SoundInput RebuildVorbis(Sample sample)
{
if (!sample.MetaData.ContainsKey(ChunkType.VorbisData))
{
throw new InvalidFormatException("No VORBISDATA chunk in FSB5 Vorbis stream.");
}
var vorbis_data = sample.MetaData[ChunkType.VorbisData] as VorbisData;
var setup_data = GetVorbisHeader(vorbis_data.Crc32);
var state = new OggStreamState(1);
var id_packet = RebuildIdPacket(sample, 0x100, 0x800);
var comment_packet = RebuildCommentPacket();
var setup_packet = RebuildSetupPacket(setup_data);
var info = CreateVorbisInfo(sample, setup_packet);
var output = new MemoryStream();
state.PacketIn(id_packet);
state.Write(output);
state.PacketIn(comment_packet);
state.Write(output);
state.PacketIn(setup_packet);
state.Write(output);
state.Flush(output);
long packet_no = setup_packet.PacketNo + 1;
long granule_pos = 0;
int prev_block_size = 0;
using (var input = new BinMemoryStream(sample.Data))
{
var packet = new OggPacket();
int packet_size = ReadPacketSize(input);
while (packet_size > 0)
{
packet.SetPacket(packet_no++, input.ReadBytes(packet_size));
packet_size = ReadPacketSize(input);
packet.EoS = 0 == packet_size;
int block_size = info.PacketBlockSize(packet);
if (prev_block_size != 0)
{
granule_pos += (block_size + prev_block_size) / 4;
}
else
{
granule_pos = 0;
}
packet.GranulePos = granule_pos;
prev_block_size = block_size;
state.PacketIn(packet);
state.Write(output);
}
}
output.Position = 0;
return(new OggInput(output));
}
public void WriteHeaders(OggStreamState oggStreamState, VorbisComment comment)
{
ogg_packet header = new ogg_packet();
ogg_packet header_comm = new ogg_packet();
ogg_packet header_code = new ogg_packet();
OggPage page = new OggPage();
Errors.CheckVorbisError(NativeMethods.vorbis_analysis_headerout(ref InternalStruct, ref comment.InternalStruct, ref header, ref header_comm, ref header_code));
Errors.CheckOggError(NativeMethods.ogg_stream_packetin(ref oggStreamState.InternalStruct, ref header)); // automatically placed in its own page
Errors.CheckOggError(NativeMethods.ogg_stream_packetin(ref oggStreamState.InternalStruct, ref header_comm));
Errors.CheckOggError(NativeMethods.ogg_stream_packetin(ref oggStreamState.InternalStruct, ref header_code));
}
public void Encode(OggStreamState oggStreamState, VorbisBlock block, Stream stream)
{
OggPacket packet = new OggPacket();
OggPage page = new OggPage();
/* vorbis does some data preanalysis, then divvies up blocks for
* more involved (potentially parallel) processing. Get a single
* block for encoding now */
while (BlockOut(block))
{
/* analysis, assume we want to use bitrate management */
block.Analyze();
block.BitrateAddBlock();
while (BitrateFlushPacket(packet) != 0)
{
/* weld the packet into the bitstream */
NativeMethods.ogg_stream_packetin(ref oggStreamState.InternalStruct, ref packet.InternalStruct);
/* write out pages (if any) */
bool eos = false;
while (!eos)
{
int result = NativeMethods.ogg_stream_pageout(ref oggStreamState.InternalStruct, ref og);
if (result == 0)
{
break;
}
page.Write(stream);
/* this could be set above, but for illustrative purposes, I do
* it here (to show that vorbis does know where the stream ends) */
if (xm.ogg_page_eos(ref page.InternalStruct) != 0)
{
eos = true;
}
}
}
}
}
