static unsigned FrameLength(FrameHeader fh)
{
unsigned bitrate = BitRate(fh);
if (!bitrate)
return 0;
unsigned samplerate = SampleRate(fh);
if (!samplerate)
return 0;
if (fh.s.layer == 3)
return (((12*bitrate) / samplerate) + fh.s.padding) * 4;
unsigned samples = 1152;
if ((fh.s.version == 0 || fh.s.version == 2) && fh.s.layer == 1)
samples = 576;
return (samples*bitrate)/(8*samplerate) + fh.s.padding;
}
bool CHolly_Theora_Video::Start()
{
m_bFrameWaiting = false;
th_info thInfo;
th_info_init( &thInfo );
thInfo.frame_width = Width();
thInfo.frame_height = Height();
thInfo.pic_width = Width();
thInfo.pic_height = Height();
thInfo.pic_x = 0;
thInfo.pic_y = 0;
thInfo.colorspace = TH_CS_ITU_REC_470BG;
thInfo.pixel_fmt = TH_PF_420; // TH_PF_444
thInfo.target_bitrate = BitRate() * 1024;
thInfo.quality = 42;
thInfo.keyframe_granule_shift = 6; // default value
thInfo.fps_numerator = FPS();
thInfo.fps_denominator = 1;
thInfo.aspect_numerator = 1;
thInfo.aspect_denominator = 1;
m_Encoder = th_encode_alloc( &thInfo );
if ( !m_Encoder )
{
return false;
}
th_info_clear( &thInfo );
SetupFrame();
WriteHeader();
return true;
}
static unsigned WalkFrames(util::Stream *st, uint64_t pos, bool *ok)
{
uint64_t end = st->GetLength();
unsigned int nframes = 0;
unsigned int nsilent = 0;
bool started = false;
unsigned int bitrate = 0;
bool vbr = false;
uint64_t streamlen = end-pos;
while (pos < (end-4))
{
unsigned char header[4];
st->Seek(pos);
unsigned rc = st->ReadAll(header, 4);
if (rc)
return rc;
FrameHeader fh;
fh.x = read_be32(header);
if (fh.s.sync != 0x7FF)
{
printf(" Sync lost at %llu (%08x %08x)\n", (long long unsigned)pos,
fh.x, fh.s.sync);
*ok = false;
return 0;
}
unsigned int len = FrameLength(fh);
if (!len)
{
printf(" Bogus header %08x at %llu\n", fh.x,
(long long unsigned)pos);
*ok = false;
return 0;
}
if (s_frames)
{
printf(" 0x%08llx: frame %u\n", (unsigned long long)pos, nframes);
}
unsigned char frame[8192];
rc = st->ReadAll(frame, len-4);
if (rc)
return rc;
unsigned int zeroes;
if (fh.s.version == 3)
{
if (fh.s.channelmode == 3)
zeroes = 17;
else
zeroes = 32;
}
else
{
if (fh.s.channelmode == 3)
zeroes = 9;
else
zeroes = 17;
}
bool silent = true;
for (unsigned int i=0; i<zeroes && silent; ++i)
{
if (frame[i])
silent = false;
}
if (silent && !started)
{
++nsilent;
if (!memcmp(frame + zeroes, "Xing", 4)
|| !memcmp(frame + zeroes, "Info", 4))
{
if (s_all)
{
printf(" Info header in frame %u\n", nframes);
printf(" Frame count %u\n", read_be32(frame+zeroes+8));
printf(" Stream length %u\n", read_be32(frame+zeroes+12));
}
}
else if (!memcmp(frame+32, "VBRI", 4))
{
if (s_all)
printf(" VBRI header in frame %u\n", nframes);
}
else
{
started = true;
if (s_all)
printf(" Audio begins in frame %u\n", nframes);
}
}
else
{
if (!started)
{
started = true;
if (s_all)
printf(" Audio begins in frame %u\n", nframes);
}
nsilent = 0;
}
if (started)
{
unsigned frame_bitrate = BitRate(fh);
if (!bitrate)
bitrate = frame_bitrate;
else if (bitrate != frame_bitrate)
vbr = true;
}
++nframes;
pos += len;
}
if (s_all)
{
if (nsilent)
printf(" Final %u frames silent\n", nsilent);
printf(" %u frames\n", nframes);
if (vbr)
printf(" Variable bitrate\n");
else
printf(" Bitrate=%u CBR\n", bitrate);
printf(" MP3 stream length %llu\n", (unsigned long long)streamlen);
}
return 0;
}
