# 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.
ParameterDVB-T/2DVB-S/2DVB-CATSCISDB-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 \ \ \ \ \