Split bit_rate_set(), one for audio, one for video.

Fixes #572.

As discussed in the issue, there's a risk that toxcore may not hold the
maximum bitrates libvpx supports, if toxcore insists on using integer
type. I initially proposed to have another flag in set(), so that we can
use unsigned type instead. iphydf came up with a better solution, that is
splitting the original functions, one for audio, one for video. Now, we
could safely replace int32_t with uint32_t.

Also: clean video_bit_rate_invalid()

Though this is not a part of issue #572, as it's used in the
toxav_bit_rate_set(), i cleaned the code. As mannol said, there should be
a check. Uint32_t is large enough to hold the maximum bitrates libvpx
supports, but user may pass a value larger than uint while smaller than
uint32_t. Thanks to the reminding from nurupo, it's no longer a stub
function.

Bitrate error enums are shared for both audio and video
https://github.com/TokTok/c-toxcore/pull/578#issuecomment-360095609, just
as iphydf said.

1 files changed, 32 insertions, 27 deletions

diff --git a/toxav/toxav.api.h b/toxav/toxav.api.h
index d6f30c67..511b9e2d 100644
--- a/toxav/toxav.api.h
+++ b/toxav/toxav.api.h
@@ -386,40 +386,45 @@ bool call_control(uint32_t friend_number, CALL_CONTROL control) {
  ******************************************************************************/
 
 
+error for bit_rate_set {
+  /**
+   * Synchronization error occurred.
+   */
+  SYNC,
+  /**
+   * The bit rate passed was not one of the supported values.
+   */
+  INVALID_BIT_RATE,
+  /**
+   * The friend_number passed did not designate a valid friend.
+   */
+  FRIEND_NOT_FOUND,
+  /**
+   * This client is currently not in a call with the friend.
+   */
+  FRIEND_NOT_IN_CALL,
+}
+
 namespace bit_rate {
   /**
-   * Set the bit rate to be used in subsequent audio/video frames.
+   * Set the bit rate to be used in subsequent audio frames.
    *
    * @param friend_number The friend number of the friend for which to set the
    * bit rate.
-   * @param audio_bit_rate The new audio bit rate in Kb/sec. Set to 0 to disable
-   * audio sending. Set to -1 to leave unchanged.
-   * @param video_bit_rate The new video bit rate in Kb/sec. Set to 0 to disable
-   * video sending. Set to -1 to leave unchanged.
+   * @param audio_bit_rate The new audio bit rate in Kb/sec. Set to 0 to disable.
    *
    */
-  bool set(uint32_t friend_number, int32_t audio_bit_rate, int32_t video_bit_rate) {
-    /**
-     * Synchronization error occurred.
-     */
-    SYNC,
-    /**
-     * The audio bit rate passed was not one of the supported values.
-     */
-    INVALID_AUDIO_BIT_RATE,
-    /**
-     * The video bit rate passed was not one of the supported values.
-     */
-    INVALID_VIDEO_BIT_RATE,
-    /**
-     * The friend_number passed did not designate a valid friend.
-     */
-    FRIEND_NOT_FOUND,
-    /**
-     * This client is currently not in a call with the friend.
-     */
-    FRIEND_NOT_IN_CALL,
-  }
+
+  bool set_audio(uint32_t friend_number, uint32_t audio_bit_rate) with error for bit_rate_set;
+  /**
+   * Set the bit rate to be used in subsequent video frames.
+   *
+   * @param friend_number The friend number of the friend for which to set the
+   * bit rate.
+   * @param video_bit_rate The new video bit rate in Kb/sec. Set to 0 to disable.
+   *
+   */
+  bool set_video(uint32_t friend_number, uint32_t video_bit_rate) with error for bit_rate_set;
 
   event status {
     /**