From 3ada73cc10e6da279bf3b6458e30343ed7d2f01e Mon Sep 17 00:00:00 2001 From: Tim Terriberry Date: Fri, 15 Oct 2010 02:52:29 +0000 Subject: 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 --- asm_arm.h | 10 ++++++---- floor0.c | 23 +++++++++++++---------- 2 files changed, 19 insertions(+), 14 deletions(-) diff --git a/asm_arm.h b/asm_arm.h index 3a3716d..c3bda00 100644 --- a/asm_arm.h +++ b/asm_arm.h @@ -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;" diff --git a/floor0.c b/floor0.c index 3f17950..5c58f77 100644 --- a/floor0.c +++ b/floor0.c @@ -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>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>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])) -- cgit v1.2.1