/**
         * Checks the video data.
         *
         * @return the number of bad frames
         */
        private int checkVideoData(VideoChunks inputData, MediaCodec decoder, OutputSurface surface)
        {
            const int TIMEOUT_USEC = 1000;

            ByteBuffer[]          decoderInputBuffers  = decoder.GetInputBuffers();
            ByteBuffer[]          decoderOutputBuffers = decoder.GetOutputBuffers();
            MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
            int  inputChunk            = 0;
            int  checkIndex            = 0;
            int  badFrames             = 0;
            bool outputDone            = false;
            bool inputDone             = false;

            while (!outputDone)
            {
                if (AppSettings.Logging.SendToConsole)
                {
                    Log.Debug(TAG, "check loop");
                }
                // Feed more data to the decoder.
                if (!inputDone)
                {
                    int inputBufIndex = decoder.DequeueInputBuffer(TIMEOUT_USEC);
                    if (inputBufIndex >= 0)
                    {
                        if (inputChunk == inputData.NumChunks)
                        {
                            // End of stream -- send empty frame with EOS flag set.
                            decoder.QueueInputBuffer(inputBufIndex, 0, 0, 0L,
                                                     MediaCodec.BufferFlagEndOfStream);
                            inputDone = true;
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "sent input EOS");
                            }
                        }
                        else
                        {
                            // Copy a chunk of input to the decoder. The first chunk should have
                            // the BUFFER_FLAG_CODEC_CONFIG flag set.
                            ByteBuffer inputBuf = decoderInputBuffers[inputBufIndex];
                            inputBuf.Clear();
                            inputData.getChunkData(inputChunk, inputBuf);
                            int  flags = inputData.getChunkFlags(inputChunk);
                            long time  = inputData.getChunkTime(inputChunk);
                            decoder.QueueInputBuffer(inputBufIndex, 0, inputBuf.Position(),
                                                     time, (MediaCodecBufferFlags)flags);
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "submitted frame " + inputChunk + " to dec, size=" +
                                          inputBuf.Position() + " flags=" + flags);
                            }
                            inputChunk++;
                        }
                    }
                    else
                    {
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "input buffer not available");
                        }
                    }
                }
                if (!outputDone)
                {
                    int decoderStatus = decoder.DequeueOutputBuffer(info, TIMEOUT_USEC);
                    if (decoderStatus == (int)MediaCodec.InfoTryAgainLater)
                    {
                        // no output available yet
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "no output from decoder available");
                        }
                    }
                    else if (decoderStatus == (int)MediaCodec.InfoOutputBuffersChanged)
                    {
                        decoderOutputBuffers = decoder.GetOutputBuffers();
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "decoder output buffers changed");
                        }
                    }
                    else if (decoderStatus == (int)MediaCodec.InfoOutputFormatChanged)
                    {
                        MediaFormat newFormat = decoder.OutputFormat;
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "decoder output format changed: " + newFormat);
                        }
                    }
                    else if (decoderStatus < 0)
                    {
                        fail("unexpected result from decoder.dequeueOutputBuffer: " + decoderStatus);
                    }
                    else                                                                         // decoderStatus >= 0
                    {
                        ByteBuffer decodedData = decoderOutputBuffers[decoderStatus];
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "surface decoder given buffer " + decoderStatus +
                                      " (size=" + info.Size + ")");
                        }
                        if ((info.Flags & MediaCodec.BufferFlagEndOfStream) != 0)
                        {
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "output EOS");
                            }
                            outputDone = true;
                        }
                        bool doRender = (info.Size != 0);
                        // As soon as we call releaseOutputBuffer, the buffer will be forwarded
                        // to SurfaceTexture to convert to a texture. The API doesn't guarantee
                        // that the texture will be available before the call returns, so we
                        // need to wait for the onFrameAvailable callback to fire.
                        decoder.ReleaseOutputBuffer(decoderStatus, doRender);
                        if (doRender)
                        {
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "awaiting frame " + checkIndex);
                            }
                            assertEquals("Wrong time stamp", computePresentationTime(checkIndex),
                                         info.PresentationTimeUs);
                            surface.AwaitNewImage();
                            surface.DrawImage();
                            if (!checkSurfaceFrame(checkIndex++))
                            {
                                badFrames++;
                            }
                        }
                    }
                }
            }
            return(badFrames);
        }
        /**
         * Edits a stream of video data.
         */
        private void editVideoData(VideoChunks inputData, MediaCodec decoder,
                                   OutputSurface outputSurface, InputSurface inputSurface, MediaCodec encoder,
                                   VideoChunks outputData)
        {
            const int TIMEOUT_USEC = 10000;

            ByteBuffer[]          decoderInputBuffers  = decoder.GetInputBuffers();
            ByteBuffer[]          encoderOutputBuffers = encoder.GetOutputBuffers();
            MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
            int  inputChunk            = 0;
            int  outputCount           = 0;
            bool outputDone            = false;
            bool inputDone             = false;
            bool decoderDone           = false;

            while (!outputDone)
            {
                if (AppSettings.Logging.SendToConsole)
                {
                    Log.Debug(TAG, "edit loop");
                }
                // Feed more data to the decoder.
                if (!inputDone)
                {
                    int inputBufIndex = decoder.DequeueInputBuffer(TIMEOUT_USEC);
                    if (inputBufIndex >= 0)
                    {
                        if (inputChunk == inputData.NumChunks)
                        {
                            // End of stream -- send empty frame with EOS flag set.
                            decoder.QueueInputBuffer(inputBufIndex, 0, 0, 0L,
                                                     MediaCodecBufferFlags.EndOfStream);
                            inputDone = true;
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "sent input EOS (with zero-length frame)");
                            }
                        }
                        else
                        {
                            // Copy a chunk of input to the decoder. The first chunk should have
                            // the BUFFER_FLAG_CODEC_CONFIG flag set.
                            ByteBuffer inputBuf = decoderInputBuffers[inputBufIndex];
                            inputBuf.Clear();
                            inputData.getChunkData(inputChunk, inputBuf);
                            int  flags = inputData.getChunkFlags(inputChunk);
                            long time  = inputData.getChunkTime(inputChunk);
                            decoder.QueueInputBuffer(inputBufIndex, 0, inputBuf.Position(),
                                                     time, (MediaCodecBufferFlags)flags);             // TODO: Not sure if it's MediaCodecBufferFlags, verify.
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "submitted frame " + inputChunk + " to dec, size=" +
                                          inputBuf.Position() + " flags=" + flags);
                            }
                            inputChunk++;
                        }
                    }
                    else
                    {
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "input buffer not available");
                        }
                    }
                }
                // Assume output is available. Loop until both assumptions are false.
                bool decoderOutputAvailable = !decoderDone;
                bool encoderOutputAvailable = true;
                while (decoderOutputAvailable || encoderOutputAvailable)
                {
                    // Start by draining any pending output from the encoder. It's important to
                    // do this before we try to stuff any more data in.
                    int encoderStatus = encoder.DequeueOutputBuffer(info, TIMEOUT_USEC);
                    if (encoderStatus == (int)MediaCodecInfoState.TryAgainLater)
                    {
                        // no output available yet
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "no output from encoder available");
                        }
                        encoderOutputAvailable = false;
                    }
                    else if (encoderStatus == (int)MediaCodecInfoState.OutputBuffersChanged)
                    {
                        encoderOutputBuffers = encoder.GetOutputBuffers();
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "encoder output buffers changed");
                        }
                    }
                    else if (encoderStatus == (int)MediaCodecInfoState.OutputFormatChanged)
                    {
                        MediaFormat newFormat = encoder.OutputFormat;
                        if (AppSettings.Logging.SendToConsole)
                        {
                            Log.Debug(TAG, "encoder output format changed: " + newFormat);
                        }
                    }
                    else if (encoderStatus < 0)
                    {
                        fail("unexpected result from encoder.dequeueOutputBuffer: " + encoderStatus);
                    }
                    else                         // encoderStatus >= 0
                    {
                        ByteBuffer encodedData = encoderOutputBuffers[encoderStatus];
                        if (encodedData == null)
                        {
                            fail("encoderOutputBuffer " + encoderStatus + " was null");
                        }
                        // Write the data to the output "file".
                        if (info.Size != 0)
                        {
                            encodedData.Position(info.Offset);
                            encodedData.Limit(info.Offset + info.Size);
                            outputData.addChunk(encodedData, (int)info.Flags, info.PresentationTimeUs);
                            outputCount++;
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "encoder output " + info.Size + " bytes");
                            }
                        }
                        outputDone = (info.Flags & MediaCodec.BufferFlagEndOfStream) != 0;
                        encoder.ReleaseOutputBuffer(encoderStatus, false);
                    }
                    if (encoderStatus != (int)MediaCodec.InfoTryAgainLater)
                    {
                        // Continue attempts to drain output.
                        continue;
                    }
                    // Encoder is drained, check to see if we've got a new frame of output from
                    // the decoder. (The output is going to a Surface, rather than a ByteBuffer,
                    // but we still get information through BufferInfo.)
                    if (!decoderDone)
                    {
                        int decoderStatus = decoder.DequeueOutputBuffer(info, TIMEOUT_USEC);
                        if (decoderStatus == (int)MediaCodec.InfoTryAgainLater)
                        {
                            // no output available yet
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "no output from decoder available");
                            }
                            decoderOutputAvailable = false;
                        }
                        else if (decoderStatus == (int)MediaCodec.InfoOutputBuffersChanged)
                        {
                            //decoderOutputBuffers = decoder.getOutputBuffers();
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "decoder output buffers changed (we don't care)");
                            }
                        }
                        else if (decoderStatus == (int)MediaCodec.InfoOutputFormatChanged)
                        {
                            // expected before first buffer of data
                            MediaFormat newFormat = decoder.OutputFormat;
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "decoder output format changed: " + newFormat);
                            }
                        }
                        else if (decoderStatus < 0)
                        {
                            fail("unexpected result from decoder.dequeueOutputBuffer: " + decoderStatus);
                        }
                        else                             // decoderStatus >= 0
                        {
                            if (AppSettings.Logging.SendToConsole)
                            {
                                Log.Debug(TAG, "surface decoder given buffer " + decoderStatus + " (size=" + info.Size + "(");
                            }
                            // The ByteBuffers are null references, but we still get a nonzero
                            // size for the decoded data.
                            bool doRender = (info.Size != 0);
                            // As soon as we call releaseOutputBuffer, the buffer will be forwarded
                            // to SurfaceTexture to convert to a texture. The API doesn't
                            // guarantee that the texture will be available before the call
                            // returns, so we need to wait for the onFrameAvailable callback to
                            // fire. If we don't wait, we risk rendering from the previous frame.
                            decoder.ReleaseOutputBuffer(decoderStatus, doRender);
                            if (doRender)
                            {
                                // This waits for the image and renders it after it arrives.
                                if (AppSettings.Logging.SendToConsole)
                                {
                                    Log.Debug(TAG, "awaiting frame");
                                }
                                outputSurface.AwaitNewImage();
                                outputSurface.DrawImage();
                                // Send it to the encoder.
                                inputSurface.SetPresentationTime(info.PresentationTimeUs * 1000);
                                if (AppSettings.Logging.SendToConsole)
                                {
                                    Log.Debug(TAG, "swapBuffers");
                                }
                                inputSurface.SwapBuffers();
                            }
                            if ((info.Flags & MediaCodec.BufferFlagEndOfStream) != 0)
                            {
                                // forward decoder EOS to encoder
                                if (AppSettings.Logging.SendToConsole)
                                {
                                    Log.Debug(TAG, "signaling input EOS");
                                }
                                if (WORK_AROUND_BUGS)
                                {
                                    // Bail early, possibly dropping a frame.
                                    return;
                                }
                                else
                                {
                                    encoder.SignalEndOfInputStream();
                                }
                            }
                        }
                    }
                }
            }
            if (inputChunk != outputCount)
            {
                throw new RuntimeException("frame lost: " + inputChunk + " in, " +
                                           outputCount + " out");
            }
        }