core-format: Add pa_format_info_get_channels()

This also fixes an issue in pa_format_info_to_sample_spec(): it did
no validation for the channels value. Now the validation is taken care
of in pa_format_info_get_channels().

3 files changed, 27 insertions, 4 deletions

diff --git a/src/pulse/format.c b/src/pulse/format.c
index 1b4a1549..424df0e6 100644
--- a/src/pulse/format.c
+++ b/src/pulse/format.c
@@ -219,7 +219,6 @@ pa_format_info* pa_format_info_from_sample_spec(pa_sample_spec *ss, pa_channel_m
 /* For PCM streams */
 int pa_format_info_to_sample_spec(pa_format_info *f, pa_sample_spec *ss, pa_channel_map *map) {
     char *m = NULL;
-    int channels;
     int ret = -PA_ERR_INVALID;
 
     pa_assert(f);
@@ -232,11 +231,9 @@ int pa_format_info_to_sample_spec(pa_format_info *f, pa_sample_spec *ss, pa_chan
         goto out;
     if (pa_format_info_get_rate(f, &ss->rate) < 0)
         goto out;
-    if (pa_format_info_get_prop_int(f, PA_PROP_FORMAT_CHANNELS, &channels))
+    if (pa_format_info_get_channels(f, &ss->channels) < 0)
         goto out;
 
-    ss->channels = (uint8_t) channels;
-
     if (map) {
         pa_channel_map_init(map);
 
diff --git a/src/pulsecore/core-format.c b/src/pulsecore/core-format.c
index 43ad4683..c2457199 100644
--- a/src/pulsecore/core-format.c
+++ b/src/pulsecore/core-format.c
@@ -74,6 +74,27 @@ int pa_format_info_get_rate(pa_format_info *f, uint32_t *rate) {
     return 0;
 }
 
+int pa_format_info_get_channels(pa_format_info *f, uint8_t *channels) {
+    int r;
+    int channels_local;
+
+    pa_assert(f);
+    pa_assert(channels);
+
+    r = pa_format_info_get_prop_int(f, PA_PROP_FORMAT_CHANNELS, &channels_local);
+    if (r < 0)
+        return r;
+
+    if (!pa_channels_valid(channels_local)) {
+        pa_log_debug("Invalid channel count: %i", channels_local);
+        return -PA_ERR_INVALID;
+    }
+
+    *channels = channels_local;
+
+    return 0;
+}
+
 int pa_format_info_to_sample_spec_fake(pa_format_info *f, pa_sample_spec *ss, pa_channel_map *map) {
     int rate;
 
diff --git a/src/pulsecore/core-format.h b/src/pulsecore/core-format.h
index 7e5d9829..06fb51f3 100644
--- a/src/pulsecore/core-format.h
+++ b/src/pulsecore/core-format.h
@@ -32,6 +32,11 @@ int pa_format_info_get_sample_format(pa_format_info *f, pa_sample_format_t *sf);
  * -PA_ERR_NOENTITY. */
 int pa_format_info_get_rate(pa_format_info *f, uint32_t *rate);
 
+/* Gets the channel count stored in the format info. Returns a negative error
+ * code on failure. If the channels property is not set at all, returns
+ * -PA_ERR_NOENTITY. */
+int pa_format_info_get_channels(pa_format_info *f, uint8_t *channels);
+
 /* For compressed formats. Converts the format info into a sample spec and a
  * channel map that an ALSA device can use as its configuration parameters when
  * playing back the compressed data. That is, the returned sample spec doesn't