Merge commit '7e42d5f0ab2aeac811fd01e122627c9198b13f01'

[ffmpeg] / libavdevice / avdevice.c

diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c
index a42d3498b56d5b083e8dca72beb5f4b3ba3a8f5b..72e1b67887f9bc7d9e63822e17fa63a29e33d0d4 100644 (file)
--- a/libavdevice/avdevice.c
+++ b/libavdevice/avdevice.c
@@ -78,6 +78,52 @@ const char * avdevice_license(void)
     return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
 }
 
+static void *device_next(void *prev, int output,
+                         AVClassCategory c1, AVClassCategory c2)
+{
+    const AVClass *pc;
+    AVClassCategory category = AV_CLASS_CATEGORY_NA;
+    do {
+        if (output) {
+            if (!(prev = av_oformat_next(prev)))
+                break;
+            pc = ((AVOutputFormat *)prev)->priv_class;
+        } else {
+            if (!(prev = av_iformat_next(prev)))
+                break;
+            pc = ((AVInputFormat *)prev)->priv_class;
+        }
+        if (!pc)
+            continue;
+        category = pc->category;
+    } while (category != c1 && category != c2);
+    return prev;
+}
+
+AVInputFormat *av_input_audio_device_next(AVInputFormat  *d)
+{
+    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
+                       AV_CLASS_CATEGORY_DEVICE_INPUT);
+}
+
+AVInputFormat *av_input_video_device_next(AVInputFormat  *d)
+{
+    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
+                       AV_CLASS_CATEGORY_DEVICE_INPUT);
+}
+
+AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d)
+{
+    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
+                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
+}
+
+AVOutputFormat *av_output_video_device_next(AVOutputFormat *d)
+{
+    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
+                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
+}
+
 int avdevice_app_to_dev_control_message(struct AVFormatContext *s, enum AVAppToDevMessageType type,
                                         void *data, size_t data_size)
 {