.             exit_program(1);
1277.         }

avconv.c:1276:13: Skipping exit_program(): empty list of specs
1274.         if (!vstats_file) {
1275.             perror("fopen");
1276.             exit_program(1);
                  ^
1277.         }
1278.     }

avconv.c:1280:5: 
1278.     }
1279. 
1280.     enc = ost->st->codec;
          ^
1281.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1282.         frame_number = ost->frame_number;

avconv.c:1281:9: Taking true branch
1279. 
1280.     enc = ost->st->codec;
1281.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
              ^
1282.         frame_number = ost->frame_number;
1283.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);

avconv.c:1282:9: 
1280.     enc = ost->st->codec;
1281.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1282.         frame_number = ost->frame_number;
              ^
1283.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
1284.         if (enc->flags&CODEC_FLAG_PSNR)

avconv.c:1283:9: 
1281.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1282.         frame_number = ost->frame_number;
1283.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
              ^
1284.         if (enc->flags&CODEC_FLAG_PSNR)
1285.             fprintf(vstats_file, "PSNR= %6.2f ", psnr(enc->coded_frame->error[0]/(enc->width*enc->height*255.0*255.0)));
