newfor.cpp

/** Newfor.cpp */

/** @file newfor.c
 * @brief Softel Newfor subtitles for VBIT2.
 * A TCP port 5570 on VBIT accepts newfor subtitling commands.
 * The main purpose is to play out pre-recorded subtititles.
 * You can also play out subtitles from a video server or
 * bridged from another subtitles source such as through a DTP600.
 * or accept any industry standard Newfor source.
 */

#include "newfor.h"

// @todo These will be converted to member variables
// bufferpacket packetCache[1]; // Incoming rows are cached here, and transferred to subtitleBuffer when OnAir

// Packet Subtitles are stored here

static uint8_t _page; /// Page number (in hex). This is set by Page Init
static uint8_t _rowcount; /// Number of rows in this subtitle
// static char packet[PACKETSIZE];

using namespace vbit;

// This is not so pretty. @todo Factor this out of TCPClient
static int
vbi_unham8 (unsigned int c)
{
    return Hamming8DecodeTable[(uint8_t) c];
}


Newfor::Newfor(PacketSubtitle* subtitle) :
    _subtitle(subtitle)
{
    ttxpage.SetSubCode(0);
}

Newfor::~Newfor()
{
}

/** initNu4
 * @detail Initialise the buffers used by Newfor
 */
/*
void Newfor::InitNu4()
{
    bufferInit(packetCache, (char*)subtitleCache ,SUBTITLEPACKETCOUNT);
}
*/


/**
 * @detail Expect four characters
 * 1: Ham 0 (always 0x15)
 * 2: Page number hundreds hammed. 1..8
 * 3: Page number tens hammed
 * Although it says HTU, in keeping with the standard we will work in hex.
 * @return The decoded page number
 */
int Newfor::SoftelPageInit(char* cmd)
{
    int page=0;
    int n;

    // Useless leading 0
    n=vbi_unham8(cmd[1]);
    if (n<0) return 0x900; // @todo This is an error.
        n=vbi_unham8(cmd[2]); // Hundreds
    if (n<1 || n>8) return 0x901;
        page=n*0x100; // tens (hex allowed!)
    n=vbi_unham8(cmd[3]);
    if (n<0 || n>0x0f) return 0x902;
        page+=n*0x10; // units
    n=vbi_unham8(cmd[4]);
    if (n<0 || n>0x0f) return 0x903;
        page+=n;
    _page=page;
    ttxpage.SetPageNumber(page*0x100);
    return page;
}

void Newfor::SubtitleOnair(char* response)
{
    strcpy(response,"Response not implemented, sorry\n");
    // Send the page to the subtitle object in the service thread, then clear the lines.
    _subtitle->SendSubtitle(&ttxpage);

    for (int i=0;i<24;i++) // Some broadcasters sent the subs out more than once. We don't.
    {
        ttxpage.SetRow(i,"                                        ");
    }
}

void Newfor::SubtitleOffair()
{
    _subtitle->SendSubtitle(&ttxpage); // OnAir will already have cleared out these lines so just send the page again
}

/**
 * @return Row count 1..7, or 0 if invalid
 * @param cmd - The subtitle row count comes as a hammed digit.
 */
int Newfor::GetRowCount(char* cmd)
{
    int n=vbi_unham8(cmd[1]);
    if (n>7)
        n=0;
    _rowcount=n;
    return n;
}

/**
 * @brief Decode the rowaddress and row packet part of a Type 2 message.
 * @param mag - This is irrelevant as mag is set up in a Type 1 message
 * @param row - The row number on which to display the subtitle
 * @param cmd - The row text
 * @brief Save a row of data when a Newfor command is completed
 */
void Newfor::saveSubtitleRow(uint8_t mag, uint8_t row, char* cmd)
{
    (void)mag; // temporary silence error about unused parameter
    // What @todo about the mag? This needs to be decoded and passed on
    if (cmd[0]==0) cmd[0]='?'; // @todo Temporary measure to defeat null strings (this will inevitably multiply problems!)
    ttxpage.SetRow(row, cmd);
}