void sei_free(sei_t* sei)
{
sei_message_t* tail;
while (sei->head) {
tail = sei->head->next;
free(sei->head);
sei->head = tail;
}
sei_init(sei, 0);
}
libcaption_stauts_t sei_parse(sei_t* sei, const uint8_t* data, size_t size, double timestamp)
{
sei_init(sei, timestamp);
int ret = 0;
// SEI may contain more than one payload
while (1 < size) {
size_t payloadType = 0;
size_t payloadSize = 0;
while (0 < size && 255 == (*data)) {
payloadType += 255;
++data, --size;
}
if (0 == size) {
return LIBCAPTION_ERROR;
}
payloadType += (*data);
++data, --size;
while (0 < size && 255 == (*data)) {
payloadSize += 255;
++data, --size;
}
if (0 == size) {
return LIBCAPTION_ERROR;
}
payloadSize += (*data);
++data, --size;
if (payloadSize) {
sei_message_t* msg = sei_message_new((sei_msgtype_t)payloadType, 0, payloadSize);
uint8_t* payloadData = sei_message_data(msg);
size_t bytes = _copy_to_rbsp(payloadData, payloadSize, data, size);
sei_message_append(sei, msg);
if (bytes < payloadSize) {
return LIBCAPTION_ERROR;
}
data += bytes;
size -= bytes;
++ret;
}
}
// There should be one trailing byte, 0x80. But really, we can just ignore that fact.
return LIBCAPTION_OK;
}
////////////////////////////////////////////////////////////////////////////////
// TODO move this out of sei
libcaption_stauts_t sei_from_caption_frame(sei_t* sei, caption_frame_t* frame)
{
int r, c;
int unl, prev_unl;
cea708_t cea708;
const char* data;
uint16_t prev_cc_data;
eia608_style_t styl, prev_styl;
sei_init(sei, frame->timestamp);
cea708_init(&cea708, frame->timestamp); // set up a new popon frame
cea708_add_cc_data(&cea708, 1, cc_type_ntsc_cc_field_1, eia608_control_command(eia608_control_erase_non_displayed_memory, DEFAULT_CHANNEL));
cea708_add_cc_data(&cea708, 1, cc_type_ntsc_cc_field_1, eia608_control_command(eia608_control_resume_caption_loading, DEFAULT_CHANNEL));
for (r = 0; r < SCREEN_ROWS; ++r) {
prev_unl = 0, prev_styl = eia608_style_white;
// Calculate preamble
for (c = 0; c < SCREEN_COLS && 0 == *caption_frame_read_char(frame, r, c, &styl, &unl); ++c) {
}
// This row is blank
if (SCREEN_COLS == c) {
continue;
}
// Write preamble
if (0 < c || (0 == unl && eia608_style_white == styl)) {
int tab = c % 4;
sei_encode_eia608(sei, &cea708, eia608_row_column_pramble(r, c, DEFAULT_CHANNEL, 0));
if (tab) {
sei_encode_eia608(sei, &cea708, eia608_tab(tab, DEFAULT_CHANNEL));
}
} else {
sei_encode_eia608(sei, &cea708, eia608_row_style_pramble(r, DEFAULT_CHANNEL, styl, unl));
prev_unl = unl, prev_styl = styl;
}
// Write the row
for (prev_cc_data = 0, data = caption_frame_read_char(frame, r, c, 0, 0);
(*data) && c < SCREEN_COLS; ++c, data = caption_frame_read_char(frame, r, c, &styl, &unl)) {
uint16_t cc_data = eia608_from_utf8_1(data, DEFAULT_CHANNEL);
if (unl != prev_unl || styl != prev_styl) {
sei_encode_eia608(sei, &cea708, eia608_midrow_change(DEFAULT_CHANNEL, styl, unl));
prev_unl = unl, prev_styl = styl;
}
if (!cc_data) {
// We do't want to write bad data, so just ignore it.
} else if (eia608_is_basicna(prev_cc_data)) {
if (eia608_is_basicna(cc_data)) {
// previous and current chars are both basicna, combine them into current
sei_encode_eia608(sei, &cea708, eia608_from_basicna(prev_cc_data, cc_data));
} else if (eia608_is_westeu(cc_data)) {
// extended charcters overwrite the previous charcter, so insert a dummy char thren write the extended char
sei_encode_eia608(sei, &cea708, eia608_from_basicna(prev_cc_data, eia608_from_utf8_1(EIA608_CHAR_SPACE, DEFAULT_CHANNEL)));
sei_encode_eia608(sei, &cea708, cc_data);
} else {
// previous was basic na, but current isnt; write previous and current
sei_encode_eia608(sei, &cea708, prev_cc_data);
sei_encode_eia608(sei, &cea708, cc_data);
}
prev_cc_data = 0; // previous is handled, we can forget it now
} else if (eia608_is_westeu(cc_data)) {
// extended chars overwrite the previous chars, so insert a dummy char
// TODO create a map of alternamt chars for eia608_is_westeu instead of using space
sei_encode_eia608(sei, &cea708, eia608_from_utf8_1(EIA608_CHAR_SPACE, DEFAULT_CHANNEL));
sei_encode_eia608(sei, &cea708, cc_data);
} else if (eia608_is_basicna(cc_data)) {
prev_cc_data = cc_data;
} else {
sei_encode_eia608(sei, &cea708, cc_data);
}
if (eia608_is_specialna(cc_data)) {
// specialna are treated as control charcters. Duplicated control charcters are discarded
// So we write a resume after a specialna as a noop to break repetition detection
// TODO only do this if the same charcter is repeated
sei_encode_eia608(sei, &cea708, eia608_control_command(eia608_control_resume_caption_loading, DEFAULT_CHANNEL));
}
}
if (0 != prev_cc_data) {
sei_encode_eia608(sei, &cea708, prev_cc_data);
}
}
sei_encode_eia608(sei, &cea708, 0); // flush
sei->timestamp = frame->timestamp; // assumes in order frames
// sei_dump (sei);
return LIBCAPTION_OK;
}
int sei_parse_nalu (sei_t* sei, const uint8_t* data, size_t size, double dts, double cts)
{
assert (0<=cts); // cant present before decode
sei->dts = dts;
sei->cts = cts;
int ret = 0;
if (0 == data || 0 == size) {
return 0;
}
uint8_t nal_unit_type = (*data) & 0x1F;
++data; --size;
if (6 != nal_unit_type) {
return 0;
}
// SEI may contain more than one payload
while (1<size) {
int payloadType = 0;
int payloadSize = 0;
while (0 < size && 255 == (*data)) {
payloadType += 255;
++data; --size;
}
if (0 == size) {
goto error;
}
payloadType += (*data);
++data; --size;
while (0 < size && 255 == (*data)) {
payloadSize += 255;
++data; --size;
}
if (0 == size) {
goto error;
}
payloadSize += (*data);
++data; --size;
if (payloadSize) {
sei_message_t* msg = sei_message_new ( (sei_msgtype_t) payloadType, 0, payloadSize);
uint8_t* payloadData = sei_message_data (msg);
size_t bytes = _copy_to_rbsp (payloadData, payloadSize, data, size);
sei_message_append (sei, msg);
if ( (int) bytes < payloadSize) {
goto error;
}
data += bytes; size -= bytes;
++ret;
}
}
// There should be one trailing byte, 0x80. But really, we can just ignore that fact.
return ret;
error:
sei_init (sei);
return 0;
}
