avconv.c:1294: error: Null Dereference
  pointer `vstats_file` last assigned on line 1284 could be null and is dereferenced by call to `fprintf()` at line 1294, column 9.

avconv.c:1275:1: start of procedure do_video_stats()
1273. }
1274. 
1275. static void do_video_stats(AVFormatContext *os, OutputStream *ost,
      ^
1276.                            int frame_size)
1277. {

avconv.c:1283:10: Taking true branch
1281. 
1282.     /* this is executed just the first time do_video_stats is called */
1283.     if (!vstats_file) {
               ^
1284.         vstats_file = fopen(vstats_filename, "w");
1285.         if (!vstats_file) {

avconv.c:1284:9: 
1282.     /* this is executed just the first time do_video_stats is called */
1283.     if (!vstats_file) {
1284.         vstats_file = fopen(vstats_filename, "w");
              ^
1285.         if (!vstats_file) {
1286.             perror("fopen");

avconv.c:1285:14: Taking true branch
1283.     if (!vstats_file) {
1284.         vstats_file = fopen(vstats_filename, "w");
1285.         if (!vstats_file) {
                   ^
1286.             perror("fopen");
1287.             exit_program(1);

avconv.c:1286:13: 
1284.         vstats_file = fopen(vstats_filename, "w");
1285.         if (!vstats_file) {
1286.             perror("fopen");
                  ^
1287.             exit_program(1);
1288.         }

avconv.c:1287:13: Skipping exit_program(): empty list of specs
1285.         if (!vstats_file) {
1286.             perror("fopen");
1287.             exit_program(1);
                  ^
1288.         }
1289.     }

avconv.c:1291:5: 
1289.     }
1290. 
1291.     enc = ost->st->codec;
          ^
1292.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1293.         frame_number = ost->frame_number;

avconv.c:1292:9: Taking true branch
1290. 
1291.     enc = ost->st->codec;
1292.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
              ^
1293.         frame_number = ost->frame_number;
1294.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);

avconv.c:1293:9: 
1291.     enc = ost->st->codec;
1292.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1293.         frame_number = ost->frame_number;
              ^
1294.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
1295.         if (enc->flags&CODEC_FLAG_PSNR)

avconv.c:1294:9: 
1292.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1293.         frame_number = ost->frame_number;
1294.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
              ^
1295.         if (enc->flags&CODEC_FLAG_PSNR)
1296.             fprintf(vstats_file, "PSNR= %6.2f ", psnr(enc->coded_frame->error[0]/(enc->width*enc->height*255.0*255.0)));
