gstreamer debug tracer使用概览

gstreamer tracer可以直接输出当前系统的开销、耗时、内存占用等状况。
使用tracer需要在debug中将tracer的打印开启。

GST_DEBUG=“GST_TRACER:7”

1. GST_DEBUG基础设定

设定打印等级

GST_DEBUG=2 //将log输出级别设定为2，WARNING

默认等级为0，即不输出任何信息。当我们需要输出log，通过设定GST_DEBUG变量的值来更改等级。对应等级参考下表

| # | Name    | Description                                                    |
|---|---------|----------------------------------------------------------------|
| 0 | none    | No debug information is output.                                |
| 1 | ERROR   | Logs all fatal errors. These are errors that do not allow the  |
|   |         | core or elements to perform the requested action. The          |
|   |         | application can still recover if programmed to handle the      |
|   |         | conditions that triggered the error.                           |
| 2 | WARNING | Logs all warnings. Typically these are non-fatal, but          |
|   |         | user-visible problems are expected to happen.                  |
| 3 | FIXME   | Logs all "fixme" messages. Those typically that a codepath that|
|   |         | is known to be incomplete has been triggered. It may work in   |
|   |         | most cases, but may cause problems in specific instances.      |
| 4 | INFO    | Logs all informational messages. These are typically used for  |
|   |         | events in the system that only happen once, or are important   |
|   |         | and rare enough to be logged at this level.                    |
| 5 | DEBUG   | Logs all debug messages. These are general debug messages for  |
|   |         | events that happen only a limited number of times during an    |
|   |         | object's lifetime; these include setup, teardown, change of    |
|   |         | parameters, etc.                                               |
| 6 | LOG     | Logs all log messages. These are messages for events that      |
|   |         | happen repeatedly during an object's lifetime; these include   |
|   |         | streaming and steady-state conditions. This is used for log    |
|   |         | messages that happen on every buffer in an element for example.|
| 7 | TRACE   | Logs all trace messages. Those are message that happen very    |
|   |         | very often. This is for example is each time the reference     |
|   |         | count of a GstMiniObject, such as a GstBuffer or GstEvent, is  |
|   |         | modified.                                                      |
| 9 | MEMDUMP | Logs all memory dump messages. This is the heaviest logging and|
|   |         | may include dumping the content of blocks of memory.           |
+------------------------------------------------------------------------------+

单独设定某一元件等级

GST_DEBUG=2,audiotestsrc:6 //将audiotestsrc等级单独设定为6

以上支持通配符：

GST_DEBUG=2,audio*:6 //将所有audio开头的元件等级设定为6

将log输出到指定文件

GST_DEBUG_FILE=/home/gst/trace.log

更改输出通道

可以将log指定到某文件或者socket。

GST_TRACE_CHANNEL=stderr

输出管道图

GST_DEBUG_DUMP_DOT_DIR=/home/gst/

2. rusage

输出资源占用信息：

GST_TRACERS=“rusage”

$ GST_DEBUG="GST_TRACER:7" GST_TRACERS="rusage" /usr/bin/gst-play-1.0 ~/Videos/test1.mp4 ~/Videos/test1.mp4
...
0:00:00.109237154 15123 0x557d7cdac750 TRACE             GST_TRACER :0:: thread-rusage, thread-id=(guint64)93997453985616, ts=(guint64)109234032, average-cpuload=(uint)151, current-cpuload=(uint)78, time=(guint64)16501669;
0:00:00.109243797 15123 0x557d7cdac750 TRACE             GST_TRACER :0:: proc-rusage, process-id=(guint64)15123, ts=(guint64)109234032, average-cpuload=(uint)39, current-cpuload=(uint)32, time=(guint64)34465689;
0:00:00.109253587 15123 0x557d7cdac750 TRACE             GST_TRACER :0:: thread-rusage, thread-id=(guint64)93997453985616, ts=(guint64)109250395, average-cpuload=(uint