H264流的演示时间不正确[Live555 OpenRtspClient] [英] Wrong Presentation time at H264 streams [Live555 OpenRtspClient]
问题描述
我将OpenRtspClient修改为
I modify the OpenRtspClient so that
-
现在，我没有将帧写入文件中，而是将它们收集在具有传入演示文稿时间的队列中
Now instead of writing frames to file I collect them in a queue with incoming presenttaion times
然后将h264帧提供给MP4多路复用器[Geraint Davies MP4多路复用器过滤器]
Then give the h264 frames to MP4 muxer [ Geraint Davies MP4 mux filter]
所以我可以将h264流保存到MP4容器中...
So I can able to save h264 stream into MP4 container...
但是问题是，一些记录的数据[不是全部] 持续时间的值有误:
But the problem is that, some of the recorded data [NOT all of them] has wrong values for time duration:
假设10分钟的记录似乎是12小时的流... VLC播放剩余时间播放最后一帧的10分钟.
Suppose that a 10 minute record seems that it was 12 h stream... VLC play the 10 minute that play last frame for the remaing time.
似乎我在Muxer中设置了错误的采样时间... 然后我调试一下，发现在时间戳上有正向和负向的戏剧性跳跃……
It seems that i set sample times wrong into the Muxer... Then i debug and see that there is positive and negative dramatic jumps at time stamps...
这是我设置时间戳的方法:
Here is how i set time stamps:
- 第一次我从H264VideoFileSink :: afterGettingFrame1函数获取了presentationTime
- 然后计算firstPresentaionTime [在开头]
- 然后收集其他时间戳记
而且我看到frameTimeStamp值显示出急剧的跳升到负值或正值... [我将这些值保留为int64]
And I see that frameTimeStamp values show dramatic jumps to negative or positive values...[ i keeep those values as int64 ]
#define TIMEVAL_TO_REFERENCE_TIME(x)
((__int64)(x.tv_sec * 1000000) + x.tv_usec) * 10
void H264VideoFileSink::
afterGettingFrame1(unsigned frameSize, struct timeval presentationTime)
{
// At the beginning [ just for once calculate firstPresentaionTime ]
firstPresentaionTime = TIMEVAL_TO_REFERENCE_TIME(presentationTime);
// for the other frames collect frames timestamps
frameTimeStamp = TIMEVAL_TO_REFERENCE_TIME(presentationTime) -
firstPresentationTime
}
我的原因是什么?
- 或者将这个"presentationTime"用于MP4混合器是个好主意吗?
- 在库中计算"presentationTime"的位置是什么?
- H264VideoFileSink :: afterGettingFrame1方法"presentationTime"值是否可能错误?
- 有人在mp4录制器中录制h264流并想分享他/她的经验吗?
推荐答案
部分回答您的问题:
- 在库中"presentationTime"是在哪里计算的?
- H264VideoFileSink :: afterGettingFrame1方法的"presentationTime"值是否可能是错误的?
- Where the "presentationTime" is calculated at library?
- Is it possible that H264VideoFileSink::afterGettingFrame1 method "presentationTime" values may be wrong?
- 演示时间基于样本的RTP时间戳.
- 不太可能，我们使用live555的时间很长，没有任何时间戳问题.如果时间戳不正确，我会怀疑RTP源(即RTSP服务器或摄像机)的时间戳不正确.使用wireshark嗅探RTP数据包以查看RTP时间戳，然后从那里转换回NTP时间，以查看连续帧之间的差异，这可能有帮助，也可能没有帮助.
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