gstreamer 中的哪个状态表示管道正常工作？
Which state in gstreamer indicates that the pipeline is working correctly?
关于Gstream状态变化，我们应该在管道正常工作时发送一个事件（Stream OK），当出现错误时我们应该发送另一个事件（Stream Error）。
通过消息回调捕获错误是有效的，但我们不知道哪个状态表明整个管道工作正常（从 src 到同步）。
GStreamer 中没有特定的错误状态（GStreamer states 是：NULL、READY、PAUSED、PLAYING (*)）。因此，您需要观察并检查是否发生任何错误。您至少应该检查：
- return value of the function for changing the state (
gst_element_set_state)
- 如果有任何错误消息发送到总线：
Errors can be received by listening to the GstBus of the
element/pipeline for GstMessage objects with the type
GST_MESSAGE_ERROR or GST_MESSAGE_WARNING. The thrown errors should be
inspected, and filtered if appropriate.
(*) 注意：实际上，完整的 list of states in the API includes also a pending state that may be relevant in some cases (see e.g. How to resume playing after paused using gstreamer?)
关于Gstream状态变化，我们应该在管道正常工作时发送一个事件（Stream OK），当出现错误时我们应该发送另一个事件（Stream Error）。
通过消息回调捕获错误是有效的，但我们不知道哪个状态表明整个管道工作正常（从 src 到同步）。
GStreamer 中没有特定的错误状态（GStreamer states 是：NULL、READY、PAUSED、PLAYING (*)）。因此，您需要观察并检查是否发生任何错误。您至少应该检查：
- return value of the function for changing the state (
gst_element_set_state) - 如果有任何错误消息发送到总线：
Errors can be received by listening to the GstBus of the element/pipeline for GstMessage objects with the type GST_MESSAGE_ERROR or GST_MESSAGE_WARNING. The thrown errors should be inspected, and filtered if appropriate.
(*) 注意：实际上，完整的 list of states in the API includes also a pending state that may be relevant in some cases (see e.g. How to resume playing after paused using gstreamer?)