+/**
+ * Trivial log callback.
+ * Only suitable for show_help and similar since it lacks prefix handling.
+ */
+static void log_callback_help(void* ptr, int level, const char* fmt, va_list vl)
+{
+ vfprintf(stdout, fmt, vl);
+}
+
+static void show_help(void)
+{
+ av_log_set_callback(log_callback_help);
+ printf("usage: ffmpeg [[infile options] -i infile]... {[outfile options] outfile}...\n"
+ "Hyper fast Audio and Video encoder\n");
+ printf("\n");
+ show_help_options(options, "Main options:\n",
+ OPT_EXPERT | OPT_AUDIO | OPT_VIDEO, 0);
+ show_help_options(options, "\nVideo options:\n",
+ OPT_EXPERT | OPT_AUDIO | OPT_VIDEO | OPT_GRAB,
+ OPT_VIDEO);
+ show_help_options(options, "\nAdvanced Video options:\n",
+ OPT_EXPERT | OPT_AUDIO | OPT_VIDEO | OPT_GRAB,
+ OPT_VIDEO | OPT_EXPERT);
+ show_help_options(options, "\nAudio options:\n",
+ OPT_EXPERT | OPT_AUDIO | OPT_VIDEO | OPT_GRAB,
+ OPT_AUDIO);
+ show_help_options(options, "\nAdvanced Audio options:\n",
+ OPT_EXPERT | OPT_AUDIO | OPT_VIDEO | OPT_GRAB,
+ OPT_AUDIO | OPT_EXPERT);
+ show_help_options(options, "\nSubtitle options:\n",
+ OPT_SUBTITLE | OPT_GRAB,
+ OPT_SUBTITLE);
+ show_help_options(options, "\nAudio/Video grab options:\n",
+ OPT_GRAB,
+ OPT_GRAB);
+ show_help_options(options, "\nAdvanced options:\n",
+ OPT_EXPERT | OPT_AUDIO | OPT_VIDEO | OPT_GRAB,
+ OPT_EXPERT);
+ av_opt_show(avctx_opts[0], NULL);
+ av_opt_show(avformat_opts, NULL);
+ av_opt_show(sws_opts, NULL);
+}
+
+static void opt_show_help(void)
+{
+ show_help();
+ exit(0);
+}
+