#include <lib/base/eerror.h>
#include <lib/dvb/teletext.h>
#include <lib/dvb/idemux.h>
+#include <lib/gdi/gpixmap.h>
+
+/*
+ This is a very simple en300 706 telext decoder.
+
+ It can only decode a single page at a time, thus it's only used
+ for subtitles.
+
+ */
DEFINE_REF(eDVBTeletextParser);
+ /* we asumme error free transmission! */
+static inline unsigned char decode_odd_parity(unsigned char *b)
+{
+ int i;
+ unsigned char res = 0;
+ for (i=0; i<7; ++i)
+ if (*b & (0x80 >> i))
+ res |= 1<<i;
+ return res;
+}
+
+static inline unsigned char decode_hamming_84(unsigned char *b)
+{
+ unsigned char res = 0;
+ res |= (*b << 3) & 8;
+ res |= (*b ) & 4;
+ res |= (*b >> 3) & 2;
+ res |= (*b >> 6) & 1;
+ return res;
+}
+
+static inline unsigned long decode_hamming_2418(unsigned char *b)
+{
+ unsigned long h24 = b[0] | (b[1] << 8) | (b[2] << 16);
+
+ return
+ ((h24 & 0x000004) >> 2) |
+ ((h24 & 0x000070) >> 3) |
+ ((h24 & 0x007f00) >> 4) |
+ ((h24 & 0x7f0000) >> 5);
+}
+
eDVBTeletextParser::eDVBTeletextParser(iDVBDemux *demux)
{
- setStreamID(0xBD); // as per en 300 472
+ setStreamID(0xBD); /* as per en 300 472 */
+
+ setPage(0x150);
if (demux->createPESReader(eApp, m_pes_reader))
eDebug("failed to create PES reader!");
else
m_pes_reader->connectRead(slot(*this, &eDVBTeletextParser::processData), m_read_connection);
-
+}
+
+eDVBTeletextParser::~eDVBTeletextParser()
+{
}
void eDVBTeletextParser::processPESPacket(__u8 *pkt, int len)
{
- eDebug("GOT TELETEXT PACKET:");
- int i;
- for (i=0; i<16; ++i)
- eDebugNoNewLine("%02x ", pkt[i]);
- eDebug("<");
+ unsigned char *p = pkt;
+
+ p += 4; len -= 4; /* start code, already be verified by pes parser */
+ p += 2; len -= 2; /* length, better use the argument */
+
+ p += 3; len -= 3; /* pes header */
+
+ p += 0x24; len -= 0x24; /* skip header */
+
+// eDebug("data identifier: %02x", *p);
+
+ p++; len--;
+
+ while (len > 2)
+ {
+ unsigned char data_unit_id = *p++;
+ unsigned char data_unit_length = *p++;
+ len -= 2;
+
+ if (len < data_unit_length)
+ {
+ eDebug("data_unit_length > len");
+ break;
+ }
+
+ if (data_unit_length != 44)
+ {
+ eDebug("illegal data unit length %d", data_unit_length);
+ break;
+ }
+
+ unsigned char line_offset = *p++; len--;
+ unsigned char framing_code = *p++; len--;
+
+ int magazine_and_packet_address = decode_hamming_84(p++); len--;
+ magazine_and_packet_address |= decode_hamming_84(p++)<<4; len--;
+
+ unsigned char *data = p; p += 40; len -= 40;
+
+ if (framing_code != 0xe4) /* no teletxt data */
+ continue;
+
+ m_M = magazine_and_packet_address & 7;
+ m_Y = magazine_and_packet_address >> 3;
+// eDebug("line %d, framing code: %02x, M=%02x, Y=%02x", line_offset, framing_code, M, Y);
+
+ if (m_Y == 0) /* page header */
+ {
+ m_C = 0;
+
+ m_S1 = decode_hamming_84(data + 2); /* S1 */
+ int S2C4 = decode_hamming_84(data + 3);
+
+ m_S2 = S2C4 & 7;
+ m_C |= (S2C4 & 8) ? (1<<4) : 0;
+
+ m_S3 = decode_hamming_84(data + 4);
+
+ int S4C5C6 = decode_hamming_84(data + 5);
+
+ m_S4 = S4C5C6 & 3;
+ m_C |= (S4C5C6 & 0xC) << 3;
+
+ m_C |= decode_hamming_84(data + 6) << 7;
+ m_C |= decode_hamming_84(data + 7) << 11;
+
+ /* page on the same magazine? end current page. */
+ if ((m_M == m_page_M) && (m_page_open))
+ {
+ handlePageEnd();
+ m_page_open = 0;
+ }
+
+ m_X = decode_hamming_84(data+1) * 0x10 + decode_hamming_84(data);
+
+ /* correct page on correct magazine? open page. */
+ if ((m_M == m_page_M) && (m_X == m_page_X))
+ {
+ handlePageStart();
+ m_page_open = 1;
+ handleLine(data + 8, 32);
+ }
+ } else
+ {
+ /* data for the selected page? */
+ if ((m_M == m_page_M) && m_page_open)
+ handleLine(data, 40);
+ }
+ }
}
int eDVBTeletextParser::start(int pid)
{
+ m_page_open = 0;
+
if (m_pes_reader)
return m_pes_reader->start(pid);
else
return -1;
}
+
+void eDVBTeletextParser::handlePageStart()
+{
+ if (m_C & (1<<4)) /* erase flag set */
+ m_subtitle_page.clear();
+}
+
+void eDVBTeletextParser::handleLine(unsigned char *data, int len)
+{
+ if (!m_Y) /* first line is page header, we don't need that. */
+ return;
+
+ int last_was_white = 1, color = -1;
+
+ std::string text;
+
+ for (int i=0; i<len; ++i)
+ {
+ unsigned char b = decode_odd_parity(data + i);
+
+ if (b < 0x10) /* spacing attribute */
+ {
+ if (b < 8) /* colors */
+ {
+ if (b != color) /* new color is split into a new string */
+ {
+ if (color != -1)
+ addSubtitleString(color, text);
+ text = "";
+ color = b;
+ }
+ }
+ /* ignore other attributes */
+ } else
+ {
+ /* no more than one whitespace, only printable chars */
+ if (((!last_was_white) || (b != ' ')) && (b >= 0x20))
+ {
+ text += b;
+ last_was_white = b == ' ';
+ }
+ }
+ }
+ addSubtitleString(color, text);
+}
+
+void eDVBTeletextParser::handlePageEnd()
+{
+ addSubtitleString(-1, ""); /* end last line */
+ sendSubtitlePage(); /* send assembled subtitle page to display */
+}
+
+void eDVBTeletextParser::setPage(int page)
+{
+ m_page_M = (page >> 8) & 7; /* magazine to look for */
+ m_page_X = page & 0xFF; /* page number */
+}
+
+void eDVBTeletextParser::addSubtitleString(int color, const std::string &string)
+{
+ if ((color != m_subtitle_color) && !m_subtitle_text.empty())
+ {
+ m_subtitle_page.m_elements.push_back(eDVBTeletextSubtitlePageElement(gRGB(0, 0xff, 0), m_subtitle_text));
+ m_subtitle_text = "";
+ } else if (!m_subtitle_text.empty() && m_subtitle_text[m_subtitle_text.size()-1] != ' ')
+ m_subtitle_text += " ";
+
+ m_subtitle_color = color;
+ m_subtitle_text += string;
+}
+
+void eDVBTeletextParser::sendSubtitlePage()
+{
+ eDebug("subtitle page:");
+ for (unsigned int i = 0; i < m_subtitle_page.m_elements.size(); ++i)
+ eDebug("%s", m_subtitle_page.m_elements[i].m_text.c_str());
+}
#include <lib/base/object.h>
#include <lib/dvb/idvb.h>
#include <lib/dvb/pesparse.h>
+#include <lib/gdi/gpixmap.h>
+
+struct eDVBTeletextSubtitlePageElement
+{
+ gRGB m_color;
+ std::string m_text;
+ eDVBTeletextSubtitlePageElement(const gRGB &color, const std::string &text)
+ : m_color(color), m_text(text)
+ {
+ }
+};
+
+struct eDVBTeletextSubtitlePage
+{
+ pts_t m_pts;
+ int m_timeout; /* in pts */
+ std::vector<eDVBTeletextSubtitlePageElement> m_elements;
+
+ void clear() { m_elements.clear(); }
+};
class eDVBTeletextParser: public iObject, public ePESParser, public Object
{
DECLARE_REF(eDVBTeletextParser);
public:
eDVBTeletextParser(iDVBDemux *demux);
+ virtual ~eDVBTeletextParser();
int start(int pid);
+ void setPage(int page);
private:
void processPESPacket(__u8 *pkt, int len);
ePtr<iDVBPESReader> m_pes_reader;
ePtr<eConnection> m_read_connection;
+
+ eDVBTeletextSubtitlePage m_subtitle_page;
+
+ int m_M, m_Y, m_X, m_S1, m_S2, m_S3, m_S4, m_C;
+
+ int m_page_M, m_page_X, m_page_open;
+
+ void handlePageStart();
+ void handleLine(unsigned char *line, int len);
+ void handlePageEnd();
+
+ std::string m_subtitle_text;
+ int m_subtitle_color;
+
+ void addSubtitleString(int color, const std::string &string);
+
+ void sendSubtitlePage();
};
#endif
git.cweiske.de / enigma2.git / commitdiff