avconv.c:1286: error: Null Dereference
  pointer `vstats_file` last assigned on line 1276 could be null and is dereferenced by call to `fprintf()` at line 1286, column 9.

avconv.c:1267:1: start of procedure do_video_stats()
1265. }
1266. 
1267. static void do_video_stats(AVFormatContext *os, OutputStream *ost,
      ^
1268.                            int frame_size)
1269. {

avconv.c:1275:10: Taking true branch
1273. 
1274.     /* this is executed just the first time do_video_stats is called */
1275.     if (!vstats_file) {
               ^
1276.         vstats_file = fopen(vstats_filename, "w");
1277.         if (!vstats_file) {

avconv.c:1276:9: 
1274.     /* this is executed just the first time do_video_stats is called */
1275.     if (!vstats_file) {
1276.         vstats_file = fopen(vstats_filename, "w");
              ^
1277.         if (!vstats_file) {
1278.             perror("fopen");

avconv.c:1277:14: Taking true branch
1275.     if (!vstats_file) {
1276.         vstats_file = fopen(vstats_filename, "w");
1277.         if (!vstats_file) {
                   ^
1278.             perror("fopen");
1279.             exit_program(1);

avconv.c:1278:13: 
1276.         vstats_file = fopen(vstats_filename, "w");
1277.         if (!vstats_file) {
1278.             perror("fopen");
                  ^
1279.             exit_program(1);
1280.         }

avconv.c:1279:13: Skipping exit_program(): empty list of specs
1277.         if (!vstats_file) {
1278.             perror("fopen");
1279.             exit_program(1);
                  ^
1280.         }
1281.     }

avconv.c:1283:5: 
1281.     }
1282. 
1283.     enc = ost->st->codec;
          ^
1284.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1285.         frame_number = ost->frame_number;

avconv.c:1284:9: Taking true branch
1282. 
1283.     enc = ost->st->codec;
1284.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
              ^
1285.         frame_number = ost->frame_number;
1286.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);

avconv.c:1285:9: 
1283.     enc = ost->st->codec;
1284.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1285.         frame_number = ost->frame_number;
              ^
1286.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
1287.         if (enc->flags&CODEC_FLAG_PSNR)

avconv.c:1286:9: 
1284.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1285.         frame_number = ost->frame_number;
1286.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
              ^
1287.         if (enc->flags&CODEC_FLAG_PSNR)
1288.             fprintf(vstats_file, "PSNR= %6.2f ", psnr(enc->coded_frame->error[0]/(enc->width*enc->height*255.0*255.0)));
