/*unsigned*/ /*uint*/
int calc_lc_bits(frame_header_t hdr)
{
switch (hdr.codec)
{
case 0:
return(16);
case 1:
case 2:
case 3:
if (hdr.stream_id == 0)
{
return(12);
}
else
{
return(16);
}
case 10:
case 13:
return(12);
default:
throw new Exception("unknown codec field " + hdr.codec);
return(16);
}
}
void parse_header(byte *buf, frame_header_t hdr)
{
hdr.codec = buf[8] & 0xf;
hdr.stream_id = (buf[8] >> 4) & 0x3;
hdr.pdu_seq = (buf[8] >> 6) | ((buf[9] & 1) << 2);
hdr.blend_control = (buf[9] >> 1) & 0x3;
hdr.per_stream_delay = buf[9] >> 3;
hdr.common_delay = buf[10] & 0x3f;
hdr.latency = (buf[10] >> 6) | ((buf[11] & 1) << 2);
hdr.pfirst = ((buf[11] >> 1) & 1) != 0;
hdr.plast = ((buf[11] >> 2) & 1) != 0;
hdr.seq = (buf[11] >> 3) | ((buf[12] & 1) << 5);
hdr.nop = (buf[12] >> 1) & 0x3f;
hdr.hef = buf[12] >> 7;
hdr.la_location = buf[13];
}
void frame_process(int length)
{
/*unsigned*/ /*uint*/
int offset = 0;
/*unsigned*/ /*uint*/
int audio_end = length;
if (has_fixed())
{
audio_end = process_fixed_data(length);
}
while (offset < audio_end - RS_CODEWORD_LEN)
{
/*unsigned*/ /*uint*/
int start = offset;
/*unsigned*/ /*uint*/
int j, lc_bits, loc_bytes, prog;
/*unsigned*/
short[] locations = new short[MAX_AUDIO_PACKETS];
frame_header_t hdr = new frame_header_t();
hef_t hef = new hef_t();
if (fix_header(this.buffer + offset) == 0)
{
// go back to coarse sync if we fail to decode any audio packets in a P1 frame
if (length == MAX_PDU_LEN && offset == 0)
{
sync.syncState = SYNC_STATE.SYNC_STATE_NONE;
}
return;
}
parse_header(this.buffer + offset, hdr);
offset += 14;
lc_bits = calc_lc_bits(hdr);
loc_bytes = ((lc_bits * hdr.nop) + 4) / 8;
if (start + hdr.la_location < offset + loc_bytes || start + hdr.la_location >= audio_end)
{
return;
}
for (j = 0; j < hdr.nop; j++)
{
locations[j] = (short)parse_location(this.buffer + offset, lc_bits, j);
if (j == 0 && locations[j] <= hdr.la_location)
{
return;
}
if (j > 0 && locations[j] <= locations[j - 1])
{
return;
}
if (start + locations[j] >= audio_end)
{
return;
}
}
offset += loc_bytes;
if (hdr.hef != 0)
{
offset += parse_hef(this.buffer + offset, audio_end - offset, hef);
}
prog = hef.prog_num;
parse_hdlc(aas_push, this.psd_buf[prog], ref this.psd_idx[prog], MAX_AAS_LEN, this.buffer + offset, start + hdr.la_location + 1 - offset);
offset = start + hdr.la_location + 1;
for (j = 0; j < hdr.nop; ++j)
{
/*unsigned*/ /*uint*/
int cnt = start + locations[j] - offset;
if (crc8(this.buffer + offset, cnt + 1) != 0)
{
Console.WriteLine("crc mismatch!");
offset += cnt + 1;
continue;
}
if (j == 0 && hdr.pfirst)
{
if (this.pdu_idx[prog] != 0)
{
Utils.Memcpy(this.pdu[prog] + this.pdu_idx[prog], this.buffer + offset, cnt);
input_pdu_push(this.pdu[prog], cnt + this.pdu_idx[prog], prog);
}
else
{
Console.WriteLine("ignoring partial pdu");
}
}
else if (j == hdr.nop - 1 && hdr.plast)
{
Utils.Memcpy(this.pdu[prog], this.buffer + offset, cnt);
this.pdu_idx[prog] = cnt;
}
else
{
input_pdu_push(this.buffer + offset, cnt, prog);
}
offset += cnt + 1;
}
}
}
