MA-LB :: Live Streaming Issues

When using CDNetworks’ live streaming services such as Media Acceleration Live Broadcast and Cloud Live, you may receive an error message from our service end or have some troubles when having a playback. Some common issues are listed as followed and attached with corresponding solutions

• What to do when the stream cannot be played or get an error message of 404?

• What to do if shuttering occurs when having a playback?

• What to do if the video is with fuzzy screen?

• What to do if the stream is abnormally interrupted?

• Why the playback address of RTMP and FLV format is normal, but the playback of HLS format address fails?

• Why I can play the stream based on m3u8 playlist, but only see images without the sound?

What to do when the stream cannot be played or get an error message of 404?

After completing the configuration of the live video, the troubleshooting methods for the inability to watch the live video are as follows:

1. Check if you have concatenated the playback URL correctly without incorrect&incomplete parameters.

a. Check whether the playback address is the correct stream pulling address. If not, please change the playback address to the stream pulling address and check whether it returns to normal.

b. Confirm whether the playback address is correct and conforms to the concatenating rules. The playback address of the live streaming is concatenated ​​according to the live streaming acceleration domain name + AppName + StreamName. Note that the URLs for different protocols are different. Common ones are:

Please take note that URLs differ from different protocols. eg:

rtmp://example.domain.com/appname/streamname

http://example.domain.com/appname/streamname.flv

http://example.domain.com/appname/streamname/playlist.m3u8

2. Check whether the domain name has been resolved to the server of CDNetworks. You can use the ping command to test the domain name of the live video to check whether the resolved CNAME is valid. If it is redirected to *.*.gccdn.net, which means that the CNAME configuration has taken effect.

If it prompts “Name or service not known”, it means that the resolution is not successful yet. You may refer to your dedicated customer service for more details.

3. Check the player.

a. Enter the playback address in other third-party players for live streaming, excluding the problem of the player itself.

b. Check whether it is a CORS-related player issue. If resources are hosted on a different origin than the origin where the player stands, proper CORS settings or policies must be enabled.  You can refer to your dedicated customer service for more details.

4. Confirm whether the playback format is supported.

a. Supported formats using Flash player on the PC: RTMP, FLV, m3u8.

b. The H5 player on the mobile phone only supports m3u8 (all iOS supported, for Android only adapting version above 4.0 and supportable mobile browser.

5. Check the authentication configuration.
a. Check whether the authentication parameters used for authentication are misspelled.
b. Check whether the request time is within the authentication expiration time.

6. Check the network status of the device
Check the network status of the local machine device and whether it can access the public network normally. You can run the ping command to test the network connection between the local device and the acceleration domain name.

What to do if shuttering occurs when having a playback?

There are many causes for the stuttering issue. Please refer to the following aspects for the possible causes and dealing according to the actual situation on site:

Stream ingest

1. Insufficient upstream bandwidth or network jitter occurs, resulting in a decrease in the data transmission rate, unable to meet the frame rate requirements for smooth playback.
It is recommended the Speedtest tool test the upstream bandwidth of your current network.

2. The bit rate, frame rate, or encoding gear is set too high, but the hardware conditions are limited, resulting in slower encoding speed and unable to meet the frame rate requirements for smooth playback.
Please try lowering the bit rate, frame rate, or encoding gear settings to check if the stuttering phenomenon is improved. If it improves, upgrading the hardware of  Stream Pushing terminal is strongly recommended.

3. The setting of video capture parameters is too low.
FPS requires at least 15 frames per second to be recognized as a smooth video by the human eye. If the FPS is less than 10 frames, the picture will have more obvious stuttering.

If there are no special circumstances, please set the video frame rate above 15 frames per second. Although the higher the frame rate of the video, the stronger the smoothness of the picture, When the frame rate exceeds 30 frames per second, the human eye cannot recognize the effect of the picture. Increasing the frame rate will also increase the bandwidth cost of video transmission. It is recommended that you set the parameters of the video properly.

Server

In order to ensure the prompt playback of the live stream and reduce the lagging of stream pulling, the server will cache the data for about 3 seconds by default, which may fluctuate according to the size of GOP.
Configure optimization strategies, etc. You may consult the dedicated customer service to provide optimization solutions, such as adding quick-start and configuring optimization strategies.

Player

1. Most players decode and display after receiving the cache. The size of the receiving buffer cache will also affect the smoothness of playback. You can reduce the impact of stuttering by adjusting the size of the receiving cache.

2. The downstream bandwidth of the player is insufficient or the network jitter, which leads to a decrease in the data reception rate and cannot meet the frame rate requirements for smooth playback.

What to do if the video is with fuzzy screen?

1. Confirm whether it is a video source problem
a. You need to confirm whether the stream ingest source is normal, and rule out the problem of the live video source.
b. You need to confirm whether the frame rate and bit rate of the push stream（stream pushing） is normal. To rule out the problem during the push stream transmission, you can check the push stream status of the streamer in Media Acceleration Live Broadcast->Sevice Quality->Push Analyse

c. Confirm whether the metadata header of the stream has changed during the push stream process, which may cause abnormal transcoding, and lead to the phenomenon of fuzzy screen. If this happens, you may consult your dedicated customer service.

2. Problems with non-video sources
a. Please check whether the player uses soft decoding.

b. Replace a new player to rule out the problem of the player.

What to do if the stream is abnormally interrupted?

1. You can first confirm whether the corresponding push stream is normal. If the push stream is terminated, stream pulling will also be interrupted.

2. Confirm whether the network condition of the player is normal. The troubleshooting process can be checked according to the subsection “What to do when the stream cannot be played or get an error message of 404?”

3. Confirm whether a single user or multiple users are abnormally interrupted. When consulting your dedicated customer service, please provide the abnormal customer’s IP address, URL, abnormal time, and other information to assist in the investigation.

Why the playback address of RTMP and FLV format is normal, but the playback of HLS format address fails?

The troubleshooting method for the playback failure of the playback address in HLS format is as follows:

1. Use the HLS format playback address provided by the FFPlay player to check the stream encoding, and whether the audio and video streams are in the correct format and complete.

2. Use the FFPlay player to test the playback effect of the RTMP and M3U8 format playback addresses to see if there is a clear error. If an error is reported, you may consult your dedicated customer service and troubleshoot according to the error code.

3. Check whether the back-to-origin Host has changed.
Note: The back-to-origin origin Host of the live streaming domain name is not allowed to be changed by default. Changing the back-to-origin Host will not affect RTMP and FLV, but will affect HLS playback.

If the problem still cannot be solved, please refer to the troubleshooting method of “What to do when the stream cannot be played or get an error message of 404?”

Why I can play the stream based on m3u8 playlist, but only see images without the sound?

In this case, It generally occurs when the push stream audio encoding is unreasonable, HLS supports audio formats: AAC, and MP3.

If the audio format of your push stream is: Nellymoser, sometimes there may be no sound in the picture. You can also test the formats of RTMP and FLV to see if there is sound to verify if it’s the error of the audio encoding. You can adjust the audio encoding format of the push stream, or consult your dedicated customer service for further assistance.