Scan Files

Scan files are used by TVHeadEnd (TVH) during the setup process to create muxes and scan for services available on those muxes. An excerpt from a scan file may look like this:

[CHANNEL] DELIVERY_SYSTEM = DVBT FREQUENCY = 226500000 BANDWIDTH_HZ = 7000000 CODE_RATE_HP = AUTO CODE_RATE_LP = AUTO MODULATION = QAM/64 TRANSMISSION_MODE = 8K GUARD_INTERVAL = 1/16 HIERARCHY = NONE INVERSION = AUTO

The location of the scan files may vary based upon the TVH version. /usr/local/share/tvheadend/data/dvb-scan/ /usr/share/tvheadend/data/dvb-scan/

Depending on the value of the DELIVERY_SYSTEM, TVH recognises the following parameters.

Parameter	DVB-T/2	DVB-S/2	DVB-C	ATSC	ISDB-T
DELIVERY_SYSTEM	✓	✓	✓	✓	✓
FREQUENCY	✓	✓	✓	✓	✓
BANDWIDTH_HZ	✓				✓
CODE_RATE_HP	✓
CODE_RATE_LP	✓
MODULATION	✓	✓	✓	✓
TRANSMISSION_MODE	✓
GUARD_INTERVAL	✓				✓
HIERARCHY	✓
INVERSION	✓	✓	✓	✓	✓
STREAM_ID	✓	✓
INNER_FEC		✓	✓
ROLLOFF		✓
PILOT		✓
PLS_CODE		✓
POLARIZATION		✓
SYMBOL_RATE		✓	✓
ISDBT_LAYERA_FEC					✓
ISDBT_LAYERB_FEC					✓
ISDBT_LAYERC_FEC					✓
ISDBT_LAYERA_MODULATION					✓
ISDBT_LAYERB_MODULATION					✓
ISDBT_LAYERC_MODULATION					✓
ISDBT_LAYERA_SEGMENT_COUNT					✓
ISDBT_LAYERB_SEGMENT_COUNT					✓
ISDBT_LAYERC_SEGMENT_COUNT					✓
ISDBT_LAYERA_TIME_INTERLEAVING					✓
ISDBT_LAYERB_TIME_INTERLEAVING					✓
ISDBT_LAYERC_TIME_INTERLEAVING					✓

Accepted values

The following values are accepted for the parameter fields. Please note that an 'accepted' value may not always be processed.

DELIVERY_SYSTEM

NONE, DVB-C, DVBC/ANNEX_A, DVBC_ANNEX_A, ATSC-C, CableCARD, DVBC/ANNEX_B, DVBC_ANNEX_B, DVB-C/ANNEX-C, DVBC/ANNEX_C, DVBC_ANNEX_C, DVBC_ANNEX_AC, DVB-T, DVBT, DVB-T2, DVBT2, DVB-S, DVBS, DVB-S2, DVBS2, DVB-H, DVBH, ISDB-T, ISDBT, ISDB-S, ISDBS, ISDB-C, ISDBC, ATSC-T, ATSC, ATSCM-H, ATSCMH, DTMB, DMBTH, CMMB, DAB, DSS, TURBO.

FREQUENCY

Frequency in hertz.

BANDWIDTH_HZ

(Bandwidth in hertz) 1700000, 5000000, 6000000, 7000000, 8000000, 10000000.

CODE_RATE_HP / CODE_RATE_LP / INNER_FEC

1/2, 1/3, 1/4, 1/5, 2/3, 2/5, 2/9, 3/4, 3/5, 4/5, 4/15, 5/6, 5/9, 6/7, 7/8, 7/9, 7/15, 8/9, 8/15, 9/10, 9/20, 11/15, 11/20, 11/45, 13/18, 13/45, 14/45, 23/36, 25/36, 26/45, 28/45, 29/45, 31/45, 32/45, 77/90.

MODULATION

NONE, AUTO, QPSK, QAM4NR, QAM/AUTO, QAM-AUTO, QAM/16, QAM16, QAM/32, QAM32, QAM/64, QAM64, QAM/128, QAM128, QAM/256, QAM256, QAM/1024, QAM1024, QAM/4096, QAM4096,VSB/8, 8VSB, VSB/16, 16VSB, PSK/8, 8PSK, DQPSK, BPSK, BPSK-S, 16APSK, 32APSK, 64APSK, 128APSK, 256APSK,8APSK-L, 16APSK-L, 32APSK-L, 64APSK-L, 128APSK-L, 256APSK-L.

TRANSMISSION_MODE

NONE, AUTO, 1k, 2k, 8k, 4k, 16k, 32k, C1, C3780.

GUARD_INTERVAL

NONE, AUTO, 1/4, 1/8, 1/32, 1/16, 1/128, 19/128, 19/256, PN420, PN595, PN945.

HIERARCHY

NONE, AUTO, 1, 2, 4.

INVERSION

NONE, AUTO, ON, OFF.

ROLLOFF

5, 10, 15, 20, 25, 35.

PILOT

NONE, AUTO, ON, OFF.

PLS_CODE

(Physical Layer Scrambling) ROOT, GOLD, COMBO.

POLARIZATION

V, H, L, R, O.

References

https://github.com/tvheadend/tvheadend/blob/master/src/input/mpegts/scanfile.c https://github.com/tvheadend/tvheadend/blob/master/src/input/mpegts/dvb_support.c https://en.wikipedia.org/wiki/DVB https://en.wikipedia.org/wiki/ISDB https://en.wikipedia.org/wiki/ATSC_standards