MediaCodec H264编码器不能在Snapdragon 800设备上工作

Question

        mBufferInfo = new MediaCodec.BufferInfo();
        encoder = MediaCodec.createEncoderByType("video/avc");
        MediaFormat mediaFormat = MediaFormat.createVideoFormat("video/avc", 640, 480);
        mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, 768000);
        mediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, 30);
        mediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, mEncoderColorFormat);
        mediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 10);
        encoder.configure(mediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);

MediaCodecInfo.CodecCapabilities capabilities = mCodecInfo.getCapabilitiesForType(MIME_TYPE);
            for (int i = 0; i < capabilities.colorFormats.length && selectedColorFormat == 0; i++)
            {
                int format = capabilities.colorFormats[i];
                switch (format) {
                    case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar:
                    case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedPlanar:
                    case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar:
                    case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedSemiPlanar:
                    case MediaCodecInfo.CodecCapabilities.COLOR_TI_FormatYUV420PackedSemiPlanar:
                    case MediaCodecInfo.CodecCapabilities.COLOR_QCOM_FormatYUV420SemiPlanar:
                        selectedColorFormat = format;
                        break;
                    default:
                        LogHandler.e(LOG_TAG, "Unsupported color format " + format);
                        break;
                }
            }

            ByteBuffer[] inputBuffers = mEncoder.getInputBuffers();
        ByteBuffer[] outputBuffers = mEncoder.getOutputBuffers();

        int inputBufferIndex = mEncoder.dequeueInputBuffer(-1);
        if (inputBufferIndex >= 0)
        {
            // fill inputBuffers[inputBufferIndex] with valid data
            ByteBuffer inputBuffer = inputBuffers[inputBufferIndex];
            inputBuffer.clear();
            inputBuffer.put(rawFrame);
            mEncoder.queueInputBuffer(inputBufferIndex, 0, rawFrame.length, 0, 0);
            LogHandler.e(LOG_TAG, "Queue Buffer in " + inputBufferIndex);
        }

        while(true)
        {
            int outputBufferIndex = mEncoder.dequeueOutputBuffer(mBufferInfo, 0);
            if (outputBufferIndex >= 0)
            {
                Log.d(LOG_TAG, "Queue Buffer out " + outputBufferIndex);
                ByteBuffer buffer = outputBuffers[outputBufferIndex];
                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0)
                {
                    // Config Bytes means SPS and PPS
                    Log.d(LOG_TAG, "Got config bytes");
                }

                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_SYNC_FRAME) != 0)
                {
                    // Marks a Keyframe
                    Log.d(LOG_TAG, "Got Sync Frame");
                }

                if (mBufferInfo.size != 0)
                {
                    // adjust the ByteBuffer values to match BufferInfo (not needed?)
                    buffer.position(mBufferInfo.offset);
                    buffer.limit(mBufferInfo.offset + mBufferInfo.size);

                    int nalUnitLength = 0;
                    while((nalUnitLength = parseNextNalUnit(buffer)) != 0)
                    {
                        switch(mVideoData[0] & 0x0f)
                        {
                            // SPS
                            case 0x07:
                            {
                                Log.d(LOG_TAG, "Got SPS");
                                break;
                            }

                            // PPS
                            case 0x08:
                            {
                                Log.d(LOG_TAG, "Got PPS");
                                break;
                            }

                            // Key Frame
                            case 0x05:
                            {
                                Log.d(LOG_TAG, "Got Keyframe");
                            }

                            //$FALL-THROUGH$
                            default:
                            {
                                // Process Data
                                break;
                            }
                        }
                    }
                }

                mEncoder.releaseOutputBuffer(outputBufferIndex, false);

                if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0)
                {
                    // Stream is marked as done,
                    // break out of while
                    Log.d(LOG_TAG, "Marked EOS");
                    break;
                }
            }
            else if(outputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
            {
                outputBuffers = mEncoder.getOutputBuffers();
                Log.d(LOG_TAG, "Output Buffer changed " + outputBuffers);
            }
            else if(outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
            {
                MediaFormat newFormat = mEncoder.getOutputFormat();
                Log.d(LOG_TAG, "Media Format Changed " + newFormat);
            }
            else if(outputBufferIndex == MediaCodec.INFO_TRY_AGAIN_LATER)
            {
                // No Data, break out
                break;
            }
            else
            {
                // Unexpected State, ignore it
                Log.d(LOG_TAG, "Unexpected State " + outputBufferIndex);
            }
        }

谢谢你的帮助！

Answer 1

您需要在对QueueInputBuffer的调用中设置presentationTimeUs参数。大多数编码器忽略了这一点，您可以为流式编码而没有问题。用于Snapdragon 800设备的编码器不是。

此参数表示帧的录制时间，因此需要在要编码的帧和前一帧之间增加我们的数量。

如果参数集与前一帧中的值相同，编码器将其丢弃。如果参数设置得太小（例如30 FPS录音时为100000)，则编码帧的质量下降。