jt1078调试时发现如果音频流先来，会导致无法推流

[zhemgshibo]

你好，jt1078调试时发现如果音频流先来，会导致无法推流。
调试发现 source_utils.go 中 ExtractVideoPacket 方法中强制指定了 index = 0 会导致数据无法推流
stream = utils.NewAVStream(utils.AVMediaTypeVideo, 0, codec, codecData.AnnexBExtraData(), codecData)

func ExtractVideoPacket(codec utils.AVCodecID, key, extractStream bool, data []byte, pts, dts int64, index, timebase int) (utils.AVStream, utils.AVPacket, error) {
	var stream utils.AVStream

	if utils.AVCodecIdH264 == codec {
		//从关键帧中解析出sps和pps
		if key && extractStream {
			sps, pps, err := libavc.ParseExtraDataFromKeyNALU(data)
			if err != nil {
				log.Sugar.Errorf("从关键帧中解析sps pps失败 data:%s", hex.EncodeToString(data))
				return nil, nil, err
			}

			codecData, err := utils.NewAVCCodecData(sps, pps)
			if err != nil {
				log.Sugar.Errorf("解析sps pps失败 data:%s sps:%s, pps:%s", hex.EncodeToString(data), hex.EncodeToString(sps), hex.EncodeToString(pps))
				return nil, nil, err
			}

			stream = utils.NewAVStream(utils.AVMediaTypeVideo, 0, codec, codecData.AnnexBExtraData(), codecData)
		}

	} else if utils.AVCodecIdH265 == codec {
		if key && extractStream {
			vps, sps, pps, err := libhevc.ParseExtraDataFromKeyNALU(data)
			if err != nil {
				log.Sugar.Errorf("从关键帧中解析vps sps pps失败  data:%s", hex.EncodeToString(data))
				return nil, nil, err
			}

			codecData, err := utils.NewHEVCCodecData(vps, sps, pps)
			if err != nil {
				log.Sugar.Errorf("解析sps pps失败 data:%s vps:%s sps:%s, pps:%s", hex.EncodeToString(data), hex.EncodeToString(vps), hex.EncodeToString(sps), hex.EncodeToString(pps))
				return nil, nil, err
			}

			stream = utils.NewAVStream(utils.AVMediaTypeVideo, 0, codec, codecData.AnnexBExtraData(), codecData)
		}

	}

	packet := utils.NewVideoPacket(data, dts, pts, key, utils.PacketTypeAnnexB, codec, index, timebase)
	return stream, packet, nil
}

[ydajiang]

好的，近两周会出一个重构版本，会修复该问题