Open wufeissdfz opened 3 years ago
pabr
commented
3 years ago leandvb with ldpc_tool has known issues when the signal is very noisy (or when there is pure noise before/after a strong signal, as in your recording).
As a workaround you can try adding "--modcods 0x80000 --framesizes 2" to the command-line. You should get at least 1.5 MB of MPEG TS from your recording. Please let me know if this helps.
wufeissdfz
commented
3 years ago leandvb with ldpc_tool has known issues when the signal is very noisy (or when there is pure noise before/after a strong signal, as in your recording).
As a workaround you can try adding "--modcods 0x80000 --framesizes 2" to the command-line. You should get at least 1.5 MB of MPEG TS from your recording. Please let me know if this helps.
Thanks a lot, I am trying to fix it as you mentioned.
wufeissdfz
commented
3 years ago leandvb with ldpc_tool has known issues when the signal is very noisy (or when there is pure noise before/after a strong signal, as in your recording).
As a workaround you can try adding "--modcods 0x80000 --framesizes 2" to the command-line. You should get at least 1.5 MB of MPEG TS from your recording. Please let me know if this helps.
After I used these parameters to filter mocods and framesizes sometimes it works well.
wufeissdfz
commented
3 years ago Thank you for your last reply.
Recently, I tried to process some DVB-S2 ACM sample with leandvb, sometimes it works well.
But somtimes the signal C/N is almost better than 15.0dB, I used the workaround which we used to filter modcods and framesizes, leandvb with ldpc_tools may stop and exit before EOF.
"--inbuf 32000000 --s16 -f 50e6 --sr 29.09e6 --gui --fd-info 2 --roll-off 0.2 --standard DVB-S2 --sampler rrc --rrc-rej 30 -v -d -d --fastdrift --framesizes 2 --fd-gse 3 --ldpc-helper ldpc_tool --buf-factor 8"
The IQ file link is https://we.tl/t-Q82VKIzHYx.
Please help me to look into this together. Thanks a lot.
pabr
commented
3 years ago If you see this on stderr, you must adjust /proc/sys/fs/pipe-max-size. Besides, you may want to multiply the value by the number of ACM modcods.
Failed to increase pipe size. Try echo 2073600 > /proc/sys/fs/pipe-max-size *** Throughput will be suboptimal.
You also need to apply the --modcods workaround to select one modcod. With "--modcods 0x40000" I get 350 kB of binary data from your recording. With "--modcods 0x1000", I get 75 kB.
Do you have a use case that requires decoding multiple modcods simultaneously ? I am afraid the current version cannot do that reliably.
Hello, Thank you for your help last time. Recently, I tried to do some test with leandvb by DekTec DTA-2115 DVB-S2 singnal generator. Sometimes leandvb may stop processing IQ file and exit before read the end of IQ file. When I used "--ldpc-helper ldpc_tool" to decode, it may cause problem.
./src/apps/leandvb --inbuf 512000000 --s16 -f 40e6 --sr 20e6 --gui --fd-info 2 --roll-off 0.2 --standard DVB-S2 --sampler rrc --rrc-rej 15 --fastdrift --fastlock --ldpc-helper ldpc_tool --nhelpers 6 -v -d -d < /data/IQREC-08-18-20-10h58m44s85_20M-5s-1f.iq > test.ts
The IQ file link is https://we.tl/t-05cciHMBFp
And ldpc_tool output
decoder failed at converging to a code word in 25 trialsRuntime summary is as follow:
When I stopped to decode, it can be run to end normally.
Runtime summary is as follow:
Please help me to look into this together. Thanks a lot.