@@ -66,7 +66,7 @@ static av_cold int init(AVFilterContext *ctx)

         (ret = ff_parse_sample_format(&aconvert->out_sample_fmt, aconvert->format_str, ctx)) < 0)

         return ret;

     if (aconvert->channel_layout_str && strcmp(aconvert->channel_layout_str, "auto"))

-        return ff_parse_channel_layout(&aconvert->out_chlayout, aconvert->channel_layout_str, ctx);

+        return ff_parse_channel_layout(&aconvert->out_chlayout, NULL, aconvert->channel_layout_str, ctx);

     return ret;

 }

@@ -116,7 +116,7 @@ static av_cold int init(AVFilterContext *ctx)

     if (!args)

         return AVERROR(ENOMEM);

     arg = av_strtok(args, "|", &tokenizer);

-    ret = ff_parse_channel_layout(&pan->out_channel_layout, arg, ctx);

+    ret = ff_parse_channel_layout(&pan->out_channel_layout, NULL, arg, ctx);

     if (ret < 0)

         goto fail;

     pan->nb_output_channels = av_get_channel_layout_nb_channels(pan->out_channel_layout);

@@ -109,7 +109,7 @@ static av_cold int init(AVFilterContext *ctx)

     if (eval->chlayout_str) {

         int n;

-        ret = ff_parse_channel_layout(&eval->chlayout, eval->chlayout_str, ctx);

+        ret = ff_parse_channel_layout(&eval->chlayout, NULL, eval->chlayout_str, ctx);

         if (ret < 0)

             goto end;

@@ -68,7 +68,7 @@ static av_cold int init(AVFilterContext *ctx)

                                      null->sample_rate_str, ctx)) < 0)

         return ret;

-    if ((ret = ff_parse_channel_layout(&null->channel_layout,

+    if ((ret = ff_parse_channel_layout(&null->channel_layout, NULL,

                                         null->channel_layout_str, ctx)) < 0)

         return ret;

@@ -615,10 +615,21 @@ int ff_parse_sample_rate(int *ret, const char *arg, void *log_ctx)

     return 0;

 }

-int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx)

+int ff_parse_channel_layout(int64_t *ret, int *nret, const char *arg,

+                            void *log_ctx)

 {

     char *tail;

-    int64_t chlayout = av_get_channel_layout(arg);

+    int64_t chlayout, count;

+

+    if (nret) {

+        count = strtol(arg, &tail, 10);

+        if (*tail == 'c' && !tail[1] && count > 0 && count < 63) {

+            *nret = count;

+            *ret = 0;

+            return 0;

+        }

+    }

+    chlayout = av_get_channel_layout(arg);

     if (chlayout == 0) {

         chlayout = strtol(arg, &tail, 10);

         if (*tail || chlayout == 0) {

@@ -627,6 +638,8 @@ int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx)

         }

     }

     *ret = chlayout;

+    if (nret)

+        *nret = av_get_channel_layout_nb_channels(chlayout);

     return 0;

 }

@@ -207,11 +207,14 @@ int ff_parse_sample_format(int *ret, const char *arg, void *log_ctx);

  * Parse a channel layout or a corresponding integer representation.

  *

  * @param ret 64bit integer pointer to where the value should be written.

+ * @param nret integer pointer to the number of channels;

+ *             if not NULL, then unknown channel layouts are accepted

  * @param arg string to parse

  * @param log_ctx log context

  * @return >= 0 in case of success, a negative AVERROR code on error

  */

-int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx);

+int ff_parse_channel_layout(int64_t *ret, int *nret, const char *arg,

+                            void *log_ctx);

 void ff_update_link_current_pts(AVFilterLink *link, int64_t pts);