diff options
Diffstat (limited to 'src/DabMux.cpp')
| -rw-r--r-- | src/DabMux.cpp | 65 |
1 files changed, 33 insertions, 32 deletions
diff --git a/src/DabMux.cpp b/src/DabMux.cpp index ca5bd08..de5b00f 100644 --- a/src/DabMux.cpp +++ b/src/DabMux.cpp @@ -529,7 +529,7 @@ int main(int argc, char *argv[]) } } - //Relatif aux fichiers d'entre + // Prepare and check the data inputs for (subchannel = ensemble->subchannels.begin(); subchannel != ensemble->subchannels.end(); ++subchannel) { @@ -603,9 +603,6 @@ int main(int argc, char *argv[]) (*component)->packet.id = cur++; } - //Initialisation a 0 des cases de la trame ETI - memset(etiFrame, 0, 6144); - // Print settings before starting etiLog.log(info, "--- Multiplex configuration ---"); printEnsemble(ensemble); @@ -624,9 +621,8 @@ int main(int argc, char *argv[]) - /*************************************************************************** - ********** Boucle principale, chaque passage cree une trame ************ - **************************************************************************/ + /* Each iteration of the main loop creates one ETI frame */ + serviceProgramInd = ensemble->services.end(); serviceDataInd = ensemble->services.end(); componentIndicatorProgram = ensemble->components.end(); @@ -641,64 +637,69 @@ int main(int argc, char *argv[]) } date = getDabTime(); - //Initialisation a 0 des cases de la trame + // Initialise the ETI frame memset(etiFrame, 0, 6144); /********************************************************************** - ********** Section SYNC du ETI(NI, G703) ************************* + ********** Section SYNC of ETI(NI, G703) ************************* **********************************************************************/ - //declare une instance d'une structure eti_SYNC - eti_SYNC *etiSync = (eti_SYNC *) etiFrame; - //****** Section ERR ******// - // 1 octet - etiSync->ERR = 0xFF; //Indique qu'il n'y a pas d'erreur - //****** Section FSYNC *****// - // 3 octets, pour la synchronisation, alterne a chaque trame entre les - // deux symboles + // See ETS 300 799 Clause 6 + eti_SYNC *etiSync = (eti_SYNC *) etiFrame; + + etiSync->ERR = 0xFF; // ETS 300 799, 5.2, no error + + //****** Field FSYNC *****// + // See ETS 300 799, 6.2.1.2 sync ^= 0xffffff; etiSync->FSYNC = sync; /********************************************************************** - *********** Section LIDATA du ETI(NI, G703) ********************** + *********** Section LIDATA of ETI(NI, G703) ********************** **********************************************************************/ + // See ETS 300 799 Figure 5 for a better overview of these fields. + //****** Section FC ***************************************************/ - // 4 octets - // declare une instance d une structure eti_FC et la place dans la trame - eti_FC *fc = (eti_FC *) & etiFrame[4]; + // 4 octets, starts at offset 4 + eti_FC *fc = (eti_FC *) &etiFrame[4]; - //****** FCT **********************// - //Incremente a chaque trame, de 0 a 249, 1 octet + //****** FCT ******// + // Incremente for each frame, overflows at 249 fc->FCT = currentFrame % 250; //****** FICF ******// - //Fast Information Channel Flag, 1 bit, =1 si le FIC est present + // Fast Information Channel Flag, 1 bit, =1 if FIC present fc->FICF = 1; //****** NST ******// - //Number of Stream, 7 bits, 0-64, 0 si reconfiguration du multiplex + /* Number of audio of data sub-channels, 7 bits, 0-64. + * In the 15-frame period immediately preceding a multiplex + * re-configuration, NST can take the value 0 (see annex E). + */ fc->NST = ensemble->subchannels.size(); //****** FP ******// - // Frame Phase, 3 bits, compteur sur 3 bits, permet au COFDM generator - // de savoir quand inserer le TII utilise egalement par le MNSC + /* Frame Phase, 3 bit counter, tells the COFDM generator + * when to insert the TII. Is also used by the MNSC. + */ fc->FP = currentFrame & 0x7; //****** MID ******// //Mode Identity, 2 bits, 01 ModeI, 10 modeII, 11 ModeIII, 00 ModeIV - fc->MID = ensemble->mode; //mode 2 demande 3 FIB, 3*32octets = 96octets + fc->MID = ensemble->mode; //mode 2 needs 3 FIB, 3*32octets = 96octets //****** FL ******// - //Frame Length, 11 bits, nb of words(4 bytes) in STC, EOH and MST - // si NST=0, FL=1+FICL words, FICL=24 ou 32 selon le mode - //en word ( 4 bytes), +1 pour la partie EOH + /* Frame Length, 11 bits, nb of words(4 bytes) in STC, EOH and MST + * if NST=0, FL=1+FICL words, FICL=24 or 32 depending on the mode. + * The FL is given in words (4 octets), see ETS 300 799 5.3.6 for details + */ FLtmp = 1 + FICL + (fc->NST); for (subchannel = ensemble->subchannels.begin(); subchannel != ensemble->subchannels.end(); ++subchannel) { - //Taille d'une trame audio mp2 en paquet de 64 bits + // Add STLsbch FLtmp += getSizeWord(*subchannel); } |