[FFmpeg-devel] [PATCH 1/4] lavd: add list devices API

[Lukasz Marek]

TODO: minor bumps, APIchange update

Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
---
 libavdevice/avdevice.c | 32 ++++++++++++++++++++++++++++++++
 libavdevice/avdevice.h | 39 +++++++++++++++++++++++++++++++++++++++
 libavformat/avformat.h | 10 ++++++++++
 3 files changed, 81 insertions(+)

diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c
index 51617fb..a418ef8 100644
--- a/libavdevice/avdevice.c
+++ b/libavdevice/avdevice.c
@@ -52,3 +52,35 @@ int avdevice_dev_to_app_control_message(struct AVFormatContext *s, enum AVDevToA
         return AVERROR(ENOSYS);
     return s->control_message_cb(s, type, data, data_size);
 }
+
+int avdevice_list_devices(AVFormatContext *s, AVDeviceInfoList **device_list)
+{
+    av_assert1(s);
+    av_assert1(s->oformat || s->iformat);
+    if ((s->oformat && !s->oformat->get_device_list) ||
+        (s->iformat && !s->iformat->get_device_list))
+        return AVERROR(ENOSYS);
+    if (s->oformat)
+        return s->oformat->get_device_list(s, (void **)device_list);
+    else
+        return s->iformat->get_device_list(s, (void **)device_list);
+}
+
+void avdevice_free_list_devices(AVDeviceInfoList **device_list)
+{
+    AVDeviceInfoList *list;
+    AVDeviceInfo *dev;
+    int i;
+
+    if (!device_list || !(*device_list))
+        return;
+    list = *device_list;
+
+    for (i = 0; i < list->nb_devices; i++) {
+        dev = &list->devices[i];
+        av_free(dev->device_name);
+        av_free(dev->device_description);
+        av_free(dev);
+    }
+    av_freep(device_list);
+}
diff --git a/libavdevice/avdevice.h b/libavdevice/avdevice.h
index a6408ea..2392cac 100644
--- a/libavdevice/avdevice.h
+++ b/libavdevice/avdevice.h
@@ -186,4 +186,43 @@ int avdevice_dev_to_app_control_message(struct AVFormatContext *s,
                                         enum AVDevToAppMessageType type,
                                         void *data, size_t data_size);
 
+/**
+ * Structure describes basic parameters of the device.
+ */
+typedef struct AVDeviceInfo {
+    char *device_name;                   /**< device name, format depends on device */
+    char *device_description;            /**< human friendly name */
+} AVDeviceInfo;
+
+/**
+ * List of devices.
+ */
+typedef struct AVDeviceInfoList {
+    AVDeviceInfo *devices;               /**< list of autodetected devices */
+    int nb_devices;                      /**< number of autodetected devices */
+    int default_device;                  /**< index of default device or -1 if no default */
+} AVDeviceInfoList;
+
+/**
+ * List devices.
+ *
+ * Returns available device names and their parameters.
+ *
+ * @note: Some devices may accept system-dependent device names that cannot be
+ *        autodetected. The list returned by this function cannot be assumed to
+ *        be always completed.
+ *
+ * @param s                device context.
+ * @param[out] device_list list of autodetected devices.
+ * @return count of autodetected devices, negative on error.
+ */
+int avdevice_list_devices(struct AVFormatContext *s, AVDeviceInfoList **device_list);
+
+/**
+ * Convinient function to free result of avdevice_list_devices().
+ *
+ * @param devices device list to be freed.
+ */
+void avdevice_free_list_devices(AVDeviceInfoList **device_list);
+
 #endif /* AVDEVICE_AVDEVICE_H */
diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 4d3cc14..dc9aeee 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -460,6 +460,11 @@ typedef struct AVOutputFormat {
      */
     int (*control_message)(struct AVFormatContext *s, int type,
                            void *data, size_t data_size);
+    /**
+     * Returns device list with it properties.
+     * @see avdevice_list_devices() for more details.
+     */
+    int (*get_device_list)(struct AVFormatContext *s, void **device_list);
 } AVOutputFormat;
 /**
  * @}
@@ -588,6 +593,11 @@ typedef struct AVInputFormat {
      * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
      */
     int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
+    /**
+     * Returns device list with it properties.
+     * @see avdevice_list_devices() for more details.
+     */
+    int (*get_device_list)(struct AVFormatContext *s, void **device_list);
 } AVInputFormat;
 /**
  * @}
-- 
1.8.3.2