QuantMatrixExtension::QuantMatrixExtension( BitReader &hdr )
{
init();
hdr.reset();
ahabassert( hdr.readbits( 32 ) == 0x000001b5 );
ahabassert( hdr.readbits( 4 ) == 3 );
load_intra_quantiser_matrix = hdr.readbits( 1 );
for ( int i = 0; i < 64; i++ ) {
intra_quantiser_matrix[ mpeg2_normal_scan[ i ] ] =
load_intra_quantiser_matrix
? hdr.readbits( 8 )
: default_intra_quantiser_matrix[ i ];
mpegassert( intra_quantiser_matrix[ mpeg2_normal_scan[ i ] ] != 0 );
}
load_non_intra_quantiser_matrix = hdr.readbits( 1 );
for ( int i = 0; i < 64; i++ ) {
non_intra_quantiser_matrix[ mpeg2_normal_scan[ i ] ] =
load_non_intra_quantiser_matrix ? hdr.readbits( 8 ) : 16;
mpegassert( intra_quantiser_matrix[ mpeg2_normal_scan[ i ] ] != 0 );
}
}
PictureCodingExtension::PictureCodingExtension( BitReader &hdr )
{
init();
hdr.reset();
ahabassert( hdr.readbits( 32 ) == 0x000001b5 );
ahabassert( hdr.readbits( 4 ) == 8 );
f_code_fh = hdr.readbits( 4 );
f_code_fv = hdr.readbits( 4 );
f_code_bh = hdr.readbits( 4 );
f_code_bv = hdr.readbits( 4 );
intra_dc_precision = hdr.readbits( 2 );
picture_structure = hdr.readbits( 2 );
top_field_first = hdr.readbits( 1 );
frame_pred_frame_dct = hdr.readbits( 1 );
concealment_motion_vectors = hdr.readbits( 1 );
q_scale_type = hdr.readbits( 1 );
intra_vlc_format = hdr.readbits( 1 );
alternate_scan = hdr.readbits( 1 );
repeat_first_field = hdr.readbits( 1 );
chroma_420_type = hdr.readbits( 1 );
progressive_frame = hdr.readbits( 1 );
if ( picture_structure != 3 ) {
fprintf( stderr, "Ahab does not support field pictures.\n" );
throw ConformanceLimitExceeded();
}
mpegassert( ((f_code_fh >= 1) && (f_code_fh <= 9)) || (f_code_fh == 15) );
mpegassert( ((f_code_fv >= 1) && (f_code_fv <= 9)) || (f_code_fv == 15) );
mpegassert( ((f_code_bh >= 1) && (f_code_bh <= 9)) || (f_code_bh == 15) );
mpegassert( ((f_code_bv >= 1) && (f_code_bv <= 9)) || (f_code_bv == 15) );
}
SequenceExtension::SequenceExtension( BitReader &hdr )
{
init();
hdr.reset();
ahabassert( hdr.readbits( 32 ) == 0x000001b5 );
ahabassert( hdr.readbits( 4 ) == 1 );
escape_bit = hdr.readbits( 1 );
profile = hdr.readbits( 3 );
level = hdr.readbits( 4 );
progressive_sequence = hdr.readbits( 1 );
chroma_format = hdr.readbits( 2 );
horizontal_size_extension = hdr.readbits( 2 );
vertical_size_extension = hdr.readbits( 2 );
bit_rate_extension = hdr.readbits( 12 );
mpegassert( hdr.readbits( 1 ) == 1 );
vbv_buffer_size_extension = hdr.readbits( 8 );
low_delay = hdr.readbits( 1 );
frame_rate_extension_n = hdr.readbits( 2 );
frame_rate_extension_d = hdr.readbits( 5 );
/* Check conformance limits */
if ( escape_bit ) {
throw ConformanceLimitExceeded();
}
/* Simple profile or Main profile */
if ( (profile != 5) && (profile != 4) ) {
throw ConformanceLimitExceeded();
}
/* 4:2:0 only */
if ( chroma_format != 1 ) {
throw ConformanceLimitExceeded();
}
}
