This topic provides solutions for common problems that you may come across while you are using LiveChannel.
Push a stream to OSS LiveChannel
For more information, see the following topics:
Case 1: The m3u8 file is missing.
Problem: The generated m3u8 file only contains the last 3 ts files by default. The m3u8 file conforms to the default rules of the HLS protocol.
PostVodPlaylistto converge the ts files generated in the specified time period into a m3u8 index file.
- The value of
EndTimemust be later than the value of
StartTime. The duration between the EndTime and StartTime must be shorter than one day.
- OSS queries all the ts files generated by the streams pushed to the specified LiveChannel in the specified time range and converges these files into a playlist.
Case 2: Failed to generate the m3u8 file
Problem: The m3u8 file is not successfully generated until the audio or video data is completely uploaded to OSS.
Solution: You can capture packets at the client side to check whether the "publish success" message is included, which indicates that the audio or video data is completely uploaded to OSS. If the message is included but the m3u8 file is not generated, you can analyze the packets sent from the client for root causes.
Case 3: The client cannot push a stream to OSS
ffmpeg -re -i 0_20180525105430445.aac -acodec aac -strict -2 -f flv rtmp://xxx.oss-cn-beijing.aliyuncs.com/live/test_1000?Expires=1540458859&OSSAccessKeyId=LTAlujianb6C9z&Signature=qwh31xQsanmao6ygCFJgovNIg%3D&playlistName=playlist.m3u8
- We recommend you use the original command to push a stream without setting additional parameters.
- If the "&" character is included in the URL used to push a stream, enclose the URL with quotation marks (""). For example: ffmpeg -re -i 0_20180525105430445.aac -acodec aac -strict -2 -f flv "rtmp://xxx.oss-cn-beijing.aliyuncs.com/live/test_1000?Expires=1540458859&OSSAccessKeyId=LTAlujianb6C9z&Signature=qwh31xQsanmao6ygCFJgovNIg%3D&playlistName=playlist.m3u8"。
- Use OBS to push a stream to check whether the problem is caused by ffmpeg.
Case 4: Lag problems occur when the m3u8 file is generated.
If the value of Type is HLS, when the duration of the video or audio data in the current ts file reaches the value of
FragDuration, OSS generates a new ts file when receiving the next key frame. If OSS does not receive the next key frame with in a time period (calculated by
max(2*FragDuration, 60s)), a new ts file is generated, which results lag in audio or video playing.
Case 5: No audio or video data is included in the generated m3u8 file.
This problem may be caused by the following reasons:
AAC headeris not sent. You can capture packets sent by the client to check whether the two headers are sent.
- The length of
RTMP messageis shorter than 2, or the length of
sequence headeris too short.
- The size of
Messageof the audio data exceeds the cache size.
codec_ ctxis important for the codec. If the audio or video data included in the parameter is incorrect, the m3u8 file may fail to be generated.
Case 6: The data upload to OSS by ffmpeg does not include audio data.
- View the logs generated by ffmpeg to check whether
- Capture the RTMP packets sent by the client to check whether