avconv.c:1288: error: Null Dereference
  pointer `vstats_file` last assigned on line 1278 could be null and is dereferenced by call to `fprintf()` at line 1288, column 9.

avconv.c:1269:1: start of procedure do_video_stats()
1267. }
1268. 
1269. static void do_video_stats(AVFormatContext *os, OutputStream *ost,
      ^
1270.                            int frame_size)
1271. {

avconv.c:1277:10: Taking true branch
1275. 
1276.     /* this is executed just the first time do_video_stats is called */
1277.     if (!vstats_file) {
               ^
1278.         vstats_file = fopen(vstats_filename, "w");
1279.         if (!vstats_file) {

avconv.c:1278:9: 
1276.     /* this is executed just the first time do_video_stats is called */
1277.     if (!vstats_file) {
1278.         vstats_file = fopen(vstats_filename, "w");
              ^
1279.         if (!vstats_file) {
1280.             perror("fopen");

avconv.c:1279:14: Taking true branch
1277.     if (!vstats_file) {
1278.         vstats_file = fopen(vstats_filename, "w");
1279.         if (!vstats_file) {
                   ^
1280.             perror("fopen");
1281.             exit_program(1);

avconv.c:1280:13: 
1278.         vstats_file = fopen(vstats_filename, "w");
1279.         if (!vstats_file) {
1280.             perror("fopen");
                  ^
1281.             exit_program(1);
1282.         }

avconv.c:1281:13: Skipping exit_program(): empty list of specs
1279.         if (!vstats_file) {
1280.             perror("fopen");
1281.             exit_program(1);
                  ^
1282.         }
1283.     }

avconv.c:1285:5: 
1283.     }
1284. 
1285.     enc = ost->st->codec;
          ^
1286.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1287.         frame_number = ost->frame_number;

avconv.c:1286:9: Taking true branch
1284. 
1285.     enc = ost->st->codec;
1286.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
              ^
1287.         frame_number = ost->frame_number;
1288.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);

avconv.c:1287:9: 
1285.     enc = ost->st->codec;
1286.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1287.         frame_number = ost->frame_number;
              ^
1288.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
1289.         if (enc->flags&CODEC_FLAG_PSNR)

avconv.c:1288:9: 
1286.     if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
1287.         frame_number = ost->frame_number;
1288.         fprintf(vstats_file, "frame= %5d q= %2.1f ", frame_number, enc->coded_frame->quality/(float)FF_QP2LAMBDA);
              ^
1289.         if (enc->flags&CODEC_FLAG_PSNR)
1290.             fprintf(vstats_file, "PSNR= %6.2f ", psnr(enc->coded_frame->error[0]/(enc->width*enc->height*255.0*255.0)));
