status_t TextDescriptions::getParcelOfDescriptions(
const uint8_t *data, ssize_t size,
uint32_t flags, int timeMs, Parcel *parcel) {
parcel->freeData();
if (flags & IN_BAND_TEXT_3GPP) {
if (flags & GLOBAL_DESCRIPTIONS) {
return extract3GPPGlobalDescriptions(data, size, parcel);
} else if (flags & LOCAL_DESCRIPTIONS) {
return extract3GPPLocalDescriptions(data, size, timeMs, parcel);
}
} else if (flags & OUT_OF_BAND_TEXT_SRT) {
if (flags & LOCAL_DESCRIPTIONS) {
return extractSRTLocalDescriptions(data, size, timeMs, parcel);
}
}
return ERROR_UNSUPPORTED;
}
// Extract the local 3GPP display descriptions. 3GPP local descriptions
// are appended to the text sample if any. The descriptions could include
// information such as text styles, highlights, karaoke and so on. They
// are contained in different boxes, such as 'styl' box contains text
// styles, and 'krok' box contains karaoke timing and positions.
status_t TextDescriptions::extract3GPPLocalDescriptions(
const uint8_t *data, ssize_t size,
int timeMs, Parcel *parcel, int depth) {
if (depth == 0) {
parcel->writeInt32(KEY_LOCAL_SETTING);
// write start time to display this text sample
parcel->writeInt32(KEY_START_TIME);
parcel->writeInt32(timeMs);
ssize_t textLen = (*data) << 8 | (*(data + 1));
// write text sample length and text sample itself
parcel->writeInt32(KEY_STRUCT_TEXT);
parcel->writeInt32(textLen);
parcel->writeInt32(textLen);
parcel->write(data + 2, textLen);
if (size > textLen) {
data += (textLen + 2);
size -= (textLen + 2);
} else {
return OK;
}
}
const uint8_t *tmpData = data;
ssize_t chunkSize = U32_AT(tmpData);
uint32_t chunkType = U32_AT(tmpData + 4);
if (chunkSize <= 0) {
return OK;
}
tmpData += 8;
switch(chunkType) {
// 'styl' box specifies the style of the text.
case FOURCC('s', 't', 'y', 'l'):
{
uint16_t count = U16_AT(tmpData);
tmpData += 2;
for (int i = 0; i < count; i++) {
parcel->writeInt32(KEY_STRUCT_STYLE_LIST);
parcel->writeInt32(KEY_START_CHAR);
parcel->writeInt32(U16_AT(tmpData));
parcel->writeInt32(KEY_END_CHAR);
parcel->writeInt32(U16_AT(tmpData + 2));
parcel->writeInt32(KEY_FONT_ID);
parcel->writeInt32(U16_AT(tmpData + 4));
parcel->writeInt32(KEY_STYLE_FLAGS);
parcel->writeInt32(*(tmpData + 6));
parcel->writeInt32(KEY_FONT_SIZE);
parcel->writeInt32(*(tmpData + 7));
parcel->writeInt32(KEY_TEXT_COLOR_RGBA);
uint32_t rgba = *(tmpData + 8) << 24 | *(tmpData + 9) << 16
| *(tmpData + 10) << 8 | *(tmpData + 11);
parcel->writeInt32(rgba);
tmpData += 12;
}
break;
}
// 'krok' box. The number of highlight events is specified, and each
// event is specified by a starting and ending char offset and an end
// time for the event.
case FOURCC('k', 'r', 'o', 'k'):
{
parcel->writeInt32(KEY_STRUCT_KARAOKE_LIST);
int startTime = U32_AT(tmpData);
uint16_t count = U16_AT(tmpData + 4);
parcel->writeInt32(count);
tmpData += 6;
int lastEndTime = 0;
for (int i = 0; i < count; i++) {
parcel->writeInt32(startTime + lastEndTime);
lastEndTime = U32_AT(tmpData);
parcel->writeInt32(lastEndTime);
parcel->writeInt32(U16_AT(tmpData + 4));
parcel->writeInt32(U16_AT(tmpData + 6));
tmpData += 8;
}
break;
}
// 'hlit' box specifies highlighted text
case FOURCC('h', 'l', 'i', 't'):
{
parcel->writeInt32(KEY_STRUCT_HIGHLIGHT_LIST);
// the start char offset to highlight
parcel->writeInt32(U16_AT(tmpData));
// the last char offset to highlight
parcel->writeInt32(U16_AT(tmpData + 2));
break;
}
// 'hclr' box specifies the RGBA color: 8 bits each of
// red, green, blue, and an alpha(transparency) value
case FOURCC('h', 'c', 'l', 'r'):
{
parcel->writeInt32(KEY_HIGHLIGHT_COLOR_RGBA);
uint32_t rgba = *(tmpData) << 24 | *(tmpData + 1) << 16
| *(tmpData + 2) << 8 | *(tmpData + 3);
parcel->writeInt32(rgba);
break;
}
// 'dlay' box specifies a delay after a scroll in and/or
// before scroll out.
case FOURCC('d', 'l', 'a', 'y'):
{
parcel->writeInt32(KEY_SCROLL_DELAY);
uint32_t delay = *(tmpData) << 24 | *(tmpData + 1) << 16
| *(tmpData + 2) << 8 | *(tmpData + 3);
parcel->writeInt32(delay);
break;
}
// 'href' box for hyper text link
case FOURCC('h', 'r', 'e', 'f'):
{
parcel->writeInt32(KEY_STRUCT_HYPER_TEXT_LIST);
// the start offset of the text to be linked
parcel->writeInt32(U16_AT(tmpData));
// the end offset of the text
parcel->writeInt32(U16_AT(tmpData + 2));
// the number of bytes in the following URL
int len = *(tmpData + 4);
parcel->writeInt32(len);
// the linked-to URL
parcel->writeInt32(len);
parcel->write(tmpData + 5, len);
tmpData += (5 + len);
// the number of bytes in the following "alt" string
len = *tmpData;
parcel->writeInt32(len);
// an "alt" string for user display
parcel->writeInt32(len);
parcel->write(tmpData + 1, len);
break;
}
// 'tbox' box to indicate the position of the text with values
// of top, left, bottom and right
case FOURCC('t', 'b', 'o', 'x'):
{
parcel->writeInt32(KEY_STRUCT_TEXT_POS);
parcel->writeInt32(U16_AT(tmpData));
parcel->writeInt32(U16_AT(tmpData + 2));
parcel->writeInt32(U16_AT(tmpData + 4));
parcel->writeInt32(U16_AT(tmpData + 6));
break;
}
// 'blnk' to specify the char range to be blinked
case FOURCC('b', 'l', 'n', 'k'):
{
parcel->writeInt32(KEY_STRUCT_BLINKING_TEXT_LIST);
// start char offset
parcel->writeInt32(U16_AT(tmpData));
// end char offset
parcel->writeInt32(U16_AT(tmpData + 2));
break;
}
// 'twrp' box specifies text wrap behavior. If the value if 0x00,
// then no wrap. If it's 0x01, then automatic 'soft' wrap is enabled.
// 0x02-0xff are reserved.
case FOURCC('t', 'w', 'r', 'p'):
{
parcel->writeInt32(KEY_WRAP_TEXT);
parcel->writeInt32(*tmpData);
break;
}
default:
{
break;
}
}
if (size > chunkSize) {
data += chunkSize;
size -= chunkSize;
// continue to parse next box
return extract3GPPLocalDescriptions(data, size, 0, parcel, 1);
}
return OK;
}
