[FFmpeg-devel] [PATCH 3/3] cmdutils: add -channel_layouts option.

[Nicolas George]

Extract of the output:

Channel layouts:
NAME        DESCRIPTION
FL          front left
<snip>
SDR         surround direct right
mono        FC
stereo      FL+FR
<snip>
octagonal   FL+FR+FC+BL+BR+BC+SL+SR
downmix     DL+DR

Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
 cmdutils.c                   |   28 ++++++++++++++++++++++++++++
 cmdutils.h                   |    7 +++++++
 cmdutils_common_opts.h       |    1 +
 doc/avtools-common-opts.texi |    3 +++
 4 files changed, 39 insertions(+)

diff --git a/cmdutils.c b/cmdutils.c
index edeab93..9f00429 100644
--- a/cmdutils.c
+++ b/cmdutils.c
@@ -979,6 +979,34 @@ int opt_pix_fmts(const char *opt, const char *arg)
     return 0;
 }
 
+int opt_channel_layouts(const char *opt, const char *arg)
+{
+    int i = 0;
+    uint64_t layout, j;
+    const char *name, *descr;
+
+    printf("Channel layouts:\n"
+           "NAME        DESCRIPTION\n");
+    while (!av_get_standard_channel_layout(i++, &layout, &name, &descr)) {
+        if (name) {
+            printf("%-12s", name);
+            if (descr) {
+                printf("%s", descr);
+            } else {
+                const char *sep = "";
+                for (j = 1; j; j <<= 1) {
+                    if ((layout & j)) {
+                        printf("%s%s", sep, av_get_channel_name(j));
+                        sep = "+";
+                    }
+                }
+            }
+            printf("\n");
+        }
+    }
+    return 0;
+}
+
 int show_sample_fmts(const char *opt, const char *arg)
 {
     int i;
diff --git a/cmdutils.h b/cmdutils.h
index 925df50..95339b2 100644
--- a/cmdutils.h
+++ b/cmdutils.h
@@ -329,6 +329,13 @@ int opt_protocols(const char *opt, const char *arg);
 int opt_pix_fmts(const char *opt, const char *arg);
 
 /**
+ * Print a listing containing all the standard channel layouts supported by
+ * the program.
+ * This option processing function does not utilize the arguments.
+ */
+int opt_channel_layouts(const char *opt, const char *arg);
+
+/**
  * Print a listing containing all the sample formats supported by the
  * program.
  */
diff --git a/cmdutils_common_opts.h b/cmdutils_common_opts.h
index 855cb88..314855b 100644
--- a/cmdutils_common_opts.h
+++ b/cmdutils_common_opts.h
@@ -10,6 +10,7 @@
     { "protocols", OPT_EXIT, {(void*)opt_protocols}, "show available protocols" },
     { "filters",   OPT_EXIT, {(void*)opt_filters  }, "show available filters" },
     { "pix_fmts" , OPT_EXIT, {(void*)opt_pix_fmts }, "show available pixel formats" },
+    { "channel_layouts", OPT_EXIT, {(void*)opt_channel_layouts }, "show standard channel layouts" },
     { "sample_fmts", OPT_EXIT, {.func_arg = show_sample_fmts }, "show available audio sample formats" },
     { "loglevel", HAS_ARG, {(void*)opt_loglevel}, "set libav* logging level", "loglevel" },
     { "v", HAS_ARG, {(void*)opt_loglevel}, "set libav* logging level", "loglevel" },
diff --git a/doc/avtools-common-opts.texi b/doc/avtools-common-opts.texi
index b05b5fa..3259ced 100644
--- a/doc/avtools-common-opts.texi
+++ b/doc/avtools-common-opts.texi
@@ -105,6 +105,9 @@ Show available pixel formats.
 @item -sample_fmts
 Show available sample formats.
 
+ at item -channel_layouts
+Show standard channel layouts.
+
 @item -loglevel @var{loglevel} | -v @var{loglevel}
 Set the logging level used by the library.
 @var{loglevel} is a number or a string containing one of the following values:
-- 
1.7.10.4