// Return TRUE if all was read. FALSE if a problem occured:
// If a bitstream syntax problem occured the bitstream will
// point to after the problem, in case we run out of data the bitstream
// will point to where we want to restart after getting more.
static int read_eau_info(struct bitstream *esstream, int udtype)
{
dbg_print(DMT_VERBOSE, "Read Extension and User Info\n");
// We only get here after seeing that start code
unsigned char *tst = next_bytes(esstream, 4);
if (!tst || tst[0]!=0x00 || tst[1]!=0x00 || tst[2]!=0x01
|| (tst[3]!=0xB2 && tst[3]!=0xB5) ) // (0x000001 B2||B5)
fatal(EXIT_BUG_BUG, "Impossible!");
// The following extension_and_user_data() function makes sure that
// user data is not evaluated twice. Should the function run out of
// data it will make sure that esstream points to where we want to
// continue after getting more.
if( !extension_and_user_data(esstream, udtype) )
{
if (esstream->error)
dbg_print(DMT_VERBOSE, "\nWarning: Retry while reading Extension and User Data!\n");
else
dbg_print(DMT_VERBOSE, "\nBitstream problem while reading Extension and User Data!\n");
return 0;
}
dbg_print(DMT_VERBOSE, "Read Extension and User Info - processed\n\n");
return 1;
}
// Return TRUE if all was read. FALSE if a problem occured:
// If a bitstream syntax problem occured the bitstream will
// point to after the problem, in case we run out of data the bitstream
// will point to where we want to restart after getting more.
static int read_eau_info(struct lib_cc_decode* ctx, struct bitstream *esstream, int udtype, struct cc_subtitle *sub)
{
debug("Read Extension and User Info\n");
// We only get here after seeing that start code
unsigned char *tst = next_bytes(esstream, 4);
if (!tst || tst[0]!=0x00 || tst[1]!=0x00 || tst[2]!=0x01
|| (tst[3]!=0xB2 && tst[3]!=0xB5) ) // (0x000001 B2||B5)
fatal(CCX_COMMON_EXIT_BUG_BUG, "read_eau_info: Impossible values for tst. Please file a bug report in GitHub.\n");
// The following extension_and_user_data() function makes sure that
// user data is not evaluated twice. Should the function run out of
// data it will make sure that esstream points to where we want to
// continue after getting more.
if( !extension_and_user_data(ctx, esstream, udtype, sub) )
{
if (esstream->error)
debug("\nWarning: Retry while reading Extension and User Data!\n");
else
debug("\nBitstream problem while reading Extension and User Data!\n");
return 0;
}
debug("Read Extension and User Info - processed\n\n");
return 1;
}
// Return an integer number with "bytes" precision from the current
// bitstream position. Allowed "bytes" values are 1,2,4,8.
// This function does advance the bitstream pointer when "advance" is
// set to TRUE.
uint64_t bitstream_get_num(struct bitstream *bstr, unsigned bytes, int advance)
{
void *bpos;
uint64_t rval;
if (advance)
bpos = read_bytes(bstr, bytes);
else
bpos = next_bytes(bstr, bytes);
if (!bpos)
return 0;
switch (bytes)
{
case 1:
rval = *((uint8_t*)bpos);
break;
case 2:
rval = *((uint16_t*)bpos);
break;
case 4:
rval = *((uint32_t*)bpos);
break;
case 8:
rval = *((uint64_t*)bpos);
break;
default:
fatal (EXIT_BUG_BUG, "bitstream_get_num: Illegal precision value [%u]!",
bytes);
break;
}
return rval;
}
// Return an integer number with "bytes" precision from the current
// bitstream position. Allowed "bytes" values are 1,2,4,8.
// This function does advance the bitstream pointer when "advance" is
// set to TRUE.
// Numbers come MSB (most significant first), and we need to account for
// little-endian and big-endian CPUs.
uint64_t bitstream_get_num(struct bitstream *bstr, unsigned bytes, int advance)
{
void *bpos;
uint64_t rval=0;
if (advance)
bpos = read_bytes(bstr, bytes);
else
bpos = next_bytes(bstr, bytes);
if (!bpos)
return 0;
switch (bytes)
{
case 1:
case 2:
case 4:
case 8:
break;
default:
fatal (CCX_COMMON_EXIT_BUG_BUG, "In bitstream_get_num: Illegal precision value [%u]!",
bytes);
break;
}
for (unsigned i=0;i<bytes;i++)
{
unsigned char *ucpos=((unsigned char *)bpos) +bytes-i-1; // Read backwards
unsigned char uc=*ucpos;
rval=(rval<<8) + uc;
}
return rval;
}
// Return pointer to first of bynum bytes from the bitstream if the
// following conditions are TRUE:
// The bitstream is byte aligned and there are enough bytes left in
// it to read bynum bytes. Otherwise return NULL.
// This function does advance the bitstream pointer.
unsigned char *read_bytes(struct bitstream *bstr, unsigned bynum)
{
unsigned char *res = next_bytes(bstr, bynum);
// Advance the bitstream when a read was possible
if(res)
{
bstr->bpos = bstr->_i_bpos;
bstr->pos = bstr->_i_pos;
}
return res;
}
// Parse the user data for captions. The udtype variable denotes
// to which type of data it belongs:
// 0 .. sequence header
// 1 .. GOP header
// 2 .. picture header
// Return TRUE if the data parsing finished, FALSE otherwise.
// estream->pos is advanced. Data is only processed if ustream->error
// is FALSE, parsing can set ustream->error to TRUE.
int user_data(struct lib_cc_decode *ctx, struct bitstream *ustream, int udtype, struct cc_subtitle *sub)
{
dbg_print(CCX_DMT_VERBOSE, "user_data(%d)\n", udtype);
// Shall not happen
if (ustream->error || ustream->bitsleft <= 0)
{
// ustream->error=1;
return 0; // Actually discarded on call.
// CFS: Seen in a Wobble edited file.
// fatal(CCX_COMMON_EXIT_BUG_BUG, "user_data: Impossible!");
}
// Do something
ctx->stat_numuserheaders++;
//header+=4;
unsigned char *ud_header = next_bytes(ustream, 4);
if (ustream->error || ustream->bitsleft <= 0)
{
return 0; // Actually discarded on call.
// CFS: Seen in Stick_VHS.mpg.
// fatal(CCX_COMMON_EXIT_BUG_BUG, "user_data: Impossible!");
}
// DVD CC header, see
// <http://www.theneitherworld.com/mcpoodle/SCC_TOOLS/DOCS/SCC_FORMAT.HTML>
if ( !memcmp(ud_header,"\x43\x43", 2 ) )
{
ctx->stat_dvdccheaders++;
// Probably unneeded, but keep looking for extra caption blocks
int maybeextracb = 1;
read_bytes(ustream, 4); // "43 43 01 F8"
unsigned char pattern_flag = (unsigned char) read_bits(ustream,1);
read_bits(ustream,1);
int capcount=(int) read_bits(ustream,5);
int truncate_flag = (int) read_bits(ustream,1); // truncate_flag - one CB extra
int field1packet = 0; // expect Field 1 first
if (pattern_flag == 0x00)
field1packet=1; // expect Field 1 second
dbg_print(CCX_DMT_VERBOSE, "Reading %d%s DVD CC segments\n",
capcount, (truncate_flag?"+1":""));
capcount += truncate_flag;
// This data comes before the first frame header, so
// in order to get the correct timing we need to set the
// current time to one frame after the maximum time of the
// last GOP. Only useful when there are frames before
// the GOP.
if (ctx->timing->fts_max > 0)
ctx->timing->fts_now = ctx->timing->fts_max + (LLONG) (1000.0/current_fps);
int rcbcount = 0;
for (int i=0; i<capcount; i++)
{
for (int j=0;j<2;j++)
{
unsigned char data[3];
data[0]=read_u8(ustream);
data[1]=read_u8(ustream);
data[2]=read_u8(ustream);
// Obey the truncate flag.
if ( truncate_flag && i == capcount-1 && j == 1 )
{
maybeextracb = 0;
break;
}
/* Field 1 and 2 data can be in either order,
with marker bytes of \xff and \xfe
Since markers can be repeated, use pattern as well */
if ((data[0]&0xFE) == 0xFE) // Check if valid
{
if (data[0]==0xff && j==field1packet)
data[0]=0x04; // Field 1
else
data[0]=0x05; // Field 2
do_cb(ctx, data, sub);
rcbcount++;
}
else
{
dbg_print(CCX_DMT_VERBOSE, "Illegal caption segment - stop here.\n");
maybeextracb = 0;
break;
}
}
}
// Theoretically this should not happen, oh well ...
// Deal with extra closed captions some DVD have.
int ecbcount = 0;
while ( maybeextracb && (next_u8(ustream)&0xFE) == 0xFE )
{
for (int j=0;j<2;j++)
{
unsigned char data[3];
data[0]=read_u8(ustream);
data[1]=read_u8(ustream);
data[2]=read_u8(ustream);
/* Field 1 and 2 data can be in either order,
with marker bytes of \xff and \xfe
Since markers can be repeated, use pattern as well */
if ((data[0]&0xFE) == 0xFE) // Check if valid
{
if (data[0]==0xff && j==field1packet)
data[0]=0x04; // Field 1
else
data[0]=0x05; // Field 2
do_cb(ctx, data, sub);
ecbcount++;
}
else
{
dbg_print(CCX_DMT_VERBOSE, "Illegal (extra) caption segment - stop here.\n");
maybeextracb = 0;
break;
}
}
}
dbg_print(CCX_DMT_VERBOSE, "Read %d/%d DVD CC blocks\n", rcbcount, ecbcount);
}
// SCTE 20 user data
else if (!ctx->noscte20 && ud_header[0] == 0x03)
{
if ((ud_header[1]&0x7F) == 0x01)
{
unsigned char cc_data[3*31+1]; // Maximum cc_count is 31
ctx->stat_scte20ccheaders++;
read_bytes(ustream, 2); // "03 01"
unsigned cc_count = (unsigned int) read_bits(ustream,5);
dbg_print(CCX_DMT_VERBOSE, "Reading %d SCTE 20 CC blocks\n", cc_count);
unsigned field_number;
unsigned cc_data1;
unsigned cc_data2;
for (unsigned j=0;j<cc_count;j++)
{
skip_bits(ustream,2); // priority - unused
field_number = (unsigned int) read_bits(ustream,2);
skip_bits(ustream,5); // line_offset - unused
cc_data1 = (unsigned int) read_bits(ustream,8);
cc_data2 = (unsigned int) read_bits(ustream,8);
read_bits(ustream,1); // TODO: Add syntax check */
if (ustream->bitsleft < 0)
fatal(CCX_COMMON_EXIT_BUG_BUG, "In user_data: ustream->bitsleft < 0. Cannot continue.");
// Field_number is either
// 0 .. forbidden
// 1 .. field 1 (odd)
// 2 .. field 2 (even)
// 3 .. repeated, from repeat_first_field, effectively field 1
if (field_number < 1)
{
// 0 is invalid
cc_data[j*3]=0x00; // Set to invalid
cc_data[j*3+1]=0x00;
cc_data[j*3+2]=0x00;
}
else
{
// Treat field_number 3 as 1
field_number = (field_number - 1) & 0x01;
// top_field_first also affects to which field the caption
// belongs.
if(!ctx->top_field_first)
field_number ^= 0x01;
cc_data[j*3]=0x04|(field_number);
cc_data[j*3+1]=reverse8(cc_data1);
cc_data[j*3+2]=reverse8(cc_data2);
}
}
cc_data[cc_count*3]=0xFF;
store_hdcc(ctx, cc_data, cc_count, ctx->timing->current_tref, ctx->timing->fts_now, sub);
dbg_print(CCX_DMT_VERBOSE, "Reading SCTE 20 CC blocks - done\n");
}
// reserved - unspecified
}
// ReplayTV 4000/5000 caption header - parsing information
// derived from CCExtract.bdl
else if ( (ud_header[0] == 0xbb //ReplayTV 4000
|| ud_header[0] == 0x99) //ReplayTV 5000
&& ud_header[1] == 0x02 )
{
unsigned char data[3];
if (ud_header[0]==0xbb)
ctx->stat_replay4000headers++;
else
ctx->stat_replay5000headers++;
read_bytes(ustream, 2); // "BB 02" or "99 02"
data[0]=0x05; // Field 2
data[1]=read_u8(ustream);
data[2]=read_u8(ustream);
do_cb(ctx, data, sub);
read_bytes(ustream, 2); // Skip "CC 02" for R4000 or "AA 02" for R5000
data[0]=0x04; // Field 1
data[1]=read_u8(ustream);
data[2]=read_u8(ustream);
do_cb(ctx, data, sub);
}
// HDTV - see A/53 Part 4 (Video)
else if ( !memcmp(ud_header,"\x47\x41\x39\x34", 4 ) )
{
ctx->stat_hdtv++;
read_bytes(ustream, 4); // "47 41 39 34"
unsigned char type_code = read_u8(ustream);
if (type_code==0x03) // CC data.
{
skip_bits(ustream,1); // reserved
unsigned char process_cc_data = (unsigned char) read_bits(ustream,1);
skip_bits(ustream,1); // additional_data - unused
unsigned char cc_count = (unsigned char) read_bits(ustream,5);
read_bytes(ustream, 1); // "FF"
if (process_cc_data)
{
dbg_print(CCX_DMT_VERBOSE, "Reading %d HDTV CC blocks\n", cc_count);
int proceed = 1;
unsigned char *cc_data = read_bytes(ustream, cc_count*3);
if (ustream->bitsleft < 0)
fatal(CCX_COMMON_EXIT_BUG_BUG, "In user_data: ustream->bitsleft < 0. Cannot continue.\n");
// Check for proper marker - This read makes sure that
// cc_count*3+1 bytes are read and available in cc_data.
if (read_u8(ustream)!=0xFF)
proceed=0;
if (!proceed)
{
dbg_print(CCX_DMT_VERBOSE, "\rThe following payload is not properly terminated.\n");
dump (CCX_DMT_VERBOSE, cc_data, cc_count*3+1, 0, 0);
}
dbg_print(CCX_DMT_VERBOSE, "Reading %d HD CC blocks\n", cc_count);
// B-frames might be (temporal) before or after the anchor
// frame they belong to. Store the buffer until the next anchor
// frame occurs. The buffer will be flushed (sorted) in the
// picture header (or GOP) section when the next anchor occurs.
// Please note we store the current value of the global
// fts_now variable (and not get_fts()) as we are going to
// re-create the timeline in process_hdcc() (Slightly ugly).
store_hdcc(ctx, cc_data, cc_count, ctx->timing->current_tref, ctx->timing->fts_now, sub);
dbg_print(CCX_DMT_VERBOSE, "Reading HDTV blocks - done\n");
}
}
// reserved - additional_cc_data
}
// DVB closed caption header for Dish Network (Field 1 only) */
else if ( !memcmp(ud_header,"\x05\x02", 2 ) )
{
// Like HDTV (above) Dish Network captions can be stored at each
// frame, but maximal two caption blocks per frame and only one
// field is stored.
// To process this with the HDTV framework we create a "HDTV" caption
// format compatible array. Two times 3 bytes plus one for the 0xFF
// marker at the end. Pre-init to field 1 and set the 0xFF marker.
static unsigned char dishdata[7] = {0x04, 0, 0, 0x04, 0, 0, 0xFF};
int cc_count;
dbg_print(CCX_DMT_VERBOSE, "Reading Dish Network user data\n");
ctx->stat_dishheaders++;
read_bytes(ustream, 2); // "05 02"
// The next bytes are like this:
// header[2] : ID: 0x04 (MPEG?), 0x03 (H264?)
// header[3-4]: Two byte counter (counting (sub-)GOPs?)
// header[5-6]: Two bytes, maybe checksum?
// header[7]: Pattern type
// on B-frame: 0x02, 0x04
// on I-/P-frame: 0x05
unsigned char id = read_u8(ustream);
unsigned dishcount = read_u16(ustream);
unsigned something = read_u16(ustream);
unsigned char type = read_u8(ustream);
dbg_print(CCX_DMT_PARSE, "DN ID: %02X Count: %5u Unknown: %04X Pattern: %X",
id, dishcount, something, type);
unsigned char hi;
// The following block needs 4 to 6 bytes starting from the
// current position
unsigned char *dcd = ustream->pos; // dish caption data
switch (type)
{
case 0x02:
// Two byte caption - always on B-frame
// The following 4 bytes are:
// 0 : 0x09
// 1-2: caption block
// 3 : REPEAT - 02: two bytes
// - 04: four bytes (repeat first two)
dbg_print(CCX_DMT_PARSE, "\n02 %02X %02X:%02X - R:%02X :",
dcd[0], dcd[1], dcd[2], dcd[3]);
cc_count = 1;
dishdata[1]=dcd[1];
dishdata[2]=dcd[2];
dbg_print(CCX_DMT_PARSE, "%s", debug_608_to_ASC( dishdata, 0) );
type=dcd[3]; // repeater (0x02 or 0x04)
hi = dishdata[1] & 0x7f; // Get only the 7 low bits
if (type==0x04 && hi<32) // repeat (only for non-character pairs)
{
cc_count = 2;
dishdata[3]=0x04; // Field 1
dishdata[4]=dishdata[1];
dishdata[5]=dishdata[2];
dbg_print(CCX_DMT_PARSE, "%s:\n", debug_608_to_ASC( dishdata+3, 0) );
}
else
{
dbg_print(CCX_DMT_PARSE, ":\n");
}
dishdata[cc_count*3] = 0xFF; // Set end marker
store_hdcc(ctx, dishdata, cc_count, ctx->timing->current_tref, ctx->timing->fts_now, sub);
// Ignore 3 (0x0A, followed by two unknown) bytes.
break;
case 0x04:
// Four byte caption - always on B-frame
// The following 5 bytes are:
// 0 : 0x09
// 1-2: caption block
// 3-4: caption block
dbg_print(CCX_DMT_PARSE, "\n04 %02X %02X:%02X:%02X:%02X :",
dcd[0], dcd[1], dcd[2], dcd[3], dcd[4]);
cc_count = 2;
dishdata[1]=dcd[1];
dishdata[2]=dcd[2];
dishdata[3]=0x04; // Field 1
dishdata[4]=dcd[3];
dishdata[5]=dcd[4];
dishdata[6] = 0xFF; // Set end marker
dbg_print(CCX_DMT_PARSE, "%s", debug_608_to_ASC( dishdata, 0) );
dbg_print(CCX_DMT_PARSE, "%s:\n", debug_608_to_ASC( dishdata+3, 0) );
store_hdcc(ctx, dishdata, cc_count, ctx->timing->current_tref, ctx->timing->fts_now, sub);
// Ignore 4 (0x020A, followed by two unknown) bytes.
break;
case 0x05:
// Buffered caption - always on I-/P-frame
// The following six bytes are:
// 0 : 0x04
// - the following are from previous 0x05 caption header -
// 1 : prev dcd[2]
// 2-3: prev dcd[3-4]
// 4-5: prev dcd[5-6]
dbg_print(CCX_DMT_PARSE, " - %02X pch: %02X %5u %02X:%02X\n",
dcd[0], dcd[1],
(unsigned)dcd[2]*256+dcd[3],
dcd[4], dcd[5]);
dcd+=6; // Skip these 6 bytes
// Now one of the "regular" 0x02 or 0x04 captions follows
dbg_print(CCX_DMT_PARSE, "%02X %02X %02X:%02X",
dcd[0], dcd[1], dcd[2], dcd[3]);
type=dcd[0]; // Number of caption bytes (0x02 or 0x04)
cc_count = 1;
dishdata[1]=dcd[2];
dishdata[2]=dcd[3];
dcd+=4; // Skip the first 4 bytes.
if (type==0x02)
{
type=dcd[0]; // repeater (0x02 or 0x04)
dcd++; // Skip the repeater byte.
dbg_print(CCX_DMT_PARSE, " - R:%02X :%s", type, debug_608_to_ASC( dishdata, 0) );
hi = dishdata[1] & 0x7f; // Get only the 7 low bits
if (type==0x04 && hi<32)
{
cc_count = 2;
dishdata[3]=0x04; // Field 1
dishdata[4]=dishdata[1];
dishdata[5]=dishdata[2];
dbg_print(CCX_DMT_PARSE, "%s:\n", debug_608_to_ASC( dishdata+3, 0) );
}
else
{
dbg_print(CCX_DMT_PARSE, ":\n");
}
dishdata[cc_count*3] = 0xFF; // Set end marker
}
else
{
dbg_print(CCX_DMT_PARSE, ":%02X:%02X ",
dcd[0], dcd[1]);
cc_count = 2;
dishdata[3]=0x04; // Field 1
dishdata[4]=dcd[0];
dishdata[5]=dcd[1];
dishdata[6] = 0xFF; // Set end marker
dbg_print(CCX_DMT_PARSE, ":%s", debug_608_to_ASC( dishdata, 0) );
dbg_print(CCX_DMT_PARSE, "%s:\n", debug_608_to_ASC( dishdata+3, 0) );
}
store_hdcc(ctx, dishdata, cc_count, ctx->timing->current_tref, ctx->timing->fts_now, sub);
// Ignore 3 (0x0A, followed by 2 unknown) bytes.
break;
default:
// printf ("Unknown?\n");
break;
} // switch
dbg_print(CCX_DMT_VERBOSE, "Reading Dish Network user data - done\n");
}
// CEA 608 / aka "Divicom standard", see:
// http://www.pixeltools.com/tech_tip_closed_captioning.html
else if ( !memcmp(ud_header,"\x02\x09", 2 ) )
{
// Either a documentation or more examples are needed.
ctx->stat_divicom++;
unsigned char data[3];
read_bytes(ustream, 2); // "02 09"
read_bytes(ustream, 2); // "80 80" ???
read_bytes(ustream, 2); // "02 0A" ???
data[0]=0x04; // Field 1
data[1]=read_u8(ustream);
data[2]=read_u8(ustream);
do_cb(ctx, data, sub);
// This is probably incomplete!
}
// GXF vbi OEM code
else if ( !memcmp(ud_header,"\x73\x52\x21\x06", 4 ) )
{
int udatalen = ustream->end - ustream->pos;
uint16_t line_nb;
uint8_t line_type;
uint8_t field = 1;
read_bytes(ustream, 4); //skip header code
read_bytes(ustream, 2); //skip data length
line_nb = read_bits(ustream, 16);
line_type = read_u8(ustream);
field = (line_type & 0x03);
if(field == 0)
mprint("MPEG:VBI: Invalid field\n");
line_type = line_type >> 2;
if(line_type != 1)
mprint("MPEG:VBI: only support Luma line\n");
if (udatalen < 720)
mprint("MPEG:VBI: Minimum 720 bytes in luma line required\n");
decode_vbi(ctx, field, ustream->pos, 720, sub);
dbg_print(CCX_DMT_VERBOSE, "GXF (vbi line %d) user data:\n", line_nb);
}
