+static void assert_file_overwrite(const char *filename)
+{
+ if (!file_overwrite &&
+ (strchr(filename, ':') == NULL || filename[1] == ':' ||
+ av_strstart(filename, "file:", NULL))) {
+ if (avio_check(filename, 0) == 0) {
+ if (!using_stdin) {
+ fprintf(stderr,"File '%s' already exists. Overwrite ? [y/N] ", filename);
+ fflush(stderr);
+ if (!read_yesno()) {
+ fprintf(stderr, "Not overwriting - exiting\n");
+ exit_program(1);
+ }
+ }
+ else {
+ fprintf(stderr,"File '%s' already exists. Exiting.\n", filename);
+ exit_program(1);
+ }
+ }
+ }
+}
+
+static void dump_attachment(AVStream *st, const char *filename)
+{
+ int ret;
+ AVIOContext *out = NULL;
+ AVDictionaryEntry *e;
+
+ if (!st->codec->extradata_size) {
+ av_log(NULL, AV_LOG_WARNING, "No extradata to dump in stream #%d:%d.\n",
+ nb_input_files - 1, st->index);
+ return;
+ }
+ if (!*filename && (e = av_dict_get(st->metadata, "filename", NULL, 0)))
+ filename = e->value;
+ if (!*filename) {
+ av_log(NULL, AV_LOG_FATAL, "No filename specified and no 'filename' tag"
+ "in stream #%d:%d.\n", nb_input_files - 1, st->index);
+ exit_program(1);
+ }
+
+ assert_file_overwrite(filename);
+
+ if ((ret = avio_open2(&out, filename, AVIO_FLAG_WRITE, &int_cb, NULL)) < 0) {
+ av_log(NULL, AV_LOG_FATAL, "Could not open file %s for writing.\n",
+ filename);
+ exit_program(1);
+ }
+
+ avio_write(out, st->codec->extradata, st->codec->extradata_size);
+ avio_flush(out);
+ avio_close(out);
+}
+