java - 无法在 Android MediaRecorder 中设置手动视频大小

Question

我在 Android 中使用 MediaRecorder 来录制视频，mu 当前参数是:

    mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
    mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
    mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
    mMediaRecorder.setOutputFile(getOutputMediaFile().toString());
    mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
    mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);

    mMediaRecorder.setVideoEncodingBitRate(2500000);
    mMediaRecorder.setVideoSize(640, 480);

我尝试过的所有设备(4.0 及以上)都支持这些参数，但是如果我将代码的最后一行更改为:

mMediaRecorder.setVideoSize(960, 540);

然后出现错误:

java.lang.RuntimeException: start failed.
android.media.MediaRecorder.start(Native Method)

谁能帮忙，因为我想以 960x540 分辨率录制视频。

Answer 1

使用这段代码会有帮助:

try {
            recording = true;
            mrec = new MediaRecorder();
            mCamera.unlock();
            mrec.setCamera(mCamera);

            //Set audio source
            mrec.setAudioSource(MediaRecorder.AudioSource.MIC);
            //set video source
            mrec.setVideoSource(MediaRecorder.VideoSource.CAMERA);

            //set output format
            mrec.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);

            int width = 0;//set whatever 
            int height = 0;//set whatever
            try {
                //get the available sizes of the video
                List<Size> tmpList = getSupportedVideoSizes();

                final List<Size> sizeList = new Vector<Size>();

                // compare the apsect ratio of the candidate sizes against the
                // real ratio
                Double aspectRatio = (Double.valueOf(getWindowManager()
                        .getDefaultDisplay().getHeight()) / getWindowManager()
                        .getDefaultDisplay().getWidth());
                for (int i = tmpList.size() - 1; i > 0; i--) {
                    Double tmpRatio = Double.valueOf(tmpList.get(i).height)
                            / tmpList.get(i).width;
                    if (EnableLog.LOG_TAG) {
                        Log.e("Width & height", tmpList.get(i).width + " x "
                                + tmpList.get(i).height);
                    }
                    if (Math.abs(aspectRatio - tmpRatio) < .15) {
                        width = tmpList.get(i).width;
                        height = tmpList.get(i).height;
                        sizeList.add(tmpList.get(i));
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

            // set the size of video.
            // If the size is not applicable then throw the media recorder stop
            // -19 error
            mrec.setVideoSize(width, height);

            // Set the video encoding bit rate this changes for the high, low.
            // medium quality devices
            mrec.setVideoEncodingBitRate(1700000);

            //Set the video frame rate
            mrec.setVideoFrameRate(30);

            //set audio encoder format
            mrec.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);

            //set video encoder format
            mrec.setVideoEncoder(MediaRecorder.VideoEncoder.H264);

            //Show the display preview
            mrec.setPreviewDisplay(surfaceHolder.getSurface());

            //output file path
            mrec.setOutputFile(output_path);

            mrec.prepare();

            mrec.start();

        } catch (IllegalStateException e) {

            e.printStackTrace();
        } catch (IOException e) {

            e.printStackTrace();
        }

还有这个:

public List<Size> getSupportedVideoSizes() {
        if (params.getSupportedVideoSizes() != null) {
            return params.getSupportedVideoSizes();
        } else {
            // Video sizes may be null, which indicates that all the supported
            // preview sizes are supported for video recording.
            return params.getSupportedPreviewSizes();
        }
    }

希望这能解决您的问题。

注意

更新 4.4.2 后，getPreviewsizes() 在 Samsung Galaxy Tab 3(7") 中不起作用(对我而言)。所以我希望预览尺寸不适用于所有设备。因此，请先检查视频尺寸，如果返回尺寸，则使用它，或者如果它返回 null，则使用我的代码中的 getPreviewsizes。

我想您收到了另一条错误消息，例如媒体记录器启动失败错误 -19？是吗？