fix: Compatible with flv video stream decoding without audio

[UmbraCi]

If the flv video stream has no audio data, but hasAudio is also true, then the video will be stuck loading. This fix determines that if there is no audio data in three seconds, then hasAudio will be changed to false

[veovera]

Great find! Curious, have you thought about using these flags to set hasAudio or hasVideo?

mpegts.js/src/demux/flv-demuxer.js

Lines 162 to 163 in c7645fa

	hasAudioTrack: hasAudio,
	hasVideoTrack: hasVideo

[UmbraCi]

Great find! Curious, have you thought about using these flags to set hasAudio or hasVideo?很棒的发现！好奇，你有没有想过用这些标志来设置 hasAudio 或 hasVideo？

mpegts.js/src/demux/flv-demuxer.js

Lines 162 to 163 in c7645fa

	hasAudioTrack: hasAudio,
	hasVideoTrack: hasVideo

I don't see this configurable property in the api.doc file, and I haven't tried it. Have you encountered the same problem and solved it by using this property configuration?

[veovera]

I have not tried it. That said probe() reads the flv header which basically states weather audio is present in the flv. Knowing that allows you to avoid waiting 3 seconds to see if audio is present?

See https://rtmp.veriskope.com/pdf/video_file_format_spec_v10_1.pdf#page=74