GB28181: Pure video stream HLS has exceptions on Apple devices

[canbylee]

Front-end: For Hikvision IPC, using pure video stream without audio channel, pushing stream to SRS using FFMPEG. If HLS is used with react-native-video, it cannot play, but VLC can play it normally. It can be played on Apple browsers, but it does not autoplay or occasionally cannot play. If the audio PMT is commented out, it seems to work normally. What is the reason for this comment? (For HLS, there must be at least one audio channel)

   if (as == SrsTsStreamAudioAAC || as == SrsTsStreamAudioMp3) {
        // use audio to carray pcr by default.
        // for hls, there must be atleast one audio channel.
        //pmt->PCR_PID = apid;
        //pmt->infos.push_back(new SrsTsPayloadPMTESInfo(as, apid));
    }

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[winlinvip]

It seems that the early standard of Apple stated that there should be at least one audio, but there may have been recent updates to HLS. It is possible to consider supporting pure video streams.

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[canbylee]

If it is pure video streaming without audio, no abnormality has been found on various platforms temporarily.

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[winlinvip]

Postpone to SRS4

[winlinvip]

Few scenarios, no plans to support.

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[geiliwanghaichao]

@canbylee hello, I have also encountered a similar problem. When streaming the camera from Hikvision/Dahua to SRS without enabling audio, using VLC to play the m3u8 file shows the following image:

When using ffplay to play, it shows the following image:

Because we are collaborating with a third party, the audio is not enabled on the front-end camera. However, when viewing it on ffplay, the audio channel is displayed, which causes the third-party decoding to fail. Following your method, by commenting out the above two lines of code, ffplay no longer displays the audio channel. Although this eliminates the error,

However, it is unknown whether this has any impact on the entire process. @winlinvip, the expert, mentioned that in "a few scenarios, there is no intention to support" this. However, currently, it is found that when using cameras from Hikvision/Dahua to push streams to SRS, this issue persists. It is unclear if there are any plans to address this problem in the future.

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[winlinvip]

Belonging to the monitoring scene is more common, Haibo can consider whether it is worth supporting.

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[duiniuluantanqin]

Repeated issue, please go to #2570 (comment)

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[winlinvip]

In HLS specfication, there should be at least one audio stream. So, HLS does not work when pure video stream is published by RTMP or WebRTC or SRT.

Workaround: Insert a silent audio stream, which means create a audio stream by FFmpeg. You can also use Camera stream feature of SRS Stack that support this feature.