//public unsafe static vpx_codec_err_t vp8_get_si(vpx_codec_alg_priv_t ctx,
// ref vpx_codec_stream_info_t si)
//{
// uint sz;
// if (si.sz >= sizeof(vp8_stream_info_t))
// {
// sz = sizeof(vp8_stream_info_t);
// }
// else
// {
// sz = sizeof(vpx_codec_stream_info_t);
// }
// memcpy(si, &ctx->si, sz);
// si->sz = sz;
// return VPX_CODEC_OK;
//}
public unsafe static vpx_codec_err_t vp8_peek_si_internal(byte *data,
uint data_sz,
ref vpx_codec_stream_info_t si,
vpx_decrypt_cb decrypt_cb,
IntPtr decrypt_state)
{
vpx_codec_err_t res = vpx_codec_err_t.VPX_CODEC_OK;
//assert(data != NULL);
if (data == null)
{
return(vpx_codec_err_t.VPX_CODEC_INVALID_PARAM);
}
if (data + data_sz <= data)
{
res = vpx_codec_err_t.VPX_CODEC_INVALID_PARAM;
}
else
{
/* Parse uncompresssed part of key frame header.
* 3 bytes:- including version, frame type and an offset
* 3 bytes:- sync code (0x9d, 0x01, 0x2a)
* 4 bytes:- including image width and height in the lowest 14 bits
* of each 2-byte value.
*/
byte[] clear_buffer = new byte[10];
byte * clear = data;
//if (decrypt_cb)
//{
// int n = VPXMIN(sizeof(clear_buffer), data_sz);
// decrypt_cb(decrypt_state, data, clear_buffer, n);
// clear = clear_buffer;
//}
si.is_kf = 0;
if (data_sz >= 10 && (clear[0] & 0x01) == 0)
{ /* I-Frame */
si.is_kf = 1;
/* vet via sync code */
if (clear[3] != 0x9d || clear[4] != 0x01 || clear[5] != 0x2a)
{
return(vpx_codec_err_t.VPX_CODEC_UNSUP_BITSTREAM);
}
si.w = (uint)(clear[6] | (clear[7] << 8)) & 0x3fff;
si.h = (uint)(clear[8] | (clear[9] << 8)) & 0x3fff;
/*printf("w=%d, h=%d\n", si->w, si->h);*/
if (si.h == 0 || si.w == 0)
{
res = vpx_codec_err_t.VPX_CODEC_CORRUPT_FRAME;
}
}
else
{
res = vpx_codec_err_t.VPX_CODEC_UNSUP_BITSTREAM;
}
}
return(res);
}
public unsafe static vpx_codec_err_t vp8_peek_si(byte *data, uint data_sz,
ref vpx_codec_stream_info_t si)
{
return(vp8_peek_si_internal(data, data_sz, ref si, null, IntPtr.Zero));
}