Add option -n to exit if output file exists.

avconv.c

@@ -119,6 +119,7 @@ static int intra_dc_precision = 8;
 static int qp_hist = 0;
 
 static int file_overwrite = 0;
+static int no_file_overwrite = 0;
 static int do_benchmark = 0;
 static int do_hex_dump = 0;
 static int do_pkt_dump = 0;
@@ -3016,11 +3017,11 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
 
 static void assert_file_overwrite(const char *filename)
 {
-    if (!file_overwrite &&
+    if ((!file_overwrite || no_file_overwrite) &&
         (strchr(filename, ':') == NULL || filename[1] == ':' ||
          av_strstart(filename, "file:", NULL))) {
         if (avio_check(filename, 0) == 0) {
-            if (!using_stdin) {
+            if (!using_stdin && (!no_file_overwrite || file_overwrite)) {
                 fprintf(stderr,"File '%s' already exists. Overwrite ? [y/N] ", filename);
                 fflush(stderr);
                 if (!read_yesno()) {
@@ -4268,6 +4269,7 @@ static const OptionDef options[] = {
     { "f", HAS_ARG | OPT_STRING | OPT_OFFSET, {.off = OFFSET(format)}, "force format", "fmt" },
     { "i", HAS_ARG | OPT_FUNC2, {(void*)opt_input_file}, "input file name", "filename" },
     { "y", OPT_BOOL, {(void*)&file_overwrite}, "overwrite output files" },
+    { "n", OPT_BOOL, {(void*)&no_file_overwrite}, "do not overwrite output files" },
     { "c", HAS_ARG | OPT_STRING | OPT_SPEC, {.off = OFFSET(codec_names)}, "codec name", "codec" },
     { "codec", HAS_ARG | OPT_STRING | OPT_SPEC, {.off = OFFSET(codec_names)}, "codec name", "codec" },
     { "pre", HAS_ARG | OPT_STRING | OPT_SPEC, {.off = OFFSET(presets)}, "preset name", "preset" },

doc/avconv.texi

@@ -113,6 +113,9 @@ input file name
 @item -y (@emph{global})
 Overwrite output files without asking.
 
+@item -n (@emph{global})
+Do not overwrite output files but exit if file exists.
+
 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
 Select an encoder (when used before an output file) or a decoder (when used

doc/ffmpeg.texi

@@ -94,6 +94,9 @@ input file name
 @item -y (@emph{global})
 Overwrite output files without asking.
 
+@item -n (@emph{global})
+Do not overwrite output files but exit if file exists.
+
 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
 Select an encoder (when used before an output file) or a decoder (when used

ffmpeg.c

@@ -131,6 +131,7 @@ static const char *audio_codec_name    = NULL;
 static const char *subtitle_codec_name = NULL;
 
 static int file_overwrite = 0;
+static int no_file_overwrite = 0;
 static int do_benchmark = 0;
 static int do_hex_dump = 0;
 static int do_pkt_dump = 0;
@@ -3247,11 +3248,11 @@ static void add_input_streams(OptionsContext *o, AVFormatContext *ic)
 
 static void assert_file_overwrite(const char *filename)
 {
-    if (!file_overwrite &&
+    if ((!file_overwrite || no_file_overwrite) &&
         (strchr(filename, ':') == NULL || filename[1] == ':' ||
          av_strstart(filename, "file:", NULL))) {
         if (avio_check(filename, 0) == 0) {
-            if (!using_stdin) {
+            if (!using_stdin && (!no_file_overwrite || file_overwrite)) {
                 fprintf(stderr,"File '%s' already exists. Overwrite ? [y/N] ", filename);
                 fflush(stderr);
                 term_exit();
@@ -4619,6 +4620,7 @@ static const OptionDef options[] = {
     { "f", HAS_ARG | OPT_STRING | OPT_OFFSET, {.off = OFFSET(format)}, "force format", "fmt" },
     { "i", HAS_ARG | OPT_FUNC2, {(void*)opt_input_file}, "input file name", "filename" },
     { "y", OPT_BOOL, {(void*)&file_overwrite}, "overwrite output files" },
+    { "n", OPT_BOOL, {(void*)&no_file_overwrite}, "do not overwrite output files" },
     { "c", HAS_ARG | OPT_STRING | OPT_SPEC, {.off = OFFSET(codec_names)}, "codec name", "codec" },
     { "codec", HAS_ARG | OPT_STRING | OPT_SPEC, {.off = OFFSET(codec_names)}, "codec name", "codec" },
     { "pre", HAS_ARG | OPT_STRING | OPT_SPEC, {.off = OFFSET(presets)}, "preset name", "preset" },