Panic on connecting client (vlc and ffplay)

[QuantumEntangledAndy]

Which version are you using?

v0.9.3

Describe the problem

After your bug fix in #41 I am able to connect the publishing client (an ios app). When attempting to play the stream the following error occurs.

2020/07/20 11:52:55 [2/1/0] [client 127.0.0.1:53142] connected
2020/07/20 11:52:55 [2/1/0] [client 127.0.0.1:53142] OPTIONS
2020/07/20 11:52:55 [2/1/0] [client 127.0.0.1:53142] DESCRIBE
2020/07/20 11:52:55 [2/1/0] [client 127.0.0.1:53142] SETUP
2020/07/20 11:52:55 [2/1/0] [client 127.0.0.1:53142] SETUP
2020/07/20 11:52:55 [2/1/0] [client 127.0.0.1:53142] PLAY
2020/07/20 11:52:55 [2/1/1] [client 127.0.0.1:53142] is receiving on path 'test', 2 tracks via udp
panic: runtime error: slice bounds out of range [:12846] with capacity 2048

goroutine 8 [running]:
main.(*serverUdpListener).write(...)
	/s/server-udpl.go:96
main.(*program).forwardFrame(0xc00022a070, 0xc000292158, 0x4, 0x0, 0x0, 0xc000300000, 0x322e, 0x80000)
	/s/main.go:525 +0x8e4
main.(*program).run(0xc00022a070)
	/s/main.go:408 +0x1e8
created by main.newProgram
	/s/main.go:264 +0xbb1

Please let me know if you need further debugging information

[QuantumEntangledAndy]

This happens on both TCP and UDP

(this is the TCP error message)

panic: runtime error: slice bounds out of range [:12903] with capacity 2048

goroutine 22 [running]:
main.(*program).forwardFrame(0xc000115ce0, 0xc00021a158, 0x4, 0x0, 0x0, 0xc000280000, 0x3267, 0x80000)
	/s/main.go:546 +0x88a
main.(*program).run(0xc000115ce0)
	/s/main.go:408 +0x1e8
created by main.newProgram
	/s/main.go:264 +0xbb1

[QuantumEntangledAndy]

So looking into this..

You have the client double buffer fixed at 2048

server-client.go:790

if c.streamProtocol == gortsplib.StreamProtocolTcp {
		c.writeBuf = newDoubleBuffer(2048)
		c.events = make(chan serverClientEvent)
}

The size of the frames are larger than this.

If I send only the first 2048 bytes of each frame (obviously this means the frame is not complete and only a portion of the picture is sent) it will work

main.go:526

buf := client.writeBuf.swap()
len_frame := 2048 // Edited to fixed size for this test
buf = buf[:len_frame]
copy(buf, frame)

I don't know enough about the details of the code to know if I should up the buffer size or send the frame over multiple buffers but I hope that this helps with the debugging.

[QuantumEntangledAndy]

I tried chunking the data but that did not work as I expected, so instead I bumped up the buffer size to 20480 (since the largest frame was 19999 bytes) c.writeBuf = newDoubleBuffer(20480) and everything is working.

[QuantumEntangledAndy]

This increasing of the buffer size only works with the TCP since the UDP uses another method hmm. Or at least the buffer is defined elsewhere. Anyway I will stop tinkering.

[aler9]

Hello, this happens because you're publishing via TCP (read buffer size = 512*1028) and reading via TCP (write buffer size = 2048) and UDP (write buffer size = 2048). The buffer sizes have been adjusted to the following values to avoid memory leaks:

• TCP read buffer size (for publishing) = 128 * 1024
• UDP read buffer size (for publishing) = 2048
• TCP write buffer size (for reading) = 128 * 1024
• UDP write buffer size (for reading) = 128 * 1024
  Please try again with v0.9.4 and let me know if it works.

[QuantumEntangledAndy]

I can confirm that this is working. Thanks for your efforts :)

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