背景
我们在做Android平台RTSP或者RTMP播放器开发的时候，需要注意的点非常多，以下，以大牛直播SDK(官方)的接口为例，大概介绍下相关接口设计：
接口设计
1. Open() 接口
Open接口的目的，主要是创建实例，正常返回player实例句柄，如有多路播放诉求，创建多个实例即可。
/**
* Initialize Player(启动播放实例)
*
* @param ctx: get by this.getApplicationContext()
*
* <pre>This function must be called firstly.</pre>
*
* @return player handle if successful, if return 0, which means init failed.
*/
public native long SmartPlayerOpen(Object ctx);
复制代码2. Close()接口
Close接口，和Open()接口对应，负责释放相应实例的资源，调用Close()接口后，记得实例句柄置0即可。
**注意：**比如一个实例既可以实现播放，又可同时录像，亦或拉流（转发），这种情况下，调Close()接口时，需要确保录像、拉流都正常停止后，再调用。
/**
* 关闭播放实例，结束时必须调用close接口释放资源
*
* @param handle: return value from SmartPlayerOpen()
*
* <pre> NOTE: it could not use player handle after call this function. </pre>
*
* @return {0} if successful
*/
public native int SmartPlayerClose(long handle);
复制代码3. 网络状态回调
一个好的播放器，好的状态回调必不可少，比如网络连通状态、快照、录像状态、当前下载速度等实时反馈，可以让上层开发者更好的掌控播放端状态，给用户更好的播放体验。
/**
* Set callback event(设置事件回调)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param callbackv2: callback function
*
* @return {0} if successful
*/
public native int SetSmartPlayerEventCallbackV2(long handle, NTSmartEventCallbackV2 callbackv2);
复制代码demo实现实例：
class EventHandeV2 implements NTSmartEventCallbackV2 {
@Override
public void onNTSmartEventCallbackV2(long handle, int id, long param1,
long param2, String param3, String param4, Object param5) {
//Log.i(TAG, "EventHandeV2: handle=" + handle + " id:" + id);
String player_event = "";
switch (id) {
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_STARTED:
player_event = "开始..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_CONNECTING:
player_event = "连接中..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_CONNECTION_FAILED:
player_event = "连接失败..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_CONNECTED:
player_event = "连接成功..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_DISCONNECTED:
player_event = "连接断开..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_STOP:
player_event = "停止播放..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_RESOLUTION_INFO:
player_event = "分辨率信息: width: " + param1 + ", height: " + param2;
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_NO_MEDIADATA_RECEIVED:
player_event = "收不到媒体数据，可能是url错误..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_SWITCH_URL:
player_event = "切换播放URL..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_CAPTURE_IMAGE:
player_event = "快照: " + param1 + " 路径：" + param3;
if (param1 == 0) {
player_event = player_event + ", 截取快照成功";
} else {
player_event = player_event + ", 截取快照失败";
}
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_RECORDER_START_NEW_FILE:
player_event = "[record]开始一个新的录像文件 : " + param3;
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_ONE_RECORDER_FILE_FINISHED:
player_event = "[record]已生成一个录像文件 : " + param3;
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_START_BUFFERING:
Log.i(TAG, "Start Buffering");
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_BUFFERING:
Log.i(TAG, "Buffering:" + param1 + "%");
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_STOP_BUFFERING:
Log.i(TAG, "Stop Buffering");
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_DOWNLOAD_SPEED:
player_event = "download_speed:" + param1 + "Byte/s" + ", "
+ (param1 * 8 / 1000) + "kbps" + ", " + (param1 / 1024)
+ "KB/s";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_RTSP_STATUS_CODE:
Log.e(TAG, "RTSP error code received, please make sure username/password is correct, error code:" + param1);
player_event = "RTSP error code:" + param1;
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_NEED_KEY:
Log.e(TAG, "RTMP加密流，请设置播放需要的Key..");
player_event = "RTMP加密流，请设置播放需要的Key..";
break;
case NTSmartEventID.EVENT_DANIULIVE_ERC_PLAYER_KEY_ERROR:
Log.e(TAG, "RTMP加密流，Key错误，请重新设置..");
player_event = "RTMP加密流，Key错误，请重新设置..";
break;
}
if (player_event.length() > 0) {
Log.i(TAG, player_event);
Message message = new Message();
message.what = PLAYER_EVENT_MSG;
message.obj = player_event;
handler.sendMessage(message);
}
}
}
复制代码4. 软解码还是硬解码？
随着Android发展越来越好，各个厂商芯片对硬解码的支持，也越来越友好，一般情况下，如果适合通用的产品，在设备性能保障的情况下，优先建议软解，如果特定机型设备，可酌情考虑硬解，硬解码，又分为264硬解、HEVC硬解，直接设置surface模式的硬解，接口如下：
/**
* Set Video H.264 HW decoder(设置H.264硬解码)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param isHWDecoder: 0: software decoder; 1: hardware decoder.
*
* @return {0} if successful
*/
public native int SetSmartPlayerVideoHWDecoder(long handle, int isHWDecoder);
/**
* Set Video H.265(hevc) HW decoder(设置H.265硬解码)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param isHevcHWDecoder: 0: software decoder; 1: hardware decoder.
*
* @return {0} if successful
*/
public native int SetSmartPlayerVideoHevcHWDecoder(long handle, int isHevcHWDecoder);
复制代码设置surface模式的硬解：
/**
* 设置视频硬解码下Mediacodec自行绘制模式（此种模式下，硬解码兼容性和效率更好，回调YUV/RGB和快照功能将不可用）
*
* @param handle: return value from SmartPlayerOpen()
*
* @param isHWRenderMode: 0: not enable; 1: 用SmartPlayerSetSurface设置的surface自行绘制
*
* @return {0} if successful
*/
public native int SmartPlayerSetHWRenderMode(long handle, int isHWRenderMode);
/**
* 更新硬解码surface
*
* @param handle: return value from SmartPlayerOpen()
*
* @return {0} if successful
*/
public native int SmartPlayerUpdateHWRenderSurface(long handle);
复制代码5. 音频输出类型
音频输出，android平台支持audiotrack模式和opensl es模式，一般来说，考虑到设备通用性，建议采用audiotrack模式。
/**
* Set AudioOutput Type(设置audio输出类型)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param use_audiotrack:
*
* <pre> NOTE: if use_audiotrack with 0: it will use auto-select output devices; if with 1: will use audio-track mode. </pre>
*
* @return {0} if successful
*/
public native int SmartPlayerSetAudioOutputType(long handle, int use_audiotrack);
复制代码6. 缓冲时间设置
缓冲时间，顾名思义，缓存多少数据才开始播放，比如设置2000ms的buffer time，直播模式下，收到2秒数据后，才正常播放。
加大buffer time，会增大播放延迟，好处是，网络抖动的时候，流畅性更好。
/**
* Set buffer(设置缓冲时间，单位:毫秒)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param buffer:
*
* <pre> NOTE: Unit is millisecond, range is 0-5000 ms </pre>
*
* @return {0} if successful
*/
public native int SmartPlayerSetBuffer(long handle, int buffer);
复制代码7. 实时静音、实时音量调节
实时静音、实时音量调节顾名思义，播放端可以实时调整播放音量，或者直接静音掉，特别是多路播放场景下，非常有必要。
此外我们还提供了音量放大的功能，支持放大至原始音量的2倍。
/**
* Set mute or not(设置实时静音)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_mute: if with 1:mute, if with 0: does not mute
*
* @return {0} if successful
*/
public native int SmartPlayerSetMute(long handle, int is_mute);
/**
* 设置播放音量
*
* @param handle: return value from SmartPlayerOpen()
*
* @param volume: 范围是[0, 100], 0是静音，100是最大音量, 默认是100
*
* @return {0} if successful
*/
public native int SmartPlayerSetAudioVolume(long handle, int volume);
复制代码8. RTSP TCP-UDP模式设置、超时时间设置或模式切换
有的RTSP服务器或摄像机，只支持RTSP TCP模式或者UDP模式，这个时候，默认设置TCP、UDP模式就至关重要，此外，我们还设计支持如TCP或UDP模式收不到数据，在超时时间后，可以自动切换到UDP或TCP。
/**
* 设置RTSP TCP/UDP模式(默认UDP模式)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_using_tcp: if with 1, it will via TCP mode, while 0 with UDP mode
*
* @return {0} if successful
*/
public native int SmartPlayerSetRTSPTcpMode(long handle, int is_using_tcp);
/**
* 设置RTSP超时时间, timeout单位为秒，必须大于0
*
* @param handle: return value from SmartPlayerOpen()
*
* @param timeout: RTSP timeout setting
*
* @return {0} if successful
*/
public native int SmartPlayerSetRTSPTimeout(long handle, int timeout);
/**
* 设置RTSP TCP/UDP自动切换
*
* @param handle: return value from SmartPlayerOpen()
*
* NOTE: 对于RTSP来说，有些可能支持rtp over udp方式，有些可能支持使用rtp over tcp方式.
* 为了方便使用，有些场景下可以开启自动尝试切换开关, 打开后如果udp无法播放，sdk会自动尝试tcp, 如果tcp方式播放不了,sdk会自动尝试udp.
*
* @param is_auto_switch_tcp_udp 如果设置1的话, sdk将在tcp和udp之间尝试切换播放，如果设置为0，则不尝试切换.
*
* @return {0} if successful
*/
public native int SmartPlayerSetRTSPAutoSwitchTcpUdp(long handle, int is_auto_switch_tcp_udp);
复制代码9. 快速启动
快速启动，主要是针对服务器缓存GOP的场景下，快速刷到最新的数据，确保画面的持续性。
/**
* Set fast startup(设置快速启动模式，此模式针对服务器缓存GOP的场景有效)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_fast_startup: if with 1, it will second play back, if with 0: does not it
*
* @return {0} if successful
*/
public native int SmartPlayerSetFastStartup(long handle, int is_fast_startup);
复制代码10. 低延迟模式
低延迟模式下，设置buffer time为0，延迟更低，适用于比如需要操控控制的超低延迟场景下。
/**
* Set low latency mode(设置低延迟模式)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param mode: if with 1, low latency mode, if with 0: normal mode
*
* @return {0} if successful
*/
public native int SmartPlayerSetLowLatencyMode(long handle, int mode);
复制代码11. 视频view旋转、水平|垂直翻转
接口主要用于，比如原始的视频倒置等场景下，设备端无法调整时，通过播放端完成图像的正常角度播放。
/**
* 设置视频垂直反转
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_flip： 0: 不反转, 1: 反转
*
* @return {0} if successful
*/
public native int SmartPlayerSetFlipVertical(long handle, int is_flip);
/**
* 设置视频水平反转
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_flip： 0: 不反转, 1: 反转
*
* @return {0} if successful
*/
public native int SmartPlayerSetFlipHorizontal(long handle, int is_flip);
/**
* 设置顺时针旋转, 注意除了0度之外， 其他角度都会额外消耗性能
*
* @param handle: return value from SmartPlayerOpen()
*
* @param degress： 当前支持 0度，90度, 180度, 270度 旋转
*
* @return {0} if successful
*/
public native int SmartPlayerSetRotation(long handle, int degress);
复制代码12. 设置实时回调下载速度
调用实时下载速度接口，通过设置下载速度时间间隔，和是否需要上报当前下载速度，实现APP层和底层SDK更友好的交互。
/**
* Set report download speed(设置实时回调下载速度)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_report: if with 1, it will report download speed, it with 0: does not it.
*
* @param report_interval: report interval, unit is second, it must be greater than 0.
*
* @return {0} if successful
*/
public native int SmartPlayerSetReportDownloadSpeed(long handle, int is_report, int report_interval );
复制代码13. 实时快照
简单来说，播放过程中，是不是要存取当前的播放画面。
/**
* Set if needs to save image during playback stream(是否启动快照功能)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param is_save_image: if with 1, it will save current image via the interface of SmartPlayerSaveCurImage(), if with 0: does not it
*
* @return {0} if successful
*/
public native int SmartPlayerSaveImageFlag(long handle, int is_save_image);
/**
* Save current image during playback stream(实时快照)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param imageName: image name, which including fully path, "/sdcard/daniuliveimage/daniu.png", etc.
*
* @return {0} if successful
*/
public native int SmartPlayerSaveCurImage(long handle, String imageName);
复制代码14. 扩展录像操作
播放端录像，我们做的非常细化，比如可以只录制音频或者只录制视频，设置录像存储路径，设置单个文件size，如果非AAC数据，可以转AAC后再录像。
/**
* Create file directory(创建录像目录)
*
* @param path, E.g: /sdcard/daniulive/rec
*
* <pre> The interface is only used for recording the stream data to local side. </pre>
*
* @return {0} if successful
*/
public native int SmartPlayerCreateFileDirectory(String path);
/**
* Set recorder directory(设置录像目录)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param path: the directory of recorder file
*
* <pre> NOTE: make sure the path should be existed, or else the setting failed. </pre>
*
* @return {0} if successful
*/
public native int SmartPlayerSetRecorderDirectory(long handle, String path);
/**
* Set the size of every recorded file(设置单个录像文件大小，如超过设定大小则自动切换到下个文件录制)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param size: (MB), (5M~500M), if not in this range, set default size with 200MB.
*
* @return {0} if successful
*/
public native int SmartPlayerSetRecorderFileMaxSize(long handle, int size);
/*
* 设置录像时音频转AAC编码的开关
*
* @param handle: return value from SmartPlayerOpen()
*
* aac比较通用，sdk增加其他音频编码(比如speex, pcmu, pcma等)转aac的功能.
*
* @param is_transcode: 设置为1的话，如果音频编码不是aac，则转成aac，如果是aac，则不做转换. 设置为0的话，则不做任何转换. 默认是0.
*
* 注意: 转码会增加性能消耗
*
* @return {0} if successful
*/
public native int SmartPlayerSetRecorderAudioTranscodeAAC(long handle, int is_transcode);
/*
*设置是否录视频，默认的话，如果视频源有视频就录，没有就没得录, 但有些场景下可能不想录制视频，只想录音频，所以增加个开关
*
*@param is_record_video: 1 表示录制视频, 0 表示不录制视频, 默认是1
*
* @return {0} if successful
*/
public native int SmartPlayerSetRecorderVideo(long handle, int is_record_video);
/*
*设置是否录音频，默认的话，如果视频源有音频就录，没有就没得录, 但有些场景下可能不想录制音频，只想录视频，所以增加个开关
*
*@param is_record_audio: 1 表示录制音频, 0 表示不录制音频, 默认是1
*
* @return {0} if successful
*/
public native int SmartPlayerSetRecorderAudio(long handle, int is_record_audio);
复制代码 /**
* Start recorder stream(开始录像)
*
* @param handle: return value from SmartPlayerOpen()
*
* @return {0} if successful
*/
public native int SmartPlayerStartRecorder(long handle);
/**
* Stop recorder stream(停止录像)
*
* @param handle: return value from SmartPlayerOpen()
*
* @return {0} if successful
*/
public native int SmartPlayerStopRecorder(long handle);
复制代码15. 拉流回调编码后的数据（配合转发模块使用）
拉流回调编码后的数据，主要是为了配合转发模块使用，比如拉取rtsp流数据，直接转RTMP推送到RTMP服务。
/*
* 设置拉流时音频转AAC编码的开关
*
* @param handle: return value from SmartPlayerOpen()
*
* aac比较通用，sdk增加其他音频编码(比如speex, pcmu, pcma等)转aac的功能.
*
* @param is_transcode: 设置为1的话，如果音频编码不是aac，则转成aac, 如果是aac，则不做转换. 设置为0的话，则不做任何转换. 默认是0.
* 注意: 转码会增加性能消耗
*
* @return {0} if successful
*/
public native int SmartPlayerSetPullStreamAudioTranscodeAAC(long handle, int is_transcode);
/**
* Start pull stream(开始拉流，用于数据转发，只拉流不播放)
*
* @param handle: return value from SmartPlayerOpen()
*
* @return {0} if successful
*/
public native int SmartPlayerStartPullStream(long handle);
/**
* Stop pull stream(停止拉流)
*
* @param handle: return value from SmartPlayerOpen()
*
* @return {0} if successful
*/
public native int SmartPlayerStopPullStream(long handle);
复制代码 /**
* Set Audio Data Callback(设置回调编码后音频数据)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param audio_data_callback: Audio Data Callback.
*
* @return {0} if successful
*/
public native int SmartPlayerSetAudioDataCallback(long handle, Object audio_data_callback);
/**
* Set Video Data Callback(设置回调编码后视频数据)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param video_data_callback: Video Data Callback.
*
* @return {0} if successful
*/
public native int SmartPlayerSetVideoDataCallback(long handle, Object video_data_callback);
复制代码16. H264用户数据回调或SEI数据回调
如发送端在264编码时，加了自定义的user data数据，可以通过以下接口实现数据回调，如需直接回调SEI数据，调下面SEI回调接口即可。
/**
* Set user data Callback(设置回调SEI扩展用户数据)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param user_data_callback: user data callback.
*
* @return {0} if successful
*/
public native int SmartPlayerSetUserDataCallback(long handle, Object user_data_callback);
/**
* Set SEI data Callback(设置回调SEI数据)
*
* @param handle: return value from SmartPlayerOpen()
*
* @param sei_data_callback: sei data callback.
*
* @return {0} if successful
*/
public native int SmartPlayerSetSEIDataCallback(long handle, Object sei_data_callback);
复制代码17. 设置回调解码后YUV、RGB数据
如需对解码后的yuv或rgb数据，进行二次处理，如人脸识别等，可以通回调yuv rgb接口实现数据二次处理。
以YUV为例：
class I420ExternalRender implements NTExternalRender {
// public static final int NT_FRAME_FORMAT_RGBA = 1;
// public static final int NT_FRAME_FORMAT_ABGR = 2;
// public static final int NT_FRAME_FORMAT_I420 = 3;
private int width_ = 0;
private int height_ = 0;
private int y_row_bytes_ = 0;
private int u_row_bytes_ = 0;
private int v_row_bytes_ = 0;
private ByteBuffer y_buffer_ = null;
private ByteBuffer u_buffer_ = null;
private ByteBuffer v_buffer_ = null;
@Override
public int getNTFrameFormat() {
Log.i(TAG, "I420ExternalRender::getNTFrameFormat return "
+ NT_FRAME_FORMAT_I420);
return NT_FRAME_FORMAT_I420;
}
@Override
public void onNTFrameSizeChanged(int width, int height) {
width_ = width;
height_ = height;
y_row_bytes_ = (width_ + 15) & (~15);
u_row_bytes_ = ((width_ + 1) / 2 + 15) & (~15);
v_row_bytes_ = ((width_ + 1) / 2 + 15) & (~15);
y_buffer_ = ByteBuffer.allocateDirect(y_row_bytes_ * height_);
u_buffer_ = ByteBuffer.allocateDirect(u_row_bytes_
* ((height_ + 1) / 2));
v_buffer_ = ByteBuffer.allocateDirect(v_row_bytes_
* ((height_ + 1) / 2));
Log.i(TAG, "I420ExternalRender::onNTFrameSizeChanged width_="
+ width_ + " height_=" + height_ + " y_row_bytes_="
+ y_row_bytes_ + " u_row_bytes_=" + u_row_bytes_
+ " v_row_bytes_=" + v_row_bytes_);
}
@Override
public ByteBuffer getNTPlaneByteBuffer(int index) {
if (index == 0) {
return y_buffer_;
} else if (index == 1) {
return u_buffer_;
} else if (index == 2) {
return v_buffer_;
} else {
Log.e(TAG, "I420ExternalRender::getNTPlaneByteBuffer index error:" + index);
return null;
}
}
@Override
public int getNTPlanePerRowBytes(int index) {
if (index == 0) {
return y_row_bytes_;
} else if (index == 1) {
return u_row_bytes_;
} else if (index == 2) {
return v_row_bytes_;
} else {
Log.e(TAG, "I420ExternalRender::getNTPlanePerRowBytes index error:" + index);
return 0;
}
}
public void onNTRenderFrame(int width, int height, long timestamp) {
if (y_buffer_ == null)
return;
if (u_buffer_ == null)
return;
if (v_buffer_ == null)
return;
y_buffer_.rewind();
u_buffer_.rewind();
v_buffer_.rewind();
/*
if ( !is_saved_image )
{
is_saved_image = true;
int y_len = y_row_bytes_*height_;
int u_len = u_row_bytes_*((height_+1)/2);
int v_len = v_row_bytes_*((height_+1)/2);
int data_len = y_len + (y_row_bytes_*((height_+1)/2));
byte[] nv21_data = new byte[data_len];
byte[] u_data = new byte[u_len];
byte[] v_data = new byte[v_len];
y_buffer_.get(nv21_data, 0, y_len);
u_buffer_.get(u_data, 0, u_len);
v_buffer_.get(v_data, 0, v_len);
int[] strides = new int[2];
strides[0] = y_row_bytes_;
strides[1] = y_row_bytes_;
int loop_row_c = ((height_+1)/2);
int loop_c = ((width_+1)/2);
int dst_row = y_len;
int src_v_row = 0;
int src_u_row = 0;
for ( int i = 0; i < loop_row_c; ++i)
{
int dst_pos = dst_row;
for ( int j = 0; j <loop_c; ++j )
{
nv21_data[dst_pos++] = v_data[src_v_row + j];
nv21_data[dst_pos++] = u_data[src_u_row + j];
}
dst_row += y_row_bytes_;
src_v_row += v_row_bytes_;
src_u_row += u_row_bytes_;
}
String imagePath = "/sdcard" + "/" + "testonv21" + ".jpeg";
Log.e(TAG, "I420ExternalRender::begin test save iamge++ image_path:" + imagePath);
try
{
File file = new File(imagePath);
FileOutputStream image_os = new FileOutputStream(file);
YuvImage image = new YuvImage(nv21_data, ImageFormat.NV21, width_, height_, strides);
image.compressToJpeg(new android.graphics.Rect(0, 0, width_, height_), 50, image_os);
image_os.flush();
image_os.close();
}
catch(IOException e)
{
e.printStackTrace();
}
Log.e(TAG, "I420ExternalRender::begin test save iamge--");
}
*/
Log.i(TAG, "I420ExternalRender::onNTRenderFrame w=" + width + " h=" + height + " timestamp=" + timestamp);
// copy buffer
// test
// byte[] test_buffer = new byte[16];
// y_buffer_.get(test_buffer);
// Log.i(TAG, "I420ExternalRender::onNTRenderFrame y data:" + bytesToHexString(test_buffer));
// u_buffer_.get(test_buffer);
// Log.i(TAG, "I420ExternalRender::onNTRenderFrame u data:" + bytesToHexString(test_buffer));
// v_buffer_.get(test_buffer);
// Log.i(TAG, "I420ExternalRender::onNTRenderFrame v data:" + bytesToHexString(test_buffer));
}
}
复制代码18. 设置视频画面填充模式
设置视频画面的填充模式，如填充整个view、等比例填充view，如不设置，默认填充整个view。
相关接口设计如下：
/**
* 设置视频画面的填充模式，如填充整个view、等比例填充view，如不设置，默认填充整个view
* @param handle: return value from SmartPlayerOpen()
* @param render_scale_mode 0: 填充整个view; 1: 等比例填充view, 默认值是0
* @return {0} if successful
*/
public native int SmartPlayerSetRenderScaleMode(long handle, int render_scale_mode);
复制代码19. 设置SurfaceView模式下render类型
format: 0: RGB565格式，如不设置，默认此模式; 1: ARGB8888格式
/**
* 设置SurfaceView模式下(NTRenderer.CreateRenderer第二个参数传false的情况)，render类型
*
* @param handle: return value from SmartPlayerOpen()
*
* @param format: 0: RGB565格式，如不设置，默认此模式; 1: ARGB8888格式
*
* @return {0} if successful
*/
public native int SmartPlayerSetSurfaceRenderFormat(long handle, int format);
复制代码20. 设置surfaceview模式下抗锯齿
需要注意的是：抗锯齿模式开启后，会增加性能消耗。
/**
* 设置SurfaceView模式下(NTRenderer.CreateRenderer第二个参数传false的情况)，抗锯齿效果，注意：抗锯齿模式开启后，可能会影像性能，请慎用
*
* @param handle: return value from SmartPlayerOpen()
*
* @param isEnableAntiAlias: 0: 如不设置，默认不开启抗锯齿模式; 1: 开启抗锯齿模式
*
* @return {0} if successful
*/
public native int SmartPlayerSetSurfaceAntiAlias(long handle, int isEnableAntiAlias);
复制代码总结
以上就是Android平台RTSP、RTMP播放器接口设计需要参考的点，对于大多数开发者来说，不一定需要实现上述所有部分，只要按照产品诉求，实现其中的40%就足够满足特定场景使用了。
一个好的播放器，特别是要满足低延迟稳定的播放（毫秒级延迟），需要注意的点远不止如此，感兴趣的开发者，可以参考blog其他文章。