havlenapetrFFMpeg OnVideoSizeChangedListener接口的实现

转载自：http://blog.csdn.net/yarpee/article/details/6910877

moruite在他的文章http://blog.csdn.net/moruite/article/details/6305944里说到了用havlenapetr-FFMpeg播放视频花屏的问题，需要自己实现OnVideoSizeChangedListener接口。网上没有找到相关的资料，自己研究了下。秉着OpenSource的观念，取之于havlenapetr-FFMpeg，还给世界。

FFMpegPlayer中添加如下接口和变量：

    // Add by yarpee start
    /**
     * Interface definition of a callback to be invoked when the
     * video size is first known or updated
     */
    public interface OnVideoSizeChangedListener
    {
        /**
         * Called to indicate the video size
         *
         * @param mp        the MediaPlayer associated with this callback
         * @param width     the width of the video
         * @param height    the height of the video
         */
        public void onVideoSizeChanged(FFMpegPlayer mp, int width, int height);
    }

    /**
     * Register a callback to be invoked when the video size is
     * known or updated.
     *
     * @param listener the callback that will be run
     */
    public void setOnVideoSizeChangedListener(OnVideoSizeChangedListener listener)
    {
        Log.d(TAG, "setOnVideoSizeChangedListener");
        mOnVideoSizeChangedListener = listener;
    }

    private static OnVideoSizeChangedListener mOnVideoSizeChangedListener;
    // Add by yarpee end

FFMpegPlayer中修改如下函数：

    private static void postEventFromNative(Object mediaplayer_ref,
                                            int what, int arg1, int arg2, Object obj)
    {
        switch(what) {
        case MEDIA_INFO_FRAMERATE_VIDEO:
            Log.d(TAG, "Video fps:" + arg1);
            break;
        case MEDIA_INFO_FRAMERATE_AUDIO:
            Log.d(TAG, "Audio fps:" + arg1);
            break;
        case MEDIA_SET_VIDEO_SIZE:
            Log.d(TAG, "Video " + arg1 + " height:" + arg2);
            if(mOnVideoSizeChangedListener != null)
            {
                Log.d(TAG, "mOnVideoSizeChangedListener != null");
                mOnVideoSizeChangedListener.onVideoSizeChanged(null, arg1, arg2);
            }
            else
            {
                Log.d(TAG, "mOnVideoSizeChangedListener == null");
            }
        }
    }

FFMpegMovieViewAndroid中修改如下函数：

    private void openVideo(SurfaceHolder surfHolder) {
        try {
            mPlayer.setDisplay(surfHolder);
            
            // Add by yarpee
            // 必须在prepare前设置listener
            mPlayer.setOnVideoSizeChangedListener(new FFMpegPlayer.OnVideoSizeChangedListener()
            {
                public void onVideoSizeChanged(FFMpegPlayer mp, int width, int height)
                {
                    // 注意此处不能用mp，mp为null
                    int videoWidth = mPlayer.getVideoWidth();
                    int videoHeight = mPlayer.getVideoHeight();
                    if(videoHeight != 0 && videoWidth != 0)
                    {
                        Log.d(TAG, "setFixedSize " + videoWidth + " height:" + videoHeight);
                        getHolder().setFixedSize(videoWidth, videoHeight);
                    }
                }
            });
            
            mPlayer.prepare();
        } catch (IllegalStateException e) {
            Log.e(TAG, "Couldn't prepare player: " + e.getMessage());
        } catch (IOException e) {
            Log.e(TAG, "Couldn't prepare player: " + e.getMessage());
        }
    }

C代码修改Mediaplayer.cpp中的如下函数：

status_t MediaPlayer::prepare()
{
    status_t ret;
    mCurrentState = MEDIA_PLAYER_PREPARING;
    av_log_set_callback(ffmpegNotify);
    if ((ret = prepareVideo()) != NO_ERROR) {
        mCurrentState = MEDIA_PLAYER_STATE_ERROR;
        return ret;
    }
    if ((ret = prepareAudio()) != NO_ERROR) {
        mCurrentState = MEDIA_PLAYER_STATE_ERROR;
        return ret;
    }
    mCurrentState = MEDIA_PLAYER_PREPARED;

    // Add by yarpee
    notify(5, mVideoWidth, mVideoHeight);
    
    return NO_ERROR;
}