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author | toma <toma@283d02a7-25f6-0310-bc7c-ecb5cbfe19da> | 2009-11-25 17:56:58 +0000 |
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committer | toma <toma@283d02a7-25f6-0310-bc7c-ecb5cbfe19da> | 2009-11-25 17:56:58 +0000 |
commit | e2de64d6f1beb9e492daf5b886e19933c1fa41dd (patch) | |
tree | 9047cf9e6b5c43878d5bf82660adae77ceee097a /mpeglib/lib/splay/dxHead.cpp | |
download | tdemultimedia-e2de64d6f1beb9e492daf5b886e19933c1fa41dd.tar.gz tdemultimedia-e2de64d6f1beb9e492daf5b886e19933c1fa41dd.zip |
Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.
BUG:215923
git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdemultimedia@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
Diffstat (limited to 'mpeglib/lib/splay/dxHead.cpp')
-rw-r--r-- | mpeglib/lib/splay/dxHead.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/mpeglib/lib/splay/dxHead.cpp b/mpeglib/lib/splay/dxHead.cpp new file mode 100644 index 00000000..a96bb553 --- /dev/null +++ b/mpeglib/lib/splay/dxHead.cpp @@ -0,0 +1,129 @@ +/*---- DXhead.c -------------------------------------------- + +decoder MPEG Layer III +handle Xing header +mod 12/7/98 add vbr scale + +Copyright 1998 Xing Technology Corp. +-----------------------------------------------------------*/ +#include <stdlib.h> +#include <stdio.h> +#include <float.h> +#include <math.h> +#include "dxHead.h" + +// 4 Xing +// 4 flags +// 4 frames +// 4 bytes +// 100 toc + +/*-------------------------------------------------------------*/ +static int ExtractI4(unsigned char *buf) +{ +int x; +// big endian extract + +x = buf[0]; +x <<= 8; +x |= buf[1]; +x <<= 8; +x |= buf[2]; +x <<= 8; +x |= buf[3]; + +return x; +} +/*-------------------------------------------------------------*/ +int GetXingHeader(XHEADDATA *X, unsigned char *buf) +{ +int i, head_flags; +int h_id, h_mode, h_sr_index; +static const int sr_table[4] = { 44100, 48000, 32000, 99999 }; + +// get Xing header data + + +X->flags = 0; // clear to null incase fail + + +// get selected MPEG header data +h_id = (buf[1] >> 3) & 1; +h_sr_index = (buf[2] >> 2) & 3; +h_mode = (buf[3] >> 6) & 3; + + +// determine offset of header +if( h_id ) { // mpeg1 + if( h_mode != 3 ) buf+=(32+4); + else buf+=(17+4); +} +else { // mpeg2 + if( h_mode != 3 ) buf+=(17+4); + else buf+=(9+4); +} + +if( buf[0] != 'X' ) return 0; // fail +if( buf[1] != 'i' ) return 0; // header not found +if( buf[2] != 'n' ) return 0; +if( buf[3] != 'g' ) return 0; +buf+=4; + +X->h_id = h_id; +X->samprate = sr_table[h_sr_index]; +if( h_id == 0 ) X->samprate >>= 1; + +head_flags = X->flags = ExtractI4(buf); buf+=4; // get flags + +if( head_flags & FRAMES_FLAG ) {X->frames = ExtractI4(buf); buf+=4;} +if( head_flags & BYTES_FLAG ) {X->bytes = ExtractI4(buf); buf+=4;} + +if( head_flags & TOC_FLAG ) { + if( X->toc != NULL ) { + for(i=0;i<100;i++) X->toc[i] = buf[i]; + } + buf+=100; +} + +X->vbr_scale = -1; +if( head_flags & VBR_SCALE_FLAG ) {X->vbr_scale = ExtractI4(buf); buf+=4;} + +//if( X->toc != NULL ) { +//for(i=0;i<100;i++) { +// if( (i%10) == 0 ) printf("\n"); +// printf(" %3d", (int)(X->toc[i])); +//} +//} + +return 1; // success +} +/*-------------------------------------------------------------*/ +int SeekPoint(unsigned char TOC[100], int file_bytes, float percent) +{ +// interpolate in TOC to get file seek point in bytes +int a, seekpoint; +float fa, fb, fx; + + +if( percent < 0.0f ) percent = 0.0f; +if( percent > 100.0f ) percent = 100.0f; + +a = (int)percent; +if( a > 99 ) a = 99; +fa = TOC[a]; +if( a < 99 ) { + fb = TOC[a+1]; +} +else { + fb = 256.0f; +} + +fx = fa + (fb-fa)*(percent-a); +//printf("%f ....... %f ...... %f\n",fa,fb,fx); + +seekpoint = (int)((1.0f/256.0f)*fx*file_bytes); + + +return seekpoint; +} +/*-------------------------------------------------------------*/ |