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上一篇文章有分析TIF事件传递流程，TvIputHal会call到JNI，JNI将event给到Java层，但是JNI层又是怎么拿到event事件的呢？
分析TIF HAL层，需要掌握：
1.HAL层主要结构体的含义
2.HAL层主要代码实现
3.Native层或JNI层load hal模块的流程
4.hal，native和jni调用关系
1.HAL层主要结构体的含义
TIF HAL层头文件路径：
hardware\libhardware\include\hardware\tv_input.h
在Java层我们定义了TvInputService，我们知道，每一种Tv input device，需要对应一个TvInputService，系统目前支持的Tv Input device类型定义如下：
enum {
/* Generic hardware. */
TV_INPUT_TYPE_OTHER_HARDWARE = 1,
/* Tuner. (e.g. built-in terrestrial tuner) */
TV_INPUT_TYPE_TUNER = 2,
TV_INPUT_TYPE_COMPOSITE = 3,
TV_INPUT_TYPE_SVIDEO = 4,
TV_INPUT_TYPE_SCART = 5,
TV_INPUT_TYPE_COMPONENT = 6,
TV_INPUT_TYPE_VGA = 7,
TV_INPUT_TYPE_DVI = 8,
/* Physical HDMI port. (e.g. HDMI 1) */
TV_INPUT_TYPE_HDMI = 9,
TV_INPUT_TYPE_DISPLAY_PORT = 10,
};typedef struct tv_input_device_info {
/* Device ID */
int device_id;
/* Type of physical TV input. */
tv_input_type_t type;
union {
struct {
/* HDMI port ID number */
uint32_t port_id;
} hdmi;
/* TODO: add other type specific information. */
int32_t type_info_reserved[16];
};
/* TODO: Add capability if necessary. */
/*
* Audio info
*
* audio_type == AUDIO_DEVICE_NONE if this input has no audio.
*/
audio_devices_t audio_type;
const char* audio_address;
int32_t reserved[16];
} tv_input_device_info_t;tv input device有各种事件类型，对于事件类型定义如下：
/* See tv_input_event_t for more details. */
enum {
/*
* Hardware notifies the framework that a device is available.
*
* Note that DEVICE_AVAILABLE and DEVICE_UNAVAILABLE events do not represent
* hotplug events (i.e. plugging cable into or out of the physical port).
* These events notify the framework whether the port is available or not.
* For a concrete example, when a user plugs in or pulls out the HDMI cable
* from a HDMI port, it does not generate DEVICE_AVAILABLE and/or
* DEVICE_UNAVAILABLE events. However, if a user inserts a pluggable USB
* tuner into the Android device, it will generate a DEVICE_AVAILABLE event
* and when the port is removed, it should generate a DEVICE_UNAVAILABLE
* event.
*
* For hotplug events, please see STREAM_CONFIGURATION_CHANGED for more
* details.
*
* HAL implementation should register devices by using this event when the
* device boots up. The framework will recognize device reported via this
* event only. In addition, the implementation could use this event to
* notify the framework that a removable TV input device (such as USB tuner
* as stated in the example above) is attached.
*/
TV_INPUT_EVENT_DEVICE_AVAILABLE = 1,
/*
* Hardware notifies the framework that a device is unavailable.
*
* HAL implementation should generate this event when a device registered
* by TV_INPUT_EVENT_DEVICE_AVAILABLE is no longer available. For example,
* the event can indicate that a USB tuner is plugged out from the Android
* device.
*
* Note that this event is not for indicating cable plugged out of the port;
* for that purpose, the implementation should use
* STREAM_CONFIGURATION_CHANGED event. This event represents the port itself
* being no longer available.
*/
TV_INPUT_EVENT_DEVICE_UNAVAILABLE = 2,
/*
* Stream configurations are changed. Client should regard all open streams
* at the specific device are closed, and should call
* get_stream版权声明：本文标题：进阶教程：深入Android TIF HAL层代码，掌握Flash中心运作机制 内容由网友自发贡献，该文观点仅代表作者本人， 转载请联系作者并注明出处：http://www.roclinux.cn/b/1772646497a3557728.html， 本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌抄袭侵权/违法违规的内容，一经查实，本站将立刻删除。
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