Commit 3ada73cc authored by Timothy B. Terriberry's avatar Timothy B. Terriberry

Fix decoder handling of floor0 when the LSP order is 1.

Header setup allows the LSP order to be as low as one, but the code in
 vorbis_lsp_to_curve() assumed it was at least two.
This wasn't terrible in libvorbis... it would multiply a nonsense (but defined)
 value into the output, and nothing more.
In Tremor, it referenced several completely undefined (stack) values, which
 could cause out-of-bounds lookup table accesses and crashes.


git-svn-id: https://svn.xiph.org/trunk/Tremor@17538 0101bb08-14d6-0310-b084-bc0e0c8e3800
parent 1e064b75
......@@ -132,8 +132,9 @@ static inline void lsp_loop_asm(ogg_uint32_t *qip,ogg_uint32_t *pip,
ogg_int32_t qexp=*qexpp;
asm("mov r0,%3;"
"mov r1,%5,asr#1;"
"movs r1,%5,asr#1;"
"add r0,r0,r1,lsl#3;"
"beq 2f;\n"
"1:"
"ldmdb r0!,{r1,r3};"
......@@ -156,9 +157,10 @@ static inline void lsp_loop_asm(ogg_uint32_t *qip,ogg_uint32_t *pip,
"cmp r0,%3;\n"
"bhi 1b;\n"
"2:"
// odd filter assymetry
"ands r0,%5,#1;\n"
"beq 2f;\n"
"beq 3f;\n"
"add r0,%3,%5,lsl#2;\n"
"ldr r1,[r0,#-4];\n"
......@@ -170,7 +172,7 @@ static inline void lsp_loop_asm(ogg_uint32_t *qip,ogg_uint32_t *pip,
"umull %1,r3,r0,%1;\n" //pi*=labs(ilsp[j+1]-wi)
"cmn r2,r3;\n" // shift down 16?
"beq 2f;\n"
"beq 3f;\n"
"add %2,%2,#16;\n"
"mov %0,%0,lsr #16;\n"
"orr %0,%0,r2,lsl #16;\n"
......@@ -184,7 +186,7 @@ static inline void lsp_loop_asm(ogg_uint32_t *qip,ogg_uint32_t *pip,
//}
/* normalize to max 16 sig figs */
"2:"
"3:"
"mov r2,#0;"
"orr r1,%0,%1;"
"tst r1,#0xff000000;"
......
......@@ -197,16 +197,19 @@ void vorbis_lsp_to_curve(ogg_int32_t *curve,int *map,int n,int ln,
#else
qi*=labs(ilsp[0]-wi);
pi*=labs(ilsp[1]-wi);
for(j=3;j<m;j+=2){
if(!(shift=MLOOP_1[(pi|qi)>>25]))
if(!(shift=MLOOP_2[(pi|qi)>>19]))
shift=MLOOP_3[(pi|qi)>>16];
qi=(qi>>shift)*labs(ilsp[j-1]-wi);
pi=(pi>>shift)*labs(ilsp[j]-wi);
qexp+=shift;
j=1;
if(m>1){
qi*=labs(ilsp[0]-wi);
pi*=labs(ilsp[1]-wi);
for(j+=2;j<m;j+=2){
if(!(shift=MLOOP_1[(pi|qi)>>25]))
if(!(shift=MLOOP_2[(pi|qi)>>19]))
shift=MLOOP_3[(pi|qi)>>16];
qi=(qi>>shift)*labs(ilsp[j-1]-wi);
pi=(pi>>shift)*labs(ilsp[j]-wi);
qexp+=shift;
}
}
if(!(shift=MLOOP_1[(pi|qi)>>25]))
if(!(shift=MLOOP_2[(pi|qi)>>19]))
......
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