MediaCodecで動画再生速度を調整する。

MediaFormatから　captureRate など各種情報を取得する


            MediaFormat mediaFormat = null;
            for (int i = 0; i < nTracks; ++i) {
                mCodecWrapper = MediaCodecWrapper.fromVideoFormat(mExtractor.getTrackFormat(i),t_s);
                if (mCodecWrapper != null) {
                    mExtractor.selectTrack(i);
                    mediaFormat = mExtractor.getTrackFormat(i);
                    break;
                }
            }
            if( mediaFormat !=null) {
                totalTime = mediaFormat.getLong(MediaFormat.KEY_DURATION);
                captureRate = mediaFormat.getInteger(MediaFormat.KEY_FRAME_RATE);
                mMovieWidth = mediaFormat.getInteger(MediaFormat.KEY_WIDTH);
                mMovieHeight = mediaFormat.getInteger(MediaFormat.KEY_HEIGHT);
            }


    public int startPlayback() {
        int update = 0;
        try {
            boolean isEos = ((mExtractor.getSampleFlags() & MediaCodec
                    .BUFFER_FLAG_END_OF_STREAM) == MediaCodec.BUFFER_FLAG_END_OF_STREAM);

            // BEGIN_INCLUDE(write_sample)
            if (!isEos) {
                // Try to submit the sample to the codec and if successful advance the
                // extractor to the next available sample to read.
                long sampletime = mExtractor.getSampleTime();
                int flag = mExtractor.getSampleFlags();

                boolean result = mCodecWrapper.writeSample(mExtractor, false, sampletime,flag);
                //boolean result = mCodecWrapper.writeSample(mExtractor, false, mExtractor.getSampleTime(), mExtractor.getSampleFlags());

                if (result) {
                    // Advancing the extractor is a blocking operation and it MUST be
                    // executed outside the main thread in real applications.
                    mExtractor.advance();
                }
            }
            // END_INCLUDE(write_sample)

            // Examine the sample at the head of the queue to see if its ready to be
            // rendered and is not zero sized End-of-Stream record.
            MediaCodec.BufferInfo out_bufferInfo = new MediaCodec.BufferInfo();
            mCodecWrapper.peekSample(out_bufferInfo);

            // BEGIN_INCLUDE(render_sample)
            if (out_bufferInfo.size <= 0 && isEos) {
                //mTimeAnimator.end();
                //mCodecWrapper.stopAndRelease();
                //mExtractor.release();
                //reset();
                mExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
            } else if (out_bufferInfo.presentationTimeUs / 1000 < totalTime) {
                // Pop the sample off the queue and send it to {@link Surface}
                update = mCodecWrapper.popSample(true);
                if( update>0){
                    try {
                        Thread.sleep((int)1000/captureRate);  //ここで再生速度の調整をしている
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            // END_INCLUDE(render_sample)

        }catch(Exception e) {
            LogOut.printf(e.toString());
        }
        return update;
    }