byte[] rebuildSubsBlock(List<SubtitleEntry> entries, int blockNumber)
{
MemoryStream mem = new MemoryStream();
BinaryWriter br = new BinaryWriter(mem);
mem.Position += 4;
foreach (SubtitleEntry e in entries)
{
if (e.blockNumber != blockNumber)
continue;
var langNumber = ((int)e.lang).ToString().ToCharArray();
br.Write(langNumber, 0, langNumber.Length);
br.Write('\r');
br.Write(Encoding.UTF8.GetBytes(e.text));
br.Write('\r');
}
mem.Position = 0;
mem.writeuint((uint)(mem.Length - 4), isBE);
return mem.ToArray();
}
private byte[] blockChangeSub(byte[] array, SubtitleEntry entry, int blockno)
{
int index = array.Length - 1;
byte[] output = null;
// Remove end zeros
while (index >= 0 && array[index] == 0x00)
{
index--;
}
int endidx = index;
int startidx = findSubsStartIndex(array, endidx);
if (startidx == 0)
throw new Exception("Error finding sub to replace");
// Read original subs
List<SubtitleEntry> origSubs = new List<SubtitleEntry>();
parseSubsBlock(origSubs, Encoding.UTF8.GetString(array, startidx + 4, endidx - startidx - 4), blockno);
// Replace new subtitle text
foreach (SubtitleEntry newEntry in subEntries)
{
if (newEntry.blockNumber != blockno)
continue;
foreach (SubtitleEntry origEntry in origSubs)
{
if (newEntry.lang == origEntry.lang)
{
origEntry.text = newEntry.text;
break;
}
}
}
// Get the modified subs block
var subs = rebuildSubsBlock(origSubs, blockno); //origSubs being the new subs
// Compute total length
int length = startidx + subs.Length;
// Align to 16 bytes
length = ((length + 15) >> 4) << 4;
output = new byte[length];
// Copy data before subs
Array.Copy(array, output, startidx);
// Copy subs
Array.Copy(subs, 0, output, startidx, subs.Length);
// Adjust lengths
MemoryStream ms = new MemoryStream(output);
ms.Position = 4;
ms.writeuint((uint)(length - 16), isBE);
if (blockno != 0)
{
ms.Position = 16;
ms.writeuint((uint)(length - 20), isBE);
}
return output;
}
