[FFmpeg-devel] [PATCHv2 3/3] avfilter/formats: do not allow unknown layouts in ff_parse_channel_layout if nret is not set

[Marton Balint]

Current code returned the number of channels as channel layout in that case,
and if nret is not set then unknown layouts are typically not supported.

Also use the common parsing code. Use a temporary workaround to parse an
unknown channel layout such as '13c', after a 1 year grace period only '13C'
will work.

Signed-off-by: Marton Balint <cus at passwd.hu>
---
 libavfilter/formats.c         | 26 +++++++++++++++-----------
 libavfilter/tests/formats.c   |  3 +++
 tests/ref/fate/filter-formats |  3 +++
 3 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/libavfilter/formats.c b/libavfilter/formats.c
index 840780d..d4de862 100644
--- a/libavfilter/formats.c
+++ b/libavfilter/formats.c
@@ -664,22 +664,26 @@ int ff_parse_channel_layout(int64_t *ret, int *nret, const char *arg,
 {
     char *tail;
     int64_t chlayout;
-
-    chlayout = av_get_channel_layout(arg);
-    if (chlayout == 0) {
-        chlayout = strtol(arg, &tail, 10);
-        if (!(*tail == '\0' || *tail == 'c' && *(tail + 1) == '\0') || chlayout <= 0 || chlayout > 63) {
+    int nb_channels;
+
+    if (av_get_extended_channel_layout(arg, &chlayout, &nb_channels) < 0) {
+        /* [TEMPORARY 2016-12 -> 2017-12]*/
+        nb_channels = strtol(arg, &tail, 10);
+        if (!errno && *tail == 'c' && *(tail + 1) == '\0' && nb_channels > 0 && nb_channels < 64) {
+            chlayout = 0;
+            av_log(log_ctx, AV_LOG_WARNING, "Deprecated channel count specification '%s'. This will stop working in releases made in 2018 and after.\n", arg);
+        } else {
             av_log(log_ctx, AV_LOG_ERROR, "Invalid channel layout '%s'\n", arg);
             return AVERROR(EINVAL);
         }
-        if (nret) {
-            *nret = chlayout;
-            *ret = 0;
-            return 0;
-        }
+    }
+    if (!chlayout && !nret) {
+        av_log(log_ctx, AV_LOG_ERROR, "Unknown channel layout '%s' is not supported.\n", arg);
+        return AVERROR(EINVAL);
     }
     *ret = chlayout;
     if (nret)
-        *nret = av_get_channel_layout_nb_channels(chlayout);
+        *nret = nb_channels;
+
     return 0;
 }
diff --git a/libavfilter/tests/formats.c b/libavfilter/tests/formats.c
index 0e8ba4a..5450742 100644
--- a/libavfilter/tests/formats.c
+++ b/libavfilter/tests/formats.c
@@ -39,6 +39,9 @@ int main(void)
         "-1c",
         "60c",
         "65c",
+        "2C",
+        "60C",
+        "65C",
         "5.1",
         "stereo",
         "1+1+1+1",
diff --git a/tests/ref/fate/filter-formats b/tests/ref/fate/filter-formats
index 4c303d8..ea85eed 100644
--- a/tests/ref/fate/filter-formats
+++ b/tests/ref/fate/filter-formats
@@ -77,6 +77,9 @@ quad(side)
 -1 = ff_parse_channel_layout(FFFFFFFFFFFFFFFF, -1, -1c);
 0 = ff_parse_channel_layout(0000000000000000, 60, 60c);
 -1 = ff_parse_channel_layout(FFFFFFFFFFFFFFFF, -1, 65c);
+0 = ff_parse_channel_layout(0000000000000000,  2, 2C);
+0 = ff_parse_channel_layout(0000000000000000, 60, 60C);
+-1 = ff_parse_channel_layout(FFFFFFFFFFFFFFFF, -1, 65C);
 0 = ff_parse_channel_layout(000000000000003F,  6, 5.1);
 0 = ff_parse_channel_layout(0000000000000003,  2, stereo);
 0 = ff_parse_channel_layout(0000000000000001,  1, 1+1+1+1);
-- 
2.10.2