Java 获取ws推送的flv格式视频帧

要获取ws推送的flv格式视频帧，您可以使用以下步骤：

1. 建立WebSocket连接并接收数据流。

2. 处理数据流并解析FLV视频信息。

3. 从FLV视频中提取视频帧。

下面是一些示例代码，演示如何获取FLV视频帧：

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;

public class FlvParser {
    private static final int FLV_HEADER_SIZE = 9;
    private static final int PREVIOUS_TAG_SIZE_FIELD_SIZE = 4;
    private static final int TAG_HEADER_SIZE = 11;
    private static final int TAG_TYPE_VIDEO = 0x09;
    private static final int AVC_PACKET_TYPE_SEQUENCE_HEADER = 0x00;
    private static final int AVC_PACKET_TYPE_NALU = 0x01;

    private static final int TAG_HEADER_TOTAL_SIZE = PREVIOUS_TAG_SIZE_FIELD_SIZE + TAG_HEADER_SIZE;
    private static final int NAL_HEADER_SIZE = 4;
    private static final byte[] NAL_HEADER = new byte[]{0x00, 0x00, 0x00, 0x01};

    private ByteBuffer mByteBuffer = ByteBuffer.allocate(1024 * 1024); // 1MB
    private List<byte[]> mNaluList = new ArrayList<>();

    public void parse(byte[] data, int length) {
        mByteBuffer.put(data, 0, length);
        mByteBuffer.flip();

        while (mByteBuffer.remaining() > TAG_HEADER_TOTAL_SIZE) {
            int previousTagSize = mByteBuffer.getInt();
            int tagType = mByteBuffer.get() & 0xff;
            int dataSize = ((mByteBuffer.get() & 0xff) << 16) | ((mByteBuffer.get() & 0xff) << 8) | (mByteBuffer.get() & 0xff);
            int timestamp = ((mByteBuffer.get() & 0xff) << 16) | ((mByteBuffer.get() & 0xff) << 8) | (mByteBuffer.get() & 0xff) | ((mByteBuffer.get() & 0xff) << 24);
            int streamId = ((mByteBuffer.get() & 0xff) << 16) | ((mByteBuffer.get() & 0xff) << 8) | (mByteBuffer.get() & 0xff);

            if (tagType == TAG_TYPE_VIDEO) {
                int frameType = (mByteBuffer.get() & 0xff) >> 4;
                int codecId = mByteBuffer.get() & 0x0f;

                if (codecId == 7) { // AVC
                    handleAvcPacket(dataSize);
                }
            }

            mByteBuffer.position(mByteBuffer.position() + dataSize + PREVIOUS_TAG_SIZE_FIELD_SIZE);

            if (mByteBuffer.remaining() < TAG_HEADER_TOTAL_SIZE) {
                mByteBuffer.compact();
                break;
            }
        }

        mByteBuffer.compact();
    }

    private void handleAvcPacket(int dataSize) {
        int avcPacketType = mByteBuffer.get() & 0xff;

        if (avcPacketType == AVC_PACKET_TYPE_SEQUENCE_HEADER) {
            // TODO: parse SPS and PPS
        } else if (avcPacketType == AVC_PACKET_TYPE_NALU) {
            byte[] naluData = new byte[dataSize - 1];
            mByteBuffer.get(naluData);
            mNaluList.add(naluData);
        }

        while (mNaluList.size() > 0) {
            byte[] naluData = mNaluList.get(0);
            int naluLength = naluData.length + NAL_HEADER_SIZE;
            byte[] frameData = new byte[naluLength];
            System.arraycopy(NAL_HEADER, 0, frameData, 0, NAL_HEADER_SIZE);
            System.arraycopy(naluData, 0, frameData, NAL_HEADER_SIZE, naluData.length);
            // TODO: handle frameData
            mNaluList.remove(0);
        }
    }
}

在上面的示例代码中，`parse()`方法处理FLV视频流，`handleAvcPacket()`方法解析AVC数据包并提取NAL单元，`NAL_HEADER`是NAL单元的头部。

当您成功解析NAL单元后，可以将它们组合成完整的视频帧，并对其进行处理。

希望这可以帮助您获取ws推送的flv格式视频帧。